Document jgK49Oq9jJMLNr9krD8jYxmmk

II DOTLICm Ambler R&D Mr. K. L. Laos Oicabir 12, 1962 Ambler R&D Pilot Pipe Machine a. A. Sctmaider - ap The following ere ay eoaaents on the proposed program under the headings of the report. B. 6. Particle else distribution may be important. Me have e suspicion that a snail fraction of large grains of silica nay be very detrimental to tool life. We cannot account for the differences of tool life in all the plants. Other factors naturally nay be stronger grain structure, shape of grains, strength of bond to canent, etc. I believe this will have to be investigated so that we can show up better specs or addition ally air separate or others to be able to standardise on tools, cutting speeds, tool cost, etc. B, 8. We are presently thinking about using a silica fron the very pure Santa Anna occurrence, ground in Waco and delivered at $9.50/ton approx imately in Hillsboro. G, 7. Plants seen to stress that flocculant improved quantity and quality of the pipe. I Just wonder if quality is improved not on account of the flocculant but because our present vat design has a separating effect on the fibers prevented by the flocculant. This possibly can be achieved by different vat operation as I indicated in the Dallas meeting. If flocculant bunches the fiber, we certainly do not eoploy fiber as efficiently as possible. We want uniform fiber distribution similar to a good paper. C. 11. investigations on pipe machine results with fibers having essentially no dust may be important. There la a possibility that the asbestos dust has s similar electric potential as the fibers and prevents the proper adhesion of the cement to the asbestos fibers. If this is so, then we should have the fibers air separated either at the mills or at the plants. How this would be effected in the plants on a mixture I do not know. CTD029862 Hr. R. L. Lana 2 December 12, 1962 D. 3. Results on Hillsboro fines are different froa tha original saaples aa changaa vara made some time In August to gat a coaraar, fraar draining product. D. 4. Not all plants waigh tha flnaa. St. Louis usas tha shoval weighing system. P. 5. Tha opinion of Hillsboro can ba dlsragarded as at that tlaa danaitles wars low dua to many othar causaa froa poor operating practices. D. 7. As Hillsboro fines are air separated, 1 cannot sea that they can have hard particles. K. 1. Tha use of Separan in the vats has bean discontinued in Hillsboro since Noveabar 1962. S. 3. Separan is ussd in Hillsboro in tha savail at a rata of approximately 1/8 lb./ton with very good results. K. 7. Our present inflow and throughflow in machine is excessively turbu lent. Decrease of this should improve affect of flocculants. F. 4. Hillsboro 0. R. ring flshaouthing has bean found since tha report was Issued to ba due to causaa beyond control of tha plant. II. 3. A fiber fluffer (Moody) is available in tha market. It was specif ically designed to open tha densely packed fiber in paper bags. CTD029863 Mr. R. L. Lanx -3- December 12, 1962 II. 5. All plants use a closed sir system on the vlllovs. II. 7. Essentially all fiber blending and mixing systems are identical except No. 1 machine in St. Louis, also Ambler and SC. Louis do not have preblenders. Hillsboro system has been shown to be satisfactory on present cycles to eleven ton output. Comments of St. Louis on screw conveyors and bucket elevators are based on experience gained with improperly selected equipment. Use of thes|devlces, properly selected as for Hillsboro, can be very satisfactory. III. 3. Hillsboro block-ups are corrected. As indicated, Hillsboro system is good for eleven tons of pressure pipe. Ambler system still has soma capacity left, the others are at the limit. There are, however, other bottlenecks, such as mandrel handling, curing, autoclaving, etc. III.4.(stock) Consistency controller has been reported by me in Dallas meeting. Suggest first use in Santa Clara and also In pilot machine. III. 5. Recirculation Rate Plant 57 is grossly exaggerated (probably half the amount Indicated). III. 6. Hillsboro block-ups were corrected with proper operating procedures. IV. 2. Nomenclature of waters should be identical. White water is same as clear savall water. At Plant 57 overflow dirty water savall also is white water. IV. 4. We should be uniform with description of water. We should also stop differentiating the different showers by manufacturer's name. For instance. CTD029864 Mr. R. L. Lanz -4- December 12, 1962 Broughton's can be had in different nozzle size and strokes. In Hills boro ve made reciprocating showers with needle showers which is principle used in our other showers except for size orifice. Showers should be classified as follows: I. Operation A. Stationery B. Reciprocating 1. Stroke inches 2. No strokes per win. IX. Nozzles A. Pen type B. Needle type C. Others III. Size A. .093" B. .031" C. Others IV. Mater Pressure at Shower Inlet V. Size of Shower Pipe 1. D. VI. Distance between Nozzles IV. 5. Saveli of Dorr type in Hillsboro as clear now as cone ssvalls. IV. 6. Closed water systea is definitely superior if we can ever find a way to use .031" needle reciprocating showers spaced 6" with white water. Advantage is the absence of the terrific problem of disposal, straea pollution, etc. Other problems nay be saturation with certain cheaicala detrimental to good pipe. Ue should strive to close the systems more and more. IV. 10. Hillsboro boiler tube trouble was caused by Inattention to water treatment which has been specifically designed for Hillsboro water. CTD029865 Hr. R. L. Lanz -5- December 12, 1962 V. 5. d. Hillsboro now uses water on Vickery. Without veter, top felt gets dirty end Vickery vacuum boxes wear out In e few months. V. 7. Steep angle to Ho. 2 vet has been eliminated at Hillsboro. VI. 6. Importance is stressed to keep ends of stripe in felt even. The whole stripe should be straight across. VI. 9. It is very important that cylinders are always run in the same di rection otherwise cylinder wire gets loose. VII. 5. d. I do not consider a very tight pipe a sign of bad roll-up. This in my opinion is the beet pipe. VII. 7. Air lancing in Hillsboro is now in a calender equipped with a top press roll. Satisfactory. VII. 11. What Hillsboro remarked is as Maloney would say "for the birds". VIII. Hillsboro Due to changes in operation, this does not apply. CTD029866 PLANT DATA QUESTIONNAIRE usnrAjjj-i'ssD propjcts cor?. XSCHNICAL Dry. PLANT DATA Plant No. ______ Location5&nager Raw IJaterials: A. Cement 1. Supplier 2. Physical & Chemical Analysis: Yes _____ No ______ Where available___ 3. Open or closed circuit grinding: Yss Ho______________ ? 4. How cement 13 handled ______________________________________ 5. Temperature: Silo ____Plant Silo Storage 5. (a) Co you measure surface area: Yes _______ Ho. __ (b) If yea, typical values ________________________________ (o' If no, do ycu consider this important X ^oS ^____ No 7- Now is cement purchased, by whom, who's responsible. 8. 'ihy Is particular cement good or bad: 9. Testing and control of cement: 10. Are there any provisions for moisture control: Yes ___ No CTD029872 (a) If yes, typical values . (b) If no, do you consider this Important* Tea . Ho 11. Specific problems____________________________ ,_________ Silica 1. Supplier* . 2. Physical a* Chemical Analysis* YesSo __ Where available _______________________________ 3. Open or closed circuit grinding: Yes So 4. How silica is handled* .. 5. (a) So you measure surface area* Yes _______ So. (b) If yea, typical values * variability* (c) If no, do you consider this Important* Yes _____ Bo. __ (d) Mesh* (e) Particle size distributions Available ______ Sot avail. 6. Experience with different mesh silicas A. _______________ B. Effect on autoclaving operation CTD029873 -3- 7. Bow is sllloa purchased, by whom, who's responsible. 8. Specific problems C. Asbestos Fiber 1. Blue fiber: Why do you use blue fiber Least amount that can be used Could you run without bluet TeeMo_____ If Tee, How 2. General opinion ot various grades of fiber: CTD029874 43. If you had choice, what fiber would you pick; why* How does dust content of fiber effect oneratloas 5. (a) Range of fiber usage to 5t. (b) Effect of high fiber content ___________________ (e) Effect of low fiber content 6. How do fiber quotas Influence operations .e 7. How does floeeulant effect fiber usages 8. (a) What means am employed to control fibers (b) Does surface area offer any advantages 9. Aware of any other fiber useful in pipe but not presently usings 10. Do purchasing specifications cover quality of fiber_____ CTD029875 11. Specific problems: 5' D. A/C Vines 1. Source of fines: ~ .2 Preparation of fines: Method Control 3. So you measure particle else distribution: Yes____ No If yes, + . 4. (a) How are fines metered out_________________________ (b) Vhere are they introduced ______________________ 5. (a) General opinion regarding effect of fines on product (b) What criteria is used to evaluate product 6. Preferred method of preparing fines CTD029876 7. Specific problems -6- B. Chemical Additives 1. What do you presently use _____________________________ 2. Where Is it addedWhat percentage How Is It controlled 3. What does It do for yous 1 machine operation In sav&ll system ____________________________ In product 4. What would you like It to do for you 5. Are there any other types you want investigated _ 6. How do additives effect film thickness* water content* vacuum requirements CTD029877 7. Specific problems and cements Rubber Rings 1. Method of storage, location, temperature, etc: 2. How is Inventory controlled (re-order points, etc.) 3. General comments, suggestions & opinion of lubricant * 4. Specific problems: CTD029878 -8- Fiber Preparation - Flow Diagram 1. Are you satisfied with present method of opening fibers: Yes_____ No _____ If not, why 2. Are you Interested in new methods of opening fibers 3. Could the mines supply more open fiber 4. General eonment on preparing fibers separately or as a blend 5. Willow Operation: SpeedRate of Feed _____ No. Hairpins Possible No. Hairpins used. Changeover Cycle _______ Sluggers ___________ Hiss. ; 6. Nixing oyoles 7. Specific problems & comments CTD029879 9Primacy Mixing & Stock Preparation PrtMw 1. ^rpe of MixerSize____ Relationship of Batoh-Size/RP input _____ 2. Batch SizeThrough Put__ Mixing CyclePeed Rate 3. Qeneral Coonents * Problem_____________ 4. Changeover tines for product mix Stock Preparation* 1. Bow_____________________________ 2. Percent solidsMakeup Mater Mixing! TypeCycleAgitation 3. Cenent-Mater Contact Tines___________________________ 4. Method of measuring and controlling stock 3* Quantity of stock being recirculated Method of addition of virgin stock CTD029880 -106. Specific problems & comments Water System: {i.e. shite water, dirty water, shower water, fresh water) 1. Fresh Water (a) Source _______________________________________________ (b) Where is it added ______________________________________ (c) Amount added- (d) pH ________ HardnessChemical Analysis: Yea Ho . (e) Is makeup pretreated _________ How 2. White Water (a) Source (b) Where is it used . (c) Amount generated . (d) Percent Solids _____________________________________________ 3. Dirty Water (a) Source _ (b) Where is it used .. (c) Amount generated (d) Percent Solids ... CTDG29881 11- b. Shower Water (a) Source_____________________________ (b) Where la It used__________________ (c) Amount used _____________________ (d) l^rpe of showers ___________________ (e) Shower water pressure & temperature (f) Cleaning of showers _______________ 5. Savall System - General Comments 6. Effect of open or closed system on Machine Operation ft Benefits of Bach Method. 7. Doea water Source Contributed to Felt ft Soreen Plug up 8. Vacuum Stptea Water (a) Source _______________ (b) Where Is it returned (c) Consents _______ CTD029882 -12 9. (a) How is Vasts water & material disposed oft (b) How Much ____________________ (o) Where _ (d) Control _____________________ (e) Program for stream pollution 10. Specific problem areas Machine Operation: 1. Speeds in General: (i.e. felt, agitator, Schneider Liner, etc.) 2. Pumps in General: (i.e. type, speed, hp., etc.) 3. Vacuum: (a) Where located ___ (b) How much________ (e) What type control CTD029883 13(d) How Is it measured ____ (e) 5|ype of boat____________ 4. Agitators (a) Where located __________ (b) What type ______________ (o) Speed __________________ (d) Direction ___________ (e) fy. requirements ________ 5 Comments on Vickery Cleaner 6. Comments on operating temperatures 7. Couch roll, (type, diameter, angle, pressure) 8. Cylinders (Diameter, wire size & mesh size, deckling etc.) CTD029884 -14- 9. (a) Stock distribution to vat and within vat (b) Overflow Heights L). Stock consistency - Comments on control* monitoring* etc. 11. Comments on Manner in which various stocks run 12. Consents on pickup at cylinders* usual problems and corrective measures. 13. Water content In film and/or pipe during operation. 14. Condition of savall during startup and during normal operation. 15- General comments on piping & valving CTD029885 16. Speolflo problems 15" Pelts TOP BOTTOM 1. Supplier _________________________ ____________ 2. Type _____________________ 3. Cost ____________ ^_________ ______________ 4. Life ______________ .______ ______________ 5. Reason for Removal ______________ 6. Cement on breaking in new felt __________________________________ 7. Comment on running %he felt 8. Cement on cleaning the felt 9. Comment on felt type CTD029886 10. Top Felt Function - Sheepsfoot Roll 11. Row to determine when felt Is no longer usStAa 12. Specific Problems Rollup Operation: 1. Coament on pressure*-thickness control 2. Are typical P vs. T curves available: Yes_____ Ho____ 3. Height of beam . 4. Comment on relationship between top & bottom felt speeds. CTD029887 -17- 5 . Signs of bad rollup - Causes, corrective measures. 6. Rate of buildup 7. Comment on Air-Lance Operations 8. Discussion of mandrels; type, cleaning, cost, etc. 9. Comment on calendaring operation 10. Discuss breaking section loose 11. Specific problems CTD029888 -18' 1. Bmragh Put Rate____________ 2. Humber of Passes ____________ 3. Dwell Time __________________ 4. Ambient Conditions by Zone Zone__________________________ Zone . Zone 5. t^ppe of Travel through Tunnel 6. Effect of daneter & Thiokener 7. Method of Control 8. Moisture content in and out 9. Theory & Recommendations 10. Physical Criteria for Judgement 11. Specific Problems CTD029889 19- Autoolaving* 1. Discuss nsthod 4 conditions prior to autoclaving 2. Discuss Loading Methods 3. Operation* (a) Cycle ________________________________ (b) Buildup Tine________________________ (o) Constant Period _____________________ (d) Blown Down__________________________ (e) Purge (f) Control _____________________________ (g) Quality of Steaa . ; __________ 4. Tppleal curves available* Tea _______ No 5. Effect of Load__________________________ Finishing* 1. Discuss finishing gperatlon (l.e. feed rate, saw blades, speeds chuck pressures, techniques, tool life). CTDO29890 21 Mlacellaneoaai 1. Flow Diagram Available! Yea,, Mo 2. __________________ _ 3. h. 5. CTD029892 PLANT DATA ANSWERS AiA" ?no wC lj corr * Pipe Technical Liv. Plant Data M.Pjnt No. J__ o -*7 Location Saicta Clara -Ull3boro Ambler St. Louis Manager Angstadt Gear Lander Maloney Paw Materials A. Cement (1) Plant Supplier 35 Ideal 57 Trinity (Div. of General Portland) 53 Lehigh, Rational 39 Missouri Portland (2) Physical and chemical analyses are generally avail able from the cement supplier on a per silo basis. This Information is utilized by Quality Control as a control media to check conformance to specifica tion and as a means of detecting material. Devia tions likely to result in poor performance. (3) There is a general lack of information at plant level regarding the manufacturing techniques em ployed by the cement supplier. Santa Clara stated that Ideal has a dry process, Hillsboro says that trinity utilizes a wet process, and St. Louis was fairly certain that Missouri Portland employs open circuit grinding. This was the content of infor mation available. (4) With one exception (St. Louis} cement is trucked in and pneumatically unloaded. The proximity of the supplier in St. Louis allows for direct air transport between plants. Periodic replacement of bends in the pneumatic lines is a minor main tenance problem. (5) Temperature: Plant 56 57 58 59 Supplier's Silo, ~*P. Plant Silo, *F. No Data No Data No Data No Data _* 40-80 Wlnter/l4o-39CP Sumner __________ * _____ * CTD029893 -2- * Quality Control records should be available, but not during tour. Temperatures are taken rather Infrequently; usually when problems are expected In the cement. (6) All plants concede that the surface area of the cement Is Important, however only two. Ambler and Hillsboro, periodically measure it. Hillsboro reported a value of 3300 hh 50 sq. cm./gro. (Blaine Method) while Ambler's data can be secured from Quality Control. St. Louis Indicated that the surface area should be controlled within a speci fied range and this was the supplier's responsi bility. St. Louis and Santa Clara were in agree ment that cement was less of a problem today than 10 years ago and in general do not blame their troubles on the cement. (7) Cement is normally ordered by the general foreman or plant manager utilizing the specifications es tablished by Quality Control. In the case of multiple suppliers the source is alternated weekly. (8) Why a particular cement is good or bad appears to be a question which the plant personnel are unable to answer. St. Louis contends that cement is one of the most stable elements in the pipe operation while Santa Clara firaly believes that past perfor mance is the only true indication of a cement's merit. On the other hand, Hillsboro is convinced that machine operation and product strength are intimately related to cement variability. Ambler is cognizant of cement differences; however, they are not in a position to correlate these differ ences with performance. (9) All plants agree to some extent that testing and control of cement at the plant level is not ade quate. The biggest question is whether the bene fits derived will warrant the additional cost. Plant personnel would welcome additional information on cement. Hillsboro has problems which are typical. They have observed during testing that a one hour difference exists between the initial and final set realized with Trinity and Universal Atlas cements, (l.e. U.A. has a longer set time). This longer set appears to result in softer pipe which is prone to board marks, pullouts and dents. Additionally they have had considerable trouble with U.A. cements causing premature blinding of the cylinder screens. CTD029894 -3- (10) None of the plants have provisions for moisture control even though they consider this to be Important. Santa Clara reported that occasion ally during the winter time condensate within the silo causes the cement to ball. (11) None of the plants was experiencing trouble with their present source of supply. Hillsboro was desirous of establishing a second source of supply. Each plant was in agreement that the cement pre sently used might not be the best available; how ever, the only criteria for Judging at this time must of necessity be past performance. St. Louis commented that at one time they suspected that too fine a grind contributed to rough bores. They have not been able to substantiate this opinion of late. B. Silica (l) Plant Supplier 56 Del Monte 57 Penna. Class Sand Corp., Silica Prod. Co 50 National Olass Sand Corp. 59 Penna. Class Sand Corp. (2) Physical and chemical analyses are available from Quality Control. (3) Little If any Information is available at plant level regarding the manufacturing techniques em ployed by the silica supplier. (4) Ambler and Santa Clara have their silica delivered by truck; St. Louis and Hillsboro used hopper bottom cars. All four employ pneumatic means to unload Into silos. (5) Santa Clara and St. Louis do not presently measure surface area of silica. Hillsboro and Ambler do. They are obtaining values of 4000 + 400 sq. cm/gm. (Blaine). All plants consider this Information to be valuable but they are not quite sure how val uable. Each plant has standardized on silica which measures 90 per cent through 200 mesh. Measure ments are normally taken by means of a wet screen analysis. All plants are also In agreement that they do not know of any Information on particle size distribution or are they aware of whether this information is available. Hillsboro raised a question as to the necessity of maintaining the CTD029895 k purity at 98.5 per cent. This was prompted by local circumstances in that they have no supplier's / in Texas and they are forced to pay a premium for f acceptable material. They would like to knov; \whether material at the 95 per cent purity level would be acceptable None of the plants have had much experience with different mesh silicas. They would be Interested in information relating to what benefits might be gained in product quality, machine operation and autoclaving cycle. St. Louis did comment that years before when the Da Inline Process was used for the manufacture of pipe the use of IkO mesh silica caused the screen to fill up. Ambler would like to have information relating product density to mesh size. Silica is purchased in the same manner ae cement General problems at the various plants are: a. Hillsboro 1 - High material cost (high freight *; caused by remote suppliers. 2 - How much importance is attached to main taining color (whiteness) in the product? 3 - Difficulty in securing data from the sup plier. b. Santa Clara 1 - Only one reliable supplier which results in occasional Interruption of supply because of equipment renewal at the source. c St. Louis 1 - Dissatisfied with present delivery times (3 to 8 days). Have considered truck de livery but the higher unit cost nr;y not br justifiable. Any savings incurred would be indirect. d. Ambler 1 - Occasional problem with moisture in silo. This usually causes difficulties daring weighing operation. CTD029896 -c;_ C. Asbestos Fiber (1) All plants contend that the major reason for using blue fiber is to aid filtration. St. Louis im plied that historical precedent must not be over looked as a minor but significant reason for its use. While all plants were reluctant to estimate the least amount of blue that could be used, they did concede that it would be possible to run with out blue at a sacrifice in production rate. Hills boro guesstimated that the lower limit might be 20 per cent, however the other plants felt that the quantity and quality of other fibers present would dictate the lower limit to be set on blue fiber. Santa Clara reported that they had in the past run with 10 to 30 per cent blue fiber in the furnish. St. Louis claimed that difficulty with pipe bore would result from the wetter film attributed to lower blue fiber contents. (2) Inexpensive short grade fibers with good filter ing properties were the unanimous selection of all the plants as the most acceptable fiber type for the manufacture of pipe. Long fibers resulted in fbequent complaints of roping and fiber clusters. These include Cassiar A/C, C&G 3 and Griqualand A. Several of the plants noted that frequent cleaning of the impeller on the recirculation pump was a must when using fibers that tend to rope. St. Louis did comment, however, that they did not think they could run on all shorts, rather they anticipated that it would be necessary to maintain a balance between long and short grade fibers. None of the plants were very happy with Bells S4K claiming that its soft, talccos nature caused poor filtration. Ambler stated that of all the fibers. Blue was graded poorest and exhibited a wide range of pro perties. While satisfied with Griqualand A, they claimed Griqualand RM gave rough bores. (3} Given a choice the plants had the following com ments regarding the fibers they would select'. a. Hillsboro - They would throw out Cassiar AC, Griqualand A and Bell S4K. . They would limit and possibly eliminate the use of Cc-f? 3 They would prefer to use Cassiar.AK, AX and Ah. The cleaner nature cf the Cassi&rs to some extent influences their choice. CTD029897 -6- b. Santa Clara - They voiced no comment since they felt they were compelled to use what they were given regardless of their preferences. c. St. Louis - In terms of money and effectiveness they would choose Cassiar AK. Their next choice would be Cassiar AX and AC. These choices they felt were prejudiced by cost. Ignoring cost they would prefer a combination of C&O 3 and 4 andTAC. They have a definite liking for African fibers. d. Ambler - Their preference was for C&C 5, Cassiar AX, AK and AS. (h) Hillsboro, St. Louis and Ambler, while convinced dust plays an important role during the machine operation, they are not quite sure to whet extent this may be detrimental. Santa Clara was more specific. They stated that the fiber duct content created a mess; tearing the cyclone to pieces and in general causing poor filtration. They were es pecially concerned with the rock and dust content associated with blue fiber. All of the plant man agers could see no reason why we paid for material (dust) which should be left at the mines. (5) Range of fiber usage Plant Percent* Min. to Max. 56 10 25* 57 9.8 16.2 12.3 16.7 59 11 17 * Not counting fiber in fines. ** Not much above 20 per cent. In general the plants agree that high fiber con tent would give better operation and e superior product. Less telescoping would be observed and more beam pressure could be applied. On the other hand, free filtration would be impeded and pro duction slower. Water removal would be a problem and attaining desired densities might be quite dif ficult. St. Louis is interested in the effect of fiber content on the ability of pipe to hold its shape, especially large diameter, thin walled pipe. CTD029898 -7- Hillsboro felt that building sewer might run better with a greater amount of a low value fiber. The plants generally conceded that low fiber con tent improved filtration and resulted in higher production rates. St. Louis added, however, that water removal at the nip was inhibited. Ambler and Santa Clara also mentioned that pickup would be more difficult and overall operation poorer. Santa Clara pointed out that machining would be difficult anc tool life shorter. They seconded Hillsboro's suggestion that the total fiber- content should be increased by substituting shorter- fibers St. Louis would be interested in improved means for making fittings from cheap furnishes. It was also suggested that the manufacture of M inch 1500 build ing sewer could be improved. Delamimfcion is quite prevalent. (6} The general consensus of the plant managers is that the fiber quotas make for troublesome and cum bersome operation. Since they have no choice, the quota usually becomes the blend and consequently they must compromise with a furnish which is less thanoptimum. Santa Clara stated that they never use less than one-half beg of fiber. The principle being - "use it up and switch." (7) Kiere are some discrepancies regarding the effect of floeculant upon fiber usage. Ambler claims it does reduce fiber usage and estimated a savings of $20,000 for last year. They added that water cir culation was increased. Hillsboro needs more data, however the3' believe fiber savings will be realized along with increased filtration and higher product densities. St. Louis and Santa Clara, however, do not think that the floeculant influences fiber content claim ing that the real benefits are derived from better machine operation, higher production rates end. bet ter overall pipe quality. 7 (8) In discussing means to control fiber, it was evident that differences of opinion do exist, Ambler keeps a close check on the amount and sequence of fibers prepared each shift. Hairpins ere changed cr a reg ular schedule and buoyancy is checked del 13- Thej' were not certain a measure of surface arer would be of any help, however they are trying a freeness tester. CTD029899 St. Louis has been without the services of a good Quality Control man for some time and as a result, they are not exercising any specific control other than submitting samples to Ambler Quality Control on a monthly basis. Santa Clara stated that they completely ignore R&D data preferring to rely on trial and error as l. basis for fiber acceptability. They felt res 1 progress would be made if the flexibility ci the fibers could be improved. They had no feeling*: regarding the use of surface area as a control feature. A regular turnover of hairpins is utilised as a means of controlling preparation. They try to process the same week after week by running so long on one side of the pins, so long on the other side, then throwing the whole lot out. Hillsboro on the other hand felt that up to date data on relative strength was essential. They have implicit faith In R&D data and use it as a basl3 for operation. They perform periodic checks on buoyancy, however their Quality Control personnel would like to know more about the theoretical as pects of the test since they are not sure how to use the data they accumulate. They were undecided on the benefits to be derived from surface area data. (9) TOie plants are not aware of any other fiber which might be useful in pipe. Santa Clara and St. Louie suggested that Amoslte might be investigated, al though they feel that it would be too brittle (10) As far as the plants know, purchasing specifications do not cover fiber quality. Even though the plants practice control measures on as received fiber, they generally feel that the present setup could be im proved The blues in particular were said to very considerably. St. Louis generally summed up th* managers' feelings when they stated they would favor tighter specs only if they were in a posi tion to do something about it. (11) None of the plants was experiencing specific pro blems with fiber, however all voiced the opinion that fiber variability could be reduced, contam ination decreased and material handling and mixing CTDO29900 -9- equipment Improved. Santa Clara's biggest dif ficulty centered on their attempts at blending long blues. They want the cheapest fibers they can get and they will make them work. Hillsboro also complained about fiber roping. They along with Ambler indicated that fiber conveyance could be improved. St. Louis needs more shorts for building sewer and air duct. D. A/C Pines (1) The primary source of fines is as follows: Ambler: Lathe turnings, hard scrap Hillsboro: Hard waste, lathe turnings St. Louis: Lathe turnings Santa Clara: Ho effort to save any particular material; pick up what scrap is available when fines must be pre pared. (2) Method of preparing fines. O versize Pines r Hammer Mi.Lx* ' Air Separator N6) E' o> ' Pines r Hammer Mill iiScreen <r Pines * 9 mesh screen CTD029901 -10- Wlth the exception of Hillsboro, which utilizes air separation, none of the plants practices any control worth mentioning. (3) No attempt is being made to determine particle size distribution at any of the plants. Hillsboro has on occasion made a screen analysis using the RoTap apparatus. Their results were not in agreement with values previously supplied by R&D and Engineer ing. Ambler uses a calibrated thumb to avoid "tomato seeds" in the fines' product. (*) At af the plants the fines are metered out by weight/and introduced into the system at the cement scale or screw. The exception is Hillsboro where the fines are^placed in the bucket elevator that handles ceotfnt and silica to the primary mixer. In general, the accuracy with which this material .ie'eontrolled is not great. (5) The general opinion regarding the effect of fines on the product was quite diverse. Hillsboro thought they were "not worth a damn" and at values above six (6) per cent, the density suffered. They stated that at low fiber percentages they might be of some help but in general the addition of fines was detrimental to filtration^--- Santa Clara sided with HUlBboro in that they also felt that fines were of no help. They suggested that the only real advantage to be gained from using them would be to cheapen the furnish. St. Louis on the contrary was in favor of using fines and if they had a choice, they would continue to use them. They contended that fines improved filtration and gave more uniform coverage on the cylinder wire. Their machine operators believe that better overall operation results from using fines. They did feel, however, that an effective ness of 5 was not really realized. At present they are using 20 per cent in building sewer. Ambler stated that in addition to reducing cost, real benefits were derived from improved flitre tion and better overall machine operation. All of the plants used product strength and density along with machine operation as criteria for eval uating the effect of fines in A/C pipe. CTD029902 -11- (6) The plants with the exception of Santa Clara would pick the Hillsboro setup as the preferred method for fines preparation, (i.e. air classification). St. Louis felt that screens were inefficient and too susceptible to blinding. Hillsboro reported they were satisfied with the present setup. The initial trouble they experienced with the hopper discharge has been overcome with the installation of a new live bottom If it was not for building sewer, Santa Clara would throw out all fines. They did concede, however, that the inclusion of fines in the fur nish did help in air lancing thin wall material. (7) Hillsboro is not experiencing any specific pro blems with A/C fines, although they did mention that hard particles are always bothersome. Sente 'Clara did not comment when questioned about spe cific problem areas. St. Louis has serious waste disposal problems and is rapidly running out of room. This is tied to the lack of adequate grinding facilities for waste pipe. They presently use a bulldozer to crush pipe. Ambler feels that the present fines are too coarse and uneven in particle size. They showed concern over the reliability and variability of supply, pointing out that fines were essential for manufac turing building sewer. Mention was also made of the relative merits of recovering only the fiber. . Chemical Additives (l) Chemical additives presently in service at the various plants are: , __ Hillsboro - Separan NP-10-^^ Santa Clara - Separan NP-10 St. Louis - Jaguar 550 Ambler - * v * Note: At time of Inquiry Ambler was having difficulties with the recently in stalled two vat system and they had suspended use of any floceulant. Prior to this time (one vat system) they were using Separan. C7D029903 -12- St. Louis felt they had inconclusive evidence regarding the use of Septran, due to improper metering of material. (2) All of the plants add the flocculant to the sys-'1 ten at the hack of the spreader trough via the ' makeup water. Usage at each plant is as follows Hillsboro Santa Clara St. Louis Ambler 1/B to 3/16 lb/ton 3/16 lb/ton 0.75 lb/ton 0.8 lb/ton (1 vat operation^ Constant volume or metering pumps are universally used for control. (3) Benefits in machine operation derived from using flocculant were generally conceded to be improved filtration and faster, smoother production rates. Ambler, Hillsboro, and Santa Clara reported cleaner savalls when using chemical additives. St . Louis has always had a clean sav&ll and cen see no im provement with the addition of flocculant. More specifically. Ambler has noted a reduction in the solids content of the overflow, Hillsboro claimed that the solids are returned to the system quicker and Santa Clara indicated that the entire system ls cleaner. Santa Clara cautioned that it is not \ advisable to use flocculant when the machine is note running. J Each of the plants said that better product qual ity resulted from using flocculant. St. Louis added that it extended trouble-free tonnage (i.e. extended felt life). (4) The plants suggested other benefits which a chem ical additive might provide. These include: Hillsboro - an aid to water removal on felt. Santa Clara - consistency control. St. Louis - aid to keeping bores cleaner and smoother.5 (5) Other worthwhile additives suggested for investiga tion include: CTD029904 -13- Ambler - wet strength agents similar to those used in paper Industry. St. Louis - no specific materials but always open to new ideas. Santa Clara - has only looked at two types (Jaguar and Separan'; thinks we should look at all of them. Hillsboro - everything and anything; would like to have optimum but are afraid to try new types. Experience with Aerofloe has ehown that It is much harder to control. (6) The plants were In accord that flocculant increases film thickness and gives a more uniform ply. Hills boro contends that water removal at the vacuum box Is Improved. Generally lower water contents were reported by all the plants, however none indicated that the vacuum requirements were reduced. Ambler added that higher speeds and pressure could be em ployed. (7) Specific problems or questions regarding the use of flocculant were: Hillsboro would like to know the optimum tech nique and location for adding floc culant to system. Also they are in terested in the performance in each of the vats for a two vat machine. What effect flocculant has on the press operation and the vacuum boxes was desired. Ambler at the time of tour they were having difficulty with using flocculant in a two vat operation and they were in terested in information related to effect causetVby different consistencies in each vat and their relationship to each other. St. Louis They stated that better equipment was needed to regulate the addition of small amounts. Information is also desired on the proximity of the in sertion point to the cylinder vat. Cfl)02995 1 y Santa Clara - ftiey went on record that they are al ways open to practical suggestions and added they were not satisfied with the present setup. Where the flocculant Is added Is tricky and although they have tried other methods (i e. 8prays, shower pipes, etc.), the re/ suits have not been satisfactory. They are convinced that It should be added at a spot as close as possible to the point of use. Consequently they feel improvements can be made. However, they did caution that unless used pro perly and reliability is established, more harm than good could result from random changes Rubber Rings (1) Storage conditions for rubber rings at the plant are: Ambler - Open bins located in cool, dark porportion of plant. Temperature Is somewhat lower than ambient. St. Louis - Open bins in separate room within plant area. Temperature Is blightly lower than ambient and uncontrolled. Santa Clara - Stored in open bins at front of plant. Ambient temperature normally encoun tered. Reported large turnover. Hillsboro - Stored In bins in air conditioned room. (2) Planning and inventory personnel or the office man ager control ring inventory either by set maximum and minimum control points or storage requirement limitations.3 (3) The plants are presently satisfied with Methocel as a lubricant. There are no major problems, however several comments are worthy of note. St. Louis has one individual who does all of the adhesive mixing. They premix all of the material prior to use and contrary to the specifications, it works well. En crustation of the Methocel on pre-belled pipe in the yard has made it difficult to determine whether fishmouthlng has occurred. CTD029906 -15- Santa Clara mentioned that the addition of soap (l.e. approximately 2 quarts of soap to 50 gallons of adhesive) to the Methoeel is definitely bene ficial in terms of assembly effort. Hillsboro complained that the application of the Methoeel in the plant was sloppy and contributed to slippery conditions. They also mentioned that they were hearing reports from the field that the lubricant was hard on the men's hands These com plaints seemed to be localized in the Texas area. (4) With the exception of Hillsboro, none of the plants were experiencing specific problems with the rubber rings or lubricant. Hillsboro was having fishmouthing problems with 6R rings on 4", 6 and 8" pipe. II. Fiber Preparation Each of the plants agreed that improvements could be made in the present method of opening fibers and they are open to practical suggestions. While not particularly familiar with other specific tech niques the plants are Interested in new methods of open ing fiber. 3. The plants were quite doubtful that the mines would be able to supply more open fiber. St. Louis and Hillsboro would like to see some improvement made in the blues. Several people mentioned a fluffer as a way of breaking up fiber wads to improve the blending operation. 4. Under the present setup for preparing fibers the plantE concede that same of the fibers are being worked too much and others too little, and it would be desirable to pre pare the individual fibers, especially the blues How ever, they feel that if the fibers were prepared in this fashion it would be impossible to blend them at a laterstage. CTD029907 5. Willow Operation Plant Speed, RPM Rate of Feed, lbs/min. No. Hairpins Possible No. Hairpins Used Changeover Cycle Sluggers jsk. 1175 _6_7jK 18 Complete Set 2 Wks. None V -51- / J51. \jgoo)(/f) 1200 48 / l8y 65 48 24 1 Flight 1 Flight @ 2 Wks. @ 1 Wk. None None -52- 1180 70 48 18 Complete Set @ 4 Wks. then every 6 {Top Mlsce1laneous At Hillsboro it was noted that the willows were running quite hot. This could conceivably be attributed to the ^ high ambient temperatures and the closed, system on air n/> ./ .nr recirculation. Santa Clara stated that using sluggers ^ resulted in additional preparation which they thought was already too great. They felt that Increased produc tion was more essential. St. Louis defended the use of sluggers on the basis that It eliminated hairpin break age . They added that a fan blade was utilized in every position on the bottom. Ambler commented on the advis ability of having a vibration shutoff in case of acciden tal Inclusion of scrap. 6. The plants reported that the fiber mixing cycle depended on the rate of usage at the machine and consequently varied according to what was being run. Normally the munsons are run half full with the fiber charged on a sequential batch basis. 7. Specific problems and comments on fiber preparation were: Ambler - Would like to have more information on mixing as a whole. Hillsboro 0 * y - The present setup is a closed, clean system in which weights can be controlled. It may , be necessary to change filling and dump cycle times to increase output. As it is 1 now, you must wait on slowest cycle le.g. fiber slow on discharge, cement slow on Lfill). Santa Clara - Building sewer runs so slew that fiber fluffs in munsons. As a result, mixing cycle is regulated and discontinuous. All other furnishes are mixed continuously. CTD029908 -17- Some Improvement should be made in the munsons to reduce the maintenance now required St. Louis - They are Interested In improving the fiber batching operation on No. 1 maohine and they cautioned that they are reaching the limit on No. 2 machine mixing system. Space limitations in and about the fiber batching areas makes It necessary for them to intermix bags of fibers on the pallets. This results in higher labor costs. j In general they commented that sc rev-: / conveyors and bucket elevators are poor means for transporting fiber, par ticularly treated fiber (quote ''for the \tirds11). III. Primary Mixing & Stock Preparation Primary Mixing 1. Plant Type of Mixer Size 56 Munson 200 cu.ft. Munson 300 cu.ft. 57 Munson 200 cu.ft. Munson 300 cu.ft. 58 Munson 120 cu.ft. Ribbon Mixer 59 Munson 200 cu.ft. Ribbon Mixer The plants did not think that there was any significant relationship between batch size and horsepower input since the units are run half full and they could not re collect any instances where the munsons drew more than a normal power load. 2. Plant Batch Size Thru Put Mixing Cycle Feed Rate 56 2300 On Demand On Demand On Demand 57 1975 On Demand On Demand On Demand 58 ---- On Demand On Demand On Demand 59 2200 On Demand On Demand On Demand CTD029909 -18- Problems with the primary mixing system are mainly mechan ical. Santa Clara mentioned minor maintenance problems with the small munsons, usually the flights. Hillsboro ported occasional block ups between the willow mill and e cyclone. Plugging of the rotor valve has also been minor problem with the trouble always occurring at the all end of a batch. All of the plant8 think that the mixing system has not W' / * y l* kept pace with the production rate pointing out that the, C- limiting capacity of the mixing system is being rapidly,/ e- approached. v-"" k. Changeover times for product mix was reported to be from 15 to 120 minutes depending on whether the furnish ef fectiveness was being Increased or decreased. The time required is mainly dependent on purging the wet portion of undesirable furnish rather than the dry mix system Stock Preparation 1. At Hillsboro and Santa Clara etock is prepared in a wet ting screw which discharges directly into the recircula tion pump pit. Ambler and the No. 2 machine at St. Louis use & semi-wet screw which discharges Into a stock chest and subsequently to the recirculation pit. Hie No. 1 machine at St. Louis differs from the No. 2 machine in that the discharge from the stock chest goes directly to the cylinder vat. Those plants still utilizing a stock chest run with as little material in the chest as possible and generally expressed a desire to eliminate it completely. 2. Water for stock makeup comes from the bottom of the dirty water savall at Hillsboro and Santa Clara. St. Louis and Ambler use white water in semi-wet screw and dirty water in makeup tank or recirculation pit. All plants depend on the system (i.e. wetting screws, stock chest, recirculation pump) to effect intimate blending of dry furnish and water. Little information as to per cent solids at this stage was available. Ambler guess timated 12 tc 18 per cent. 3. All of the plants contended that the cement-water contact time was low, in the neighborhood of 5 to 15 minutes. Based on the system sizes observed and the consistency of the stock and the output per hour reported, there exists some doubt as to the validity of the times re ported . CTD029910 -19- Rollup time Is the baeic means for controlling stock con sistency at all plant locations. Santa Clara felt there was definite need for a controller with high reliability and simple operation and maintenance tc measure and con trol stock consistency. Hillsboro employe a rheostat to speed up or slow dov.-r. discharge'1 of? solids to wetting sore>'- The quantity of stock repotted as being recirculated et each plant was as follows; Plant Recirculation Rate, OPM 5S U rLarge Amount > 57 rap tc 4000 GPfl 58 at least 50^ 59 ? (Large Amount; The method of addition of virgin stock was covered under item No. 1 - Stock Preparation. 6. Specific comments and problems brought up by the plants were; Ambler - Would like to know mere about what changes are occurring in the stock and machine opera tion at any given ihstanc*. They felt a step in this direction would be 0 reliable measure and control of consistency. St. Louis - They are most desirous of eliminating the stock chest on No. 1 machine. Santa Clara - They mentioned that a consistent, uniform overflow was essential to a good pipe pro file or shape. In discussing the wetting ' screvr they added that almost all of the water going to the machine is added at the screw. Time ar.d again they stressed the need for rugged, low maintenance controls and systems. Hillsboro They are interested in the time-constant concept. That is, they would like to know how long does it take for materiel fin all phases of the operation) to get where it is going and what actual or implied changes are occurring at any one time. Along these aame lines they felt that improvement could be made in making a more uniform stock which would help to smooth out consistency devia tions during rollup. Thev reported block--- ups of the wet feed screw! Mention was also 'maae of varying the head in the recircula tion pit to control tight pipe and to regu late cement hydration time. The stock con- CTD029911 -20- slatency In the vats was estimated at 6 to 10 per cent solids with the solids in the distribution trough running from 0.5 to 1 per cent higher. IV. Water System 1. Fresh Water Plant: No. 56 Source: Borough of Santa Clara Where Added: Broughton Showers Amount Added: Approximately 42 0PM. pH: 7.4 Hardness: 226 ppm as CaCO? Chemical Analysis Available: Yes Is makeup treated: No Plant: No. 57 Source: City of Hillsboro Where Added: Ditch to Settling Basin Amount Added ? - Controlled each shift by testing alkalinity of system. Try to keep al kalinity about 1200 ppm as CaCO^. Values over 1800 ppm @ CaCOo results in soft sloppy pipe. pH: 7.8 to 8.4 Hardness: ---- Chemical Analysis Available: Yes Is makeup treated: No. (only in settling basin). Plant: No. 58 Source: K&M Plant 1 Reservoir Where Added: Savall System, Broughton Showers Amount Added: 50 0PM. pH: -------- --------- Hardness: ------- Chemical Analysis Available: No Is makeup treated: No Plant: No. 59 Source: City of St. Louis Where Added: Fill tanks, broughton showers, pump seals Amount Added: ------ pH: 6 Hardness: 114 ppm as CaCOj Chemical Analysis Available: Yes Is makeup treated: No CTD029912 -21" 2. White Water Plant: No. 56 Source: Top of Clear Savall Where Used: Pelt Showers Aaount Generated: -- (.093" cat eye nozzle) Percent Solids: ------- Plant: No. 57 Source: Overflow Dirty Water Savall^ Where Used: Felt and cylinder Showers, Vickery Cleaner, Vacuum Boxes. Amount Generated: ------ Percent Solids: ------ Plant: No. 58 Source: Clear Water Savall Where Used; Mixing Screw, Felt Showers Amount Generated: -----Percent Solids: ? (guesstimate 0.2$) Plant: No. 59 Source: White Water Savall Where Use: Wetting Screw, Felt Showers, wash down & Circulated through Vacuum Boxes. Amount Generated*. ------Percent Solids j ------ 3. Dirty Water Plant: No. 56 Where Used: Semi-wet Screw Amount Generated: -----Percent Solids: ------ Plant: No. 57 Source: Bottoms of Savall Where Used: Wetting Screw & Makeup Water Amount Generated: Less than 500 OPJ Percent Solids: ------- 7 c. Plant: No. 58 Source: Cylinder Discharge to Savalls Where Used: Makeup Amount Generated: 800 GPM to Savall-"' Percent Solids: 1.2 -C7 CTD029913 -22- Plant: No. 59 Source: Dirty Water Save.ll Where Used: Recireulation Pvunp @ #1 Makeup Tank < #2 Amount Generated: -----Percent Solids: ------ 4. Shower Watca Plant: No. 56 Source? Fresh Water and White Water Where Used: Fresh Water used in Broughton Showers White Water used in Felt Showers. Amount Used: -----Type of Showers: Broughton for Cylinders. Pipe with Cat-Eye Nozzles for Felts. Shower Pressure: Broughton <3 100 psig Sc 6C*F r & Temperature: Cat Eye @ 60 to 75 psis & 20e'P. Shower Cleaning Cycle: Broughton only when plugged. Cat-Eye builds up cn outside and iecleaned several times each shift. Plant: No. 57 Source: Shower Savall Where Used: Felt and Cylinder Shower Amount Used: -----Type of Showers: Straight Stream Showsrc with 0.093" opening for cylinders. Cat-Eye shov?er with fan-type 0.093" opening for felts. Shower Pressure & Temperature: Both showers @ 100 psig & 95 to 105fF. An appropriation has been approved for a 250 psig felt shower. Shower Cleaning Cycle: Quite a bit of cleaning, at least several times each shift. Plant: Ho. 58 Source: Fresh Water & White Water Where Used: Fresh water vised for cylinders and felt rinse, white water for fe3t cleaning. Amount Used: -----Type of Showers: Broughton for fresh water systems. Pipes with cat-eye ncssles for white water systems. Shower Pressure & Ten^perature: Both showers @ 100 psig. Fresh water @ approximately 80F. White water similar to temperature of system, 100 to 105F. Shower CleardLng Cycle: Broughton Showers cleaned only when plugged. White water showers cleaned once per week, screens cleaned, daily. CTD029914 -23- Plant : No. 59 Sources Freeh Water and White Water Where Ueed: Fresh Water used for Cylinder, White Water for Felts. Amount Used: ---- type of Showers: Broughton for Cylinders, Cat-Eye Nozzles in pipe for Felt Cleaning. Cat-Eye Nozzle lias 0.093" opening. Shower Pressure te Temperature: Broughton @ 100 psig !e 90 to IOC F. Cat-Eye Showers @ 4o to 55 PS 9C F Shower Cleaning Cycle: Felt Showers cleaned two times each shift, the Broughton shorer once each shift. Both are giver, good clesnlng once every 2k hours. 5. When questioned about the Savall system, all of the plants stated that the conventional cone type Savall did a better Job of clarifying the top water. The major didadvantage seems to be that they are harder to clean. St. Louis wondered whether or not the water system was too big, Hillsboro complained that they were required to beer all their water in a tank located outdoors and this was. quite time-consuming and uneconomical during the winter. They also questioned the feasibility of using this same tank for water treatment purposes. Sante Clare recom mended the use of rubber hose on the savall discharge.to prevent block-ups. .6 The relative merits of operating with an open or closed system was discussed with the plants. Santa Clara had no comment since they had never operated with a closed system. Hillsboro said there were no benefits to a closed system other than water conservation and were much in favog-jofLan open system claiming a supply of good, fresh water improves the operation. Ambler re'ported that prior to using the Broughton showers they operated with a closed system and forming ir> the Savalls was prevalent. The magnitude of foam seems to change with the seasons of the year and was particularly bed for one to two shifts following a felt change. Tney concluded by stating that the Broughton showers vir tually eliminated this foaming condition. Sc. Louis said an open system created a problem in maintaining water temperatures. Since it doer not take them longer than one hour to saturate a fresh water system with re spect to alkalinity, they felt the ust of additional fresh water would only tax further the already inade quate heating media. CTD029915 7. St. Louis stated that the water source does/not con tribute to felt and screen plug up. AmtSTfir suspected that it did* Santa Clara had no doubt that it contri butes and Hillsboro was firaly convinced that it did. Ambler would like to know more about the composition of the material that builds up on the rolls, screens and felt. They have had problems removing this material in the past. 8. Vacuum System Water With the exception cf Hillsboro which uses lake water, the plants use fresh water for the seal on the vacuum pumps. This water is normally not returned to the system. The water which Is extracted from the felt along with white water which the plants use to keep the vacuum boxes clean (i.e. by continual flushing) is returned to the dirty savall. Hillsboro stated that the tail pumps and lines to the separators are too small. Ruberoid~trtS~rSported eg using dlapiaragmfl ymi-ya ***" fhi i st. Louis also indicated that addi tional work should be done on separators end improved means for maintaining the vacuum seal. 9. The wet waste disposal facilities at the various plants are schematically shown below. Comments on their oper ation and merit are included in the notes. CTD029916 -25- Splllage to *he drainage ditch feeding the settling basins depends on the alkalinity of the system. Nor mally the spillage is continuous and amounts to approx imately 35 GPM. V<hen one half of the disposal system Is filled, it ia taken off 3tream and the surface water pumped into the other based which has remained in oper ation. The vjet solids are then removed by means of a front end loader and trucked to a quarry two miles away. Hillsboro stated that they were planning to put in earth retention dams to further dry the solids prior to re moval. At present they have no formal stream pollution program even though the state of Texas does have pol lution law3. Some question was raised as to whether solids entrained and dissolved In the water overflowing to the swamp might be detrimental to cattle. They are not sure whether further treatment is required. St. Louis has no specific program for stream pollution. Their disposal facility simply consists of pumping the solids-laden water to an open pond formed by earth em bankments and allowing the solids to settle out. The water is either lost by evaporation or underground seep age to a nearby creek. Heavy rainfalls can cause pro blems. Periodic surveillance of the ditch is made to minimize solids loss. CTD029917 SiLm -2.6''ex Solids V?aste water containing entrained and dissolved solids are pumped from the plant to the settling basins where the solids settle out and the clear overflow Is directed to a clear water reservoir and then returned to the plant. Excess overflow is diverted to a surface sewer leading to a creek. The primary basins are cleaned every six months. Wet solids which are removed are spread out and allowed to dry prior to being taken to the dump. Santa Clara has no specific stream pollu tion program at the moment. They recommend large shal low basins as the preferred method for solids removal. In the past they have had some problems with waste acid originating upstream in the creek resulting In preci pitation upon contact with the waste water effluent over flowing from the settling basins. CTD029918 AMBLER Ambler presently has no Ccratl stream pullut.jon pro gram. Water with entrained and dissolved solids is pumped from the plant.0 either of the two primary settling basins when?' the bulk of the sclidt ere dropped out. The c^fear overflow then passe? through a series of .filter beds for further c3 trifles tiers prior to discharginirwTr*waste water to the creek. No spe cial treatment is involved ana clarification and de nuding is dependent on settling alone. The effluent CTD029919 amountsyto approximately 25 to 5C gpm. Ih? basins and filter beds are periodically drained and the wet solids removed and hauled to the dump. Ambler also mentioned that a better means for drying these solids, is needed. Sone question was raised en to the feasibility of recovering the fiber by air floatation 10. Other specific' problems mentioned during conversations cn waste disposal were as follows: Ambler said that When, the savalls are dumped, which Is about once a week* they have trouble with the settling basins overflowing. Removal of the wet sludge an annoying problem at all of the plants. Hillsboro in addition to the sludge problem has water problems in. ^ general. These problems ere twofold in nature; (1} con' ^ eervation of water (e.g. Rainfall = 33" Loss by evEpor- / *. ation c 53"; and (2/ chemical composition arid hardness > of water. The water supply was reported tc have caufcgJL J . boiler tube troubxCr Santa uiara was not experlencir.y any trouble rith~waate disposal at present. They thought a closed system would solve everything, although they were quick to admit that this is not an eury solution. St. Louis would like help in all aspects of waste die-* pcsal that Includes dry as well as wet material. V. Machine Operation fl, Speeds in Generals Plant Pelt Speed, fpro Agitator Speed,rpu Schneider Liner a. Stroke, inches b. St rokes /minute c. No. of Paddles d. Spacing, inches 85-110 112 16 18 5 150-2CC 20 12 5 -fr 130 18 16.7 7 12 _5SL 90* 100 115 #i. #2. 20 24 13-3 15 77 Note: Santa Clara commenting on felt speed thought t i: for optimum running it was best to start revfelt. fast {110 fpm) arid finish lev- (Sfj fpm!. . Tnlr generally will increase roll-up times towards the end of felt life, however they were of the opinion that the necessity of maintaining roll-vr time constant was mainly a dictate of ma.nag'en:e.; . In regard to the Schneider Liner with the exac tion of improving flex in Bewer and 4 inch pr-orsure pipe Sants Clara did not ft-ei it v:as needed C7D029920 Hillsboro mentioned that the felt speed can be varied to position the slug within the pipe. They also stated that for thinner consistency stock they may reduce the agitator speed t.o 130 rprn (i.e. for 4 inch pipe). Ambler said that increasing the agitator speed caused crowned pipe to flatten out. St. Louie only uses the Schneider Liner on 3 through 8 inch sizes. (2) No detailed information on type, speed, hp., etc. on the various pumps used throughout the plants was ob tained during the plant tour. Specific questionnaires will be forwarded to the plant engineer when required. (3) Vacuum: Ambler's vacuum setup consists of three boxes. The first is located prior to the first vat facing the felt face; the second is an inverted box located be tween the vats on the back side of the felt; the final box is located midway between the pickup and the man drel on the back of the felt. Control is reported as not good and the vacuum drawn varies. Values are mea sured by means of a gage located on the main separator. The boxes are rectangular with a face plate consisting of alternating one inch slots and bars. The inverted box has smaller openings. At. St. Louis both single cylinder machines have two boxes. They are located prior to the cylinder and mid way between the pickup and the mandrel. Measure end control is by gage only and the amount of vacuum drawn depends on what is being run. An average value is 12 inches of Hg. Ihe boxes are 12 inches wide with con ventional one inch openings. On machine No. 1 both boxes are tied into a vacuum pump. The situation on No. 2 machine is somewhat different. The box prior to the cylinder is connected to a blower while the second box is hooked to a vacuum pump. TOie setup at Hillsboro has four vacuum boxes arranged as follows: a. 1 prior to no. 1 cylinder. b. 1 inverted box between vats. c. 2 boxes between pickup and mandrel. They only use one of the boxes located between the pickup and the mandrel. Control is exercised by pinch ing back on a wafer valve with the resultant change CTD029921 -3C~ measured by a gage located on the tank and boxes. The vacuum drawn is kept below 10 Inches of Hg. and varies. It Is very low on a new felt and up to 1C Inches of Hg. on an old felt. The vacuum drawn is moderated to prevent blinding the felt in the nip and to minimize drag likely to alter the proper top and bottom felt speed differential. Heavy chattering has resulted with high vacuums and every precaution has been taken to eliminate this condition. Including singeing the felt on the back side. The vacuum boxes are 14 inches wide with a flat, slotted cover with 1-1/2 inch openings. Santa Clara has a setup similar to Hillsboro with one exception. They have only one box between the pickup point and the mandrel. Control is poor and values are recorded either by a gage or a chart. Values normally run 9 inches of Hg. With the exception of the inverted box which has a semi-circular cross section, the boxes are rectangular with slotted covers. Santa Clara men tioned that the boxes are cleaned once a week. (4} There are two basic types of agitators in use throughout the plants. They are: American Style A English Style At Ambler they have two English type agitators Ir. each vat. lhe direction of rotation Is the same as the cyl inders. They do not use the agitated weir prior to vat Ho. 2 but let the stock go directly from the spreader trough to the cylinder vat. Hillsboro has two agitators per vat, one American style and one English style. The weir upstream of vat No. 2 has an American style agitator. They stated that they prefer the American style on the basis that better agi tation is realized. The ends of the agitators are CTD029922 -31- shrouded for 10 inches to minimize turbulence near the ends and to prevent poor fiber distribution. A consent was dropped that precautions are taken to keep the agitators as well as the felt idler rolls in balance at all times. St. Louis has two agitators in each vat* one agitator in the weir for No. 1 machine and two agitators in the weir for No. 2 machine. All agitators are of the American style. The vat agitators are shrouded for 8 inches on the end and clear the cylinder by approx imately one-half to three-quarters of an inch. Santa Clars has two agitators in the vats and one in . the weir prior to vat No. 2. All are American in style and rotate in the same direction as the cylin ders. The ends of the vat agitators are shrouded for almost 24 inches and clearance between cylinders and the agitator is one inch or less. They felt that im provement in the agitator is needed. Several complaints were voiced againBt chain-driven units. The consensus of opinion was that independent or direct coupled drives performed much better Hills boro has already taken steps to incorporate this change on their wet machine. (5) Comments regarding the merits of the Vickery Cleaner were as follows: a. Ambler - They would like to have one. b. Santa Clara - A very worthwhile Investment which pays for itself in terms of extended top felt life. As long as water plates are good the unit functions well. Replace ment of these plates if frequent and main tenance costs high. Better cleaning techniques for unit are needed. Each pump system handles two units (i.e. vacuum box and cleaner). c. St. Louis - They reported that they can't do with out them and that prior to their use the top felt got dirty when running large di ameter, heavy walled pipe. The only al ternative without the Vickery was to slow down. It is also helpful on small pipe and felt life in general has been greatly extended. Five shoes with a L-6 Nash pump CTD029923 -32- are used on machine No. 1 and 7 shoes with a 2-7 Nash pump on No. 2 machine. St. Louis also mentioned that the cycle of the Vickery cleaner might be speeded up. d. Hillsboro - Hillsboro also considered the Vickery cleaner worthwhile. When using an Albany woven top felt, they found it essential; with a Hardman 100 per cent synthetic felt, they C ____________ _ can no* uflf employ only the vacuum portion of the unit. They commented they -- might like to see one tried on the bottom felt. (6) All of the plants operate with vat temperatures between 90 and lOS^F. They maintain that the higher temperature aids filtration. Ambler added that they felt the hotter water speeds set time. At low temperatures the pipe was reported to be soft and prone to denting. St. Louis stated that 80*F. seemed to be the cut off point. None of the plants has had experience with higher temperatures. Hillsboro even though they had reservations regarding higher temperatures wants more information in this area Specifically they were interested at what temperature you kill cement. St. Louis mentioned that operating tem peratures are a real problem during winter time. (7) Little information on the couch roll and its optimum use was available at the plants. Physical dimensions and properties may be obtained by writing to the plant engineer. Generally they are from 15 to 16 inches in diameter and are offset 9 inches from center towards the rear end of the machine. There was interest expressed in determining the optimum angle of couch and couch roll loading. Santa Clara felt the present con struction would not sustain increased loading. Hi11bboro would like to have higher couch roll pressures. In addition they questioned the steep angle of contact the felt makes with the cylinder in vat Nc. 2 in a stei down two vat arrangement. The feeling was that this was not as good an arrangement as in Santa Clara where the vats are further apart. (8) Cylinder Data: Plant Cylinder Type Cylinder Diameter (inches) Mesh Size 56 -- 32 50/10 51 a. Downingtown b. English 30 to 31 a. 30/10 b 30/- 18 _ 32 50/10 12. 32 50/10 CTD029924 -33- Notes: The cylinder wire is stainless steel and is usually applied by an outside vendor (e.g. Sinclair). With the exception of St. Louis, the cylinders are decked in to 13 ft. 3 Inches using Pliobond. St. Louis uses Propoloid K. Tht difference in the American (Dovmlngtown) and English cylinders at Hillsboro is in con struction (i.e. spider & wire spacing). The English cylinders have square support rods while the Downingtown has round rods. The English cylinder has a heavier chime ring normally retains more water. Hillsbcrojiset: the English cylinders in No. 1 vat Physical damage was reported as usual cause for failure. Ambler stated that the proper mesh size is a function of machine speed. They also think vacuum cylinders ought to be looked inco again. St. Louis was thinking of dropping to 40 mesh. Santa Clara felt going to 30 mesh was too mush of a Jump. They mentioned that previous trials with 30 mesh wire had resulted in too much drainage and excess solids going to the savall. (9) At all the plants stock is distributed to the vat by means of a spreader trough. Distribution is normally not good and diversion blocks or pans are utilized to avoid soft ends on the pipe. Ambler has found these are most effective when placed directly behind the cylinder for a two vat machine. Even under these cir cumstances control is not good and correctione must be made constantly. All of the plants were in accord that a better method is needed. Hillsboro thought Blow ing down everything to minimize velocity, including the weir agitator, would help. They postulated that air beat into the stock might be contributing to fiber sep aration through flocculation and floatation. St. Louis cautioned that slowing down the agitator speed changes the pipe profile causing the pipe to crown. Santa Clara shrouds their weir agitator, however they c*.o not think a weir box 1b necessary claiming thtt it only collects dirt. They believe distribution problems originate prior to the weir in the spre&der trough. The use of a baffled bubble at the heae of the spreader trough was thought by Santa Clara to result in betteruniformity. Each of the plants reported that the height of the over flow was critical and influenced the pipe prefix? . The CTD029925 -34- height of the stock in the vats was from 8 to 9 inches above the shaft. Overflow over the dam varied from 1 to 1-1/2 inches. St. Louis felt that thorough studies of pipe density versus linear position along the pipe would be the first step into understanding optimum dis tribution patterns. (10) All of the plants generally agree that the present means for monitoring and controlling stock is not good. Santa Clara stated they run everything according to rollup time and considered that this would serve as a good criteria for controlling consistency. They had no pre ference as to the best place to locate a controller. St. Louis claimed that thin consistency gave tight pipe and that present practices on controlling consistency were by "the seat of the pants." They considered it desirable not only to measure and control consistency but in addition be able to predict likely results. They added that lower mandrel change time and reduced 8lug were converted to good consistency control. Hills boro presently is using lamination thickness to control stock consistency. They try to maintain 0.050 inch, adding water if stock is too thick. Ambler was of the opinion that under present operating conditions stock consistency control was virtually non-existent. (11) In commenting on manner in which various stocks mn Ambler stated that most changes were due to diameter rather than furnish. Santa Clara said this in another way. They felt the greatest difference was between thin walled goods and other pipe. The thin walled pipe was reported as very difficult to air lance. The visual complaint was uneven opening along the pipe length. Santa Clara thought that it was a crime to use the machine for building sewer. St. Louie reported that building sewer had to be run with thin consistency and unless the 12 second mandrel change time could be re duced, heavier consistencies were out of the question. At present St. Louis runs 6 inch and above on machine No. 2 and have had production rates up to 7 tons per hour. They can't handle smaller diameter or thin walled material on No. 2 machine and are realizing 3 tons per hour for building sewer on No. 1 machine. Hillsboro said the longer fiber stock gave more trouble with fiber blotches, roping and door reinforcement quite evident. (12) Pickup on the cylinders waB reported by Ambler to look blotchy, ropey and coarse. What precise corrective measures can be taken to eliminate this condition they are not sure. Hillsboro also claimed that fiber clus ters hurt, however they reported that they normally encounter little trouble with pickup on the cylinders. They run a heavier consistency in vat No. 1 than in CTD029926 -35- vat No. 2 with the resultant laminations for vat No. 1 equal to 0.035 inches and for vat No. 2 0.015 Inches. They did report a considerable drop off problem. This was attributed to long shutdowns between mandrel changes and to losing vacuum on the Inverted box. Shower fog rewetting the ply can also cause dropoff. Santa Clara said one of the biggest problems with a two vat system was the pickup of the second ply. Boll back on the No. 2 cylinder was not uncommon. A little run off is exper ienced but Santa Clara felt this was not critical. Santa Clara stated that the ponding of water behind the No. 2 couch roll depended on the vacuum pulled on the inter mediate box and that they favored a low vacuum. Santa Clara added that vacuum cylinders were too complicated and were not needed. St. Louis with single vat machines thought most pickup problems were eliminated by keeping the cylinders clean. The Broughton showers were re ported as a big help. (13) Ambler reported that the water content in the web varies with felt life and after the last vacuum box ran from 32 to 38 per cent. Hillsboro quoted values of 45 per cent prior to the suction box and 30 to 35 per cent after it. If two vacuum boxes were used in series values as low as 26 per cent were realized. They are presently getting 18 to 20 per cent in the pipe off the machine. They also mentioned that displacement of the anvil roll relative to the center line of the mandrel influences water content. St. Louis said that the water content in their web ran 33 to 34 per cent prior to the mandrel pickup point. Santa Clara said that the only water con tent that was important was that in the pipe coming off the machine. They are realizing approximately 20 per cent and would like to have it even lower. The real proof of the pudding they contend is to look at the den sity. (14) None of the plants saturate the savall system prior to start up. St. Louis reported that starting with fresh water within one hour the system is saturated. Ambler and Hillsboro also use fresh water to start. Hillsboro generally uses partially lake water and clear well water. They never use city water. Santa Clara does not use any fresh water to fill the savall system but reuses the water stored in the holding system from the previous Bavall discharge. (15) All of the plants prefer rubber hose to regular piping for vise as stock lines. Little trouble was reported with piping associated with water lines, both process and shower. St. Louis mentioned that they never use elbows and Hillsboro recommended that lines be as straight as possible. All plants UBe as few valves as possible. CTD029927 Where valves are used, Santa Clara and St. Louis found plug valves acceptable even though they are not per fect and fine control Is not possible. Hillsboro re ported that they have had trouble with kinks that de velop In the hose carrying clear water overflow from the dirty water savall to the clear water savall. Ambler commented that in order to keep the bottom valve open on No. 1 savall# they must run a lot of material out of the unit. Ambler also mentioned that the exist ing vacuum system layout Is very poor and the separator lines give out. They think a new system Is required. On the subject of vacuum pumps and systems# Santa Clara cleans their vacuum pumps every few months with In hibited muriatic acid. Santa Clara felt that the whole field of construction materials for pumps, pipes# etc. / which would not build up Is a fertile development field.. Presently Santa Clara spends 5 hours a week @ 4200/hr./ In maintenance to Insure a clean# working system. (16) St. Louis suggested that another area where further work is required is vat design. Hillsboro wants infor mation on proper angle of attack for the felt during rollup and couching. They also would like more data on vat design# proper overflow heights and specific measures to Improve drainage to overcome flaking. Santa Clara re-emphaslzed the need for continual machine Im provement especially with foolproof# maintenance free equipment. VI. Pelts (l) to (5) Supplier# Type, Cost# Life# Reason for Removal: AMBLER: Though Ambler has used Albany Top felts# they have gone almost exclusively to Hardman Top Felts. This is a 100 per cent nylon felt manufactured by Hardman 8. Son Ltd.# London# England. They cost between $800 and $900 depending on current price per pound. The felt is good for approximately 240 hours and is us ually removed because of general wear. For the bottom felt Ambler used either a Dryeor or Albany felt. Both are needled felts with the Albany containing 45 per cent synthetic and the Dryeor 30 per cent. The synthetic Is usually nylon. The Dryeor costs from $1100 to $1200 with a life of 140 to 150 hours while the Albany costs approximately $1350 and CTD029928 -37- averages 20 to 30 hrs. less. For economic reasons Ambler prefers Drycor, however they claim the Albany handles easier and shows less resistance when being driven. As with the top felt usual reason for re moval is general wear. SANTA CLARA - Santa Clara vises an Albany top and bottom felt. Both are plain woven felts. The top felt cost approximately $900 and normally lasts 140 hrs. The bottom felt runs $1350 and is good for 140 hrs. Replacement usually is because the felt wore out or has been damaged. ST. LOUIS - St. Louis uses three top felt suppliers. Hardman, Draper and Albany. The Draper and Albany felts are woven and contain synthetic fiber up to 75 per cent. CoBts and running hours are as follows: Hardman - $ 800 Draper - 790 Albany - 760 - 170 hrs. - 140 hrs. - 80 hrs. Usual reason for removal is that felt is worn out. For bottom felts, St. Louis uses either a woven Albany or a needled Drycor. The Albany costs $1050 and lasts 84 hours, whereas the Drycor costs $1250 end runs for 120 hours. Felts usually just wear out. HILLSBORO - The top felts at Hillsboro are either Hard man or Albany. Both are woven felts. The Hardman is 100 per cent synthetic with a needled face. Costs and running hours are as follows: Hardman - $ 1000 - 220 hrs. Albany - $ 1000 - 75 hrs. Felts are replaced either because they are filled up or have worn out. Hillsboro's bottom felt is either a Drycor or an Albany. Both felts are needled and contain synthetic fibers. The Drycor runs for 100 hours and costs $1400. The Albany gives 100 hours and is priced at $1300. Felts are replaced for same reasons as above. CTD029929 -38- (6) When breaking in the new felt all the plants recom mend that the felt be kept clean and reasonably free of grease. On actual startup, Hillsboro and Santa Clara wet down and run at a slightly reduced speed. St. Louis also wets down thoroughly but starts fast. Aaibler starts dry at a slow speed, levels and measures the felt and then wets down using the showers. All of the plants stressed the importance of keeping thejsoAm~< of the stripe even. Santa Clara also mentioned the necessity of loading thejsck rolls properly. (7) All of the plants concur that the most singularly im portant factor in running a felt is maintaining the stripe even. Ambler stated some bowing will occur. Santa Clara simply said don't abuBe felts in any way. St. Louis trims off excess on wide felts and Hillsboro likes to run felts as loose as the operation will ner- I0it VU- ( -ftr* /*****<< (8) The plants were in general agreement that better means for cleaning the felt are needed. Ainbler suggested this would include the whlpper. Most of the plants hesitate to try the conventional acids and washes pre ferring to wait for results detailing an easy, prac tical means. Hillsboro suggested that with the exist ing setup, it is necessary to recognize a dirty felt and use lots of water. They suggested higher shower pressures in range of 175 to 200 psig. They claimed a clean felt was the most essential factor to good oper ation. St. Louis recommended that the mhlppers be kept spanking, thediowers unplugged and the suction boxes open to avoid premature dirty felts. They also mentioned that felts will not clean up after shutdown. (9) Santa Clara prefers woven type felts claiming that need led felts are good up to 60 hours then plug and are ' trouble from then on. They know that an aoid wash helps but they are not interested because of the corro sion problem. St. Louis' preference for felt type de pends on the machine in question. On machine No. 1 they prefer needled felts and on machine No. 2 a woven felt. They stated that a needled felt runs with a drier film but will plug up sooner. Ambler prefers a needled. felt claiming that it cuts down telescoping and water marks and reduces ovality problems. They suggested that the cylinders be driven to prevent the face wire from slipping due to the pull exerted by the felt. Hillsboro prefers a needled felt. They stated that woven felts are horrible and cause thin wall pipe. Their theory is that more even pressure distribution is achieved with a needled felt due to the absence of CTD029930 -39- VII. knuokles. In addition they contend a thicker felt permits more water removal. They also recommended synthetic fiber contents of 45 per cent or higher to Insure adequate strength. (10) The consensus of opinion among the plants is that the top felt function is primarily to assist in the removal of water. Hillsboro and St. Louis added that it acts as a cushion and means for pressure distribution. St. Louis suggested that it prevents sticking and in es sence might be considered a parting compound. Ambler however thought that it may contribute to pulled bores. All of the plants expressed an Interest in a sheepsfoot roll. (11) The plants determine whether a felt is no longer usable solely by visual inspection, experience and their ability to make satisfactory pipe. A tool for measuring qu&nitatively the closeness of a felt would be desirable but only if the results realised could be translated to ac tual machine performance. (12) Ambler at the time was having no specific problems with felts. Santa Clara stated that grease spots resulting from installation wee minor and that felts in general were damaged rather than worn out. This damage was caused by stones in the fiber and other foreign objects that get into the system. Rarely do they have trouble with wrinkling, but when they do the men must shut down the operation and run the felt until the wrinkles are out. This they do on their own time. St. Louis re marked that variability in felt size is a problem at times. They have had trouble with Albany felts narrow ing down between the suction box and the press section, consequently when ordering they are liberal with felt width feeling that they can always take some off but can not add any if short. Hillsboro reported that Hard man felts while stable are always wide. They also feel that felt uniformity and stability could be Improved for all suppliers. Rollup Operation (l) Hillsboro thinks that when the Minneapolis-Honeywell thickness controller is working it is unbeatable. However, they have had trouble with the unit. They did find that old fashioned leathers work best in the CTD029931 -40- pistons on the press roll. The hard rubber rings tried Initially resulted in oil leakage. Santa Clara while not satisfied with their present setup know how to operate it and will not consider tearing it out to evaluate a new system. The only way they thought a new system could be properly eval uated was to check it out in parallel with the exist ing setup. In any case they want something that is simple and requires little maintenance. Ambler agreed that the existing setup is not the best but once thickness control is establshed it is not bad. They do not know of a better system to date. St, Louis feels a lot of work can be done in this area, in particular what is the optimum pressure reduction. By starting high and ending low their densities have improved. They have increased density by upping the lower pressure. They remarked that sudden pressure buildup results in bagging and fracturing the pipe. Their general feeling was that the Askania unit does not_do_the job. ^ (2) Typical pressure reduction curves are available from the plants. (3) Weight of the beam is as followsi Plant Wgt. of Beam, Tons 56 3.8 57 3.8 58 3.8 59 No. 1 = 4.0 Ho. 2 3.8 (4) All of the plants stated that the top felt should lead and help the bottom felt. This ensures a tight jalpe.--After the first few laminations the press ^section should tilt towards the rear of the machine as \an indicator of this overdrive. Ambler reported that on 12 inch pipe the top felt gets dirty early and the top felt amperage must be reduced to keep the felt clean. They experience no trouble with pipe below 6 v>V v/ inches in diameter. All agreed that more information Is needed to establish the optimum speed differential/ Santa Clara felt that more water could be removed by varying the angle of contact between the mandrel and the anvil roll but they thought that the stress ef fects would be the over-riding factor in the final decision. CTD029932 -41- (5) The most common signs of bad rollup are: a. telescoping b. rough bore c. blotching, flowers and streaks 7 d. very tight pipe, / s'** The plants felt that telescoping was mainly caused by either improper pressure reliefer poor waterremoval. St . Louis addefi ^hatPthe ends are a good criteria for judging pipe and telescoping was the most certain sign of bad rollup. Rough bore can also result under conditions likely to cause telescoping; in addition. Ambler mentioned that high nip moisture and too high a buoyancy are contributing factors. Santa Clara reported that they sandblast their mandrels every 100 passes to help prevent pulled bores. St. Louis stated that blotching and flowers in the pipe indicate that the box is getting heavy and that this can result in poor rollup. Any abnormal appear ance or streaks in the pipe was also reported as an indicator of poor rollup. This latter effect was usually found to be caused by dirty felts or cylinders. Other indications that something is wrong^are in creased rollup times and Pipe which~is very hard to air lance and break. This latter circumstance does "not mean the pipe TsTbad, rather that the operation, is difficult. J Water marks (i.e. small cracks about 3/4 inch in length at 43 to the horizontal on the inside of the pipe} are also indicative of poor rollup. All of the above problems were reported as being in timately connected to water removal, proper stock dis tribution end condition of cylinder and felt. Hills boro also suggested that the positioning of the anvil roll was Influential. Ambler remarked that they use nozzles on the deckle to get proper alignment of the plies on the mandrel. CTD029933 -42- (6) The rate of buildup at Ambler, St. Louis and Santa Clara is controlled by rollup time as reported by Quality Control in the Making Particulars. Hills boro has their own rollup times based on 0.050 inch lamination thickness. Ambler commented that under the present setup and rollup times handling is a problem with 4 inch pipe. (Note: Rollup times re ported by Quality Control are average and vary from plant to plant). (7) Santa Clara felt that air lancing was a source of trouble and wished that it was unnecessary. They do not know what alternative to suggest but did express interest in electrolytic stripping. St. Louis suggested that air lancing be held to a minimum. They stated that blowing too long or at too high a pressure caubed the pipe to blow apart or the ends to tear out. Their recommendation is to air lance nearly parallel to the mandrel (e.g. difference of 30 or less) until you see the pipe open or detect a difference in air sound. Experience they felt was the best teacher. They concluded by saying that thin wall pipe was harder to break and the duration of air lancing was dependent on pipe size. Hillsboro air lances in the calendar but this has not been satisfactory with tight pipe. Even so they p fer to air lance at this point. Ambler said that all air lancing was by chance and continual source of trouble. They feel it must be dene prior to calendaring and at present air lance both ends of the pipe in the machine for 1/3 to 1/2 the circumference. They employ two signals ( 1. ready 2. inject) to control the timing and duration of the lancing operation. (8) All of the plants agreed that the present pipe opera tion requires too many mandrels. Ambler felt they would like to know more about sand blasting since it Is costly and would like to do their own. In the case of damaged mandrels, in particular oval mandrels, they stated that it is cheaper to buy new ones than reworking the old ones. They prefer heavy walled, spuncast mandrels because of the surface obtained even though the extra weight requires more careful handling. Ambler commented that better looking bores are a result of sand blasting. CTD029934 -43- Hillsboro prefers the thick walled American mandrels to the thin walled English mandrels claiming that the latter resulted in bent pipe. Sandblasting they felt was ndt primarily -a cleaning operation but a prooess improvement and maintenance item required to prevent telescoping and rough bores. St. Louis reported that dents, out of roundness and straight ness were the biggest and most frequent problems with man drels. They use American mandrels that are 18.5 feet long. Up to 14 inches in diameter they can use mill run material, over 14 inches in diameter the machine cut surfaces are too rough and must be sanded off with a disc sender. Their sand blasting schedule is approximately every 100 passes. They stated that they have had no luck with aluminum man drels and do not think they would take the beating that steel does. Santa Clara remarked that roughing up the mandrel surface sure helps but they do not know exactly why. Most of the problems with mandrels they felt occurs below 6 inches in diameter in the form Of bent mandrels. Santa Clara has an outside craftsman Who straightens mandrels when required. Their cleaning schedule as previously noted is approximately every 100 passes. They take precautions to remove scrap A/C resulting from pulled bores during this time. Each of the plants preferred to run with hot mandrels pointing to the fact that better operation results the second time through. (9) St, Louis and Amibler expressed a desire to know more about the calendaring operation since they felt present know-how was incomplete. In particular they are interested in the relationship between the spread of the rolls and mandrel diameter. Ambler presently has a 5 to 10 second calendar ing cycle. Santa Clara is satisfied with their present oalendar setup. They remarked that what air lancing does not accomplish in the machine calendaring does by forcing the air bubble along the pipe length. They do not recommend holding the pipe section down during calendaring, claiming that this helps to blow the pipe. Hillsboro feels their present setup is adequate and since they also air lance during calendaring, they feel they CTD029935 -44- should have a hold down on all sizes to minimize the dur ation of air lance. Presently they hold down on 4 and 6 inch sizes only. They suggested a third roll for this purpose. The calendar rolls turn in the same direction as the machine, (10) Vlth the exception of Hillsboro, the pipe sections are broken loose manually with a spanner wrench. With 6 and 8 inch pipe this can be done while the section is being calendared, larger sizes are done in a V-groove trough and at St. Louis where big sizes are encountered it is really hard work and quite a problem. Hillsboro has an automated devlee whleh they said works well, They did complain that the raising and lowering of the device was too slow. Several plants indicated an Interest in Hills boro's setup. (11) Santa Clara said that they had no specific problems re lated to rollup but Just keeping things In phase and mov ing smooth was always a problem. St. Louis stated they would like to Improve their mandrel change times especially on Ho. 1 machine. They said they liked Hillsboro's man drel feed and change. . . . . * ft Jvr1 Hillsboro remarked that cement hydration time is more `re important than top drive in effecting tightness of they pipe. They also said that the press cylinders can cause the pipe to bump and bounce unless sufficient cvishion is allowed for. Ambler again expressed a desire to change vacuum system as a means to Improve rollup. They complained that the design of the second cylinder obstructed visual observa tion. CTDO29936 VIII. Curing 1 through 11. SANTA CLARA -45- O @ 10-12# h20 ZONE 2 o. _cu_ .Q a ao 3 - 8.5 Tons/Hr, 18 - 20# h2o Dwell Time, Min. Temperature, F. Humidity Air Plow Mandrel Pulled Zone 2 60 170-175* ? Parallel to Pipe Zone 1 60 240-250 ? Parallel to Pipe At Santa Clara temperature and speed through the tunnel are varied to effect the desired curing cycle. Steam at 60 pslg is the heat source. They try not to dry out the pipe more than they have to, but Invariably the ends do CTD029937 JD. 7-8)8 H2 -46- dry out especially with thin walled goods. Even so they reported that the faster production rate on thin wall pipe usually results in a pipe that on an overall basis is not hard enough. They stated that different curing results were obtained depending on what type of pipe they run and mentioned that they have had some big low head material collapse. This they attribute to low fiber content. They have no special curing theory and pointed out that natural drying has not proved detrimental. If they had to choose they would prefer longer tunnels at lower temperatures on the premise that time Is the single most Important factor. They are not convinced that humidity does any good and feel that a saturated steam environment presents a lot of pro blems due to rusting. Their basic criteria, for determining the effect of cure is hardness and ability to handle without damage. Specifically they pointed out that the transfer techniques are troublesome and most damage to the pipe ocOfcred during the handling operations. In particular, they recommended plugging certain vunerable sections in the auto clave trayB to prevent them from flattening out while being handled by truck drivers. The plugs are removed prior to autoclaving. HILLSBORO (\ (.--N\ ^ -------ZO-N-E--2--------(!1--iii--1rI n1I--Zi:jpNE ri 1! !s no _o i O L__L i l U i. Mandrel Pulled 12 - 14# HgO Variable Tonnage __L_ 10-22:15 F0 r\ Dwell Time, Min. Temperature, *P. Humidity Air Plow Zone 2 90-lV>5 250-260* ? As Shown Zone 1 60-75 . 270-300* ? As Shown CTD029938 -47- Hillsboro regulates temperature and speed to control the curing cycle. Heat Is obtained from 150 pelg steam and controlled for each air pass by means of part low regulator. No control is exercised on humidity. They reported hxaaidity values of 13 per cent in Zone 1, 20-25 per cent In the first part of Zone 2, and 40-65 per cent for the second part of Zone 2; however these values were determined by wet and dry bulb measurements and due to the elevated temperatures thought to be erroneous. The pipe does not turn going thru the tunnel. They repotted that light walled pipe causes trouble because of dents picked up after the mandrel is stripped. They commented that nobody has licked the trans fer points to date. They did not postulate any curing theory and requested help and information in this area. Their criteria for acceptance on cured pipe le hardness and handleabllity. AMBLER Zone 1 Swell time, Min. Temperature, F. Humidity Air Plow 75 a 200-220 ? Parallel to Pipe Zone 2 80 165 170 ? Parallel to Pipe Zone 3 80 130 ? Parallel to Pipe CTO029939 -43- Note: Zones 2 and 3 are not phy3ioally separated. Ambler uses conveyor speed and temperature to regulate curing cycle. Steam at 105 psig Is available for heating. The $ipe does not turn going through the tunnel and on the second and third pass the pipe rides on bars. This means of conveyance and the handling in general they said was hard on the pipe and resulted in dents and damaged pipe. They also stated that small diameter pipe, in particular 4 inch, was not hard enough coming out of the tunnel. . They advanced no particular theory on curing but stressed the need for mechanical improvement in transfer and material handling equipment. Their criteria for judging pipe was also handleability. ST. LOUIS - No. 1 Machine Dwell Time, Min Temperature, P Humidity Air Plow Heat Source 80-90 220 ? As Shown Gas Fired Blowers CTD029940 No. 2 Machine Dwell Time, Min. Temperature, P. Humidity Air Plow 60-90 230-Summer 190-Wlnter ? Parallel to Pipe 105-120 150 ? Parallel to Pipe 105-120 Cool (120?) ? Parallel to Pipe Curing cycles at St. Louis are controlled by observation and resultant corrections to speed and temperature. No. 1 tunnel Is gas fired and No. 2 tunnel uses 5 steam heaters on the top and 2 steam heaters on the bottom. (Note! Zones 2 and 3 are not physically spparated). They supplement their heat supply by trying to keep the mandrels hot to minimize heat losses associated with heating the mandrel. Their criteria for Judgement Is pipe haroness aid handleablllty and they feel that time on the mandrel Is the ruling fac tor. They avoid too much heat claiming that the mandrel is hard to pull. This Is an exception and normally they are short on heat and would like to have higher temperatures or longer tunnels. This is especially true for the small sizes and during the winter time. They did not express any spe cific theory on curing pipe but would like to see some sort of an accelerated cure developed. CTD029941 -50- As a sidelight they mentioned that under certain conditions of temperature and humidity they have a serious condensate problem in the plant. On some days they said it literally rains. IX. Autoclaving (l) and (2) Loading techniques at the various plants are as follows: HILLSBORO: Pipe is loaded in trays out of the curing tunnel using hairpin type hooks to prevent dents. The piled trays are then dipped to rewet prior to autoclaving. The pipe then sits from 20 minutes to 4 hours before it is autoclaved. They stated they would like to know the optimum time pipe should be held before autoclaving. Presently they are getting 16 to 17 per cent water be fore autoclaving. AMBLER: Pipe is piled on buggies directly out of the curing tunnel, rewet and then autoclaved. Interim storage Is outside without plugging the pipe. They mentioned that the softer pipe resulting from higher production has reduced tray loading. They reported that they have had 8 inch sewer crack in the load. SANTA CLARA: Santa Clara uses an auxiliary mandrel to tenderly load pipe coming from the tunnel onto sand bottomed buggies. Vulnerable pipe sections are plugged and pieces of felt are used to prevent crowning. The buggies are stored outside and autoclaved as soon as possible, usually within one day. They mentioned that they control coup ling stock age carefully. ST. LOUIS: Pipe is loaded directly onto cars from the curing tunnel. Those cars from No. 2 machine go directly to the autoclav5 tube8 while pipe from No. 1 machine 1b held over for 8 hours prior to autoclaving. The pipe is stacked carefully to prevent distortion but the ends are not plugged. Pipe from No. 1 machine is loaded into several CTDO29942 -51- can at once to prevent collapse due to premature build ing up of the load. In the summer storage is outside. In the winter, pipe is left indoors to prevent the pipe from freezing and subsequently blistering during auto claving. (3) Autoclave Operation Plant Number a. Cycle, Hrs. b. Buildup Time, Hrs. 0. At oonstant pressure, Hrs. d. Blow Down, Hrs. e. Purge f. Control -26. -2L. -5- -52_ 10-12 12 12 12 2 1-1/2 1-1/2 1 8-10 10 10 10 1/2 1/2 1/2 1 No No No No Steam Pressure Through Valve (4) Typioal Autoclave Cycle Curves are available from each plant on request. (5) None of the plants thought that the size of the load had any effect on the autoclave cycle or cure. Z. Finishing (l) and (2) The status of the finishing operation reported by the plants is as follows* HILLSBORO* They said that they had a good many problems with fin ishing and felt a lot of work was needed in this area. Their experience with throw away tools has been poor. In addition they stated they were costly. They have had considerable success with diamond wheels and were high on its merits. They remarked that they thought tool life depended on the wetting and setting times experienced by the material. In general they concluded that overall they were in poor shape. ST. LOUIS: St. Louis felt that they were in satisfactory shape as far as finishing was concerned. They were not having any particular problems with the lathe and they felt the vertical boring mill was doing the best Job ever. They mentioned that all outs were profile cuts and that ovality problems associated with air pressure on the ohucks had been resolved. They were extremely happy CTD029943 -52- with the diamond wheel on the coupling cutoff stating that they were getting 89#000 outs as compared to a previous standard of 2,000 cuts In addition to sal vaging an extra coupling. They said that they did not want anything to do with throw away tools. They also wondered what was to be gained from using the pencil sharpener lathe especially since a varied product mix of large diameter would result In excessive changeover time. They did express an Interest In Santa Clara's diamond core cutter even though they thought it would be too costly. AMBLER: Ambler was not particularly bothered by any finishing problem# however they did complain that their lathes were too light and required excessive maintenance. They said tools were an occasional problem and more in formation should be available on tool life. They ex pect to install a diamond cutting Wheel in the near future. SANTA CLARA: Santa Clara commented that money Is made and lost in the pipe machine and not the finishing department. Pre sently they reported that three crews in the finishing department can keep up with three shift operation. They said that other than minor mechanical problems# the lathes were generally good and the Rogers mill runs like a top. Their tool life is reasonable and the dia mond wheel was doing a good Job on unautoclaved material. They would like to see eome Improvements in the machin ing of the coupling 0.1). and the coupling cutoff. {3) Ambler reported that the dust situation was under study at time of plant trip. St. Louis said their dust con ditions were better than ever and finding a suitable hose to carry away chips from the fittings operation was the only specific problem they had to report. Santa Clara felt they had a dust problem on the saw which sufficient funds could easily solve. Hillsboro's over all dust control was reported as good but they were having equipment trouble# in particular the dust bags were bothersome. XI Testing (l) All of the plants agreed that two bottlenecks to faster production were: C7D029944 -53- a. time required to fill with the hydrotester setup b. the excessive attention required in maintaining loads for the five second dwell on the flex tester. Santa Clara said that they were not sure they liked external heads on the hydrotester. Their major com plaint was that the heads were too slow coming in. St. Louis mentioned that stenclllzing on small pipe was also a production bottleneck. They would like to see a faster, cheaper method devised. CTD029945 DEVELOPMENT RECOMMENDATIONS CERTAIN-TEED PRODUCTS CORP. *\ Pipe Technical Dlv. Plant Data I. Raw Materials A. Cement Virtually everyone will concede that cement technology is complex and that the degree to which known funda mentals have been correlated with A/C pipe manufacture Is rather Incomplete. However these inadequacies would appear, at least from a practical standpoint, to be more of an academic void than a current operating pro blem. Each of the plants is capable of processing their present cements with acceptable results. Undoubt edly problems do and will arise from time to time which are a result of source deviations. These are normally few and far between and are best resolved by standard control procedures. The fact that significant differ ences In filtration rate, plasticity and water retention ability do exist between cements has not been ignored. Here again this recognized variability is best elimin ated by restrictive specifications. The foregoing dis cussion is not meant to Imply that cement can be ignored or that optimum operation has been achieved. What is meant. Is that rarely can problems be solely attributed w to the cement. Problems which are encountered and at first glance seem to be created by the cement have been in most Instances precipitated by other factors. These factors, to cite a few, might include system temperature, water composition and contact time. On this premise It is recommended that routine cement evaluation not be con ducted on the pilot pipe machine, rather experimentation should be devoted to correlating the idiosyncrasies of cement with compensating process variables. Specifi cally this work should be aimed at developing operating techniques and parameters for the successful processing of quicker setting cements. An ultimate objective would be to effect an improved cement cure on the mandrel. Since a development program of this type would initially entail working In areas of poor operation valuable in formation should be secured regarding corrective measures for existing problems. Finally this program should be supplemented by a comprehensive and comparltive evalua tion of the cements presently used. All physical and chemical properties should be included in this study. This work will not only serve to pull together all known and previously unknown data, but more Importantly it will provide an excellent reference base for future work. CTD029946 2- - B. Silica No major technical effort needs to be expended on silica. The material is quite stable and relatively inexpensive and almost all considerations are by nature economical. Adequate control and restrictive specifications provide the easiest and most logical approach to potential pro blems . A finer mesh silica might result In Improved product quality, however any benefits derived would more than likely be offset by increased costs. A similar line of reasoning is applicable to purity levels. Since the silica requirement for autoclaving remains constant, greater quantities of less pure materials must be util ized to achieve the same results. This added material consumption tends to negate any initial cost advantage. In addition the higher percentage of impurities can only tend to increase the prevalence of uniformity complaints and frequency of product rejects. What could be of value would be a thorough analysis and compilation of the physical and chemloal properties for each of the silicas presently used. This would update existing knowledge and provide the needed background for preparing more inclusive material specifications. C. Asbestos Fiber Asbestos fiber represents a lucrative development field in which significant coat advantages oan be realized from optimum fiber usage. Since in the manufacture of A/C pipe fiber constitutes the lion's share of the mater ial cost commpn sense dictates that a continual effort must be made to derive the cheapest possible furnish consistent with good operation and acceptable product quality. Practical experience and laboratory test data account for much of what we now know about the efficient use of fiber. An economic analysis of this information determines fiber allocations which in turn are a reason able representation of the selected furnish. While this approach is an attempt to formalize fiber selection, con siderably more work needs to be done to translate exist ing fiber technology in terms of actual machine operation. For this reason it is recommended that the pilot pipe machine be programmed to correlate fiber properties with controllable process variables. This work should not include routine testing but should be directed at estab lishing physical criteria which must be met to adapt CTD029947 -3- niachine operation to low cost fibers. It would be preferable If the program did not freeze machine design cr operation but deliberately created problem situations, in this way those process variables which compensate for fiber deficiencies can be determined and satisfactory operation achieved. For instance, the means for econom ically processing slow filtering fibers might be resolved. Other possibilities include the elimination of long fibers and blue fiber along with the thorough evaluation of the benefits of chemical additives. D. A/C Fines Nothing fundamental needs to be done with A/C fines. While there are mixed reactions regarding the merits of fines in the final analysis they are essentially an economic measure. An ideal solution would be to eliminate them completely. Since this is not practical, it might be ad visable to determine the upper limit of use for given quality levels and the most efficient means for processing resultant furnishes. In addition, specific problems or products connected to fines might be investigated. It is not recommended that any work beyond this be undertaken especially on the pilot pipe machine. 5. Chemical Additives Chemical additives appear to be an enticing development field with unlimited potential and opportunity for sig nificant process and product improvement. Previous work barely scratched the surface of this diversified tech nology and for this very reason a broad survey approach directed at evaluating the multiplicity of existing pro ducts is quite impractical. Preferably pilot machine studies with additives 3hould be restricted to satisfying specific needB or requirements created by process studies primarily devoted to solving the basic problems related to cement, fiber, curing, etc. These studies have been outlined in other sections of this report. F. Rubber Rings Rubber rings and related design changes are basically a quality control or product development responsibility and do not fit into the pilot pipe machine program. CTD029948 -4- II. III. Fiber Preparation In many respects fiber preparation is synonymous with efficient fiber usage. It therefore follows that any comprehensive development program must consider the impact which fiber preparation has on the overall oper ation. This implies that either the existing prepara tion techniques should be optimized or entirely new processes developed. In either oase this work should be an intimate part of the pilot pipe machine program. Any detailed study should take into account three fac tors . 1. Faster and more efficient fiber opening. 2. Ways and means for increasing fiber throughput. 3. The required technology to blend and successfully process more open fibers. Factor 3 could be made an integral part of the fiber studies previously mentioned while factors 1 and 2 would entail evaluating new equipment and processes. Chemical opening of fibers might be a remote possibility. Primary Mixing and Stock Preparation Presently the basic problems with the dry mixing systenr/ are mostly mechanical. Nevertheless there exists t*>e possibility that the dry mix cycle could be the^limting factor to Increased production qn4y^h pilot pipe machine program should include provisions for op timizing existing practices and developing new equipment for intimately blending at high throughput rates. Any development work in this area should be done in conjunc tion with fiber preparation since the opened fiber is the critical component. Immediate attention should be given to better means for stock preparation. Existing practices for wetting the stock appear to be rather crude and intimate blending is an implied rather than an explicit operation. All mixing is a function of the total wet system and no pro visions are employed to control stock uniformity. A natural outgrowth of this work should be tc determine the merits of and the necessity for consistency control. If the latter answer is affirmative, the program can be expanded to encompass the evaluation, selection and placement of sensing and control equipment. This equip ment should provide maximum sensitivity and reliability simply and with a minimum amount of maintenance. <,- CTD029949 -5- V?. Water The role which water plays in the manufacture of A/C pipe can not be Ignored. Quite obviously any fresh ::ater entering the system will quickly lose Its iden tity and by itself will have little influence on the operation. However, the solids which are normally present in every water supply, depending on their con centration and composition, can significantly alter the system's chemical equilibrium and under certain circumstances in combination with specific cements produce detrimental solids precipitation. Water treat ment may provide a solution but in general can be quite expensive, particularly when operating with an open system. This suggests that the pilot pipe machine pro gram might attempt to determine if it is possible to operate with a closed system and what factors must be regulated to maintain a stable system. This would give some insight into the benefits of a completely satur ated system and if feasible, provide an excellent solu tion to waste disposal problems. V. Machine Operation The physical operation of a pipe machine is one big question mark. If any area requires clarification and needs to be elevated to a technology, it is this one. This does not mean to imply that current operation is necessarily wrong but to emphasise the general lack of evidence or agreement to support many of the accepted practices. When considering the number of variables encountered and their involved relationships, this is not wholly unexpected. It is only with extreme diffi culty that individual cause and effect can be isolated and even then there is considerable reservation whether the relationship developed will be more valid upon ap plication than the present "seat of the pants'1 tech nology. Consequently in preference to singling out specific variables for study it is recommended that the pilot pipe machine program concentrate on the overall operation in terms of increased production and improved product quality. 3y natural attrition and repeated run ning those variables which have a significant influence on the process should evolve and adequate limitations can be placed on their operating range. Variables in question, to name a few, are felt speed, agitator speed and direction, vacuum,vat design, stock distribution, overflow heights and temperature. CTD029950