Document b5jOY307xkvzX0GJaya1YDXYk

BUSINESS CONFIDENTIAL PROJECT REPORT USE OF ASBESTOS AS A PIQMENT IN PAPER COATINGS authorsi G. B. Kelly G. W. Buttrick supervisori F. J* Welch datEi October 20, 1969 PROJECT NO.i 113A28 FILE NO.i 12802 SUMMARY The constantly rising costs of mailing publications hcs promoted an intense interest in ways of reducing the weight of paper and paper coatings employed. Currently, the use of needle shaped pigments to lower the density and increase the coverage of paper coatings has been attracting much attention. Since Carbide's high-purity chrysotile asbestos approaches the dimensions of the needle shaped pigments currently being promoted as useful in this application, its use in paper coating formulations was investigated, and found to be feasible. _ The asbestos can be dispersed together with typical clay pigments to form reasonably fluid dispersions at up to 25% asbestos based on the clay. At higher concen trations, the viscosity increase is so great that the dispersions must be diluted to impracticcily low levels (under 45% total solids). No difficulty was experienced in coating the clayasbestos formulations, but attempts to use 100% asbestos resulted in serious streaking problems which could not be overcome. The asbestos imparts increased brightness, opacity, and ink holdout to coatings when used in the optimum range of 5 to 10% asbestos in the pigment. Some decrease in pick resistance was noted in this range. Most of the increase in brightness and opacity is lost when the coating is calendered on smooth rawstock, but the loss is minimized on rough rawstock. Indications are that asbestos will be useful in base coats to fill rough rawsfocks efficiently, or on lightweight publication papers. A patent memo has been written concerning the use of asbestos in paper and board coatings. It is planned to discuss these results with paper companies to determine their interest. INTRODUCTION Within the last year a growing interest in the use of needle-shaped pigments has been noted in the paper coating field, particularly for publication papers. This is exemplified by two papers dealing with such pigments presented at the Coating Conference in May 1969 (1 )(2), and much discussion among the personnel present. RESEARCH AND DEVELOPMENT DEPARTMENT CHEMICALS AND PLASTICS UNION CARBIDE CORPORATION SOUTH CHARLESTON, WEST VIRGINIA 113A28 -2- The interest in needle shaped pigments arises from the desire to achieve lower bulk densities in the coatings for publication grades of paper. Needle shaped pigments do not pack as densely as the platelet-shaped clay particles currently used as the main pigment in paper coatings. When mixed with clay, the needle shaped pigments tend to lower the bulk density of the mixture without seriously detracting from the smooth surface normally obtained with clay coatings. Examples of needle-shaped pigments currently being investigated are PKT (a potassium titanate), acicular calcium carbonate, and a new analog of Satin White as yet unidentified. Satin Wiite itself which has been virtually obsolete for some years is also being reexamined for possible utility in this special application in spite of the difficulty in handling this material. The reason behind this sudden interest in needle shaped pigments is the current high cost of mailing and the fear that postal rates will continue to rise. To exercise some control over this major cost item, publishers are demanding a lighter weight publication paper. Currently, the avercge publication paper has a 36-lb basis weight, based on a 28-lb ra*stock coated with 4 lbs of coating on each side. Some 34-lb basis weight paper is being made and the goal is 30 to 32 lbs. Since it is virtually impossible to get a rawstock of less than 25 or 26 lbs with sufficient strength to withstand the coating operation the coat weight must be reduced to 2 or 3 lbs per side, causing a seriously decreased opacity and low ink holdout. Correction of the opacity with titanium dioxide is possible, but the expense seriously detracts from the possible savings. Therefore, means of lowering the density of the coating are being sought. Obviously with a lower density coating, a thicker coating will result at the same coat weight per unit area, and an increase in thickness will usually result in greater opacity. Previous work by Buttrick (3) and Kelly (4) had indicated that asbestos might have some application in this field. The shape of the Carbide high-purity asbestos fibers approaches that of the needle-shaped pigments currently being investigated, it also has a high brightness and is relatively cheap, both of which ere highly desirable in a pigment. Furthermore, asbestos has been shown to be synergistic with titanium dioxide in other applications, which would be advantageous if additional opacity was desired. For these reasons a further investigation of asbestos in publication papers was initiated. This report discusses the preparation of asbestos-clay dispersions, the effect of asbestos on the coating properties, the effect of calendering on the coating properties with asbestos, and the possible utility of asbestos in several types of coatings. DISCUSSION Asbestos tends to absorb large amounts of water and to mot together, so thot only dilute suspensions flow readily, and these tend to settle out rapidly on standing. From the previous work of Buttrick and Kelly (3)(4) it appeared that the usual clay dispersants would work on a mixture of clay and asbestos to give reasonably fluid dispersions at high solids. 113A28 -3- As a first step in this investigation, the amount of asbestos which could be successfully dispersed in clay to give a reasonable viscosity at 70% f was explored with two types of clay - a ^2 coating clay (HT clay) and a delaminated clay (Nuclay). The results are shown in Table I. The delaminated clay gave lower viscosities than the No. 2 coating clay, by almost exactly half in the 7-1/2% asbestos dispersion, paralleling the difference in the viscosity without asbestos. It appears that up to about 10% asbestos can be tolerated in the clay dispersion at 70% solids without exceeding a practical viscosity for the handling of the dispersion. At 20% asbestos, the solids of the-dispersion must be reduced to about 55% solids for easy handling. At 100% asbestos, a very poor dispersion is obtained with poor flow properties. The total solids had to be reduced to 20,9% to obtain a marginally acceptable flow. Thus, the practical limit of the use of asbestos appears to be about 25% by weight of the clay in a dispersion, as at higher asbestos levels, the total solids of the dispersion must be reduced to such a low level that the formulation of most coating colors becomes difficult or impossible. Asbestos as a "High Bulking" Pigment In order to evaluate the bulking properties of asbestos, two of the clay-asbestos slurries (7-1/2% asbestos) were diluted-with water and allowed to settle 5 days in graduated cylinders in comparison with plain clay slurries. The dilution was 170 g of slurry (approxi mately 100 ml) diluted with 200 g of water. The results were 69 ml of settled Nuclay vs 91 ml of the Nuclay-asbestos slurry; and 69 ml of ^2 coating clay vs 110 ml of clayasbestos slurry. There was no evidence of flocculation, as the clay-asbestos sediment was well packed and difficult to redisperse in the supernatant liquid. The asbestos increased the bulk of the settled clay from 32 to 59.5%, confirming our theory that asbestos should be a high-bulking pigment in combination with clay. Water Retention Although asbestos significantly increased the viscosity of the clay slurry, the water retention of the slurry was slightly decreased by asbestos. Using the Baroid filter test for water retention, a 70% clay slurry gave a filtrate of 9.5 ml whereas a 65% clay-5% asbestos slurry gave a filtrate of 11 ml. (In this test, increased water retention is demonstrated by a decreased volume of filtrate when 300 g of slurry is subjected to filtration under 100 psi air pressure for 30 minutes. Excellent water retention would be less than 2 ml filtrate.) Good water retention in a coating minimizes binder migration, dewatering at the point of application, and helps prevent streaking. Even in the form of a simple coating color with Dow 620 latex, the clay-asbestos pigment gave 7.0 ml of filtrate as compared with 6.0 ml for the control with no asbestos. It is evident that the asbestos contributes nothing in the way of water retention to the pigment slurry or to coating colors, and if anything, it is slightly detrimental to water retention. II3A28 -4- Effect on Coating Properties Clay-asbestos pigment mixtures perform well in the laboratory trailing biade coating process at levels up to 20% asbestos in the pigment. However, due to the low total solids of the coating colors at this level, the exploration of higher concentrations was not undertaken, except for one attempt to use asbestos as the sole pigment in a coating color. When 100% aiestos was formulated with 16% oxidized starch, based on pigment, as a binder, it was impossible to coat smoothly with either a trailing blade or a wire-wound rod. The asbestos fibers bunched up in the nip of the blade or rod and produced severe streaks. Variations in pressure on the blade, speed, and several types of substrate (Andover, Time/Life, and unbleached Kraft) mode no noticeable difference in the tendency to streak. It is believed that up to 25% asbestos could be incorporated into a coating color with clay before the high viscosity forced ihe total solids down to on impractically low level for easy handling and use in most coating processes, but higher levels would be impractical. Fifteen coating formulation.- were mode up with arbestos contents of from 5 to 20% of'the pigment, using starch and store hr latex binder systems and two varieties of clay, a ^2 coating clcy and delaminated clay. These formulations ere shown in Tables li and III. The coatings were applied to a lightweight publication paper (Time-Life) and to heavier weight coating stock at coat weights from 3 to 13 lbs per ream. The properties of the coated paper are given in Tables IV and V. . In examining the properties of the uncalendered coated papers it is epparent that brightness and opccity show consistent improvement of 1 ro 2 points with asbestos present as compared to the controls with no asbestos. The ir.k holdout is clso improved by osbestes with high-starch binders, but with the 14-4 latex-starch binder the irk holdout is slightly lower. The porosity end pick resistance are generally decreased by asbestos, but the decreases are not so lurge as to be a serious problem in most applications. The brightness end opacity improvement with asbestos should be particularly attractive in lightweight publication papers as pointed out previously; and the highbulking characteristics should also be particularly useful in base coats on rough substrates. Effect of Calendering On supercolendering, the brightness ond opccity of all the sheets was lowered as expected. Unexpectedly, however, the advantage in brightness ond opacity with 5% asbestos was largely lost on supercclendering (Table iV). This was disappointing and puzzling. A possible explanation was that tr.e asbestos in the coating caused the coating to hove an internal porous structure similar to "bubble coating", which was collapsed on 113A28 -5- supercalendering. Hie internal structure'would contribute to increased brightness and opacity by multiple refraction at the coating interfaces within the porous coating, and these interfaces would be lost if the coating were compressed or collapsed from the pressure of calendering. If such porosity exi$ted,it would have to be of the unbroken bubble type, as the porosity of the coating by air permeability is decreased by the presence of asbestos except at the higher levels of asbestos in the coating. It was reasoned that a coating on a rough substrate should lead to less loss in brightness and opacity, as the roughness of the substrate would partially protect the coating from excessive pressure in passing through the calender. That is, the high spots in the substrate would carry a high percentage of the load, leaving the coating in the valleys with less pressure. This was tried by coating a coarse brown Kraft paper with two formulations: H (control) and I (containing 7-1/2% asbestos in the pigment) (Table III). The two coatings were applied simultaneously with a blade coater - one coating on the left half and one on the right half of the blade. The resultant side by side coating showed clearly that the side with asbestos gave better coverage of the brown paper than the control. The difference persisted even after supercalendering at 1000 pli and 150F, 2 passes. After supercalendering the side with asbestos measured 64 in brightness against 61 for the control. Both sides measured 100% opacity due to the hecvy weight of the Kraft substrate, but-on examining the coatings by strong transmitted light, the superior opacity of the side containing asbestos was easily evident to the eye. Since one of the uses visualized for a needle-shaped pigment is the efficient filling of rough surfaces on paper, it would appear that asbestos would be suitable in this application - not only from the better brightness and opacity, but also from the better holdout due to the higher viscosity, and the increased bulk of the clay-asbestos pigment mixtures. A patent memo has been written, covering the use of asbestos in coatings at concentrations from 1 to 25% based on the pigment. FUTURE WORK The feasibility of using asbestos in coating formulations has been demonstrated. The possible use of asbestos in coatings will be discussed with paper companies to determine their interest based on our data. Any further work in this area will depend upon the paper companies' response to the properties we have demonstrated in the work to date. 113A28 -6- EXPERIMENTAL The following materials were used in this investigation: Pigments Description Supplier HT clay Nuclay Asbestos Rawstocks Andover Escanaba Ti me* Li fe Binders Stayco M Pen ford gum 250 PenTord gum 280 Dow 620 PCX 10 Misc. TSPP Nopco Cl 04 Parez 707 ^2 coating clay Delaminated clay HP open . 50 lb coating stock 35 lb publication grade 28 lb publication grade Englehard Minerals & Chemicals Co. Freeport Kaolin Co. Union Carbide Corp. Copco Paper Co. Mead Paper Co. Time, Inc. Oxidized corn starch - low viscosity Hydroxyethylated corn starch medium viscosity Hydroxyethylated corn starch medium viscosity Carboxylated styrene butadiene latex Carboxylated styrene-acrylic latex A. E. Staley Co. Penick & Ford Co. Penick & Ford Co. Dow Chemical Co. Union Carbide Corp. Tetrasodium pyrophosphate Tech, (dispersant) Calcium stearate, 50% dispersion Melamine formaldehyde Mathieson, Coleman & Bell Nopco Chemical Co. Cyanamid Preparation of Dispersions 5% Asbestos Charge: 1425 g 75 g 2.17 g 630 g Clay (predispersed) Asbestos HP TSPP Water The dry ingredients were placed in a Sigma Blade Mixer (1/2 gallon size) and mixed for a few minutes. The water was then added gradually over a space of 5 minutes. Mixing was continued for 30 minutes, and then the dispersion was diluted to 70% J by the addition of 14 g of water. The dispersion was fluid,measuring 1520 cps on a Brookfield RVF Viscometer at 10 rpm and 570 cps at 100 rpm. The control was made up in the same way using 1500 g of clay, and 0.15 g of TSPP. 113A28 -7- 7-1/2% Asbestos A. Charge: 1480 g 120 g 590 g 1.94 g Clay (predispersed ^2 coating clay) Asbestos HP Water TSPP .. After dispersion, 100 g water was added to dilute the suspension to 70% J. B. Charge: 1480 g Delaminated clay (Nuclay) 120 g . Asbestos 5.74 g TSPP 590 g Water Dispersed and diluted as in A, above. 9% Asbestos Charge: 2145 g 150 g 90 g ~ 4.5 g ^2 Coating clay 70% dispersion Asbestos HP Water TSPP -.......... ' The slurry and water were placed in the Sigma Blade mixer and the asbestos was added slowly and the mixing continued for 30 minutes. The dispersion was `diluted to 70% $ by the addition of 25 g of water. 20% Asbestos Charge: 1280 g 320 g 7.0 g 1190 g Delaminated clay (Nuclay) Asbestos HP TSPP Water The clay, TSPP, and csbestos were mixed in the Sigma Blade Mixer and the water added slowly. The mixing was continued for 30 minutes. At this point the mix was far too thick and viscous and it was necessary to dilute it with 123 g of water to bring the solids down to 55% to get a reasonable viscosity that could be handled.' 100% Asbestos Charge: 1000 g Asbestos HP 10 g TSPP The asbestos was charged to the Sigma Blade Mixer along with the TSPP, and water was added slowly until a workable mass was achieved. This required 2000 g of water. More water was added during the 30 min. mixing time as the mass remained dry. After 30 minutes, it was necessary to dilute the mixture further to reduce the solids to 20.9% to get a marginally fluid dispersion. 113A28 -8- Preparation of Coating Colors The starches were cooked at the indicated % solids by adding the dry starch to the water with good agitation and raising the temperature to 90-95C after the starch was thoroughly wetted out. The cooking at 90-95C was continued for 20 minutes with mild agitation, and the starch solution was then cooled to 50C. The coating colors were prepared by weighing out the pigment dispersions and slowly adding the natural adhesive with good agitation, followed by the latex if any and finally the lubricant. Any necessary water in the formulation was added with the pigment dispersion. The viscosity of the cocting color was measured at room temperature with c Brookfield RVF Viscometer. Coatings The coatings were applied to the rawstock by manual trailing blade or wire wound rod, depending upon the coating weight desired (heavier weights were applied by rod). Some very low coat weights were applied with the Time-Life mechanized trailing blade laboratory coater. However this machine is slow to operate and is only used for very low coat weights or somewhat higher weights (up to about 5 lbs per ream) when very uniform coatings are desired. The coatings were drum dried.at 20QF for 30 seconds in each case. Coat weights were measured by weighing a piece of drum-dried rawstock, coating the weighed paper and then reweighing after the coating was drum dried. The coat weight was calculated from the increase in weight and the area of the coated sample to give pounds per ream (3300 sq ft). Evaluation All evaluation tests were rur. by the appropriate TAPPI methods with the exception of porosity: Brightness T-452, M58 - Photovolt instrument Gloss T-480, TS65 - Gor.nde'' instrument Opacity T-425, M60 - Photovolt instrument K&N Ink RC 19 Modified - Stain measured by brightness test IGT Pick T-499 - modified by use of Westvaco arm inking device The porosity (air permeability) was measured with the Sheffield porosity tester using the method supplied by the manufacturer. This method is much faster than the TAPPI method (Gurley Porosity) and is quite satisfactory for comparison between samples as in this work. The standard deviation is - 34 ml/min in a sample averaging 200 ml/min. 113A28 -9- Baroid Filter Test (Water Retention) 300 g of the coating color are placed in the dry Baroid pressure filter on a sheet of Whatman ^50 filter paper. The pressure filter is closed and a 25 ml graduate is placed under the outlet. Air at 100 psig is admitted to the filter chamber above the coating color and maintained for 30 minutes. The volume of filtrate is then read. Water retention varies inversely with the volume of filtrate. Coating colors with excellent water retention will show only a slight filtrate (0 to 2 ml) in 30 minutes. Coating colors with very poor water retention show 25-35 ml of filtrate in the same length of time. The Baroid Filter apparatus is obtainable from the Baroid Division of National Lead Co. BIBLIOGRAPHY (1) Chaudet, J. H., Brooks, A. M., end McGoury, T. E., "A New High-Bulking Pigment", to be published in TAPPI, (2) Waldeck, W. F., "An Additive Pigment for Lightweight Coating", to be published in TAPPI. (3) Buttrick, G. W., unreported work - Reference 27GWB101; 111, September 1968. (4) Kelly, G. B. and Buttrick, G. W., Evaluation of Union Carbide Latexes as Coating Binders for Web-Offset Printing Papers, Project Report, March 28, 1969, File No. 11693. Attachments: 5 Tables 113A28 TABLE I HP ASBESTOS-CLAY DISPERSIONS IN WATER USING TSPP AND A SIGMA BLADE MIXER Clay ^2 Coating clay (Predispersed) % Asbestos 0 5 Total Solids 70 70 % TSPP (1) 0.30 Brookfield Viscosity, cps 10 rpm 100 rpm 740 250 Water Retention 9.5 ml, 30 min. 0.43 1,520 570 11 ml, 30 min. 70 1,950 -- -- 9 70 0.37 14,000 6390 -- Nuclay (delaminated) 0 *0.3 - 590 -- -- 7* 70 0.36 1,010 -- -- . 20 70 0.44 Very pasty-no flow 20 55 0.44 12,650 -- 100 20.9 1.0 50,000 Tends to dewcter on standing 113A28 TABLE II FORMULATIONS FOR COATINGS Ingredients ^2 Coating clay 70% J dispersion (HT clay) AB 286 -- Parts by weight CDE F 286 -- 286 -- G 286 Starch - Penford Gum 280, 25% solution 144 144 *2 Coating clay - 65% ) n . HP Asbestos 5% ) 70% d,sper!,on -- 286 -- 286 -- 286 -- Calcium stearate dispersion 50% 4444444 (Nopco C-104) ...... Dow 620 Latex 50% ---- 32 32 56 56 -- Starch - Stayco "M" 30% solution ---- 67 67 27 27 134.5 Water ---- 4 4 23 23 Total solids 55 55 60 60 60 60 57 Binder parts per 100 parts of pigment 18 18 18 18 18 18 20 Reference: 22GBK108 O 0CM0 >o o>| 00 CM *55 ir1 <2 o 00 --* ClOO 5 ^ wo CO CO WO co -- WO CO CO CO 3 CO II 0'M0 CO CO 00 CO CM O CO o M3 CO o 00 CM CM CM cs O 00 o 00 o CM CO o CM wo uo wo I WO I FORMULATIONS AT HIGHER ASBESTOS CONTENTS on O CO 00 CO CM -- o CO 00 CO CM c o c o 4) Q. c T3 o o sP c o C o fi!CO CM < CO c o ^5 \ O) c CL c o X 0) o CL fX OvXO rx U0 WO COM IX xo oX T> 11 18 fz O "O i? o c: ts Ec -Gul .2 <D Q_ OX X o W0 <D C0l 4- D OV) nXP o CO o vXO u O IX o o Q_ CK o Jd c o 0w 0> Q0_ ov> vXO wo CM Xo lx O rx x 4u.) t5 o *Xn CwMo Z 0u X p 0) oL. o0) oo 1 -Cu Eo C-> CK X _o u O) c 4-- o o cn o o 4> -Qto uO IX X EX D 05 Ua. 4) N -- _o "O u 05 c c ao. Id X z> <D n oto c o o u _c uu. -C X Ol_ HP A ci lie p LO Uo CM =*b CM o =lfc uo o CO 4) o 0) Q_ wo wo oo CO CM X _o u no S On I0n .E tc -Q0 -2 0) a_ QX KO vO lO oCN O X 0) 5o o "o D O Reference: 22GBK129 23G8K7&12 21GBK107 r5 8a se o n ^ o n n i 88.6! U 2s n r* n 2* ; 55 55 IS SS ojonrj No'K p2l as sfe l*\ id 3? a; fts ss k k --- r 33 33 sa ss ss !3 SI 33 If -i 5~ s*. 85 SS O2n So SR S sRN SKR --------- g o <o <o -o is ar $ RR 32- ni m oo n* <0 0 >* ou V\ (rt o z = s %a a; 13.0 i- ss . ,8s if-i t I' i*K~ o~5o e Js?o3 00 5 II ill r * wt t- f l 58 ^,6u0, 8o- 8* nn 8; o> > o- < 33 S o yNjO^ <* n ^i b.? n 0 E <3-i Us; <5 k-S. j .s*i I j u" SJ_ j -,SiI-a** ^iu,n ?-! O*< jti* O Could not be cooled - Streoked badly due to asbestos bunching up in n ip o f blade or rod. o a: z 8 <h~ oUhcmcooJ<o. X -*-" z3 ** ou -= o8.: oo OK 5" oJ O 3- U-> -- CO ^ ""7o. SU j ICfNNO. OoCO oo OO CNOT 3^ OO o CtM ooCM 8ir> :0 O *0 OO ION iOs. 00 o> --CM --00 o n V CM CO CO wo -- ---O --IT) 00 o O TT >0 CN -- CO CO CO o 'd -- co co or fN IN CO co T^ CO CO O CO nt co C0CMM0 CO--M' CCCMMO --CoM 0oIN0. oCTMT oo IN TT CO CM oo O uo -- CM CO CO CO CO CNOT 0N0T 0N0T N00T OO U0 UO -o o uo wo zo zo iZ-- oo< zO n<JN aCft.j 7o7" 4) o ^ t)" -Uc183ENHOx co '* wSo O< S& _ .5 -- P< O< t. O o P u CM UCo 8CnM<5 uooN oCoM Is* -5 LoO O-oJr U1OON55 0< oo o CM 1,850 - - 6,500 20 -- 100% Asbestos Storch Slayco "M " 20 113A28 DISTRIBUTION Mr. R. C. Boltz, NYO Dr. W. L. Carrick, 312 Mr. C. W. Glancy, 511 Mr. J. F. Hoover, 511 Dr. K. L. Hoy, 511 Mr. C. G. Landes, Raleigh, N Mr. J. S. Lovell, 511 Mr. C. S. Maxwell, 511 Dr. W. P. Miller, 511 ' Dr. H. B. Rhodes, Niagara Fall Mr. N. J. Setter, NYO-29 Mr. J. Sidlovsky, NYO Mr. J. J. Smith, 511 Mr. J. H. Stevens, NYO Dr. R. Stickle, 511 Mr. A. T. Walter, 511 Mr. W. E. Whitehurst, 511 Librarian, 525 Information Retrieval Authors BUSINESS CONFIDENTIAL r:;; f PROJECT REPORT ORIGINAL COPY _| ASBESTOS DUST RESULTS OF AIR ANALYSES AT THE BOUND BROOK PLANT authors. R. w. Cope (2) supervisor. N. H. Ketcham (2) 0ATE| June 8, 1972 PROJECT NO.i 910E10 file no.. 17258 SUMMARY Air analyses for asbestos were taken at Units A, B, C, and R1 during the manufacture of phenolic resins. The work was requested by Mr. D. R. Albright as a part of the continuing Bound Brook Plant industrial hygiene program. The results show that there are asbestos dust con centrations exceeding the OSHA emergency standard during the preparation of some products. These analyses amplify the need for air monitoring for all manufacturing conditions and products so that the exposure of personnel can be adequately defined and plans made to correct the dust problem areas. INTRODUCTION Mr. D. R. Albright requested that several air samples be taken during the manufacture of phenolic resins containing asbestos. This visit was scheduled for May 18, 1972, when lines A, B, and C in Building 3 were all on asbestos modified materials. DISCUSSION The most recent information from the National Institute for Occupational Safety and Health recommends that worker exposure to asbestos be monitored by personal exposure samples. During previous evaluations in Bound Brook Plant manufacturing areas, the sampling equipment was held as close as possible to the face level of the operators. The samples taken during this visit were obtained by placing the equipment directly on the operator at the working location in order to comply with the NIOSH recommendation. The results of dust counts for Units A and B, Building 3, were about the same as has been found in previous determinations when products are being made with low asbestos concentrations, see Tables I and II. The percent of asbestos in the products was 9% on each unit. When the percentage of asbestos is low, the results of air analyses have been under the emergency standard of 5 fibers greater than 5 microns in length. research and development department CHEMICALS AND PLASTICS UNION CARBIDE CORPORATION SOUTH CHARLESTON, WEST VIRGINIA BUSINESS CONFIDENTIAL 2 910E10 Unit B was on a product containing 30% asbestos. Table III shows that the analytical results were correspondingly high. The only previous comparison we have was when Unit C was on product 5310. The concentration at the charging hood at that time was 9.2 fibers. The only difference apparent in the two units is that the Unit B charging hood is in a more confined area than the Unit C hood. This would tend to cause higher dust concentrations over short sampling periods. The area of highest asbestos fiber concentration over most of the work shift is at the charge roll of Unit Rl, Building 6. The product was 3700 green containing 57% asbestos. The approximate 10 fibers found Here exceed the emergency standard and will require respiratory protection. Both operators working in the area were wearing face masks. The mixer man is also exposed to very high asbestos concentrations when charging asbestos to the unit. This is only done about twice per shift but will still make respiratory protection mandatory. He was wearing a face mask. CONCLUSIONS The results of these air analyses illustrate the need for monitoring units using asbestos for all manufactur ing conditions and products. This is the only way we have of accurately defining the exposure of personnel to asbestos so that meaningful plans can be made for controlling any dust problems we find. - -.....- . - NOTEBOOK REFERENCES: 11CWR 3 Attachments: 4 Tables Manuscript Date: Date Typed: RWC/whn June 6, 1972 June 8, 1972 R. W. G business CONFIDENTIAL 910E10 TABLE I ASBESTOS DUST BUILDING 3, UNIT C Date Time Sampling Description and Location Asbestos Fibers >5 Microns 5-18-72 9:45 a.m. Product BMNS 5440. Personal sampler on the operator charging asbestos to the unit. Sampling time = 12 minutes. Time to charge 7 bags of asbestos = 1.75 minutes. 1.8 5-18-72 10:10 a.m. Product BMNS 5440. Personal sampler on the operator at the charge roll. Sampling time = 30 minutes. 1.2 BUSINESS CONFIDENTIAL 910E10 TABLE II ASBESTOS DUST BUILDING 3, UNIT A Date Time Sampling Description and Location Asbestos Fibers >5 Microns 5-18-72 10:47 a.m. Product BMNS 5333. Personal sampler on the operator at the charge roll. Sampling time = 20 minutes. 1.0 5-18-72 1:35 p.m. Product BMNS 5333. Personal sampler on the operator charging asbestos to the unit. Sampling time = 6 minutes. Time to charge 4 bags of asbestos = 1 minute. 2.2 EU5INESS CONFIDENTIAL 910E10 TABLE III ASBESTOS DUST BUILDING 3, UNIT B Date Time Sampling Description and Location Asbestos Fibers >5 Microns 5-18-72 5:09 p.m. Product BMND 5303. Personal sampler on the operator at the charge roll. Sampling time = 15 minutes. 5.3 5-18-72 5:38 p.m. Product BMND 5303. Personal sampler on the operator charging asbestos to the unit. Sampling time = 6.3 minutes. Time to charge 13 bags of asbestos = 6 minutes. 18.0 BUSINESS CONFIDENTIAL 910E10 TABLE IV ASBESTOS DUST BUILDING 6, UNIT R1 Date Time Sampling Description and Location Asbestos Fibers >5 Microns 5-18-72 5-18-72 1:50 p.m. 4:40 p.m. - Product 3700 green. Personal sampler on the operator at the charge roll. Operator wearing face mask. Sampling time = 20 minutes. Product 3700 green. Personal sampler on the mixer man during the charging of asbestos. Sampling time =11.5 minutes. Time to charge 29 bags of asbestos = 11.5 minutes. 9.8 49.5 5-18-72 1:12 p.m. ' Product 3700 green. Personal sampler on the mixer man. He made only one half a mix during the sampling period. Sampling time = 105 minutes. Total Dust mg/m^ 6.6 DISTRIBUTION . D. R. Albright, 312 . R. A. DeCoudres, 312 . R. E. Graebert, 312 . H. R. Guest, 511 Dr. C. S. McKinley, 312 Mr. D. C. Metz, 312 Mr. J. M. Swalm, 312 Dr. J. J. Welsh, NYO-4 Mr. J. P. Zuccarelli, 312 Information Retrieval