ed 089 027 masson, don, ed. title the story of the

DOCUMENT RESUME

ED 089 027 CE 001 073

AUTHOR Masson, Don, Ed.TITLE The Story of the Plastics Industry.INSTITUTION Society of the Plastics Industry, Inc., New York,

N.Y.PUB DATE Oct 72NOTE 44p.

EDRS PRICE MF-$0.75 HC-$1.85 PLUS POSTAGEDESCRIPTORS Chemical Industry; *Development; *Industry;

Manufacturing; *Merchandise Ihformation; OrganicChemistry; *Plastics; Production Techniques

IDENTIFIERS *Plastics Industry

ABSTRACTThis is an illustrated informative booklet, designed

to serve members of the Society of the Plastics Industry, Inc., andthe plastics industry as a whole. It provides basic information aboutthe industry's history and growth, plastics raw materials, typicaluses of plastics, properties, and methods of prccessing andfabricating. (Author/DS)

The story of the LJ

industry

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U.S. DEPARTMENT OF HEALTH;LDLICATION & WELFARENATIONAL INSTITUTE OF

EDUCATION7L.V, DOT''''AENT HAS BEEN REPROr EyAcTLy AS RECEIVED FROM1.-ir -17 RSON OR ORGANIZAT ;ON ORIGIN

IT POINTS OF 'ITV.; OR 0; INIONSSTATE? DO NOT NECESS:.R!LY REEVE.ENT OFFICIAL NAT ,ONAL INSTITL OF

DUCAT ION POSITION OR ROUE

FOREWORD

This is an informative booklet, designed to servemembers of The Society of the Plastics Industry, Inc.,and the plastics industry at: a whole. It providesbasic information about the industry's history,growth, plastics raw materials typical end useswith illustrations, properties, methods of processingand fabricating. It should not be considered as anencyclopedia or technical directory.

Additional copies of this booklet may be obtained atcost from the Public Relations Committee of SPI fordistribution to employee groups, civic organizationsavid educational institutions.

Permission to quote or reproduce parts of thisbooklet is granted, provided full credit isgiven toThe Society of the Plastics Industry, Inc.

TWELFTH REVISED EDITION

Prepared under the direction ofThe Public Relations CommitteeTHE SOCIETY. OF THEPLASTICS INDUSTRY, INC.250 Park Avenue, New York, N, Y. 10017

Edited by Don Masson

Printed by The John B. Watkins Company

October, 1972

The story of the

COTindustry

In 1868, a young printer mixed py-roxylin, made from cotton and nitricacid, with solid camphor. John WesleyHyatt came up with Celluloid, the firstAmerican plastic. Even more impor-tant, he started what is now one of thefew billion dollar industries in theUnited States the plastics industry.

Now in its greatest growth period,the U. S. plastics industry in 1969 pro-duced over 16 billion pounds of resins.With a more than 200 per cent increasein production in the last ten years, theindustry has grown both in volumeand in variety of materials, each withspecial properties.

More and more businessmen havesought information on how plasticscan improve their products, cut theircosts, streamline their production.Students, technicians, workers havesought facts on employment oppor-tunities, plastics courses offered bycolleges and trade schools, and sup-plementary information sources.

The growth of the plastics industryhas been so rapid, however, that publicawareness of the sources of informa-tion on the major plastics, their char-acteristics and proper use has not keptabreast of the interest of either thebusinessman or the student.

This booklet :s prepared by TheSociety of the Plastics Industry, Inc.,representing 1,350 companies engagedin some phase of the plastics industry,to answer basic questions about theindustry, its materials and productionmethods.

1=IMIMPIIIMINEMENIM

How the

Industry

Grew

A century ago there was no such thing as acommercial plastic in the United States. Wehad not learned that by combining such basicorganic materials as oxygen, hydrogen, nitro-gen, chlorine and sulfur, new man-made ma-terials could be created materials which,through variations in the amount and com-bination of basis organic and inorganic in-gredients, could be made with almost anyquality desired in an end product.

In creating the first commercial plastic inthe United States in 1868, John WesleyHyatt did so in response to a competitionsponsored by a manufacturer of billiard balls.It came about when a shortage developed inivcry from which billiard balls were made.Hyatt, a determined full-time printer andpart-time inventor, developed Celluloid. Con-currently, in England, development was inprogress on the use of pyroxylin in lacquersand in other coating materials.

Celluloid, the first American plastic, wassoon found to have many uses. Coloredpink, it was quickly adopted by dentists asa replacement for hard rubber in dentureplates. It will be remembered as the ma-terial from which wipe-clean collars, cuffsand shirt fronts were made, and as thewindow curtains on the early automobiles.The first photographic film used by Eastmanwas made of Celluloid in the '80's to pro-duce the first motion picaire film in 1882.

Forty-one years were to pass before the

2 THE STORY OF THE PLASTICS INDUSTRY

plastics industry took its second major stepforward, In 1909, Dr. Leo Hendrik Baeke-land introduced phenol-formaldehyde resins.While others in the field of chemistry 1-adexperimented with the combination of phenoland formaldehyde, Dr. Baekeland was thefirst to obtain a controllable reaction betweenthe two.. The first phenolic in this countrywas given the trademark, Bakelite, coinedfrom his name.

Dr. Baekeland was also the first to developtechniques for converting this plastic to com-mercial use. His patents covered the produc-tion of a phenolic that could be cast (likemarbleized clock bases), a compound thatcould be formed under heat and pressure(like an electric iron handle), and solutionsthat could be used in making laminates (likerestaurant table tops),

From 1909 to 1926 two more plastic ma-terials were developed cold molded andcasein. Then, the tempo of plastics develop-ment increased consistently as is evident inthe accompanying list which gives the yeareach plastic was introduced and identifies itwith a familiar product for each type ofplastic.

Cellulose acetate was the next large-vol-ume plastic to be developed commercially inthis country. Launched in 1927, it wasavailable only in sheets, rods and tubes until1929 when it appeared as a molding mate-rial and became the first injection-moldedplastic.

The first of the vinyl resins, polyvinylchloride, came on the market in this countryin 1927. The vinyls now constitute quitea family of resins, the most important ofwhich besides polyvinyl chloride arepolyvinyl acetate, polyvinyl chloride-acetate,polyvinyl acetal, polyvinylidene chloride.

While polystyrene became commerciallyavailable in this country in 1938, it is oneof the oldest synthetic resins. It dates backto 1831 when it was first isolated. Today,polystyrene is one of the volume plastics,most familiar in toys and housewares.

Polyethylene was introduced in 1942. Itwas originally produced in England and firstmade in the United States for the U. S. Navy

as an important electrical insulation. Poly-ethylene became the first plastic to reach abillion pound annual production rate.

INTRODUCTION OF PLASTICS MATERIALS

DATE :IMAtERIALF tiimpLE.

EYE GLASS FRAMES1868 CELLULOSE NITRATE

1909 PHENOL-FORMALDEHYDE TELEPHONE HANDSET

1909 COLD MOLDED )(Noes AND HANDLES

1919 CASEIN KNITTING NEEDLES

1926 ALKYD ELECTRICAL BASES

1926 ANALINL-FORMALDEHYDE TERMINAL BOARDS

1927 CELLULOSE ACETATE TOOTH BRUSHES, PACKAGING

1927 POLYVINYL CHLORIDE RAIN COATS

1929 UREA-FORMALDEHYDE L IGHTING FIXTURES

1935 ETHYL CELLULOSE FLASHLIGHT CASES

1936 ACRYLIC BRUSH BACKS, DISPLAYS

1936 POLYVINYL ACETATE FLASH BULB LINING

1939 CELLULOSE ACETATE BUTYRATE IRRIGATION PIPE

1938 POLYSTYRENE OR STYRENE KITCHEN HOUSEWARES

1938 NYLON (POLYAMIDE) GEARS

1938 POLYVINYL ACETAL SAFETY GLASS INTERLAYER

1939 POLYVINYLIDENE CHLORIDE AUTO SEAT COVERS

1939 MELAMINE-FORMALDEHYDE TABLEWARE

1942 POLYESTER BOAT HULLS

1942 POLYETHYLENE SQUEEZABLE BOTTLES

1943 FLUOROCARBON_ INDUSTRIAL GASKETS

1943.

SILICONE MOTOR INSULATION

1945 CELLULOSE PROPIONATE AUTOMATIC PENS AND PENCILS

1947 EPDXY TOOLS AND JIGS

1948 ACRYLONITRILE-BUTADIENE-STYRENE LUGGAGE

1949 ALLYLIC ELECTRICAL CONNECTORS

1954 POLYURETHANE OR URETHANE FOAM CUSHIONS

1956 ACETAL AUTOMOTIVE PARTS

1957 POLYPROPYLENE SAFETY HELMETS

1937 POLYCARBONATE APPLIANCE PARTS

1959 CHLORINATED POLYETHER VALVES AND FITTINGS

1962 PHENOXY BOTTLES- -TYPEWRITER CASES1962 POLYALLOMER_..---- -----_------_____- ________----_-_----------

1964 IONOMER SKIN PACKAGES-1964 BATTERY CASES

_

POLYPHENYLENE OXIDE

1964 FOLTIMIDE BEARINGS

1964 ETHYLENE-VINYL ACETATE HEAVY GAUGE FLEXIBLE SHEETING

1965 PARYLENE INSA-ATING COATINGS

1965 POLYSULFONE ELECTRICAL/ELECTRONIC PARTS

3

The plastics industry runs into billions ofboth dollar volume of finished products andin the pounds of raw material produced,Three plastic materials have reached or ex-ceed 2 billion pounds :annual production:Polyethylene 3.8 billion; Vinyl 2.8 bil-lion: and Styrene. 2.5 billion. The Societyof the Plastics Industry, Inc., estimates thatthe production of all synthetic plastics and

resin materials in 1967 was about 14.47 bil-lion pounds. This fact, alone, is indicative ofthe importance of the plastics industry in ourv, odd today..

Plastics companies numbering over 5,700are located throughout tin United States.Approximately 50 per cent are in the East,34 per cent in the Midwest, 13 per cent onthe West Coast, and 3 per cent. elsewhere.

SYNTHETIC PLASTICS AND RESIN Di ATERIALS PRODUCTION

U. S. TANIFP COMMISSION

tstiotatsl by The Society of tile Plastics lslostry,lc

14,470,000,

6,143,000,000 LBS.

3,738,916,000 LBS.

2,150,518,000 LBS.

818,020.000 LBS.

276,814,363 LBS.

95,133,384 IBS.

30,867,752 LBS.

5,944,133 LBS.

1922 1e30 1935 1940 1945 1950 1955


1960 1987

Plastics

Partner

of Today's

Living

Plastics pixy a vital role in peace, defense,and in war. They were instrumental in thedevelopment of the automobile, airplane,missile and communications. They providedthe material needed to develop the automo-bile ignition system. They made possiblethe pioneering flights of Alcock and Brown,Lindbergh, Byrd, Shepard, and Glenn. Itis said that the Wright Brothers in the '80'sused plastics cellulose nitrate solutions onglider wings and on the wings of the planein which they made their historic flight in1903.

The lifelines of all communications tele-phone, radio, television, radar, sonar, tele-star are based on plastics as insulation andother vital components. The comfort of ourhomes is increased in countless ways . .

through foamed cushions for furniture, easy-to-clean upholstery, protective coatings forthe home and industrial equipment, soft illu-mination for translucent lighting, floor cover-ings that are resistant to spilled liquids andfoods. All of these and many more can beattributed to resins and plastics. Without

5

them we might soon be back in the "darkages."

The continuing development of new plas-tic materials broadens the industry's field ofapplications. Even more, it is indicative ofplastics' ability to produce equally goodproducts at a lower cost, better products atthe same cost, or products that could not bemanufactured without them.

World War II gave great impetus to theindustry. In meeting exacting defense servicerequirements, plastics demonstrated theirversatility and wide range of important prop-erties, They proved their high tensile andimpact strength, lightness, resistance to cor-rosion, low moisture absorption, resistance tosalt water and many chemicals, transparency,adaptebility to varied climatic conditions,and flexibility even at low temperatures.

Designers, engineers, and architects con-stantly analyze material and performance re-quirements of varied products to determinethe suitability of plastics for new end uses;and plastics materials are being formulatedwith scientific precision and skill to meetthese new market applications.

The plastics industry is continuing to ex-pand its facilities of research, developmentand production .. . to meet both civilian anddefense requirements. The Society of thePlastics Industry, Inc., estimates that since1946 the plastics industry has at least tripledits investments in raw materials plasticsplants. Hundreds of millions of dollars arebeing spent in plastics research for the de-velopment of new resins and the improve-ment of existing plastics to meet the multi-fold requirements of modern industry.

Today, plastics are accepted as basic ma-terials used by designers and engineers. Theytake their place in industry along with metal,glass, wood and paper.

=11=MINIEM=m11

Plastics:

What They.

Are

1.1.1111i1

Plastics are man-made materials, in contrastto nature's materials like wood and metal.A generally accepted definition is: Any oneof a large and varied group of materials con-sisting wholly or in part of combinations ofcarbon with oxygen, hydrogen, nitrogen andother organic and inorganic elements which,while solid in the finished state, at somestage in its manufacture is made liquid, andthus capable of being formed into variousshapes, most usually through the applica-tion, either singly or together, of heat andpressure.

THERMOPLASTIC:

Mese plisticsieCome Soft when exposed;to sufficient heat and herded when cooled,no matter hovi often' thi process is

group fall ABS;'....: (iCrylenitrile-bittadieneltyrene);

acrylic; MP cellulosiCiwethylene-vinyl.acetate; fluorocarbon, lOnOmer, nylon,parYline;phaniuty;irlyalliner, polycar-,_bona* polyethylene, PoliphenylOxide;:`:pliiimideiPolypropyiene; polystyrene;

lystilfOne; urethane; and vinyl.

THERMOSET:PO :

:the plastics materials belonging,tp_ thisgrew Piiiajet into permanent Sharkyihe

pressure "are aka .tiiitherif:fOrrning.'. Hiheatink willnot Softens

niaterialS;ilhirmOietting pliStICSVinciutle: alkyd, amino 'Ind -Unita

in; cold molded, ePoitY;PhenOlIC.;polYirster,7anWsilieone.'


Plastics are a family of materials not asingle material each member of which hasits special advantages.

Being man-trade, plastics raw materialsare capable of being variously combined togive most any property desired in an endproduct. But these are controlled variationsunlike those of nature's products.

The widespread and growing use of plas-tics in almost every phase of modern livingcan be credited in large part to their uniquecombinations of advantages. These advan-tages are light weight, range of color,, goodphysical properties, adaptability to mass-production methods and, often, lower cost.Some plastics can be sterilized.

Aside from the range of uses attributableto the special qualities of different plastics,these materials achieve still greater varietythrough the many forms in which they canbe produced.

They may be made into definite shapes likedinnerware and electric switchboxes.

They may be made into flexible film andsheeting familiar as shower curtains andupholstery.

They may be made into sheets, rods andtubes that are later shaped or machined intointernally-lighted signs, airplane blisters.

They may be made into filaments for usein household screening, industrial strainersand sieves.

They may be made into netting in a vari-ety of patterns and sizes.

They may be used as a coating on textilesand paper.

They may be used to bind together suchmaterials as fibers of glass and sheets ofpaper or wood to form boat hulls, airplanewing tips, table tops.

They may be used as adhesives, and inlacquers and paints uses which are butmentioned in this booklet which deals spe-cifically with solid forms of plastics.

Whatever their properties or form, plas-tics all fall into one of two groups thethermoplastic or the thermosetting.

7

The Industry

That Produces

Plastics

Today, a minimum of 5,700 companies inthe United States make plastics their busi-ness. They divide into three large categorieswhich sometimes overlap the plastics ma-terials manufacturer who produces the basicplastic resin or rompourfd, the processorwho converts plastic into solid shape, thefabricator and finisher who further fashionsand decorates the plastic.

PLASTICS MATERIALS MANUFACTURERS

The primary function of the materialscompanies is the formulation of a plasticfrom basic chemicals. This plastic com-pound is sold in the form of granules, pow-der, pellets, flake, and liquid resins or solu-tions for processing into finished products.Some plastics materials companies may go astep further and form the resin into sheets,rods, tubes, film.

The membership of The Society of thePlastics Industry, Inc. lists 175 companies asmanufacturers of plastics materials in theUnited States. A majority are chemicalmanufacturing companies. Some purchasechemicals from which they formulate theplastic resins and compounds. Some onlymake the compound, purchasing the resin.

THE PROCESSOR

Plastics processors divide into several dif-ferent classifications:

MATERIAL MANUFACTURERS MOLDERS

MOLDERS produce finished products byforming the plastic in a mold of the desiredshape. They number about 1,700.

EXTRUDERS divide into two groups. Thefirst group turns out sheets, film, sheeting,rods, tubing, special. shapes, pipe, wire cov-ering. The second group includes producersof the thread-like plastic filaments which,when woven into cloth, find use as seat cov-ers for autos, buses, trains and furniture,and as insect and industrial screening. Ex-truders number in all about 300.

FILM AND SHEETING PROCESSORS makevinyl sheeting and film either by calendering,casting, or extruding. There are about 60companies in the field.

HIGF.-PRESSURE LAMINATORS form sheets,rods and tubes from paper, cloth and woodimpregnated with resin solutions. These com-panies are about 50.

REINFORCED PLASTICS MANUFACTURERSLiqUid resinspolyesters, epoxies, phenolics,and silicones are combined with such re-inforcements as glass fibers, asbestos, syn-thetic fibers and sisal to form strong, rigidstructural plastics and plastic products bymolding or forming. There are about 400companies.

COATERS make use of calendering, spreadcoating, preimpregnating, and dipping and


FABRICATORS

vacuum deposition to coat fabric, metal andpaper with plastics. They number over 70.

THE FABRICATOR AND FINISHER

Plastics sheets, rods, tubes and specialshapes are the principal forms with whichfabricators and, finishers work. Using alltypes of machine tools, they complete theconversion of these plastics forms into suchfinished products as industrial parts, jewelry,signs.

Vacuum forming is an important methodof fabricating sheet mate' ials. Working withrigid sheet material, fabricators also formsuch things as airplane canopies, televisionlenses.

One of the newest and largest branches ofthe plastics industry comprises companiesthat produce from plastic sheeting and filmsuch articles as shower curtains, rainwear,inflatables, upholstery, luggage, closet acces-sories.

Between the producer of the film andsheeting and the fabricator of a finishedproduct there may be a printer who printsa design on the material, and an embosserwho forms a textured pattern on its surface.

Other finishers metal-plate rigid plasticparts or otherwise give them decorative orpractical surface markings.

There are approximately 1500 fabricatorsworking on rigid plastics and another 1500engaged in making film and sheeting intofinished products.

The Plastics

Materials

They Work

With

ABS PLASTICS

ACRYLONITRILE-BUTADIENE-STYRENE

ABS plastics are thermoplastic materials de-veloped in 1948. There is also a SAN (styrene-acrylonitrile) version of this family of plastics.

TYPICAL USESPipe, pipe fittings, wheels. football helmets,safety helmets, textile bobbins, TV antennabrackets, valve bodies, refrigerator parts, bat-tery cases, automotive parts, cable flodts, toteboxes, water pump impellers, terminal blocks,strike brackets, business machine trays, chil-dren's skates, utensil handles, tool handles,radio cases are typical products.

PROPERTIESStrong and tough ABS plastics possess out-standing impact strength in combination withhigh mechanical (tensile, flexural, etc.) strength.Some formulations offer excellent toughnessdown to 60°F.Heat resistance These compounds can be usedat temperatures of 175°F. to 212°F. Newerformulations withstand temperatures greaterthan 212°F.

Chemical resistance ABS plastics are resistantto acids, alkalis, salts and, in many cases, toaliphatic hydrocarbons.

Electrical qualities ABS plastics have goodoverall electrical properties.

9

Dimensional stability Parts are dimensionallystable under a wide variety of conditions.

FORMS AND METHODS OF FORMINGABS plastics are available as powder or granulesfor injection molding, extrusion and calenderingand as sheet for vacuum forming.

ACETAL RESIN

Acetal resin is a rigid thermoplastic developedin 1956.

TYPICAL USESThis resin was developed for use in fields oncedominated by die-cast metals. Uses includeautomobile instrument clusters, carburetorparts, gears, bearings and bushings, door han-dles, plumbing fixtures, and moving parts inhome appliances and business machines.

PROPERTIESRigidity Acetal resin is extremely rigid with-out being brittle. It retains these propertiesunder adverse conditions of temperature andhumidity.

Chemical resistance Resistant to most sol-vents.

Odorless, tasteless, non-toxic.

Strength Extreme toughness, outstandingtensile strength, stiffness, and fatigue life.

FORMS AND METHODS OF FORMINGAcetal resin is produced in powder form formolding and extrusion.

ACRYLIC

Acrylic, or polymethylmethacrylate, plastic is

a thermoplastic material, commercially intro-duced in the U.S.A. in 1936. A copolymer,methyl methacrylate-styrene is also available.

TYPICAL USESAirplane canopies and windows, camera lenses,facing paneis, dome structure enclosure glazingin building construction, outdoor signs, lightingdiffusers, automobile tail lights, nameplates forhome appliances. TV shields, and skylights.

PROPERTIESOptical clarity Acrylics offer exceptional clar-ity and good light transmission. In crystal-clearform, acrylic can pipe light pick it up at oneedge and transmit it unseen, even around curves.Strength Acrylics are strong. rigid and re-sistant to sharp blows. Contact with cleaningcloths containing grit, kitchen scouring powdersand such abrading materials as steel woolshould be avoided.

Weather and temperature resistance Weather-ing does not affect the transparency, physicalstability and electrical properties of acrylic.Long outdoor exposure of colorless acrylic hasno significant effect on its use as a transparentmaterial. Acrylic does not become brittle atlow temperatures, Some cast acrylic composi-tions withstand bOing water, and heat-resistantmolding composions are undistorted up to200°F. Acrylics will not withstand steamsterilizing and, if subjected to boiling water,will start to lose shape. This acrylic plastic ma-terial has a slow burning rate and does notflash ignite.

Electrical properties Acrylic is an excellentinsulator.

Color and texture Acrylics are inherentlycolorless but are also produced in a full rangeof transparent, translucent and opaque colors.They are also made with corrugated and pat-terned surfaces. This plastic is warm andpleasant to the touch.

Odorless, tasteless, non-toxic.

Chemical resistance Acrylics are unaffectedby most household chemicals such as weak andstrong alkalis, bleaching compounds and win-dow cleaning solutions, by salt, vinegar, animaland mineral oils, waxes, and foods commonlyencountered in the home. This plastic is at-tacked ,by perfume, gasoline, cleaning fluids,acetone, chloroform, and strong solutions ofoxidizing acids.

1 0 THE STORY OF THE PLASTICS INDUSTRY

FORMS AND METHODS OF FORMINGAcrylics are available as rigid sheets, rods andtubes, and molding powders.

Plastic products can be produced by fabricat-ing of sheets. rods and tubes, hot forming ofsheets, injection and compression molding ofpowder, extrusion, casting.

ALKYD

Alkyd plastic is a thermosetting material, de-veloped in 1926, which has its widest applica-tion in enamels, paints, lacquers and similarapplications. It was introduced as a moldingmaterial in 1948. Production in 1967 is esti-mated at around 680,000,000 lbs.

TYPICAL USESRepresentative applications of alkyd moldingmaterials are parts of automobile starters, fuses,light switches, electric motor insulator andmounting cases, television tuning devices andtube supports. Enamels and lacquers for auto-mobiles, refrigerators, stoves, farm machineryare typical uses for the liquid form of alkydplastic.

PROPERTIESElectrical properties Alkyd molding materialshave excellent dielectric strength and will resistmore than 350 volts per mil. They have highresistance to electrical leakage. Molded alkydmaterials also afford excellent arc resistance.Weather and temperature resistance Alkydmolding powders have excellent heat resistanceand are dimensionally stable under high tem-peratures. They also have good resistance tomoisture.

Chemical resistance Molded alkyd is resistantto acids, ketones, esters, alcohol, chlorinatedcompounds, essential oils.

FORMS AND METHODS OF FORMINGAlkyds are available as molding powder andliquid resin.

Finished molded products are produced bycompression molding.

- staF

. ...... 1.....

7'

1. Automative parts molded ofacrylonitrile - butadiene - styreneplastic. Metallized dash panelsand instrument cluster take tookof metal, but incorporate greaterdurability and impact resistance.

2. Colorful telephone desk setsare molded of ABS plastic whichprovides outstanding impactstrength and is unaffected byperspiration.

3. Acetal molded switch back(foreground) for electric wind-shield wiper control is fitted tometal housing above. The acetalmolded slide (right) moves insideswitch back and makes metal tometal contact with lugs to ac-tivate wipers and for speedcontrol.

4. Weather and break resistance,light weight and clarity are rea-sons for using acrylic sheet forthe dome enclosure.

5. Molded alkyd distributor capused on racing car engine. Alkydwas used because of its highelectrical surface resistivity andretention of superior electricalproperties at under-the-hood rac-ing temperature.

6. Base of this circuit breaker,used in aircraft power generatorsystems, is molded of allylic. Useof glass-filled diallyl phthalateresip-base compound virtuallyeliminated rejects.

ALLYLIC

Ally lics are thermosetting materials developedsince World War II. The most widely used ofits prepolymers, diallyl phthalate resin, was in-troluced commercially in 1949.

TYPICAL USESElectronic parts, electrical connectors, bases,and housings, etc. Low and high pressure lami-nates, both reinforced plastics and decorativetypes.

PROPERTIESElectrical High dielectric strength, low elec-trical loss, low dielectric constant over a widefrequency range, excellent insulation resistanceand arc resistance. Unmatched ability to retainits excellent electrical properties under condi-tions of high humidity with rapid and full re-covery of properties on drying.

Heat, Moisture, Staining, Chemical, andWeather Resistance Ally lic plastics can beproduced to withstand constant use at up to350° F. and colored products have excellentcolor stability at high temperatures.

These plastics have practically no moisture ab-sorption and are highly resistant to decomposi-tion by practically all chemicals. Consequently,allylic plastics are highly stain resistant.Allylics have superior resistance to the adverseeffects of weathering, and even thin overlayswill greatly improve the weathering ability ofother materials such as polyester glass fibersheet.

Odorless, Tasteless, Insoluble.

Unusual Dimensional Stability During andAfter Molding.

Color Ally lic plastics can be produced in afull range of opaque and transparent colorswhich are stable under the most adverse con-ditions.

FORMS AND METHODS OF FORMINGAllylics are available in the form of monomersand prepolymers. Also available are ready -to-

1 2 THE STORY OF THE PLASTICS INDUSTRY

use molding powders with a variety of fillersor prepreg of coated glass fiber, other textiles,paper, etc.

Finished articles be made by transfer,compression, injection or extrusion molding;lamination; coating, both powder and liquid;impregnation.

A7,7:1NO PLASTICS

MELAMINE AND UREA

Amino plastics are thermosetting materials.Melamine, developed in 1939, and urea, de-veloped in 1929, together reached a productionlevel in 1967 of approximately 740,000,000 lbs.

TYPICAL USES

Melamine Familiar in colorful tableware,melamine also finds wide use in distributorheads, buttons and hearing aid cases. It is alsoused in laminate surfaces, like table tops, as aplywood adhesive, for baking enamel finishes,and as a textile and paper treatment.

Urea Representative molded urea productsare closures, scale housings, lamp reflectors,radio cabinets, electrical devices, buttons, appli-ance housings, stove knobs and handles. Inresin form it is used as baking enamel coatings,plywood adhesives, and paper and textile treat-ment.

PROPERTIES

Colorful Both melamine and urea offer a fullrange of translucent and opaque colors, colorswhich have the advantage of being lightfast.They give a glossy surface.

Strength Both melamine and urea are veryhard, scratch-resistant materials. They arestrong but not unbreakable, and should beguarded against hard blows. There are specialhigh shock-resistant and tl'ipact-resistant types.Chemical resistance Both melamine and ureaare unaffected by detergents, cleaning fluids

(like carbon tetrachloride and gasoline), nailpolish and remover, alcohol, oils, grease.

Heat and weather resistance Melamine andurea perform satisfactorily over a wide tem-perature range from as low as 70°F. for bothplastics to a continuous operating temperatureof 170°F. for urea and 210°F. for melamine.They maintain their dimensions well and, formost indoor uses, may be considered complete-ly permanent. Neither material should be usedin an oven or over a flame, as discoloration orcharring may occur. However, neither will burnor soften in contact with a flame.

Electrical characteristics Both melamine andurea have good electrical qualities.

FORMS AND METHODS OF FORMINGThe amino plastics (melamine and urea) areavailable as molding powders or granules, asa foamed material, in solution and as resins.

Finished products can be made by compres-sion, transfer, plunger molding and laminatingwith wood, paper.

CASEIN

Casein, the product of the protein of skim milkreacted with formaldehyde, is a thermosettingmaterial developed in 1919.

TYPICAL USESButtons and buckles, beads, game counters,knitting needles, atthesives, toys and novelty-

- counter items are all typical applications forcasein plastic.

PROPERTIESColor and appearance Casein takes a brilliantsurface polish and has a wide color range ofnear transparent and opaque colors. Manyextremely interesting and unusual variegatedpatterned color effects can be achieved withthis thermosetting material.

Strength Casein is a strong, rigid plastic. Itresists the effects of both blows and flexing.

13

Chemical resistance Casein products with-stand dry cleaning and are not adversely af-fected by contact with such liquids as gasoline,nail polish, organic solvents and chemicals.

Weathering and water resistance Casein isadversely affected by humidity and tempera-ture changes. Immersion in liquids for longperiods at room temperature or short periods atboiling temperature will cause casein to absorbWater, swell, soften and break easily. It be-comes more brittle as the temperature drops be -.low freezing, and withstands only moderatelyelevated temperatures without becoming pliableor discoloring. It is not recommended for con-tinuous outdoor exposure.

FORMS AND METHODS OF FORMINGCasein is available in rigid sheets, rods andtubes, as a powder and liquid.

Finished products are made by machining ofthe sheets, rods and tubes.

CELLULOSICS

There are five types of cellulosics, all thermo-plastic. Cellulose nitrate was developed in 1868,cellulose acetate in 1927, cellulose acetate bu-tyrate in 1938, ethyl cellulose in 1935 andcellulose propionate in 1945. They reached avolume of approximately 195,000,000 lbs. in1967.

TYPICAL USESCellulose acetate is used for rigid packagingand is familiar as recording tape, photographicfilm, as a lamination for book covers, in spec-tacle frames, toys, lamp shades, vacuum cleanerparts, combs, shoe heels.

Cellulose acetate butyrate is used for packagingand in steering wheels, portable radio cases,pipe and tubing, tool handles.

Cellulose propionate is used In packaging, ap-pliance housings, telephone hand sets, pens.

continued on page 15

1. Electrically heated compart-mented baby food dish is moldedof melamine which resists attackfrom food, juices and detergents,and is break resistant.

2. Facewide sun shade is madeof colorfully printed celluloseacetate sheet. Shade is personalwind-and-sun shield that letswearer look at world throughnew Op eyes. Flipped up, it be-comes a bonnet; flipped down, aprotective veil to cut glare andwind.

3. Transparent cellulose acetatebutyrate pipe is used to Wowcups several hundred feet fromthe manufacturing area to thepacking and shipping department.

4. Crystal-clear flowmeter col-umn made from extruded cel-lulose propionate plastic. Four-sided column on rotatable basepermits direct and instant reading of flow rate for any of fourinert industrial welding gases.

5. Cold molded plastics are usedfor electrical appliance connec-tors and plugs, wiring devices,heat resisting ferrules, adapterswhere precision tolerances andheat resistance are prime factors.

6. Epoxy/glass filament woundexternally reinforced pressurevessel, showing the combinationhelical winding and circumferential winding to attain design re-quirements.

7. Epoxy-based surface coatingscure rapidly, withstand shockand exposure to chemicals, oil,grease and severe weathering.

3. One-use sanitary medical syringe eliminates costly steriliza-tion. Syringe is blow-moldedfrom ethylene-vinyl acetate, im-mediately packaged, and remainssterile and ready for use. Resincombines toughness, flexibilityand clarity.

{'

Ethyl cellulose is favored for edge moldingson cabinets, electrical parts, flashlights.

Cellulose, nitrate is familiar in shoe heel covers,and as a fabric coating.

PROPERTIESStrong and durable Cellulosics are among thetoughest of plastics. Normal rough usage willnot break cellulose parts. They retain a lus-trous finish under normal conditions thoughabrasives will scar their surface.

Colorful The cellulosics may be transparent,translucent or opaque in a wide variety of col-ors and in clear transparent.

Temperature and weather resistance All thecellulosics will withstand moderate heat. Ex-cept for cellulose acetate butyrate and cellulosepropionate which are suitable for outdoor use,cellulosics should not be exposed to continuousoutdoor Weathering.

Electrical characteristics All the cellulosicshave good electrical properties and are suitableinsulators against usual domestic and industrialcurrents.

TYPESCellulose acetate (C/A) This cellulosic isresistant to most household chemicals, oil, gascrline and cleaning fluids but should be kept awayfrom alcohol, alkalies. This plastic is odorless,and tasteless. It is unaffected by normal mois-ture and moderate heat and will withstandnormal usage at below freezing temperatures.Water resistance and dimensional stability areimproved in high acetyl C/A.

Cellulose acetate butyrate (CAB) and Cellu-lose propionate (CP) Special weather-re-sistant formulations of these cellulosics aloneare suitable for outdoor use. Some types maybe used in water approaching boiling, and alltypes cara stand quite rough usage at sub-zerotemperatures. Their moisture absorption rateis low. CAB and CP are resistant to mosthousehold chemicals, but are adversely affectedby alcohol, alkalies, paint removers, acetone.

Ethyl cellulose (E/C) Of the cellulosics,E/C best maintains its toughness and resiliency

continued on page 16

at sub-zero temperatures. It also offers gooddimensional stability over a wide range of tem-peratures and humidity conditions. It is un-affected by alkalies, weak acids, but should bekept away from cleaning fluids, oils, solvents.

Cellulose nitrate (C/N) This is made onlyas sheet, film, rod and tube and in solution forcoating because it is flammable and cannot besubjected to molding. C/N offers a wide rangeof colors and variegated color effects. It is re-sistant to most acids and alkalies.

FORMS AND METHODS OF FORMINGCellulose acetate is available as pellets, sheets,film, rods, tubes, strips, coated cord. It can bemade into finished products by injection, com-pression molding; extrusion; blow-molding andvacuum forming of sheets; laminating; ma-chining; coating.

Cellulose acetate butyrate is available in pellets,sheets, rods, tubes, strips, and as a coating.It can be made into finished products by injec-tion, compression molding; extrusion blowingand drawing of sheet; laminating; machining;coating.

Cellulose propionate is available in pelicts forinjection, extrusion, or compression molding.

Ethyl cellulose is available as granules, flake,sheet, rod, tube, film and foil. It can be madeinto finished products by injection, compressionmolding; extrusion; drawing; machining.

Cellulose nitrate is available as rods, tubes,film, sheets for machining and eas a coating.

COLD MOLDED

Cold molded plastics are thermosetting mate-rials developed in 1909. There are three types:bitumin, phenolic, and cement-asbestos.

TYPICAL USESCold molded plastics find use in switch basesand plugs, arc barriers and shoots, 3rd rail in-sulators, in small gears, handles and knobs,


tiles, furnace covers, jigs and dies, in gamemarkers and toy building blocks.

PROPERTIESCold molded plastics possess resistance to highheat, most alkalis and solvents, water and oils.They also exhibit good arc resistance.

FORMS AND METHODS OF FORMINGCold molded plastic materials are available ascompounds.

Finished articles are produced by moldingusing heavy pressure in a rapid cycle, and bysubsequent curing.

The bitumin and phenolic types of coldmolded materials are cured either in ovens orat room temperature.

The cement-asbestos type of cold molded ma-terial is first cured in the presence of moistureand it is then baked.

EPDXY

Epoxy resins are thermosetting and were firstmanufactured in the United States about 1947.Production totalled approximately 145,000,000lbs. in 1967.

TYPICAL USESProtective coatings for appliances, plant struc-ture' and equipment, automobiles, pipe, cansand drums, gymnasium floors and other hard-to-protect surfaces.

They firmly bond metals, ceramics, glass, plas-tics, hard rubber and are used in combinationwith glass fibers to manufacture reinforcedplastics products. Other products are: Printedcircuits, laminated tools and jigs, ducts andliquid storage tanks. Epoxies are employed mostcommonly in casting, potting, laminating, coat-ing and adhesive-bonding applications.

PROPERTIESElectrical qualities Epoxies have good elec-trical properties.

Water and weather resistance Epoxy base ad-hesives, due to their resistance to various chemi-

cals and weathering, may be used where cor-rosion resistant joints are required.

Chemical resistance Epoxies are resistant tomany chemicals. They have found widespreaduse for surface coating due to their excellentadhesion, durability and chemical resistance.

Strength Epoxies have good flexibility.

FORMS AND METHODS OF FORMINGEpoxies are available as molding compounds,resins, foamed blocks, liquid solutions, adhe-sives, coatings, sealants.

ETHYLENE-VINYL

ACETATE

Ethylene-vinyl acetate (EVA) copolymers areflexible thermoplastic resins. Moldable gradeswere develop; d in 1964.

TYPICAL USESPresent and potential uses for these new rub-ber-like plastics cover a variety of products,such as molded mechanical goods milk dis-penser tubing, syringe bulbs, hospital sheetingand similar hospital and pharmaceutical items.Others include shower curtains, greenhousecovers, disposable gloves, inflatable toys, andpool liners. Some grades meet Food and DrugAdministration requirements for food pack-aging.

PROPERTIESFlexibility Flexible without plasticizer overa wide range of low and medium temperatures,including better low temperature flexibilitywhen compared to vinyls.Impact strength High, even at extremely lowtemperatures.

Resilience Excellent "snap-back.'

Flex life High resistance to flex cracking orenvironmental stress cracking.

FORMS :AND METHODS OF FORMINGEVA molding compounds are formed by injec-tion molding, extrusion and blow molding.

17

FLUOROCARBONS

Fluorocarbons are thermoplastic materials intro-duced in 1943. They include tetrafluoroethylene(TFE), chlorotrifluoroethylene (CTFE), vinyli-dene fluoride (PVF2), and fluorinated ethylene-polypropylene (FEP).

TYPICAL USESFluorocarbon resins are used in industrialapplications such as: gaskets and packings,seals, piston rings, and sealants (i.e. threadsealant tape), linings for vessels, valves, pumps,pipe and fittings, hose, etc., bearing pads, slipjoints, pipe slides, expansion plates, anti-sticksurfaces (in form of films, sheeting and coat-ings), electrical wire insulation and compo-nents; and other miscellaneous items (i.e. bel-lows, filters, pipe, tubing, and laboratory ware).They are used in consumer and householdapplications as coatings for frying pans, cookingutensils, rolling pins.

PROPERTIESChemical resistance Fluorocarbon resins haveunmatched chemical resistance to most indus-trial chemicals and solvents.

Thermal stability Fluorocarbon reins retainuseful properties from cryogenic to elevatedtemperatures, exceeding the temperature rangeof all other plastics.

Low coefficient of friction and anti-stick prop-erties a Fluorocarbon resins have one of thelowest coefficients of friction known for solidsand exhibit unmatched anti-stick characteristics.

FORMS AND METHODS OF FABRICATIONFluorocarbon resins are applied as powders,granules or dispersions. They can be molded,extruded, hot or cold formed, machined, andare also applied as 'coatings.

1. Miniature, subminiature andmicrominiature terminals, moldedand fabricated from fluorocar-bons, are used for componentsfor circuitry in TV, UHF micro-wave computers and other criti-cal electronic circuits.

2. Plastic sheet compression-molded from ionomer resin hashigh transparency and flexibility.Quarter-inch sheet is easilyflexed by girl, indicating use asface protection for industrialsafety equipment.

3. lonomer can be tailored forskin packaging of hardware itemsand other consumer products.

4. Auxiliary gasoline fuel tankfor utility automobile is moldedof nylon. Irregular in shape andmade without seams or joints,the nylon tank is designed to fitinto compact space below driv-er's seat. Using nylon, engineerswere able to design tank to meetunusual space requirements.

5. Woven fabric of nylon mono-filament is used for handbagsand shoes in matching colors.Nylon fabric resjsts attack andstaining by oil, grease and com-mon chemicals.

6. Parylenecoated lithiummetalgranules at left do not reactwith water on which they float.Unprotected granules at right re-act instantly and violently.

IONOMER

The ionomers are a new family of thermoplas-tic resins developed in 1964. The term ionomerwas coined to indicate that the polymer con-tains inorganic as well as organic materialslinked by both covalent and ionic bonds.

TYPICAL USESIonomers can he tailored for a very wide va-riety of end uses; skin packaging applications,extrusion coatings and laminations for foodpackaging, molded items for housewares, toys,tool handles, bottles, closures and vials, wireand cable insulation, extruded shapes, tubingand sheeting. Flat sheeting can he thermo-formed info covers, trays and irregular shapes.

PROPERTIESTransparent and tough Ionomers combinetransparency with toughness, especially at lowtemperatures and are more resilient than poly-ethylene.

Chemical resistance Ionomers arc virtuallyunaffected by oils and greases. irhey are re-sistant to bases, dilute acids, hydrocarbons,ketones, alcohols and esters. Resistance toliquid absorption is high by comparison withmany plastic materials of comparable trans-parency. Certain grades of ionomers arerecommended for food packaging; meeting therequirements of food additives resulations.Exceptional corona resistance in electrical in-sulation.

Tasteless, odorless.

Color In the natural state it is crystal clear.This new resin can be readily colored withcomplete uniformity and has a high capacitylevel for fillers while retaining serviceable prop-erties.

Adhesion Ionomers can be heat sealed andcan provide adhesion from a molten state tosubstrates, including metals.

FORMS AND METHODS OF FORMINGThis plastic is injection molded, blow molded,extruded as shapes, film, substrate coatings andwire insulation, and thermoformed.

19

NYLON (POLYAMIDE)

Nylon, the generic name for a family of polya-midc resins with related but not identical chemi-cal compositions, is a thermoplastic materialdeveloped in 1938.

TYPICAL USESNylon is a familiar material for tumblers, slidefasteners, faucet washers, gears. As a filamentit is used as brush bristles, fishing lines.

PROPERTIESResistant :o extremes of temperature Nyloncan be safely boiled and steam sterilized. Also,freezing temperatures do not adversely effect it.However, nylon is not recommended for contin-uous outdoor exposure. It is self-extinguishing.Strong and long wearing Nylon is tough,having high tensile, impact and flexural strength.In part, its resistance to hard blows is due to itsresiliency, allowing it to give a little when hit.Though the hard, glossy surface of nylon is veryresistant to abrasion, scouring powders and steelwool should not be used in cleaning.

Chemical resistance Nylon is unaffected byall common work-a-day chemicals, greases andsolvents except mineral acids. It is fairly e.isilystained by coffee, tea and colored foods.

Electrical characteristics Very good.

Cojor Nylon varies from transparent toopaque depending on the thinne'ss of the article.It comes in a range of soft colors.

FORMS AND METHODS OF FORMINGNylon is available as a molding powder and assheets, rods, tubes and filaments.

Finished products can be made by injection,compression, molding, blow molding, and ex-trusion.

PARYLENE

Parylene is a family of thermoplastic materialsintroduced in 1965.

TYPICAL USESSophisticated applications include: insulatingand protective coatings for paper, fabric, ce-ramics, metals, and electronic parts such asphoto cells, micro-circuits, memory units, andcapacitors; encapsulation of reactive materials;and ultra-thin pellicles.

PROPERTIESHigh-temperature resistance Parylenes havehigh melting points (500°F.-750°F.) Thermalendurance in air is moderate, but for short term(1000 hr.) use, temperatures of about 200°F.to 240°F. are practical. For long term (10yr.), data indicates that temperatures in therange of 140°F to 175°F. are optimum.

Cryogenic Steel panels coated with paryleneand chilled in liquid nitrogen to 320°F. withstand impacts of more than 100 in.-lb. in amodified falling ball impact test.

Dimensional stability Parylene shows out-standing dimensional stability with respect tochanges in relative humidity.

Chemical resistance Parylenes resist attackand are insoluble in all organic solvents up to300°F. They are unaffected by stress-crackingagents and are also resistant to permeation byall solvents with the exception of aromatichydrocarbons. Gas and moisture vapor barrierproperties are excellent.

Electrical Dielectric properties of parylenesare extremely good. Near absolute zero, onetype of parylene provides the best electrical in-sulation of any known plastic.

FORMS AND METHODS OF FABRICATION

Parylene can be deposited as a uniform, con-tinuous, adherent film or formed on a surfacetreated with a release agent and then strippedfree. Any material that can withstand relativelyhigh vacuum can be coated.

20 THE STORY OP THE PLASTICS INDUSTRY

PHENOLIC

Thermosetting phenolics were developed in 1909.Production was approximately 1.1 billion lbs.in 1967.

TYPICAL USESAutomobile distributor heads and insulation,telephone handsets, radio and television cabinets,electrical insulation, washing machine agitators,appliance parts, molded drawers, tube bases,bonds for abrasives, brake linings, protectivecoatings, juke box housing parts, novelties,jewelry, pulleys, handles, dials, knobs, lami-nated wood frame members.

PROPERTIESStrong and hard Phenolics are hard, rigid,strong. The average phenolic will withstandknocks, such as are common with camera hous-ings. Special impact-resistant molding phenolicscan be employed where use is even morerigorous. Their smooth, lustrous surface willgive excellent service under severe conditions.

Heat and cold resistant Phenolics have goodheat resistance up to 300°F. and some above.Mineral and glass reinforced phenolics will per-form up to 400°F. continuously. Moreover,they are poor conductors of heat, being cool tothe touch when used as handles for cookingutensils. They do not support combustion orundergo change from freezing temperatures.

Electrical characteristics Phenolics are excel-lent insulators. Special low-loss electrical in-sulating materials are available.

Chemical and water resistance Water, al-cohol, oils, greases and mild acids and commonsolvents do not adversely affect phenolic parts.Where extreme chemical resistance is requireda special chemical resistant type is available.Phenolics, as a whole, do not absorb water andretain their luster, strength and rigidity.

Color As molding materials they are opaqueand are produced in black, brown, mottled wal-nut and dark colors. They tend to yellow uponexposure to light. Colorability distinguishescast from molded phenolic. Cast phenolics are

produced in transparent, translucent and opaquecolors, and in variegated effects.

TYPESPhenol-formaldehyde Molding materials areconsidered the "work horses" of the plastics in-dustry, They are combined with various fillers

woodflour, chopped fabric, paper pulp, as-bestos, mica depending upon the ultimate usefor which they are intended. These plastics arealso produced as bonding resins, resins for pro-tective coatings, adhesives. Finished productsare made by compression. transfer, plungermolding; casting; laminating; coatings.

Cast phenolic These are resins cast to formand are usually machined into finished products.They are strong, rigid and dimensionally stable,heat resistant, hard to scratch, water and chemi-cal resistant. They are produced in a widerange of colors and variegated patterns, likeonyx and marble. They are produced as sheets,rods, tubes and in special forms.

Phenol-furfural This type has most of theproperties of phenol-formaldehyde resins andplastics. It offers high strength, durability, di-mensional stability and good electrical charac-teristics. Dark in color. Molding advantage isextended flow at low temperatures, fast cure athigh temperatures. It is available as moldingcompounds, liquid resins, varnishes and ce-ments. Phenol-furfurals are made into finishedproducts by compression, transfer and injectionmolding; low-pressure molding; coatings; im-pregnating; laminates.

Resorcinol This type is used primarily asroom-setting adhesives in laminated gear blanksand laminated wood frame members. Outdoorexposure is good. Low temperature curing isan advantage in the lamination of heavy struc-tures with thick sections. Resorcinols come assolids and liquids and are made into productsby laminating; impregnating; coating; foaming.

FORMS AND METHODS OF FORMINGPhenolics are available as a molding compoundto which different fillers may be added; as pre-forms, boards and blanks; for impregnants,bonding agents, coatings, foams. Finished prod-ucts are made by: injection, compression, trans-fer, plunger molding; casting; laminating.

21

PH EN OXY

Phenoxies are thermoplastic materials intro-duced in 1962.

TYPICAL USESEnd uses for phenoxy compounds include clearblow-molded bottles, cosmetic, drug and foodcontainers and other packaging applications:molded electronic parts for computers, electri-cal appliance housings: sporting goods and bat-tery cases; extruded pipe; and in adhesives :Andcoatings.

PROPERTIESOptical Crystal-clear, water-white phenoxyresins can be colored with dyes or pigmentsthrough the full range from delicate transpawnttints to opaque colors.

Mechanical Phenoxy exhibits an excellentbalance of high rigidity, strength, hardness, andtoughness, and is a practical engineering mate-rial, Parts can be economically and rapidlyproduced to meet tight tolerances and to holdtheir shape and size.

Thermal Phenoxy retains its high tensilestrength and rigidity right up to its heat dis-tortion point, Fabricated parts can he used inload bearing applications at temperatures ashigh as 160°F. to 170°F.

Barrier The permeability of phenoxy, par-ticularly to oxygen, is the lowest of any melt-processable polymer. Oxygen permeability is1/20 that of high density polyethylene.

Chemical Phenoxy is resistant to attack byacids and alkalies, but swells and ultimatelydissolves in solvents. It is also resistant tohydrocarbons, and most household cleaningcompounds.

FORMS AND METHODS OF FORMINGPhenoxy pellets may he blow-molded, injectionmolded or extruded with ease. Finished partsare readily joined by conventional methods.Phenoxy is also supplied as resins for adhesivesand as resins or in solution form for surfacecoatings.

POLYALLOMER

Polyallomers are a class of crystalline polyole-fin polymers prepared from at least two mono-mers by copolymerization. The resulting poly-mer chains comprise polymerized segments ofeach of the monomers used

Thermoplastic, piopylene-ethylene polyallo-mer was developed and introduced in the UnitedStates in 1962.

TYPICAL USES

Automobile windlace and cowl panels, pipefittings, self-hinged cases and containers, note-book binders, closures, toys, shoe lasts, film andsheet for packaging and vacuum forming.

PROPERTIES

Propylene-ethylene polyallomer combines manyof the best characteristics of crystalline poly-propylene and linear polyethylene.

Compared with general-purpose polypropyl-ene, it offers lower brittleness temperature,higher impact strength, less notch sensitivity,and greater melt strength.

It offers better color, lower susceptability toblushing, and better moldability than impact-grade polypropylene. It also possesses superiorresistance to fatigue from flexing ... the "built-in" hinge property.

Compared with linear polyethylene, it offerssuperior processability, a higher softening point,greater dimensional stability and surface hard-ness, lower and more uniform shrinkages, andlower mold density. It possesses the outstand-ing dielectric properties common to the poly-olefin plastics.

FORMS AND METHODS OF FORMING

Propylene-ethylene polyallomer can be proc-essed by injection molding and extrusion onconventional thermoplastic equipment. Sheetmade of polyallomer is generally superior tosheet made of other polyolefins for vacuumforming.


POLYCARBONATE

Polycarbonates are thermoplastics developedcommercially in 1957.

TYPICAL USESPolycarbonates are used to provide framelessdesign, where a combination of structural rigid-ity and outer housing are necessary in one part;and double insulation where a secondary outerhousing is necessary to protect the operatorwhen using an electrically operated device.

Air conditioner housings; handles of electrictools: power drills, saws, routers, impactwrenches, hedge clippers; home appliances:electric can openers and shavers; street lightglobes; lighting diffusion panels; lamp coatings;sunglass lenses and frames; telephone fingerwheels; fishing reels; covers for baby foodwarmers and baby bottles; glazing; coffee pots;electric.] connectors; blood oxygenators; rocketlauncher handles; water pump impellers; elec-tric knife handles.

PROPERTIESMechanical Exceptionally high impactstrength, heat resistance, rigidity, dimensionalstability. Parts made from poiycarbonate resincan take hammer blows without shattering andcan withstand small caliber bullet force withoutbeing pierced or shattered. Polycarbonates canalso be reinforced with glass fibers for evengreater dimensional stability and rigidity.

Heat resistance Polycarbonates maintaintheir stability at operating temperatures up to240°F. Self extinguishing.

Electrical Good,

Chemical resistance Resistant to oil. Stainresistant. Non-corrosive.

Color Transparent. Good colorability andgloss.

FORMS ANT) METHODS OF FABRICATION

Polycarbonate resin is primarily a molding ma-terial. It may also take the form of film, ex-trusions, coatings, fibers or elastomers.

3

it

1. A heavy metal frame for thisBraille typewriter has been re-placed with a one-piece, multi-part frame molded of highstrength phenolic. Frame ismolded to tolerances as accu-rate as .003 to permit carriageand other moving parts to func-tion with fingertip ease.

2. Durable carrying case ofpolyallomer provides portabilityfor industrial gas mask. Light-weight 2 lb. case Is molded inone piece and includes back,front, hinges, handles and snapclasps. Case is strong enough tohold mars weight, resilientenough to resist impact andtracking. Integral tinges havebeen tested 12 million timeswithout cracking.

3. Low shrinkage and dimen-sional stability give phenoxy theedge in molding the precisionframes necessary in these elec-tronic sub-assemblies, known asdiode sticks.

4. Visor cl polycarbonate pro-vides excellent optical proper-ties and high strength protectionfor astronaut during walk In

space. Polycarbonate plastic wasstrongest transparent materialtested.

5. Polyester reinforced fiberglass canoe Is of sandwich con-struction with high strength andlow weight. A layer of poly-urethane foam gives 150 poundflotation in excess of hull weight.

POLYESTER

Polyesters are thermosetting materials. Devel-oped in 1942, they reached a production levelof about 495,000,000 lbs. in 1967.

TYPICAL USESPolyester resins are used to impregnate clothor mats of glass fibers, paper, synthetic fibers,cotton and other fibers in the making of rein-forced plastics for use in boats, automobilebodies, pipe, luggage, aircraft components, in-terior partitions and skylights or translucentroofs for buildings, scuff plates, film developingtrays. They are used in cast form for jewelsand lenses, and are combined with acrylics toproduce peatlescent buttons that resist heat.

PROPERTIESAdaptability to large parts Products up to500 sq. ft. in area are practicable because theycan be formed under low or no pressure and atlow or room temperatures.Strength These plastics are strong and tough.The strength, rigidity or flexibility of laminatesand moldings may be varied through the QP1eC"tion of the reinforcing material. Polyestershave a superior surface hardness.Chemical and water resistant Polyesters arehighly resistant to most solvents, acids, basesand salts. They also offer a low water absorp-tion rate and good weathering qualities.Electrical properties These plastics have highdielectric qualities.

Colorability These plastics can be made in arange of bright and pastel colors.

FORMS AND METHODS OF FORMINGPolyesters are produced as liquids, dry pow-ders, premix molding compounds, and as castsheets, rods and tubes. A special fire-retardantgrade is available. Premix compounds are madefrom these basic resins to produce compressionand transfer molded parts for automobiles,household utensils, electrical appliances, fix-tures and tools.

They are formed by reinforcing, molding,casting, impregnating, premixing.


POLYETHYLENE

Polyethylene is a thermoplastic material. De-veloped in 1942, this plastic reached a produc-tion level of about 3.8 billion lbs. in 1967.

TYPICAL USESPolyethylene is familiar as the material forflexible ice cube trays, tumblers, dishes, car-boys and rigid and squeezable bottles, pipe andtubing, bags for candy and food products, raincapes, meteorological balloons, dry cleaners'bags for clothing, artificial flowers, greenhouses,silo covers, insulation, freezer bags, toys, mois-ture barriers under concrete and in walls, andcoated paper for freezer wrap. Many of theseproducts can be made with low, medium, orhigh density polyethylene, depending on theflexibility or rigidity required.

Some formulations are specifically approvedby U. S. Food and Drug Administration regu-lations. Semi-conductive and vulcanizable poly-ethylene has recently been developed for outerjacketing on communications and power cables.Copolymers such as ethylene-vinyl acetate andethylene acrylate are also available.

PROPERTIESStrong and flexible Depending on density,polyethylene is flexible or rigid. Either form isvery resistant to breakage. Its surface is hardenough to withstand normal use but abrasivecleaners should be avoided.

Heat and cold resistant This plastic canwithstand temperatures down to 100°F. with-out becoming stiff and brittle. Also, some for-mulations may be subjected to boiling waterand sterilization. It should not be used over anopen flame or in a hot oven.

Electrical characteristics Polyethylene offersexcellent insulating properties.

Odorless, tasteless.

Resistant to water and weathering Polyethyl-ene is moistureproof, but allows passage ofoxygen. Recommended for some outdoor ap-plications.

Chemical resistant This plastic is highly re-sistant to chemicals and is unaffected by foodacids, household solvents and by short contactwith cleaning fluids.

Color and appearance This wax-like plasticis available as a clear transparent, translucentor opaque material. Made in a range of colors.

FORMS AND METHODS OF FORMINGPolyethylene is available in pellet form, pow-der, sheet, film, filament, rod, tube and foamed.

It may be made into finished articles by in-jection, compression, blow molding; extrusion,calendering, coating, casting, vacuum forming.

POLYIMIDE

Polyimides, a new class of non-melting plastics,were announced in 1962. They share the linearstructure of the thermoplastics, yet, like ther-mosetting plastics, they have no measurablemelting point.

TYPICAL USESPolyimides are used in a wide range of appli-cations in extreme environments at both highand low temperatures. Examples are aerospaceparts, valve seats, bearings, seals and retainerrings. Industrial applications include compres-sor vanes, piston rings, bearing separators, con-nector inserts, and relay actuators. A polyimidefilm is produced for cable wrap, motor slotliners, formed coil wrap, flexible circuits, tapes,hose and tubing. A polyimide enamel is pro-duced for wire insulation, and polyimide lami-nates and adhesives are also available.

PROPERTIESHeat resistance Excellent. Polyimides retaina significant portion of their room temperaturemechanical properties up to at least 750°F. andcan be used continuously in air at 500°F. with-out any loss of properties.

Electrical Very good.

Wear resistance Excellent frictional charac-teristics and very good wear resistance.

25

Other properties Polyimides possess excellentbearing qualities, resist radiation, exhibit lowout-gassing in high vacuum, and maintain theirexcellent properties at cryogenic temperatures.


Polyimides are supplied in the form of finishedprecision parts, as wire enamel, laminates, ad-hesives, film, and as the resin bond in diamondabrasive products. Because polyimides do notmelt, fabricated parts are made by machining,punching or by direct forming techniques.

POLYPHENYLENE OXIDE

Polyphenylene oxide resins are thermoplasticsdeveloped in 1964.

TYPICAL USESPolyphenylene oxides have a wide range of ap-plications as electrical insulating parts batterycases, coil forms, computer modules steriliz-able medical and surgical instruments, house.hold appliances exposed to hot water andplumbing equipment, including valves, pumpsand plumber's brass goods.

PROPERTIESColor Presently opaque, beige.

Impact strength Excellent.

Tensile strength Polyphenylene oxide main-tains a high level of strength and rigidity overa broad temperature range.

Dimensional stability Parts molded of poly-phenylene oxide withstand large loads for longperiods of time without significant change indimension. Parts possess high modulus andlow creep.

Thermal Polyphenylene oxide has a widetemperature range, a brittle point of approxi-mately 275°F. and a heat distortion point of375°F. at 264 psi,

Electrical Polyphenylene oxide has excellentcontinued on page 27

1. Blow-molded polyethylene bot-tles for industrial, automotiveand chemical specialties arecolorful, easy to handle, chemi-cally resistant and often serveas self-dispensers.

2. High voltage submarine cableis protected with extruded poly-ethylene insulation, which en-sures high dielectric strength,low dielectric loss, and excellentstability of electrical and physi-cal properties when in contactwith sea water.

3. Gears made of polyimide intwo different aircraft anti-colli-sion lighting assemblies operatesatisfactorily at very high ambi-ent temperatures. These gearsare strong enough for the hightoads encountered, while oper-ating continuously at 300°F. andhigher.

4. Sterilizable mediol equip-ment made from polyphenyleneoxide is autoclavable and low incost.

5. Enlarger printer for amateurphotographers is molded fromasbestos - reinforced polypropy-lene, a stiffer, more heat resist-ant material without sacrificingpolypropylene's surface hard-ness, resistance to flexural fa-tigue, impact strength and re-sistance to chemicals and stresscracking.

B. Refrigerator door liners arethermoformed from a singlesheet of highimpact styrene.They withstand slam-bang im-pacts of clay-in and day-out serv-ice at refrigerator temperatures.

7. Animated toys benefit fromthe unusual toughness of extrahigh impact polystyrene.

B. Subminiature printed circuitcard-edge connector at left, andrack-and-panel connector at rightare precision mulded from poly-sulfone.

1

dielectric properties maintained over a widetemperature and frequency range.

Hydrolytic stability Polyphenylene oxide re-sists steam, aqueous chemicals, acids and bases.


Polyphenylene oxide resins are fabricated by allconventional techniques including extrusionand molding.

POLYPROPYLENE

Polypropylenes are thermoplastic materials firstintroduced if:: the United States in 1957. Pro-duction of polypropylene in 1967 reached620,000,000 lbs.

TYPICAL USESSafety helmets, pipes and fittings, valves, pack-aging film and sheets, sterilizable bottles, wireand cable insulation, battery boxes, refrigeratorparts, waste baskets, tubs for washing machines,flexible hinges, housewares and household ap-pliance parts.

PROPERTIESFlex life Polypropylenes have excellent flexlife.

Mechanical In general, polypropylene is anoutstanding electrical insulation material. It hasvery low dielectric constant, essentially unaf-fected by frequency or temperature over rangestested. It shows a low loss factor.

Surface hardness The surface hardness andscratch and abrasion resistance of polypropy-lene are superior to other low-cost polymers.

FORMS AND METHODS OF FORMINGPolypropylene can be processed by injectionmolding, blow molding and extruded on con-ventional thermoplastic equipment. Films madeof polypropylene may be heat-sealed with thesame equipment used for polyethylene and canbe laminated to paper, cloth or aluminum.Polypropylene is also produced as a foamplastic.

POLYSTYRENE OR STYRENE

Polystyrene is a thermoplastic.1938, its production totaled2,550,000,000 lbs. in 1967.

Developed inan estimated

TYPICAL USESKitchen items, refrigerator food containers,toys, battery cases, instrument panels, wall tile,portable radio housings, premiums, are typicalproducts made from polystyrene or styrene.

Styrene copolymers and terpolymers areavailable which offer greater toughness and im-pact properties, higher heat resistance, or otherspecial qualities.

PROPERTIESOptical qualities, color, texture Polystyreneor styrene is available as a clear transparent,translucent or opaque material in a rainbow ofcolors. It can be produced with a smoothsatiny surface or a special texture.

Tasteless, odorless.

Electrical qualities Polystyrene or styrene hasvery good all-round dielectric properties.

Water and weather resistance Articles made ofpolystyrene or styrene hold their dimensions wellunder conditions of normal use. It should notbe exposed to continued outdoor use. The ma-terial's water absorption rate is low.

Resistance to heat and cold Polystyrene orstyrene is not harmed by continuous use at foodfreezer temperatures. It can be subjected, forshort periods, to heat approaching the boilingpoint of water. If greater heat resistance is

desired, a special type may be used. This plasticwill burn slowly if subjected to a direct flame.

Chemical resistant Most foods, drinks andusual household acids, oils, alcohol, vinegar,have no effect on polystyrene or styrene. Thisis not true, however, of citrus fruit rind oil,cleaning fluids, gasoline, turpentine, nail polishand remover, which will harm the material.

Strength Polystyrene or styrene is hard andrigid and withstands ordinary household use.It is not recommended for articles subject to


serae impact or flexing. Abrasives should beavoided when cleaning. For higher strengthaml impact resistance, glass-filled types area wail able.

YORMS AND METHODS OF FORMINGPolystyrene or styrene is available as moldingpowder and granules, sheets, rods and othershapes, foamed blocks, as liquid solutions andadhesives, coatings.

Finished products may be made from poly-styrene or styrene by injection, compressionmolding and by extrusion, laminating and ma-chining.

POLYSULFONE

Polysulfones are thermoplastic materials de-veloped in 1965.

TYPICAL USESPolysulfone finds wide use in appliance hous-ings; "under-the-hood" automotive components;hand power tool housings; computer parts;switches; circuit breakers; extruded pipe, sheet-ing, and wire coatings; and in structural bond-ing and laminating formulations.

PROPERTIESResistant to extremes of temperature Poly-sulfone possesses the highest use temperature ofany melt processable thermoplastic and verylow creep under toad. It is inherently self-extinguishing. It maintains a high degree of itsmechanical and electrical properties in con-tinuous service at temperatures ranging from150°F. to over 300°F.Color Supplied in a variety of transparent andopaque colors, polysulfone can be dry-coloredwith certain dyes.

Mechanical strength Polysulfone has high ten-sile strength and modulus and a good stress-strain behavior pattern typical of rigid ductilematerials.

Chemical and solvent resistance Polysulfoneis highly resistant to mineral acid, alkali, and

salt solutions. Resistance to detergents, oilsand alcohols is good even at elevated tempera-tit:AN under moderate levels of stress.

Electrical properties Electrical properties ofpolysulfone are excellent over a wide tempera-ture range and even after immersion in wateror exposure to high humidity.

FORMS AND METHODS OF FORMINGPolysulfone resins may be used as adhesivesand can be fabricated by extrusion, injectionmolding, blow molding and thermoforming.Formed parts can be processed by all standardmachining methods, joined by solvent or heatsealing techniques, and surface decorated withease.

.1POLYURETHANE OR URETHANE

Industrial interest in urethane plastics in thiscountry has grown rapidly in recent years.Urethanes were introduced commercially in1954.

TYPICAL USESThese versatile materials have been used forsome time abroad for a variety of purposes andin many different forms, such as flexible to rigidfoams, solid elastomers and plastics, coatingsfor wood, metal, wire and textiles, adhesives,bristles.

Urethane foams are favored for cushioning,mattresses, insulated clothing, padding, toys,packing, rug underlays, sponges, mats, crashpads, lightweight structural parts and applianceinsulation.

Solid articles formed by molding, extrusion orcasting include elastic printing rolls, abrasivewheels, cable insulation, automotive parts, bris-tles, tire treads, and airplane structures.

Urethane coatings impart outstanding protec-tive and decorative effects to wood, metals, rub-ber, textiles, concrete, paper, leather, plasticsand many other products.

29

PROPERTIES

SOLID MATERIALS:

Tough and shock resistant Elastomeric typeshave unusual abrasion and tear resistance.

Adhesion Isocyanates are among the fewsubstances effective for adhering synthetic rub-ber to synthetic fibers in the manufacture oftires, and for uniting rubber with metals andceramics. Urethanes are used as adhesives forbonding leather to leather, foams to varioussubstrates, etc.

Resistance to chemicals and other agents Thecured plastics are remarkably resistant to a widevariety a deteriorating agents, such as commonchemicals, including organic solvents, and pe-troleum products. Water-, moisture-, rot- andvermin-proof. Special polymers can be com-pounded to be flame - resistant.

FOAMED MATERIALS:

Flexible foams can be made in a broad rangeof firmness and resilience and in varying densi-ties. These foams have properties suitable forcushioning, shock- and sound-absorption, andheat insulation. Rigid foams are beginning tofind large use as thermal insulation. Becauseurethanes can be foamed-in-place, their areasof use are greatly enhanced.


SOLID TYPE:

Fabrication is generally carried out startingwith two reactants; polyisocyanate and polyol.These raw materials are supplied as liquid orsolid organic di-isocyanates, to be combinedwith special polyesters or polyethers or as pre-polymers (partially reacted). Final articles canbe extruded, molded, calendered, or cast inshapes as desired. They are then cured to finalform.

FOAMED TYPE:

The raw materials are polyols, polyisocyanates,water and catalyst mixtures. Foams can bemade by either a prepolymer or one-shot proc-ess, in both slab stock and also in moldedforms.

SILICONE

Silicones were commercialized in the early1940's.

TYPICAL USES

The big outlets for silicones are in the elec-trical industry where they are used for coilforms, switch parts, induction heating appa-ratus, as insulation for motors and generatorcoils, and in power cables.

In thermoplastic and thermosetting resinsystems silicone coupling agents are used tostrengthen the bond between glass fibers or min-eral fillers and resins. As little as 0.001% sili-cone (based on total weight) can double thestrength of glass/reinforced thermoplastics.

PROPERTIES

Heat resistant Silicones exhibit high heatstability. Silicone insulation has shown itselfhighly stable up to 350°F to 590°F. dependingon whether it is used with glass fiber, mica,or asbestos.

Electrical qualities Silicones have very gooddielectric properties, particularly after exposureto moisture and elevated temperatures. Theyoffer a low power factor over a wide frequencyrange.

Chemical and water resistant Silicones arewater repellent, weather resistant and highly re-sistant to mineral acids, and also corrosive saltsolutions.


Silicones are available as molding compounds,resins, coatings, greases, fluids and as siliconerubber.

They may be made into finished articles by:compression and transfer molding, extrusion,coating, calendering, impregnating, laminating,foaming, casting.


VINYL

The vinyls, which are thermoplastic materials,are produced in seven major types. Introducedin 1927, all the vinyls were estimated as totaling2.8 billion lbs. in 1967.

TYPICAL USESThe vinyls are produced in several forms:flexible or elastomeric, inflexible or rigid, cellu-lar or foam.

They are familiar as raincoats, garment bags,inflatable water toys, shower curtains, uphol-stery, draperies, garden hose, wire and cable in-sulation, phonograph records, clear blow-Mold-ed packaging containers, gaskets, weatherstrip,electric plugs, floor and wall covering andcoated materials.

PROPERTIESStrong and abrasion resistant All types ofvinyls are tough and strong, though only theflexible types can be bent back and forth with-out weakening or tearing. The surface of allvinyls resists the abrasion of normal use andspecial types are available with very high wearresistance. Abrasive cleaners should not beused.

Chemical and water resistant Vinyls, withthe exception of some non-rigid types, are un-affected by prolonged contact with water, oils,foods, common chemicals and cleaning fluidssuch as gasoline and naphtha. They should allbe kept away from chlorinated solvents, nailpolish and remover, and moth repellents. Vinylsenjoy a very slow rate of water absorption.

Resistance to heat and cold Vinyls in generalwithstand continuous exposure to temperaturesup to 130°F., the range usually encountered inhousehold operation. Flexible types and fila-ments are unaffected by higher temperatures.On the cold side, vinyls perform satisfactorilyat food freezing temperatures. Vinyls are slowburning; certain types self-extinguishing. Theyshould be kept from contact with direct heat.

Wide color range Vinyls are produced inclear form and in a wide range of colors which

1. Trim straight lines of modernfurniture are assured by use oflong-lasting polyurethane foamcushions, which will retain theirshape despite long wear, whileoffering exceptional seatinw com-fort.

2. Flexible "concrote"a newconstruction material that lookslike concrete, but can be bentlike rubber. The base compoundis a spacedeveloped siliconerubber. The material is used asa topping for highways, patios,swimming pools. It withstandsthe ravages of weather, water,freezing and cracking.

3. Lightweight, weather resistantpolyvinyl chloride is used Inmodern homes for gutters, downspouts, leaders and siding.

4. Vinyl-chloride acetate sheet-ing finds use as liners for ponds,reservoirs and irrigation ditches,effectively preventing loss ofwater due to seepage.

5. Exterior vinylmetal laminatesdecorate this laboratory build-ing. Application involves vinyllaminated to aluminum with asandwich of polyurethane foamand gypsum board. This boardIs, in turn, laminated with in.tenor vinyl which becomes theinterior wall.

6.j Young traveler rides in lux-urious comfort on a padded carseat made from soft vinyl foam.

may be clear, translucent or opaque. They maybe printed or embossed.

Weathering Vinyls are generally recom-mended for indoor use, though special typesare made for use out-of-doors.

Electrical qualities Vinyls generally have ex-cellent electrical properties.

TYPESPolyvinyl acetal This type vinyl falls intothree groups: polyvinyl formal, polyvinyl acetaland polyvinyl butyral. Polyvinyl butyral is fa-miliar as the interlayer for safety glass.

Polyvinyl acetate This, vinyl material is odor-less and tasteless, slow-burning, colorless, in-soluble in water, fats, tvaxes and aliphatic hy-drocarbons. It is used for heat-sealing films,flashbulb linings, paints, adhesives.

Polyvinyl alcohol This vinyl is characterizedby its imperviousness to all water insoluble sol-vents and gases, animal and vegetable oils. It isstrong and abrasion resistant. It is used in papercoating and sizing. Cast polyvinyl aloe of is

used as a mold release in molding polyesterresins with glass fiber for airplane parts, boats,etc. Internally plasticized polyvinyl alcohol isused as a water soluble film for packaging soaps,detergents, dyes.

Polyvinyl carbazole This vinyl is character-ized by its combination of desirable electricalproperties. Typical applications are structuralcomponents for low-loss electrical assemblies.

Polyvinyl chloride This vinyl can be madein a wide range of flexibility. It offers unlimitedcolors, toughness and high resistance to acids,alkalies and alcohol. It has wide use as pipeand extruded profiles, wire and cable insulation,work gloves, flooring, upholstery and foam ap-

32 THE. STORY OF THE PLASTICS INDUSTRY

plications. It is also produced as film andshoring.

Polyvinyl chloride-acetate Available in rigidand flexible form. It is familiar in shower cur-tains, rainwear, phonograph records, shoe sol-ing, wire insulation, coated fabrics, surfacecoatings.

Polyvinylidene chloride This vinyl may bemade into both flexible and rigid form. It isfamiliar as an extruded monofilarnent which iswoven into upholstery fabric and screening. Itis also used as pipe and tubing.

FORMS AND METHODS OF FORMINGPolyvinyl acetal is available as molding pow-der; sheet, rod and tube. It can be formed by:molding, extruding, casting, calendering.

Polyvinyl acetate is available as granules, film-forming emulsions, adhesives.

Polyvinyl alcohol is available as molding pow-der, sheets, film, tube and rod. It. can be formedby: molding, extrusion, casting.

Polyvinyl carbazole is available as powder,lumps, film. It can be made into articles by_ :compression and injection molding, casting.

Polyvinyl chloride is available as resins, latices,coatings, organosols, plastisols, compounds. Itcan be made into finished products by molding,extrusion, calendering.

Polyvinyl chloride-acetate is available as mold-ing powders, organosols, plastisols, sheets, rods,tubes. It can be made into finished productsby compression, injection and slush molding,calendering, casting, extrusion and as coatings.

Polyvinylidene chloride is available as moldingpowder, sheets, rods, tubes. It can be madeinto products by injection, compression, trans-fer molding, extrusion, casting.

Processing

Plastics

BLOW MOLDING

Blow molding is a method of forming used withthermoplastic materials.

Basically, blow molding consists of stretch-ing and then hardening a plastic against a mold.There are two general methods of doing thistype of thermoplastic molding: the directmethod and the indirect method, encompassingseveral variations of each.

In the direct method, a gob of molten ther-moplastic material is formed into the roughshape of the desired finished product. Thisshape is then inserted in a female mold and airblown into the plastic, as into a balloon, toforce it against the sides of the mold. Theformed material is then cooled before removalfrom the mold.

In the indirect method, a thermoplastic sheetor special shape is first heated, then clampedbetween a die and cover. Mr pressure forcedbetween the plastic and the cover forces thematerial into contact with the die, which hasthe contour desired in the finished product. Theplastic is cooled before removal from contactwith the die.

CALENDERING

Calendering can be used to process thermo-plastics into film and sheeting, and to apply aplastic coating to textiles or other supportingmaterials. Film refers to thicknesses up to and

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including 10 mils, while sheeting includes thick-nesses over 10 mils.

In calendering film and sheeting, the plasticcompound is passed between a series of threeor four large, heated, revolving rollers whichsqueeze the material between them into a sheetor film. The thickness of the finished materialis controlled by the space between the rolls. Thesurface of the plastic film or sheeting may besmooth or matted, depending on the surfacingon the rollers.

In applying a plastic coating to a fabric orother material by the calendering process, thecoating compound is passed through two tophorizontal rollers on a calender, while the un-coated material is passed through two bottomrollers, emerging as a smooth film which is an-chored to the fabric when fabric and.film passbetween the same rolls.

CASTING

Casting may be employed for both thermo-plastic and thermosetting materials in makingspecial shapes, rigid sheets, film and sheeting,rods and tubes.

The essential difference between casting andmolding is that no pressure is used in castingas it is in molding.

In casting, the plastic material is heated to afluid mass, poured into either open or closedmolds, cured at varying temperatures depend-ing on the plastic used, and removed from themolds,

Casting of film (and some sheeting) is doneon a wheel or belt, or by precipitation in achemical bath.

In the case of wheel or belt casting, theplastic is spread to the desired thickness on thewheel or belt as it revolves or moves and as thetemperature is increased. The film is then driedand stripped off.


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COATING

Thermosetting and thermoplastic materials mayboth be used as a coating. The materials to becoated may be metal, wood, paper, fabric,leather, glass, concrete, ceramics or otherplastics.

Methods of coating are varied and includeknife or spread coating, spraying, roller coat-ing, dipping, and brushing. Calendering of afilm to a supporting material, described undercalendering, is also a form of coating. A newmethod for applying plastics to metals is calledthe fluidized bed process.

In spread coating, the material to be coatedpasses over a roller and under a long blade orknife. The plastic coating compound is placedon the material just in front of the knife, andis spread out over the material. The thicknessof the coating is regulated by the speed at whichthe material is drawn under the knife, and theposition of the knife.

In roller coating, two horizontal rollers areused. One roller picks up the plastic coatingsolution on its surface Sand deposits it on thesecond roller which, in turn, deposits the coat-ing solution on the supporting material.

A plastic coating may also be applied byspraying it through a spray gun or by brushingit over the material to be coated as in silkscreen work. Articles to be coated may also bedipped into a solution of plastics until the de-sired thickness of coating is achieved, and thendried.

COMPRESSION MOLDING

Compression molding is the most commonmethod of forming thermosetting materials. Itis not generally used for thermoplastics.

Compression molding is simply the squeez-ing of a material into a desired shape by ap-plication of heat and pressure to the materialin a mold.

1

Plastic molding powder, mixed with suchmaterials or fillers as woodflour, cellulose andasbestos to strengthen or give other added qual-ities to the finished product, is put directly intothe open mold cavity. The mold is then closed,pressing down on the plastic and causing it toflow throughout the mold. It is while the heatedmold is closed that the thermosetting materialundergoes a chemical change which perma-nently hardens it into the shape of the mold.The three compression molding factors pres-sure, temperature and time the mold is closedvary with the design of the finished article andthe material being molded.

EXTRUSION

Extrusion molding is the method employed toform thermoplastic materials into continuoussheeting, film, tubes, rods, profile shapes, fil3-ments, and to coat wire, cable and cord.

In extrusion, dry plastic material is firstloaded into a hopper, then fed into -a long beat-ing chamber through which it is moved by theaction of a continuously revolving screw. Atthe end of the heating.- chamber the moltenplastic is forced out through a small openingor die with the shape desired in the finishedproduct. As the plastic extrusion comes fromthe die, it is fed onto a conveyor belt where itis cooled, most frequently by blowers or by im-mersion in water.

In the case of wire and cable coating, thethermoplastic is extruded around a continuinglength of wire or cable which, like the plastic,passes through the extruder die. The coatedwire is wound on drums after cooling.

In producing wide film or sheeting, the plas-tic is extruded in the form of a tube. This tubemay be split as it comes from the die and thenstretched and thinned to the dimensions desiredin the finished film.

In a different process, the extruded tubing isinflated as it comes from the die, the degree ofinflation of the tubing regulating the thicknessof the final film.

35

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FABRICATING

Fabricating covers operations on sheet, rod,tube, sheeting, film and special shapes to makethem into finished products. The materials maybe thermosetting cz thermoplastic.

Fabricating divides into three broad catego-ries machining; cutting, sewing and sealing ofElm and sheeting; and forming.

Machining:Machining is used on rigid sheets, rods, tubes

and special shapes. The various operations in-clude grinding, turning on a lathe, sawing,reaming, milling, routing, drilling, tapping.

Cutting, sewing, sealing of film and sheeting:In this category of fabricating fall all the op-

erations involved in fashioning plastic film andsheeting into finished articles like inflatabletoys, garment bags, aprons, raincoats, luggage.

For all these articles, the film or sheetingmust first be cut to pattern. This cutting maybe done in a press by a power-driven hand-operated knife or by other methods.

It remains to join the various pieces of film.This may be done by sewing or heat sealing.Cements are rarely used in fabricating film.

Forming:In working with flexible thermoplastic sheets,

the first step is usually the cutting or blankingout of sections roughly approximating the di-mensions of the finished article. This blankmay be beaded for added strength, creased andfolded into final form a box, for example.Or deep drawing may be employed, using maleand female molds to shape the plastic blank.

Rigid sheet may also be molded to final form.There are a number of methods of thus shap-ing a sheet. In vacuum forming or molding,the heated sheet is damped to the top of afemale mold and either drawn down into themold by vacuum or forced down by air pres-sure. In snapback forming, the heated sheet isdrawn into a vacuum pot and a male mold low-ered inside the bubble formed by the sheet. Asthe vacuum is released the hot sheet snaps backagainst the male mold.

36 THE STORY OF THE PLASTICS INDUSTRY/

In addition, rigid sheets can be fabricatedinto finished products by welding them togetheras in thermoplastic structural products. Theseitems include hoods, veining systems, ductwork, tank linerr4. -storage tanks, machinerycovers, and other allied products.

The welding torch itself is perhaps the mostimportant piece of equipment used in thisprocess. There arc t.vo basic types of torchesavailable which accomplish this procedure sat-isfactorily. The first and more popular is thetorch which heats the welding gases electrically.The second type uses an open flame of eitheracetylene or propane gas which transfers itsheat to a coil through which the welding gasis passed.

Standard procedures as established by the in-dustry should be utilized to evaluate weldingperformance of thermoplastic structures.

FINISHING

The finishing of plastics includes the differentmethods of adding either decorative or func-tional surface effects to a plastic product.

Film, sheeting and coated materials:These forms of plastics may have the texture

of their surface changed, either during process-ing or after, by being pressed against a heatedroller or mold that is embossed with a pattern.

Colorful patterns may also be printed on thesurface of film, sheeting and coated materialeither by letter press, gravure or silk screening.

Rigid plastics:There are a wide variety of methods of add-

ing decorative effects to the surface of rigidplastic parts. One is metal plating, accomplishedthrough metal spraying, vacuum deposition ormetal dusting and painting.

Other means of decorating involve stampingthe finished product, printing by silk-screen oroffset, engraving, etching or air blasting.

Molded Products:Decorative textures on molded products are

often achieved by incorporating them into themolds.

HIGH-PRESSURE LAMINATING

Thermosetting plastics are most generally usedin high-pressure laminating which is distin-guished by the use of high heat and pressure.These plastics are used to hold together the re-inforcing materials that comprise the body ofthe finished product. The reinforcing materialsmay be cloth, paper, wood, fibers of glass.

The end product of high-pressure laminatingmay be plain flat sheets, decorative sheets as incounter tops; rods, tubes or formed shapes.

Whatever the final shape, the first step inhigh-pressure laminating is the impregnating ofthe reinforcing materials with plastics.

In producing a flat surface, impregnatedsheets are stacked between two highly polishedsteel plates and subjected to heat and high pres-sure in an hydraulic press which cures the plas-tic and presses the plies of material into a singlepiece of the desired thickness. In making high-pressure tubing, resin-treated reinforcing sheetsare wrapped, under tension and/or pressure,around a heated rod. The assembly is thencured in an oven. In producing formed shapes,the reinforcing material is cut into pieces thatconform to the contour of the product, fittedinto the mold and cured under heat and pressure.

INJECTION MOLDING

Injection is the principal method of formingthermoplastic materials. Modifications of theinjection process art sometimes used for ther-mosetting plastics.

In injection molding, plastic material is putinto a hopper which feeds into a heating cham-ber. A plunger pushes the plastic through thislong heating chamber where the material issoftened to a fluid state. At the end of thischamber there is a nozzle which abuts firmlyagainst an opening into a cool, closed mold.The fluid plastic is forced at high pressurethrough this nozzle into the cold mold. As soon

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as the plastic cools to a solid state, the moldopens and the finished plastic piece is ejectedfrom the press.

The problem with injection molding of ther-mosetting materials is that, under heat, theseplastics will first soften, then harden to an in-fusible state. Thus it is essential that no soft-ened thermosetting material in the heatingchamber be allowed to remain there longenough to set.

Jet molding, offset molding and moldingusing a screw-type machine overcome this prob-lem by liquefying the thermosetting plastic ma-terial just as it goes through the injection nozzleinto the mold, but not before.

PULP MOLDING

Thermosetting plastics are used in pulp molding.In this process a porous form, approximating

the shape of a finished article, is lowered into atank containing a mixture of pulp, plastic resinsand water. The water is drawn off through theporous form by a vacuum. This causes the pulpand resin. mixture to be drawn to the formand adhere to it. When a sufficient thicknessof pulp has been drawn onto the form, it isremoved and then molded into final shape.

REINFORCING

Reinforced plastics mostly employ thermosetplastics, though some thermoplastics are used.

Reinforced plastics differ from high-pressurelaminates ia that very low or no pressure isused in the processing. The two methods arealike in that in both, the plastic is used to bindtogether the cloth, paper or glass fibers rein-forcing material used for the body of the prod-uct. The reinforcing materials may be in sheetor mat form, and their selection depends on thequalities desired in the end product.


Reinforced plastics offer exceptionally highstrength with low weight. Also, they lend them-selves to easy, economical fabrication, requir-ing relatively little pressure and heat for curing,and employing types of molds and other equip-ment that represent a fraction of the investmentcost for metal fabricating dies and machinery.Thus, they make possible considerably largerplastics products.

A number of different techniques may be em-ployed in the production of reinforced plastics.In making formed shapes, impregnated rein-forcing material is cut in accordance with theshape of the finished product into one piece ora number of pieces. The pattern or patterns areplaced on a male mold in enough volume togive the final thickness and form. Molding iscompleted in heated, mated dies. A single moldmay be used. The impregnated reinforcing ma-terial may be laid up on a male mold, insertedin a rubber bag from which all air is withdrawnso the bag presses around the layup, and curedin an oven. If a female mold is used, a dia-phragm is placed over the end of the mold sothat when air is withdrawn from within themold, the diaphragm is drawn down inside themold to press against the layup of resin im-pregnated materials.

In producing a continuous laminate, a webof reinforcing material passes through a bathof plastic resin, between rolls or under wiperbars that remove excess resin, and then betweensheets of cellophane or coated paper. Thusprotected, top and bottom, the material goesthrough the curing oven. After curing, the cel-lophane or paper is stripped off.

ROTATIONAL MOLDING

This technique is used to fabricate hollow, one-piece flexible parts from vinyl plastisols orfrom polyethylene powders.

Essentially, rotational molding consists ofcharging a measured amount of resin into awarm mold which is rotated in an oven abouttwo axes. Centrifugal force distributes theplastic evenly throughout the mold and the heat

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39

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melts and fuses the charge to the shape of thecavity. After removing and cooling the mold,the finished part is extracted. Rotational mold-ing is particularly suited to the production ofvery large parts, size being limited only by thecapacity of the oven.

The advantages of this type of molding are:low mold cost, strain-free parts, and uniformwall thickness.

SOLVENT MOLDING

Thermoplastic materials are used in this proc-ess of forming.

Solvent molding is based on the fact thatwhen a mold is immersed in a solution andwithdrawn, or when it is filled with a liquidplastic and then emptied, a layer of plastic filmadheres to the sides of the mold.

Some articles thus formed, like a bathingcap or vial, are removed from the molds. Othersolvent moldings remain permanently on theform as, for example, a plastic coating on ametal tube.

THERMOFORMING

Thermoforming of plastic sheet has developedrapidly in recent years. Basically, this processconsists of heating thermoplastic sheet to aformable plastic state and then applying airand/or mechanical assists to shape it to thecontours of a mold.

Air pressure may range from almost zero toseveral hundred psi. Up to approximately 14psi (atmospheric pressure), the pressure is ob-tained by evacuating the space between thesheet and the mold in order to utilize this at-mospheric pressure. This range, known asvacuum forming, will give satisfactory repro-duction of the mold configuration in the ma-jority of forming applications.

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"When higher pressures are required, they areobtained by sealing a chamber to the top sideof the sheet and building pressure within bycompressed air. This system is known as pres-sure forming.

Essentially, vacuum and pressure forming arevariations of the same basic technique, eventhough the difference in the formed parts maybe significant.

Variations of thermoforming include: straightforming; drape forming; plug and ring forming;slip forming; snap-back forming; reverse-drawforming; air slip forming; plug-assist forming;plug-assist-air-slip forming; and machine dieforming.

TRANSFER MOLDING

Transfer molding is most generally used forthermosetting plastics.

This method is like compression molding inthat the plastic is cured into an infusible statein a mold undcr heat and pressure. It differsfrom compression molding in that the plasticis heated to a point of plasticity before itreaches the mold and is forced into a closedmold by means of an hydraulically-operatedplunger,

Transfer molding was developed to facilitatethe molding of intricate products with smalldeep holes or numerous metal inserts. The drymolding compound used in compression mold-ing sometimes disturbs the position of the metalinserts and the pins which form the holes. Theliquefied plastic material in transfer moldingflows around these metal parts without causingthem to shift position.

Educational

Facilities

Each year more schools, colleges and uni-versities are adding instructions in plasticsto their curricula. As interest grows, newcourses are added, old courses realigned tobetter prepare students for the needs of theplastics industry.

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Publications

and Books

A wealth of information is contained in tradeand technical magazines and technical booksfor and about the plastics industry. A listingof these publications is available.

Films About

Plastics

The Society of the Plastics Industry, Inc.,has a list of motion picture films, film stripsand slides that are available from various or-ganizations for showing. The list describesthe subject of each slide or film.

For these lists write to

THE SOCIETY OF THEPLASTICS INDUSTRY, INC.Public Relations Department250 Park AvenueNew York, N. Y. 10017

Printed in U.S.A.

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Documents