Document JJJGBGgVwEnxxMjQa3bK0OmqK

If PLAINTIFF'S 1 IfI i EXHIBIT E 54 I I MAY/JUNE 1966 INSULATION DIRECTORY/ ABBREVIATIONS SYMBOLS CONSTANTS EQUIVALENTS CONVERSION .TABLES ; ; GLOSSARY FORMULAS ASSOCIATIONS CONCEPTS APPLICATIONS MATERIALS WIRE & CABLE CIRCUITS " PARTS COMPONENTS TEST INSTRUMENTS PRODUCTION EQUIPMENT . MANUFACTURERS DISTRIBUTORS TRADE NAMES STANDARDS & SPECIFICATIONS NUMBER 6 SC-ELEC-04195 3--PRODUCT INFORMATION fectiort 3-8: Flexible Cloth, Film, Fiber, Mat, - , fetal, and Paper Composite Insulations fyw Developments "High temperature polyamide paper yomex'' nylon 1 has been combined many other flexible insulation ierials to form composites with a iriety of properties. The paper is :ribed in section 3-4. It does not ?*elt or support combustion--above jsposC, it will char and can be con joined by fire, but it won't burn independently. The paper is said to offer a unique combination of good ikctrical properties, long useful life temperatures well above class 180. and outstanding mechanical strength, toughness. and resistance to abuse. The paper reportedly resembles the beet rag paper in tensile and tear jtreDgths. flexibility, and toughness. It itj-ecognized for use up to 220C. -*-Tl . , 1,, Composite applications include turn, btyer, or barrier insuiation in trans- kwxners; slot, phase, and wedge in- sdadon in motors and generators; and many other uses where hisrh tem perature resistance is required. Some of the typical composites follow: Polyamide Popr/Polyter Film The combination of polyamide paper with polyester film represents an improvement in cut-through resistance under severe overload conditions and superior thermal aging character istics compared with many other poly ester film composites. Two- and threeply composites are common. The film provides reinforcement and/or die lectric strength as needed. Polyamide Paper/Polyimide Film Composites of polyamide paper with polyimide film offer advantage; similar to the polyester film composites but the polyimide provides heat re sistance more in keeping with that of the paper (well above 200C con tinuous). The film is flame resistant, does not melt, and is infusible. Con structions are both duplex and tri plex. Other Polyamide Paper Composites High temperature polyamide ha; also been combined with many other materials in order to obtain specific properties. For example. FEP and FTFE film composites for heat resist ance and low coefficient of friction. Asbestos or asbestos-glass mat for high temperature stability, good compres sive creep characteristics, and flame resistance. Unidirectional glass or glass fabrics for increased mechanical strength and thermal conductivity as well a; thermal stability and flame resistance. \ amished glass fabrics add dielectric strength to these features. Polyester mat can be used to facilitate absorption of varnishes and resins. ^ Development work is reported on composites made with different types of purified asbestos papers in combi nation with polyimide film and FEP film. They would appear to qualifv for class 155 or 180- : Aotior Credits: This section was prepared by the * editorial jtatr with the Assistance of others acknowledged at the end of ; 'this section. Introduction Some insulating materials are out standing electrically, but may lack certain physical properties for a par ticular application. Others may be suitable in physical properties, but lack the electrical characteristics re- quired. Likewise, thermal, chemical, and moisture resistance properties may be factors. When this problem is encountered, it can often be solved by laminating one or more material; together to form a composite insulation. Since practically any materia] can be com- Secrion 3-S: Flexible Composites 143 blued with another, many different constructions have been made, and many new ones will be made in the future. However, one thing must always be kept in mind when considering com posite insulations: Many physical and electrical properties of a composite insulation are not better than those of the material having the superior properties. This often means there is no addition of property values as a result oi a combination of materials. The same holds true for adhesives when used to bond the materials to gether. The composite is no better than the adhesive used. An adhesive must be chosen to withstand the oper ating conditions for which the com posite was developed, except in cases where the adhesive only facilitates assembly and deterioration of the ad hesive will not cause contamination. The purpose of this Encyclopedia section is to list the major composites available together with their applica tions and general property features. Because materials can be combined in practically any thickness to obtain various property values, it is not prac tical in most cases to attempt to pro vide details here on specific property values or thicknesses. The reader is advised to refer to the other sections for a more thorough discussion of the various individual materials used to make composite insulations. Abo, mica paper composites are not cov ered here but are discussed in Section 3-15 (Mica Products). Throughout this section, the terms "duplex" and "triplex" are used in the various descriptions. Duplex means a laminate of two lavers, e.g., silicone varnished glass/asbestos paper. Triplex means a triple layer laminate, e.g., silicone glass/asbestos paper/silicone glass. It should be remembered that nearly all flexible materials can be combined--if a particular combina tion is not mentioned here, reference to other sections on the individual materials should provide pertinent information. ASBESTOS PAPER COMPOSITES Asbestos is an inorganic compound whose melting point is well in excess of 1000F. Although several compa nies manufacture asbestos products, papers for electrical use must be of a highly purified grade- The principal ones used in composites are of either the short fiber types or long fiber asbestos-glass types. All are covered by Military Specification MILT3503C as to purity of asbestos. Short fiber asbestos papers are classified as to the amount and compo sition of the binder they contain. Those containing organic binders are recommended for class 130 use by the paper manufacturer. Equipment manufacturers, however, often use these products in composite form above class 130 temperatures. The more expensive papers contain from 15% to 25% polyvinyl acetate as a binder. Less expensive class 130 pa pers contain from 10% to 20% starch, wood pulp, or nitrile rubber. Class 155 papers contain from 40 to 50% epoxy resin. Class 180 papers con tain from 15% to 50% silicone resin as the binder. Tensile and tear strengths are very low and depend upon amount of binder used. Short fiber papers are also available without a binder which allows them to he used from class 130 through class 180 temperatures depending upon the equipment manufacturer's impregnat ing resin. These materials are low in abrasion resistance but have compara tively high tensile strength and are relatively inexpensive in composite form. These papers are made of a highly purified asbestos base. The fibers are thoroughly cleaned and matted in a wet felting process. Long fiber papers have lower or ganic content (2% to 6%) than the short fiber papers and are manufac tured with various amounts of glass fiber content. Glass fibers improve the physical properties and result in a lower-density, open structure paper which can be easily saturated. As with short fiber papers, the dielectric prop erties will greatly depend upon the saturating or impregnating resins used. Asbestos Paper/Polyethylene film Both duplex and triplex laminations of asbestos paper and polyethylene film are produced. The polyethylene is used for its electrical and its tnoistu and chemical resistance properti-. However, the composite is limited far as high temperature applicatio are concerned, due to the temperate limitations of the polyethylene fib Asbestos Paper/Polyester Rosie Treated Glass Clots Combination asbestos paper a: modified polyester resin treated gk cloth meets the requirements of cla 155 insulating materials. The isulation can be formed and creaswith minimum loss of dielectr strength. Bond retention is good. T1 material is used as layer insulation dry type transformers and slot i sulation in rotating equipment. Asbestos Poper/Oieores/noes Varnished Glass Cloth Both duplex and triplex combi n tions of this composite insulation a: available as sheet and rolls. It is class 130 insulating material havii very good physical and electric properties plus good heat resistanc It is easy to handle and permits fori ing and creasing with minimum lo of dielectric strength. Bond retenti is goad. The plain asbestos paper a sorbs the electrical insulation varniused in impregnating transformer The varnished glass cloth gives add protection to the impregnated insul tion. Triple and duplex combinatio find application as layer insulation dry type transformers and slot insul tion in rotating equipment. .Asbestos Paper/Resin Treated Polyester Mat This composite material is costructed of polyester fiber non-wovi mat which has been securely bond' to asbestos paper by application suitable resins which have been cup under heat and pressure rolls. TI polyester mat has very good elons tion properties which are imparted the over-all insulation. It is main used to give additional strength to a bestos paper for ease of handling ai moisture resistance purposes. Havii good high-temperature characteristiit should be applicable to sevet classes of operating temperatures u pending on the type of resin used f bonding. 144 insulation Directory/Encyclopedia issue. May/June, 1966 JU Paper/Silieone Yarniihed >** Cl*t* ^oplex structures of silicone var ied glass and asbestos paper are in transformers requiring im- j^jation with silicone varnishes. ^licotie varnished glass cloth has jjSaient electrical properties that are to the composite insulation. iOe* Treefed Aibestos Pop*r/ -fcomt &lett Cloth jjlah heat resistance to class 180 gjhient temperatures and overloads . possible with a construction consist^g'of both silicone treated glass cloth ofl asbestos paper. It is available as ofo duplex and triplex constructions, "he triplex material is not as flexible ^jhe duplex, but it is possible to ,nn and crease it -with a minimum ,if dielectric strength. rtted Afbettot Toper/ Aets Cloth Vben purified asbestos is bonded i plain glass cloth, a porous structure salts having poor electrical proper- However, this construction is ay good for use in transformers that e' impregnated with suitable electwil insulating varnishes. The comioatior. verv easily soaks up the var- and. alter baking, the composioe has good electrical properties. netted Asbestos faper/Pelyostor Asbestos paper laminated to polyiter film is available in a variety of uplex and triplex constructions. The idectric strength properties are good, at-the power factor and dielectric Tcstant tend to be high, especially i the three-ply combination. Here aria, the composites are meant for ablating transformers when the -msformer is subsequently impregned with class 130 insulating varaites. The asbestos readily accepts k-varnish impregnation, and after iking the insulation is a heterogene- composition with excellent elec"e#l and physical properties. The anposlte in duplex form is also used * * cable binder. siKod Aibeitot Paper/Unidirectional '* Yarns Two layers of asbestos paper reinreed with unidirectional glass yams up a composite that is chiefly used as a hinder for cables. A com- ' monly available construction consists of 0,004" purified asbestos paper re inforced with sixteen No. 150-1/0 ! yams per inch. These continuous filfl- ! ment yams have a nominal diameter j of 0.0069". ; PatHied Asbestos Poper/Gloss Clotk. Polyvinyl Acetate Adhesive \ : Several duplex and triplex con structions are made from purified ! asbestos paper and leno (open weave) ! and tightly woven glass cloth bonded [ with polyvinyl acetate adhesive. The j asbestos sheet may contain varying i amounts of polyvinyl acetate ranging from small amounts to saturation. j Duplex leno glass cloth/asbestos \ paper constructions are made by ' bonding a continuous sheet of poly- I vinyl-acetate-saturated purified ashes- | tos to 7-mil leno glass cloth (scrim) j with a polyvinyl acetate adhesive. Be- j sides affording an economical method of reinforcing and strengthening the i asbestos sheet, the glass doth provides j one surface with the abrasion resist ance of glass. This material is used for coil insulation, slot liners, phase sepa rators. rotor bar wrapping, binding j tapes ior motor coils, and layer or i wrapper insulation in transformer j windings. j Triplex leno glass/asbestos paper \ constructions consist of a sheet of ; 7-mi! leno glass sandwiched between j two continuous sheets of polyvinyl- \ acetate-saturated purified asbestos | paper, all securely laminated with j polyvinyl acetate adhesive. Pressure j rollers are employed, and a relatively j dense sheet results. This greater den- j sity results in a considerably higher i dielectric breakdown strength than the duplex material. Uses include coil insulation, slot liners, phase separa- : tors, rotor bar wrapping, binding [ tape for motor coils, and laver or wrapper insulation in transformer ; windings. Both the duplex and triplex i constructions are reported to have thermal stability above class 130. ! Duplex tightly woven glass cloth/ \ asbestos paper differs from the above j constructions in that the asbestos sheet j is more than 85% highly purified ! asbestos fiber and contains only a j small amount of polyvinyl acetate i resin to facilitate controlled satura- j at your service.,. arvey LAMINATED, INSULATIONS' v 1 | ! 1 / 'I_ v \"^ \... stock, or custom (Our laminations are even used for high altitude balloons, and parachutes.) We've been making things stick together lor more than thirty years Arvey laminates all the standard flexible dielectric composrtes--film. foil, fabric, paper, asbestos--you name it. But even more, we make custom laminations that nobody has been able to duplicate. One reason is our facility for formulating special adhesives and saturants. Combine this with our unique LAMCOTE^ process, experience, and a youthful eagerness to be Of service, ana you have a total com bination that's pretty hard to beat. Why not make us prove itf Send for free literature, samples, and/or a salesman. (We promise not to drop him from a parachute.) LAMCOTE DIVISION sip vey 3500 N. KIMBALL AVENUE CHICAGO. ILLINOIS 60618 (312) 463-1400 300 COMMUNIPAW AVENUE JERSEY CITY, NEW JERSEY 07304 (201) 333-5000 Print ID/E 41 on deader Service Card Section 3-8: Flexible Composites 145 tion. These composites adapt very well to coating or treating with various electrical insulating resins and var nishes and perform well through the temperature range of class 130 insula tion. In the thinner grades, the mate rial is very flexible, while the thicker grades are stifi. Specific uses are slot liners, phase separators, layer, wrap per, and barrier insulation, rotor bar wrapping, intercoil insulation, motorcoil binding tapes, and cable wrap ping. The triplex construction consists of tightly woven glass cloth inserted be tween two layers of asbestos sheet and bonded with polyvinyl acetate ad hesive. The construction is denser than the duplex material and has a greater dielectric strength for a given nominal thickness. It, too, can be sat urated with insulating varnishes and resins. It has considerable flexibility in the thinner gauges, while the thicker material is rather rigid. Spe cific applications include slot liners, phase separators, layer, wrapper and barrier insulation, rotor-bar wrap ping, inter-coil insulation, motor-coil binding tapes, and cable wrapping. Silicone Resin Treated Purified Aibcitcs Paper/Glast Cloth, Silicone Adhesive A very good class 180 insulating material, this composite is reported to remain thermally stable at tempera tures up to 250C. Manufactured in duplex construction, it consists of a sheet of standard purified asbestos paper, saturated with silicone resin, backed with tightly woven glass cloth and bonded with silicone adhesive. FLAKED GLASS PAPER COMPOSITES Flaked glass paper is made on standard paper making machines us ing approximately 15% cellulose (kraft or glassine pulp) as the binder. This material is normally used in com posite bonded to either polyester film or glass cloth. The flake tends to dust during handling, and this can be min imized in composites by proper selec tion of bonding resins and other processing conditions. Flaked glass laminates bonded with epoxy resins are currently being used at class 155 temperatures. The material has excellent electrical properties--dielec tric strength of the individual flake is up to 2800 vpm. Because it is a non-hygroscopic material and only susceptible to moisture adsorption (which is negligible), it offers definite advantages over other high tempera ture materials such as asbestos which must be completely impregnated to reduce the problem of moisture ab sorption. Flaked Glass/Polyester Film The combination of flaked glass sheet and polyester film creates tough materials, possessing high mechanical strength, chemical inertness, thermal stability, and high dielectric strength. The composites are available in a multitude of duplex and triplex con structions. They are used as motor and generator magnet wire wrapping, slot and phase insulation; and trans former coil wrapping, layer and bar rier insulation. Flaked Glaet/Glati Cloth This composite combines the phys ical properties of glass fabric with the very good dielectric properties of the flaked sheet. When subjected to high temperature, the material demon strates good thermal conductivity and dimensional stability while maintain ing dielectric properties. It has good impregnation characteristics, excel lent cut-through resistance, and high moisture resistance. Suggested uses in clude motor and generator magnet wire wrapping and coil insulation (usually tape); and transformer layer, barrier and coil insulation. FISHPAPER COMPOSITES Fishpaper is made from high-grade rag paper by chemical treatment with zinc chloride. It has a harder surface and is stiffer with higher dielectric and physical strength properties than ordinary rag paper. Its forming quali ties are very good. It has been usu ally combined with varnished cambric and cellulose acetate film. Fhhpaper/Ceffalate Acetate Film Cellulose acetate film is combined with fishpaper to produce an insulat ing materia] having a high dielectric strength without gready increasing the thickness of the paper. In addi tion, the film imparts qualities of toughness, and moisture and chemical resistance. - Fltkpaper/Vareithed Cambric Both bias cut and straight cut var- nished cambric are combined with! fishpaper to produce a rugged insula-4 tion having high dielectric strength,] A tough, flexible and long-lived in-? sulating adhesive is used to bond the' two materials. The two types of fabric have sim ilar properties except that the straighl cut does not have as much stretch or elongation as the bias cut. Both yel low and black varnished cambrics ate used. There is not much difference be tween these two materials, except that the black tends to have slightly bette^ dielectric strength while the yellow* ' may be slighdy better in respect t<^ abrasion resistance. The major u: for these materials is as motor si insulation. KRAFT PAPER COMPOSITES Kraft paper made from selected? wood puip is an economy electricaT paper. It has somewhat less dielectno and physical strength than otherj papers. However, in combination witlr celiuiose acetate or polyester film, it* is still a superior insulating material^ to most other papers alone. Kraft Popr/Ciloio*o Acetate Film This composite is available in vari^ ous duplex and triplex combination Application is limited, but the mate rial has been put to some use as pha separators in motors. Kraft/Pelyeiter Film In general, these composites havi much better physical and chemical properties than the kraft/cellulos acetate combinations. Although the; are used mainly as transforroei insula tion, they can also be used as slo and phase insulation in rotatini equipment where service requirement are less critical and economy is an ini portant factor. The composites ar rated class 105. The material is available in bot# duplex and triplex constructions. cause kraft paper is manufactured thin gauges, these constructions >4 particularly suitable for small unij where space is critical. MG PAPER COMPOSITES Rag paper, as the name denotes. 146 Insulation DirectoryEncyclopedia Issue, May/Jtuit, 1966 per foil are being used for shielding purposes and as conductors in trans formers and coils. In some cases, the foil is centered on a wider width of kraft paper so that the extra paper edge or margin provides additional electrical and mechanical protection to the conductor. Copper is also combined with water repellent paper and resin impregnated paper for use as flexible printed cir cuit materials. Po/y*sfer Film/Aluminam or Copper Foil One composite is commonly avail able as 0.00035" aluminum foil bonded to 0.002" polyester film with an oil-resistant adhesive containing no chlorine. Its over-all thickness is 0.0025". Used in oil-filled cables, it is designed to have a minimum oil resistance of 20 hours at 125C. A seam overlay material for cable application is a lamination of alumi num foil/paper/poivester film. It is used to shield the corrugated metal seam from penetrating the outer poly ethylene jacket during sheathing operations and prevents a thin spot from occurring in the longitudinal forming of the corrugated aluminum seam. It also provides for a tighter cable and makes it possible to reduce the thickness of the outer jacket. Other composites of polyester film with copper foil in a variety of fin ished thicknesses are used for printed circuits, conductors in coils, cable shielding, and for electrostatic shield ing wraps on bobbin wound and toroidal coiis and transformers. For winding applications such as in mag net coils, the polyester film strip might be wider than the copper foil so that the extra edge margin will protect against turn to turn flash-over. For printed circuits, cover sheets of poly ester film are available with a heat sensitive backing for protecting cir cuit, PTFE-Fluorocarboit/Aluminum Foil This composite has aluminum foil, 0.0002" to 0.005" thick, coated on one or both sides with PTFE film without use of adhesives. The fluorocarbon coatings are from 0.00006" to 0.004" thick. Applications include use in ca pacitors and transformers. /ctiowlidfaMt The editor* *re indebted to the following person* who have reviewed, commented on, or made suggestions for improving this sec tion: L P. Connors, TRW Electro Insula tion, TRW Inc, Pittsburgh, Pa.; Douglas Wachs, 3M Co, St. Paul, Minn.; M. T. Chlystek, Insulating Materials Div,, Westinghouse Electric Corp., Trafiord, Pa.; Lloyd N. Smith, New Jersey Wood Finish ing..Co, Woodbridge, NJ.; Harry R. Pan coast, Polychem Div, The Budd Co, New. ark, Del.; John P. Paulicb, Lamcote Div, Arvey Corp, Jersey Gty, N'J.; and Mark P. Koerner, Chase-Foster, Inc, Providence, R.I. SUPPLIER DIRECTORY LISTING IMPORTANT: For fabricated op converted com* posite insulation products, see other sections, espe cially section 3-22. NOTE: Numbers in parentheses fallowing each product covered in this section correspond with the numpert shown in front of each supolier of products listed here (thus indicating which firms supply composites mode from .the product con* corned)* Rather than listing all the numerous com posites passible, oniy single products used in com posites hove been listed. If Q supplier's identifying number is listed after two different single prod ucts, this would generally indicate that the supplier would be able to supply a composite mode from the two products concerned. Only company nomes ore listed here see Port 4, section *-t, for ad dresses of suppliers, daId foce type indicates advertisery^-see advertisers' fisting at back of book for page number of advertisements. Product! Covered in this Section Aluminum (J, 2, 4. S 7. $.9 19 J] 74 25, 28] Asbesvos pacer (1.4 5 7, 13. 14 !. 24) ' Asbestos paper, silicone resin ireareo (I 4 5 J2 14, !8, 24) , . Asbestos paper, purified M 5. 17. 13. 14. IS, 24. 28) Asbestos paper, purifies, polyvinyl accrete treated (I, 4. 5. 7, 13, 14. 18. 24) Asbestos paper, purifieo, silicone resin treated (4 5, 13. 14, 15, 18, 23) Cellulose acetate film (I. 4, 5. 21, 24. 28} Copper (I, 4, 7, 9, |!. 14, 21, 22. 24, 25. 25, 27, 28) Cotton cioHv pjeoresinous varnished (1, 4, IS, 21. 23, 24, 26) Fishpaper (I, 4. 5. 7. 2J. 24. 25) Raseo glass (4. 24) huonnateo ethviene propyierse fiim (I, 5 5 9jj 24) ` Sdoth (4, 5. 9, 12, 14, 19, 2!. 24 24) Glass cloth, oieoresmous varnisneo (4 12 J4. 21. 23. 24 . 24} Glass cloth, polyester resin treated (4 5, 9 12. 15 21,23,24 . 24! Glass cloth, silicone resin treated (2, 4, 5, 12 16. 21,23 . 24. 25) Glass yarns, unidirectional (2. 5. 12. 24) Kraft paper (I, 4. 5 7. 12. It. 20. 21, 24 . 25. 26.' Nvion film (ertmdeo--no aanesive) (9, 21, 24)1 Poivamiae tiber peoer (heat resistant tvpe tr named ,`Nomei") [2, 3, 4. 5. 7 12. 19, 21. 24)^ Poiycorbonate fiim (I, 5. 9. 21, 2S) Poivester fiim (!, 2. 4. S, 7, 9, 10 12 14 19 21,1 25. 24. 27. 28) Poivesrer mat {t. 4 5. 9. 14. 21 22. 24) Poivethviene (I. 5. 7, 10 |4 ;7. I? 2n Poiyim>ae firm (2, 3, 4. 5, ?, 2! 2< 7?' Polypropviene film (1. 4 S 7. 1C 17, 21) Polytetrefiuoroetfiviene fism (i 2 3 4 5 4 II, 14. 21. 24. 25) Rag paper (I. 4. i*. 2' 24 24 28! Rope paper (1, 4. 12. 20. 21. 24 2t 28) Suiphate paper, unb-eacheo (J, 4. 5, 20. 2D Suppliers of the Preceding Products 1-- ARVer CORP,, LAMCOTE DIV. 2-- THE BORDEN CHEMICAL CO., MY5TIK TAP: DIV. 3-- THE BUDD CO.. POLYCHEM DIY. 4-- Chase-Foster, Inc. 5-- Chase if Sons (no. 6-- Cnemplast Ire. 7-- 0ENNISQN MFG, CO., INDUSTRIAL PROP UCTS DIV. 8--DODGE FIBERS CORP. 9-- Dooqe Fibers Corp.. Circuit Materials Div. 10-- EXTRUDO FILM CORP. 11-- Garfoct Inc., Gariocic Electronic Products Div 12-- Generol Electric Co.. Insulating Material* Dept. 13-- JOHNS-MANYILLE 14-- 3M CO. fS--NATVAR CORP. fADYJ Flexible Electrical Insulations and New Heat Shrinkable Tubing Natvar Corporation 209 Randolph Avenue W oodbridge, TV, J. 07095 Turn to page 179 16--NEW JERSEY WOOD FINISHING CO. 17-- Plymouth Rubber Co.. Jrc. 18-- RAY06STOS-MANHATTAN, INC. ASBESTO: TEXTILE DIV. 19--R, J. Reynoios Tobacco Co., Arcner Alurmnu Div. 2D-RIEGEL PAPER CORP. 21-- Rlegel Paoer Corp., industrial Films Div. 22-- ROGERS CORP. 23-- SUN CHEMICAL CORP., ELECTR.O-TECHN CAL PRODUCTS DIV. 24-- TRW ELECTRO INSULATION. TRW INC. 25-- ~etlo InousiHet 25--Westingnoute Electric Corp., Insulating Mate rials Div. 27-- G. T. Schielda+il Co.. Electrical Prooycts Oiv. 28--LENNI PRODUCTS. INC. ISO Insulation Directory/Encyclopedia Issue, May/June, 1966