Document p22M5vk4Q6qEONwOoX8qRQZw6

FILE NAME: CERAMICS (CER) DATE: 1947 Mar 10 DOC#: CER052 DOCUMENT DESCRIPTION: Journal Article - Glass Fibers as an Engineering Material Mn* E L. Shamer EdUnr^n-Chief InwiM H. Svca Editor W m . M. A<*onst N ew t end Markets Edttoe D. B. W iL iw Engineering Editor J. D. S hoe Steel Plant Editor Cut Hubbard Machine Tool Editor Don S. O dot Art Editor Allen C . O at Conrulting Editor ASSOCIATE EDITORS w . J. Campbell Jat DeEvlu WALTER F . TOKRCE F . A. Buoo* Vance Bell JOUN pAWNA Jr. ASSISTANT EDITORS II. C. T uttle D olores K. Blaba Henry J. H oltx L. J. Skvderin Joitn S. Morgan XI. T . BonoEiuiorp RESIDENT EDITORS E. C. Keevtzbero WoxMnc/on Editor T. N. Sand iter Associate Editor, Washington F\. K. P rior J'artrru Editor, N ew York L. K. Ilnow H t Associate Editor, N ew York E. F. Rom Chicago Editor ' J. C. Sullivan Pittsburgh Editor A. II. Allen Detroit Editor Vin c e n t D k l I'o r t l'uroftcan Editor, Ism Him EDITORIAL CORRESPONDENTS R. W. Kincet, Birmingham L. C. Fbldmann, buffalo Sam i'Kl S. 0 < u t, ClndrirMfi Mac H utchens Si . Lout C lohoe R. Reiss, Foungfaum Maurice Beam, Los Angeles Houbkt BoTTOHrr, S an Francfcoo 11. C. Him ., Sriiffl# C. K. C a t m , Dallas K. S. Tobxn, Toronto ). A. Horton, Birmingham, Eng. Leon Jaudoin, Paris, Franca MAIN OFFICE Toulon Building, Cleveland 13. Ohio BRANCH OFFICES S tw York 1 7 ................................ 18 East 3rd St. Chicago 11 ...................520 North Michigan Ave. Filttburgh 1 9 ..........................2800 Koppen Bldg. DenoU 2 ..........................................8500 Cass Ave. Waihtngton 4 ................ 056 National Press Bldg. Lot Angelat 4 ......... 130 N. New Hampshire Aya. London......... t Carton S t , Westminster, S.W . 1 Business Stag an Pag 4 The M a g a z i n e of M e t a lw o rk in g and Metalprodueing VOL. 120, NO. 10 MARCH 10, 1947 NEWS * As the Editor Views the N e w s ............ ........................ 55 Coal Strike Tlicat Deferred by High Court Ruling Against Lewis . .. 59 * Present, Past and Pending ................................................. 61 High Steel Output To Ease Supply P in c h ..................................... 62 Automotive Industry Holds First Place Among Leading Steel Users 03 Some Hope Held Out for Revival of Shipbuilding P ro g ra m .............. 64 RFC Seen Out of Metal Business by End of June 63 Production of Tig Iron Rises During January 05 Foundries Im reusing Capacity . . .. , GG Warner ic Sssascy Plans Creator D iversification................ 67 * Windows of Waslungton .................................................. 65 Some Projected Plants Deferred on West C o a s t................ 72 Los Angeles Wants Severely Affected by Sheet Steel Shortage . . . 72 Labor Covcmment Prescribes More "Austerity" for United Kingdom 73 A Mirrors of M o to rd o m ........................................................... 75 Eastern Stainless Steel Corp. Boosts Capacity for S h e e ts..................... 78 * Briefs .................................................................. 79 * The Business Trend ......................................... .SO * Men of In d u s try ............................................. 82 * Obituaries ........................................................ 87 * Construction and Enterprise .......... ............... I5S TECHNICAL Mobile Laboratory Measures Stresses in Loaded Steel Trailers . . SH Seen and Heard in the Machinery F ie ld .............. . . go Joining Magnesium Alloys-- Part V I I ............................................. go Heat Treatment of High Speed Steels-- Conclusion............................... go Glass Fibers as an Engineering M aterial..................................... gg Engineering Newt at a Glance .......................................................... . jqq "Made-To-Ordcr" Steel Buildings'.................................................. jq j Progress In Steelmaking--Blast Furnace Thermal Requirements--Part II 106 . Measuring Force and Horsepower In Automobile Engines . . . . . ........... j j g New Products and Equipment ' ...................................... jg j Helpful Literature ___ .................................................................. j g j ; /a^ k e t s -- " " r - ,^ Inflationary Forges Pushing Prtocs Illghre on Metallic* . . . . . j 1 37 . ' Market Prices and CornpUrt\!iv.'-...s i y / . .... . J ? . . .. . . . . . 138 1 Prices Rise on Nonferrous Metal Mancets . . . . . . . . . / j'. j'45 . -- :------- ; ':& /. 7 ; x . / " i v i Index to Adhoertitm. . . . . , . rV'- IVnolet regular foatum.'-J/A' r ` "yS.Jr ' ' 168 .. ` ' i - O : '. '(Aj'.'." i '- r ^ . V-.'V yciV 'j; . - A aL , .m ^1 I -.-iv- \ H -i big- 1--Class-fiber thermal insulation be ing installed in the roof of an industrial plant l i &- - 1-lght-wclght glass-fiber material possisscs acoustical as well as thermal in sulating properties. Here it is being installed in the cabin of an airplane Fig. 3--These glass-fiber reinforced plastic aircraft parts illustrate adaptability of the ma terial to fabrication of complex and com ' pound-curve parts Fig. 4--Strength properties attainable with cross-laminated glass-plastic laminates and parallel-laminated glass-plastic laminates os compared wlih corresponding properties of 24 ST aluminum and structural steel to their yield point. Values are based on laminates made xcith heat-treated non-directlonal glass >1 cloth end a representative loro pressure restn molded at 15 psi pressure r <* v Fig. 5--Comparison of the energy absorbing values of gloss fibers and other materials *> w \ ' * >f^V ; \V IV 0 C''>-.. t- i `V ' - W O - l 7 V : U ; v -'j . VO-" ' .V'.v/V/-., \ ' . - ^ 57ti:V i,-' -- ! . *>V* 4: rv . i t M f / esainee/usuji GLASS fibers possess the greatest tensile strength-w eight ratio of any commercial material either occuring in nature or synthesized by m an. Fibers averaging 23 one- hnndred-thousandths in. in diam eter have a tensile strength of m ore than 250,000 psi. Kxpci mental glass fibers have been produced w ith a diam eter of 2 ono-hundred- thousandths in. and with tensile strengths considerably higher than this value. Fibrous glass is an engineering m aterial in the sam e sense th at steel, copper and aluminum arc engineering m aterials, and like them , it is produced in a great variety of types an d forms. Real sta rt tow ard comm ercially useful glass fibers w as m ade in 1031. In that year, research aimed at the development of the necessary processes was initiated in this country by Owens-Illinois Class Co., m anufacturer of glass con tainers, and by Com ing Class Works, m anufacturer of glass specialties ranging from light bulbs to laboratory glassware and giant telescope mirrors. From 1931 to 1938 Owens-Illinois nnd Corning, working separately toward the same goal, spent millions of dollars on the experimental and developm ent w ork re- cpiired to create the m anufacturing processes and acquire the knowledge needed, not only to produce glass in useful fiber form, but to make practical its pro duct ion on a com m ercial scale. Rapid progress was m ade in im proved m an ufacturing processes and products, and in developing markets. i - nitw `` ' L ate in 1938 Owens-Com ing Fibcrelas Corp. was formed to continue the manufacture of Fibcrglas (glass fiber) materials, to carry on further 1 ?& . icseareh. to explore additional new uses, and to adapt the materials to still other uses w hich their inherent properties made them uniquely qual ' s4*.VJ ified to serve. Properties of Fibrous Class: There is no universal engineering m aterial, in the sense of a m aterial th at pos- COMPARATIVE PROPERTIES ' C 'C tt LOAvneift L - - i P0'0l'*l Lom.nfli! . 2 4 ST. 'ZZZZD * % C r t p o o .TVJO CV0OU If sp oc * A ' *>.000 00.000 f*>,000 ' POUNDS PER SOvARE inc h CCMPARATivC P RO PERTIES D o i t LC"v''Ct* P o 'O l't t L O iAO' m L Z . J ? 4 S TA iw Hn w^ CIZI3 . SfruClufO Sl*f< f T : ^ . . . ` B O ?WJ>' SO.-'X) 75,000 stR{ jKi wc`Cht vS-'V i'- i ' I? v ' - -cH ... w U i 'M i ^} 1 CNERGT ABSORPTION O'CTT f bf f* s c - - : .o , 1^ C'ZW ' *: 1 -.tt** | 0 5 . ` G 20 21 3 o 7 ti. CNOATiON . POUNDS PER SQUARE INCH - -400,000 300,000 Piano Win V0 00010" Glatt Fibers 0-00020 Stointess Steal 200,000 Monti 100,000 Mtlol Structural Steel 24 ST " Tfotti# Fib*# TENSILE STRENGTH VARIOUS M ATERIALS 0.00015" SPECIFIC TENSILE STRENGTH VARIOUS M A TER IALS B IS a cubic foot of uncompressed glass filters of the wool-like type used for thermal insulation weighs only H4 lit, and is ap proximately 100 times lighter than a cubic foot of bulk glass. Figs. 5 and 7 give some physical properties of glass fibers in comparison with other materials. Class,fibers possess high dimensional and physical stability. Although they may lie ns fine as gosvuner. the filters arc neither more nor less than micro scopically thin glass rods. Because they have no cellular inter-structure they can not absorb moisture. Their surfaces can lte wot, but moisture cannot get into tin- fibers. Moisture, therefore, cannot cause them to shrink, stretch or swell. At tension approaching b r e a k i n g strength the fillers show an elongation up to 3 per cent. The fibers cannot rot or oxidixe, for the elements of the glass are Fig. (1--Installing glass-fiber ther mal Insulation in the refrigerated compartment of a merchant ship Fig. 7 -- Tensile strength oj in already in a complete state of oxidation. They arc unaffected by weak alkalis, and by ni ids in tlicii most concentrated forms, except hydrofluoric and phosphoric acids. Finally, the fibers arc completely incombustible. In meeting requirements for thermal dividual glass fibers, in the order of 300,000 psi, is compared with the tensile strengths of a number of other materials. Chart A shows tensile strengths per sq In.; chart li shows specific tensile strengths, obtained by dividing t e n s i l e strength by specific gravity--in other words the ansucr thus de rived expresses the strength as strength per pound insulating materials that would stand up under the Strains, .stresses, sihratiou and hueudity conditions to winch cnmh.il ships and bomlier and fighter planes were sulijcctid during World War II. the Fihcrglas Corp. and applicators of it< materials developed many improxcnicnts in products and insulation methods. These arc reflected in the postw-ar u v s of glass fibers in such standard prewar applica tions as the thermal insulation of homes, refrigerators, food and lievcr.ige eout.iin- susses properties which fit It to meet nil requirements for all conceivable end uses. With any material therefore, a first step is to determine what properties it does possess--both those which will contrib ute to its wide acceptance and those which ma> prove a handicap. The next logical step is to determine what end ur-s its combination of properties fit it for. Flexibility is the property of glass fibers which distinguishes them from all other forms of glass. Glass fibers are flexible for Just one reason. They are almost incredibly thin in relation to their length. Steel Is rigid In a illicit, short ' piece, but heat it and draw it out into a ' fine wire and it becomes extremely flexible. The same is true of glass, but to be truly flexible the diameter of the glass must be much smaller in relation to length, titan is required in the case of steel. ' Cast aluminum, bulk glass and glass fibers all have about the same specific gravity--2.6 for aluminum, 2.5 for bulk glass, and 2.4 for glass fibers. However, ers, roasters, stoves ami water In alers.. . freight and passenger planes, railroad cars, trucks, hoses and merchant slops... factories and other ty pes of industrial and commercial buildings and their equip ment. Forms and Applications: The resilient mass of intricately interlaced glass fibers which is tlie basis of all forms of Fiber glas thermal and acoustical insulation may be composed of fibers ranging in diameter from 5 to 55 one-hundred-thous andths in., depending upon the purpose for which the insulation is to be em ployed. The wool-like mass can be in stalled in Use form oj bats, rolls, bulk fibers or shredded fibers. Blankets into which the mass can be formed can be faced with paper, a fabric or a metal mesh. Sheets and boards Into which the mass can be fabricated can be given a variety of surface treatments, Including a sanded, smooth finish on one side, a paper or fabric facing on one side, and an overall asphalt coating. They can be given a hard surface by facing them on one or both sides with sheets of plywood /TEEL s*-> 'J (oi a nv o : at to t'. \ or even xvilli a plastic material. Predetermined density of the rigid and semirigid forms can range from 2.5 to <J lb per cu ft. Density of the other forms can be varied by compression over a similar range. The K factor, at 50* mean temperature difference, ranges from 0.2S for the wool-like uncompressed forms at normal density of 1Vi lb per cu ft., to 0.23 for a 9 lb density board. Low thermal conductivity is due primarily to the millions of air spaces entrapped by the interlaced fibers. These air spaces arc poor conductors of heat. In addition, where the fibers cross and touch each other they have exceedingly small con tact points, llcat, therefore, cannot pass readily from one fiber to another. Air spaces, and the tremendous sur face area presented by the mass of fibers, absorb and break up sound waves. When glass liber bats, tolls, blankets, sheets or hoards are installed immediately behind a perforated surface of metal, asbestos board, fiber board or similar material, a noise reduction factor as high as 0.95 mav he obtained, the exact figure de pending upon the form, thickness nod density of the fibrous glass, the type of finish and the method of installation. Class fiber thermal and sound insulat ing materials are inherently firesafe and possess immunity to rot and decay. In addition, tho materials provide no sus tenance for Insects or vermin of any kind. Fropcrly installed, they do not settle dosvn under shock or vibration, leaving gaps for heat or sound to pass through; rather, unless bonded with a resin, the compressed fibers tend to fluff out filling any voids. The amount of moisture picked up by the massed fibers from humid air Is small. Fibcrglas thermal and sound insulation is one of the group of mineral wool in sulations, including rock wool and slag wool, with which applicators and users have been familiar for a half century. The bat, roll, bulk and shredded forms arc suitablo for use in all temperatures from subzero to approximately 1000* F. lints anil rolls arc widely used in stoves, roasters, water heaters, Industrial ovens __also for tho insulation of homes and oilier buildings, railroad cars, ships, buses, and trucks. Bulk fibers arc gen erally employed as an accessory material, fur stuffing or packing into odd spaces. The shredded form of instil.itlim Is used wherever pnucmatic .ipplic.itIon is called for. Fibrous gl iss blankets faced with flamc- proofed muslin or Lraft paper are used extensively to insulate buildings, refriger ated freight cars, railway passenger can, trucks, trailers and buses. Blankets with a facing of noncombustible glass fiber cloth arc used to insulate aircraft and aircraft equipment such as gasoline heat er exhausts, heal exchanger ducts, and other high-temperature pipes, tubing, ducts and fittings. W ith a metal-mesh facing, the blankets are employed for tho insulation of healed equipment such as boilers, tanks, industrial ovens, large ducts and breechings. Class fibers in the form of semirigid sheets or boards are used for building insulation and for shipboard bull and bulkhead insulation. They are also em ployed in all types of low and mediumtemperature equipment up to about 600* F. In equipment operating at tempera tures aliovo 450* F, the resin used u a binder disappears from the hot side, leaving a layer of unbonded fibers which fulfills its insulation function with un impaired efficiency up to 1000' F, so long ns it is enclosed by supporting sur faces. Sheathed on all sides with n tough, durable asphalt coating, a board made of the glass fibers is widely used in cold . storage service, and performs efficiently under conditions of moisture and temper Fig. fi -fibcrg la s insulating cement being applied over Fibcrglas racial mesh blankets used to insulate a large tank Fig 9-- Comparative strength properties attainable with cross-laminated glassplastic laminates and parnllcl-laminatcd glass-plastic laminates as compared ature variations such as exist in refrig erated spaces. An asphalt-enclosed board with a density of 9 lb per cu ft can be ( Flcasc turn to Page 127) with corresponding properties el 21 ST aluminum and structural steel io their yield point COMPARATIVE Cross Lominotes I. I...I 24 ST Aluminum r/sA -rw PROPERTIES Farollel Laminatesi Structural Steel I "72272 March 10. 1947 Cu --u 23 7773 O 25 50 75 FOOT P O U N D S, IZOD TEST COMPARATIVE Cross Lominotes C 2 3 24 ST Aluminum re st jse i* f! |w P R O P E R T IE S Porotlel Uom inotesCS Strudurot Steel - 3 III i0n.0l u0 O 4C6 i JZ*K? J o ttfi asaiK^ S4 i i m S S xC r POUNDS PER SOUARE INCH 99 Glass Fibers (Continued from Page 99) used for tlic insulation of floors and the construction of self-supporting--but not In.ul-lioaring--partitions. A 0-11) density, asphalt-enclosed board is made for use only on ceilings, and on walls where the structure carries the whole load. These boards, which can be molded into cylindrical form, provide a conven ient and efficient material for insulating steam and other pipes in all standard sizes up to 30 in. inclusive for tempera tures up to COO* F. A blanket-type in sulation with a metal-mesh facing is employed for insulating pipes up to 1000* F in sizes from 3 in. up. A high-temper ature block is available for insulating boilers, breechings, heated tanks, casings, ducts and other hcatrd process equip ment operating at temperatures up to 1800 F. Fabrics: Incombustibility and dimen sional stability arc largely responsible for the numerous current uses of glass filiir textiles. Tensile strength of stand ard glass textile fibers is in the order of 2Ti0,000 psi. Average fiber diameters range from 22 to 38 onc-lumdrcd-thousnndths in. Realizable strength, after the fibers have been fabricated into yams and fabrics, is somewhat less than the strength of the individual fillers, and is influenced by the construction of the yate and weave of the fabric. The breaking strength, however, is considerably higher than that of other textile materials of comparable thickness and construction. The incombustibility and dimensional stability of the glass filters arc retained in the yams and fabrics. Like the fibers, the y a r n s show an elongation up to 3 per cent at maximum tension. Fabrics have little or no stretch, except that due to the weave. Moisture changes do not cause stretch or shrinkage. Both yarns and fabrics have good electrical insulat ing eh iraderistics. Like the fibers, the fabrics arc unaffected by weak alkalis, and by acids, except hydrofluoric and phosphoric acids. Fabrics of Fibcrglas coated with syn thetic rubbers and resins developed for war uses have high tear strength, with stand repeated flexing, are resistant to destruction by fungi, and have high di mensional stability. Other prbpcrtics vary with the coating employed, but coated glass fabrics are being produced which arc flameproof and have high resistance to moisture penetration and to the effects of contact with gasoline, oil, chemicals and greases. I'resent uses include aircraft battery covers, oid pressure switch diaphragms, aircraft tape for expansion Joints of hot air ducts, protective clothing for workers in chemical plants and protective carry ing eases for precision instruments. Fer- M.irch 10. 1947 M an pow er and machinery perform the actual work of pro duction-- at a speed governed by the flow of materials. The most competent manpower and the most efficient machinery c'.n't do the job alone. Towmotor Fork Lift Trucks can pro vide the third 'M '-- materials -- in a controlled flow that keeps manpower and machinery operating at capacity. Better learn now how Towmotor Fork Lift Trucks and Accessories can help increase your rate of production. We've prepared a Pocket Catalog that points the way. Send for Special Bulletins Describing the Towmotor REVOLVING CARRIAGE SIDE SHIFTER UNLOADER UPENDER SCOOP CRANE ARM RAM EXTENSION rORKS EXTENSION IACKREST OVERHEAD OUARD TOWMOTOR CORPORATION D IV ISIO N 1, 1326 CAST 152ND STRICT, C U V IIA N O 10, OHIO FORK LIFT TRUCKS and T R A C T O R S CCE1VINC r i O C m i N C s t o i a c c oistiisution 127 tunn.incc ol the umtcriul in this I.Lst ap plication has created a potential demand for It in other similar applications where leather or organic fabric construction has been used. One such application is durable, light-weight luggage. Class fiber tapes, braids, cloths and slccvings, impregnated with a suitable varnish were being widely employed as electrical insulation in motors, genera tors, transformers and other electrical units before the war. The same char acteristics that caused this kind of elec trical insulation to be so widely used in war applications--a small space factor and rcslsiancc to high temperatures and moisture penetration-- are proving a major aid to design engineers in their continuing efforts to give electrical equip ment greater stamina and to reduce the 6izc nnd weight of units required to do a given job. For special uses, glass fiber insulated motors have been made that weigh only a pound per horsepow'er. Class-Rcinforccd Mastics: In fabricat ing gin's fiber-reinforced plastics, layers if Fiberglas cloth arc impregnated with a low-pressure, thermo-setting resin and arc placed, one on top of another, until n laminate of the desired thickness is built up over or in a mold; or the lami nate may he built up and then draped over, or shaped in, a mold. The mold, and the laminate formed to the desired shape, arc placed in an oven where the laminate is cured. Because the low, or contact, pressure resins polymerize without giving off volatiles, it is possible to cure them In any desired shape merely by holding them In contact with the mold. This makes possible the .fabrication of very large parts the whole top of a railway car or the hull of a boat, for instance-- without the expense nnd physical limi tations imposed hy (lie use of highpressure presses. It also means the elimination of ex pensive dies and jigs for since high stres ses arc not applied to the molds they o.ni lie of inexpensive construction. All this adds up to the fact low-pressure, glass-reinforced plastics can simplify and lower the cost of fabricating many parts, particularly large parts and those In volving- compound curves. They permit a frequency of design change that Is uneconomic where there is a heavy in vestment in costly dies. In general, their field appears to be the range and variety of parts that are produced in the hundreds or thousands rather than in the millions, and in th e ,- prodnetion of which, because of their relatively small volume, the cost of expensive metal dies is u prohibitive or burdensome factor. . Class-plastic laminates can be given a highly polished finish in any desired 128 color hy spray-painting tlu-in with cellu- losc-acctatc or cellulose-nitrate based finishes. Also, a polished, color finish can be applied by impregnating the glass mat with a resin to which the color has been added, and bonding the mat to the laminate in the mold. . In machining glass-plastic combina tions, ordinary machlno shop equipment is used, but at higher speeds than in the machining of metals. The mechanic who could make a part if it were metal can, with a little experience, do an equally workman-like job on glass-plastic laminates. For longer tool life, carbide or cnrhldo tipped tools should lie used. These glass plastic combinations pos sess 'xtremcly high strength in propor tion to their weight. Test specimens have shown tensile strengths of frrm 50, 000 to 80,000 psi, compression strengths of over 50,000 psi, and impact strengths of over 30 ft lb, as compared with 2 ft 111 for ordinary plasties. Comparative properties of gliss-plustic laminates, steel, and aluminum arc given m Figs. 4 and 9. Aircraft parts base provided the most spectacular applications cl glass-plastic combinations, but they are also widely used for the fabrication of tools, dies and jigs, and for panel boards nn which electrical control instruments arc mount ed. Designers and engineers are experi menting with the material for such products as boats and canoes, pissengcr car and truck body parts, furniture, kitchen and bathroom assemblies, re frigerator and radio cabinets, and dozens of additional articles where attainment of light weight combined with high strength and ease of fabrication is the goal. Air Fillers and Tower racking: One of the first commercial uses of glass fil ers was for air filtrati.... in which puls of rel.itisely coarse libers, treated with an adhesive, were employed to strain dust and pollen from the air circulated hy forced-wnnn-air healing systems, and nlr conditioning systems. Today glass filler air filters arc becoming a stand ard requirement for these systems in homes, factories, stores, theaters and other buildings. They are also widely employed in industrial plants to collect abrasive dusts created by manufacturing proc esses. A recent development is the use of these coarse fibers as packing for dis tillation columns, acid coalescers, catalyst towers, and scrubbing or washer towers. The fibers are used for this purpose by the petroleum chemical, distilling, steel nnd other industries. The great sur face area nnd large free volume of the material increase operating efficiency ond speed production. Fibrous c t-ss Mats: The thin, felted Fiberglass mats which, by holding the power-producing ma/crial in place, gave longer life to storage batteries in military automotive equipment during the war, were used for the same purpose in pas senger cars, buses and trucks before the war, and arc again being widely used In storage batteries for peacetime auto motive equipment. In addition, new uses for the mat have been developed. In roll form, it is being employed as a material for wrapping undeground oil, gas and other pipe lines to protect them against corrosion and electrolytic action. It can lie wrapped around bitumen nr coal tar-coated pipe, thus forming a continuous water-tight bond. The ma terial has negligible moisture pick-up and its tensile strength is preserved through a wide range of temperatures and exposuro to organic solvents and soil acids. These mats are being employed as the base for a new photic laminated ma terial. possessing a low anil stable loss factor over a wide frequency range, the laminate greatly extends the field for plastic coil forms, condenser spacers, stand-off insulators, etc., in radio, radar, television nnd other high-frequency elec tronic devices. In hniljing up the lami nate, glass filler mats arc impregnated with a thermo-setting aniline-formalde hyde resin, and arc cured under high pressure. In addition to its low loss factor, the laminate possesses high strength, high temperature resistance, dimensional stability and resistance to fungus attack. CnnJ maehin.diility is another important property nf the lami nate. Fibrous glass mat is also being em ployed as a base material for gaskets and sheet packing. The mat acts as a carrying medium inr synthetic resins suitable for applications requiring re sistance to heat, oil ami acids. Classbase gaskets now being manufactured show high pressure resistance, good chemical durability and little flow under flango pressure. LISTS ELECTRODE INCORRECTLY In the January 8, 1947 advertisement of The Champion Rivet Co., Cray Devil No. 2 electrode wax listed as a 6013 rod. ' This was an error as the rod is, in reality, 6012. The .Graydac Is the Champion 6013 rod. Publication of a new 108-pagc manual. No. 15, by Bantam Bearings Division, Torrington Co., South Bend, Ind., com pletes a scries of three volumes published to provide full bearing engineering data and to furnish nn authoritative guide in the propet selection nf suitable antifric tion bearings for all types of installations. /TEEL