DOCUMENT RESUME

ED 089 027 CE 001 073

AUTHOR Masson, Don, Ed. TITLE The Story of the Industry. INSTITUTION Society of the , Inc., New York, N.Y. PUB DATE Oct 72 NOTE 44p.

EDRS PRICE MF-$0.75 HC-$1.85 PLUS POSTAGE DESCRIPTORS Chemical Industry; *Development; *Industry; Manufacturing; *Merchandise Ihformation; Organic Chemistry; *Plastics; Production Techniques IDENTIFIERS *Plastics Industry

ABSTRACT This is an illustrated informative booklet, designed to serve members of the Society of the Plastics Industry, Inc., and the plastics industry as a whole. It provides basic information about the industry's history and growth, plastics raw materials, typical uses of plastics, properties, and methods of prccessing and fabricating. (Author/DS) The story ofthe LJ

industry

U.S. DEPARTMENT OF HEALTH; LDLICATION & WELFARE NATIONAL INSTITUTE OF EDUCATION 7L.V, DOT''''AENT HAS BEEN REPRO r EyAcTLy AS RECEIVED FROM 1.-ir -17 RSON OR ORGANIZAT ;ON ORIGIN IT POINTS OF 'ITV.; OR 0; INIONS STATE? DO NOT NECESS:.R!LY REEVE .ENT OFFICIAL NAT ,ONAL INSTITL OF DUCAT ION POSITION OR ROUE

N FOREWORD

This is an informative booklet, designed to serve members of The Society of the Plastics Industry, Inc., and the plastics industry at: a whole. It provides basic information about the industry's history, growth, plastics raw materials typical end uses with illustrations, properties, methods of processing and fabricating. It should not be considered as an encyclopedia or technical directory. Additional copies of this booklet may be obtained at cost from the Public Relations Committee of SPI for distribution to employee groups, civic organizations avid educational institutions. Permission to quote or reproduce parts of this booklet is granted, provided full credit isgiven to The Society of the Plastics Industry, Inc.

TWELFTH REVISED EDITION

Prepared under the direction of The Public Relations Committee THE SOCIETY. OF THE PLASTICS INDUSTRY, INC. 250 Park Avenue, New York, N, Y. 10017 Edited by Don Masson Printed by The John B. Watkins Company

October, 1972 In 1868, a young printer mixed py- roxylin, made from cotton and nitric acid, with solid camphor. John Wesley Hyatt came up with Celluloid, the first American . Even more impor- tant, he started what is now one of the few billion dollar industries in the United Statesthe 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 increase The story of the in production in the last ten years, the industry has grown both in volume and in variety of materials, each with special properties. More and more businessmen have sought information on how plastics COT can improve their products, cut their costs,streamlinetheirproduction. industry Students, technicians, workers have sought facts on employment oppor- tunities,plastics courses offered by colleges and trade schools, and sup- plementary information sources. The growth of the plastics industry has been so rapid, however, that public awareness of the sources of informa- tion on the major plastics, their char- acteristics and proper use has not kept abreast of the interest of either the businessman or the student. This booklet :s prepared by The Society of the Plastics Industry, Inc., representing 1,350 companies engaged in some phase of the plastics industry, to answer basic questions about the industry, its materials and production methods. 1=IMIMPIIIMINEMENIM plastics industry took its second major step forward, In 1909, Dr. Leo Hendrik Baeke- land introduced phenol-formaldehyde resins. How the While others in the field of chemistry 1-ad experimented with the combination of phenol Industry and formaldehyde, Dr. Baekeland was the first to obtain a controllable reaction between Grew the two.. The first phenolic in this country was given the trademark, Bakelite, coined from his name. Dr. Baekeland was also the first to develop techniques for converting this plastic to com- mercial use. His patents covered the produc- tion of a phenolic that could be cast (like A century ago there was no such thing as a marbleized clock bases), a compound that commercial plastic in the United States. We could be formed under heat and pressure had not learned that by combining such basic (like an electric iron handle), and solutions organic materials as oxygen, hydrogen, nitro- that could be used in making laminates (like gen, chlorine and sulfur, new man-made ma- restaurant table tops), terials could be createdmaterials which, From 1909 to 1926 two more plastic ma- through variations in the amount and com- terials were developedcold molded and bination of basis organic and inorganic in- casein. Then, the tempo of plastics develop- gredients, could be made with almost any ment increased consistently as is evident in quality desired in an end product. the accompanying list which gives the year In creating the first commercial plastic in each plastic was introduced and identifies it the United Statesin1868, John Wesley with a familiar product for each type of Hyatt did so in response to a competition plastic. sponsored by a manufacturer of billiard balls. Cellulose acetate was the next large-vol- It came about when a shortage developed in ume plastic to be developed commercially in ivcry from which billiard balls were made. this country.Launched in 1927,it was Hyatt, a determined full-time printer and available only in sheets, rods and tubes until part-time inventor, developed Celluloid. Con- 1929 when it appeared as a mate- currently, in England, development was in rial and became the first injection-molded progress on the use of pyroxylin in lacquers plastic. and in other coating materials. Thefirst of the vinyl resins, polyvinyl Celluloid, the first American plastic, was chloride, came on the market in this country soon found to have many uses.Colored in 1927. The vinyls now constitute quite pink, it was quickly adopted by dentists as a family of resins, the most important of a replacement for hard rubber in denture which besides are plates.It will be remembered as the ma- polyvinyl acetate, polyvinyl chloride-acetate, terial from which wipe-clean collars, cuffs polyvinyl acetal, . and shirt fronts were made, and as the While became commercially window curtains on the early automobiles. available in this country in 1938, it is one The first photographic film used by Eastman of the oldest synthetic resins.It dates back was made of Celluloid in the '80's to pro- to 1831 when it was first isolated. Today, duce the first motion picaire film in 1882. polystyrene is one of the volume plastics, Forty-one years were to pass before the most familiar in toys and housewares.

2THE STORY OF THE PLASTICS INDUSTRY was introduced in 1942. It as an important electrical insulation. Poly- was originally produced in England and first ethylene became the first plastic to reach a made in the United States for the U. S. Navy billion pound annual production rate.

INTRODUCTION OF PLASTICS MATERIALS

DATE :IMAtERIALF tiimpLE.

1868 CELLULOSE NITRATE EYE GLASS FRAMES 1909 PHENOL-FORMALDEHYDE TELEPHONE HANDSET 1909 COLD MOLDED )(NoesAND 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 () GEARS 1938 POLYVINYL ACETAL SAFETY GLASS INTERLAYER 1939 POLYVINYLIDENE CHLORIDE AUTO SEAT COVERS 1939 MELAMINE-FORMALDEHYDE TABLEWARE 1942 BOAT HULLS 1942 POLYETHYLENE SQUEEZABLE 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 OR URETHANE FOAM CUSHIONS 1956 ACETAL AUTOMOTIVE PARTS 1957 SAFETY HELMETS 1937 APPLIANCE PARTS 1959 CHLORINATED POLYETHER VALVES AND FITTINGS 1962 PHENOXY BOTTLES _..----1962 -----_-----POLYALLOMER-_____-- -______----_-_------TYPEWRITER CASES 1964 IONOMER SKIN PACKAGES - _ 1964 POLYPHENYLENE OXIDE BATTERY CASES 1964 FOLTIMIDE BEARINGS 1964 ETHYLENE-VINYL ACETATE HEAVY GAUGE FLEXIBLE SHEETING 1965 PARYLENE INSA-ATING COATINGS 1965 ELECTRICAL/ELECTRONIC PARTS

3 The plastics industry runs into billions of resin materials in 1967 was about 14.47 bil- both dollar volume of finished products and lion pounds. This fact, alone, is indicative of in the pounds of raw material produced, the importance of the plastics industry in our Three plastic materials have reached or ex- v, odd today.. ceed 2 billion pounds :annual production: Plastics companies numbering over 5,700 Polyethylene 3.8 billion; Vinyl2.8 bil- are located throughout tin United States. lion: and Styrene.2.5 billion. The Society Approximately 50 per cent are in the East, of the Plastics Industry, Inc., estimates that 34 per cent in the Midwest, 13 per cent on the production of all synthetic plastics and the West Coast, and 3 per cent. elsewhere.

SYNTHETIC PLASTICS AND RESIN Di ATERIALS PRODUCTION U. S. TANIFP COMMISSION 14,470,000,

tstiotatsl by The Society of tile Plastics lslostry,lc

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

4THE STORY OF THE PLASTICS INDUSTRY them we might soon be back in the "dark ages." The continuing development of new plas- tic materials broadens the industry's field of Plastics applications. Even more, it is indicative of Partner plastics'abilityto produce equally good products at a lower cost, better products at of Today's the same cost, or products that could not be manufactured without them. Living World War II gave great impetus to the industry. In meeting exacting defense service requirements,plasticsdemonstratedtheir versatility and wide range of important prop- erties, They proved their high tensile and impact strength, lightness, resistance to cor- rosion, low moisture absorption, resistance to salt water and many chemicals, transparency, Plastics pixy a vital role in peace, defense, adaptebility to varied climatic conditions, and in war. They were instrumental in the and flexibility even at low temperatures. development of the automobile, airplane, Designers, engineers, and architects con- missile and communications. They provided stantly analyze material and performance re- the material needed to develop the automo- quirements of varied products to determine bileignition system.They made possible the suitability of plastics for new end uses; the pioneering flights of Alcock and Brown, and plastics materials are being formulated Lindbergh, Byrd, Shepard, and Glenn.It with scientific precision and skill to meet is said that the Wright Brothers in the '80's these new market applications. used plasticscellulose nitrate solutions on The plastics industry is continuing to ex- glider wings and on the wings of the plane pand its facilities of research, development in which they made their historic flight in and production .. . to meet both civilian and 1903. defense requirements. The Society of the The lifelines of all communications tele- Plastics Industry, Inc., estimates that since phone, radio, television, radar, sonar, tele- 1946 the plastics industry has at least tripled starare based on plastics as insulation and itsinvestments in raw materialsplastics other vital components. The comfort of our plants. Hundreds of millions of dollars are homes is increased in countless ways .. being spent in plastics research for the de- through foamed cushions for furniture, easy- velopment of new resins and the improve- to-clean upholstery, protective coatings for ment of existing plastics to meet the multi- the home and industrial equipment, soft illu- fold requirements of modern industry. mination for translucent lighting, floor cover- Today, plastics are accepted as basic ma- ings that are resistant to spilled liquids and terials used by designers and engineers. They foods. All of these and many more can be take their place in industry along with metal, attributed to resins and plastics.Without glass, wood and .

5 =11=MINIEM=m11 Plastics are man-made materials, in contrast to nature's materials like wood and metal. A generally accepted definition is: Any one of a large and varied group of materials con- Plastics: sisting wholly or in part of combinations of carbon with oxygen, hydrogen, nitrogen and What They. other organic and inorganic elements which, while solid in the finished state, at some Are stage in its manufacture is made liquid, and thus capable of being formed into various shapes, most usually through the applica- tion, either singly or together, of heat and 1.1.1111i1 pressure.

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_ this grew Piiiajet into permanent Sharkyihe pressure "are aka .tiiitherif: fOrrning.'. Hiheatink willnot Softens niaterialS;ilhirmOietting pliStICSV inciutle: alkyd, amino 'Ind -Unita in; cold molded, ePoitY;PhenOlIC.; polYirster,7anWsilieone.'

0 THE STORY OF THE PLASTICS INDUSTRY Plastics are a family of materialsnot a single materialeach member of which has its special advantages. Being man-trade, plastics raw materials are capable of being variously combined to The Industry give most any property desired in an end product. But these are controlled variations That Produces unlike those of nature's products. The widespread and growing use of plas- Plastics tics in almost every phase of modern living can be credited in large part to their unique combinations of advantages. These advan- tages are light weight, range of color,, good physical properties, adaptability to mass- production methods and, often, lower cost. Some plastics can be sterilized. Today, a minimum of 5,700 companies in Aside from the range of uses attributable the United States make plastics their busi- to the special qualities of different plastics, ness. They divide into three large categories these materials achieve still greater variety which sometimes overlap the plastics ma- through the many forms in which they can terials manufacturer who produces the basic be produced. plastic resin or rompourfd, the processor They may be made into definite shapes like who converts plastic into solid shape, the dinnerware and electric switchboxes. fabricator and finisher who further fashions They may be made into flexible film and and decorates the plastic. sheeting familiaras shower curtains and upholstery. PLASTICS MATERIALS MANUFACTURERS They may be made into sheets, rods and The primary function of the materials tubes that are later shaped or machined into companies is the formulation of a plastic internally-lighted signs, airplane blisters. from basic chemicals.This plastic com- They may be made into filaments for use pound is sold in the form of granules, pow- in household screening, industrial strainers der, pellets, flake, and liquid resins or solu- and sieves. tions for processing into finished products. They may be made into netting in a vari- Some plastics materials companies may go a ety of patterns and sizes. step further and form the resin into sheets, They may be used as a coating on textiles rods, tubes, film. and paper. The membership of The Society of the They may be used to bind together such Plastics Industry, Inc. lists 175 companies as materials as fibers of glass and sheets of manufacturers of plastics materials in the paper or wood to form boat hulls, airplane UnitedStates.A majority are chemical wing tips, table tops. manufacturing companies. Some purchase They may be used as adhesives, and in chemicals from which they formulate the lacquers and paintsuses which are but plastic resins and compounds. Some only mentioned in this booklet which deals spe- make the compound, purchasing the resin. cifically with solid forms of plastics. Whatever their properties or form, plas- THE PROCESSOR ticsall fall into one of two groupsthe Plastics processors divide into several dif- or the thermosetting. ferent classifications:

7 MATERIAL MANUFACTURERS MOLDERS FABRICATORS

MOLDERS produce finished products by vacuum deposition to coat fabric, metal and forming the plastic in a mold of the desired paper with plastics. They number over 70. shape. They number about 1,700. THE FABRICATOR AND FINISHER EXTRUDERS divide into two groups. The Plastics sheets, rods, tubes and special first group turns out sheets, film, sheeting, shapes are the principal forms with which rods, tubing, special. shapes, pipe, wire cov- fabricatorsand, finishers work.Using all ering. The second group includes producers types of machine tools, they complete the of the thread-like plastic filaments which, conversion of these plastics forms into such when woven into cloth, find use as seat cov- finished products as industrial parts, jewelry, ers for autos, buses, trains and furniture, signs. and as insect and industrial screening. Ex- Vacuum forming is an important method truders number in all about 300. of fabricating sheet mate' ials. Working with rigid sheet material, fabricators also form FILM AND SHEETING PROCESSORS make such things as airplane canopies, television vinyl sheeting and film either by calendering, lenses. casting, or extruding. There are about 60 One of the newest and largest branches of companies in the field. the plastics industry comprises companies that produce from plastic sheeting and film HIGF.-PRESSURE LAMINATORS form sheets, such articles as shower curtains, rainwear, rods and tubes from paper, cloth and wood inflatables, upholstery, luggage, closet acces- impregnated with resin solutions. These com- sories. panies are about 50. Between the producer of the film and REINFORCED PLASTICS MANUFACTURERS sheeting and the fabricator of a finished LiqUid resinspolyesters, epoxies, phenolics, product there may be a printer who prints and siliconesare combined with such re- a design on the material, and an embosser inforcements as glass fibers, asbestos, syn- who forms a textured pattern on its surface. thetic fibers and sisal to form strong, rigid Other finishers metal-plate rigid plastic structural plastics and plastic products by parts or otherwise give them decorative or molding or forming. There are about 400 practical surface markings. companies. There are approximately 1500 fabricators working on rigid plastics and another 1500 COATERS make use of calendering, spread engaged in making film and sheeting into coating, preimpregnating, and dipping and finished products.

8THE STORY OF THE PLASTICS INDUSTRY Dimensional stability Parts are dimensionally stable under a wide variety of conditions. The Plastics FORMS AND METHODS OF FORMING ABS plastics are available as powder or granules Materials for injection molding, extrusion and calendering and as sheet for vacuum forming. They Work With ACETAL RESIN

Acetal resin is a rigid thermoplastic developed in 1956.

ABS PLASTICS TYPICAL USES ACRYLONITRILE-BUTADIENE-STYRENE This resin was developed for use in fields once dominated by -cast metals.Uses include automobileinstrumentclusters,carburetor ABS plastics are thermoplastic materials de- parts, gears, bearings and bushings, door han- dles, plumbing fixtures, and moving parts in veloped in 1948. There is also a SAN (styrene- home appliances and business machines. acrylonitrile) version of this family of plastics. TYPICAL USES PROPERTIES Pipe, pipefittings,wheels.footballhelmets, Rigidity Acetal resin is extremely rigid with- safety helmets,textilebobbins, TV antenna out being brittle.It retains these properties brackets, valve bodies, refrigerator parts, bat- under adverse conditions of temperature and tery cases, automotive parts, cable flodts, tote humidity. , water pump impellers, terminal blocks, Chemical resistance Resistant to most sol- strike brackets, business machine trays, chil- vents. dren'sskates,utensilhandles,toolhandles, Odorless, tasteless, non-toxic. radio cases are typical products. Strength Extreme toughness,outstanding PROPERTIES tensile strength, stiffness, and fatigue life. Strong and tough ABS plastics possess out- standing impact strength in combination with FORMS AND METHODS OF FORMING high mechanical (tensile, flexural, etc.) strength. Acetal resin is produced in powder form for Some formulations offer excellent toughness molding and extrusion. down to 60°F. Heat resistanceThese compounds can be used at temperatures of 175°F. to 212°F. Newer formulations withstandtemperaturesgreater ACRYLIC than 212°F. Chemical resistanceABS plastics are resistant to acids, alkalis, salts and, in many cases, to Acrylic, or polymethylmethacrylate, plasticis aliphatic hydrocarbons. a thermoplastic material, commercially intro- Electrical qualities ABS plastics have good duced in the U.S.A. in 1936. A copolymer, overall electrical properties. methyl methacrylate-styrene is also available.

9 TYPICAL USES FORMS AND METHODS OF FORMING Airplane canopies and windows, camera lenses, Acrylics are available as rigid sheets, rods and facing paneis, dome structure enclosure glazing tubes, and molding powders. in building construction, outdoor signs, lighting Plastic products can be produced by fabricat- diffusers, automobile tail lights, nameplates for ing of sheets. rods and tubes, hot forming of home appliances. TV shields, and skylights. sheets, injection and of powder, extrusion, casting. PROPERTIES Optical clarity Acrylics offer exceptional clar- ity and good light transmission. In crystal-clear form, acrylic can pipe lightpick it up at one edge and transmit it unseen, even around curves. ALKYD Strength Acrylics are strong. rigid and re- sistant to sharp blows. Contact with cleaning cloths containing grit, kitchen scouring powders Alkyd plastic is a thermosetting material, de- and such abrading materialsassteelwool veloped in 1926, which has its widest applica- should be avoided. tion in enamels, paints, lacquers and similar Weather and temperature resistance Weather- applications.It was introduced as a molding ing does not affect the transparency, physical material in 1948. Production in 1967 is esti- stability and electricalproperties of acrylic. mated at around 680,000,000 lbs. Long outdoor exposure of colorless acrylic has TYPICAL USES no significant effect on its use as a transparent material.Acrylic does not become brittle at Representative applications of alkyd molding low temperatures, Some cast acrylic composi- materials are parts of automobile starters, fuses, tions withstand bOing water, and heat-resistant lightswitches,electric motor insulator and molding composions are undistorted up to mounting cases, television tuning devices and supports. Enamels and lacquers for auto- 200°F.Acrylicswillnotwithstand steam mobiles, refrigerators, stoves, farm machinery sterilizing and, if subjected to boiling water, are typical uses for the liquid form of alkyd will start to lose shape. This acrylic plastic ma- plastic. terial has a slow burning rate and does not flash ignite. PROPERTIES Electrical properties Acrylic is an excellent Electrical properties Alkyd molding materials insulator. have excellent dielectric strength and will resist more than 350 volts per mil. They have high Color and texture Acrylics are inherently resistance to electrical leakage. Molded alkyd colorless but are also produced in a full range materials also afford excellent arc resistance. of transparent, translucent and opaque colors. They are also made with corrugated and pat- Weather and temperature resistance Alkyd ternedsurfaces.Thisplasticis warm and molding powders have excellent heat resistance pleasant to the touch. and are dimensionally stable under high tem- peratures. They also have good resistance to Odorless, tasteless, non-toxic. moisture. Chemical resistance Acrylics are unaffected Chemical resistance Molded alkyd is resistant by most household chemicals such as weak and to acids, ketones, esters, alcohol, chlorinated strong alkalis, bleaching compounds and win- compounds, essential oils. dow cleaning solutions, by salt, vinegar, animal and mineral oils, waxes, and foods commonly FORMS AND METHODS OF FORMING encountered in the home. This plastic isat- Alkyds are available as molding powder and tacked ,by perfume, gasoline, cleaning fluids, liquid resin. acetone, chloroform, and strong solutions of Finished molded products are produced by oxidizing acids. compression molding.

1 0THE STORY OF THE PLASTICS INDUSTRY 1.Automative parts molded of - staF acrylonitrile - butadiene - styrene ...... plastic.Metallized dash panels 1 and instrument cluster take took of metal, but incorporate greater durability and impact resistance.

2. Colorful telephone desk sets are molded of ABS plastic which provides outstanding impact strength and is unaffected by perspiration.

3.Acetal molded switch back (foreground)for electric wind- shield wiper control is fitted to metal housing above. The acetal molded slide (right) moves inside switch back and makes metal to metal contact with lugs to ac- tivatewipersandforspeed control.

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

5. Molded alkyd distributor cap used on racing car engine. Alkyd was used because of its high electrical surface resistivity and retention of superior electrical properties at under-the-hood rac- ing temperature.

6. Base of this circuit breaker, used in aircraft power generator systems, is molded of allylic. Use of glass-filleddiallylphthalate resip-base compoundvirtually eliminated rejects.

7' use molding powders with a variety of fillers ALLYLIC or prepreg of coated glass fiber, other textiles, paper, etc. Finished articles be made by transfer, compression, injection or extrusion molding; Ally lics are thermosetting materials developed ; coating, both powder and liquid; since World War II. The most widely used of impregnation. its prepolymers, diallyl resin, was in- troluced commercially in 1949. TYPICAL USES Electronic parts, electrical connectors, bases, A7,7:1NO PLASTICS and housings, etc. Low and high pressure lami- nates, both reinforced plastics and decorative MELAMINE AND UREA types.

PROPERTIES Amino plasticsarethermosettingmaterials. Electrical High dielectric strength, low elec- Melamine, developed in 1939, and urea, de- trical loss, low dielectric constant over a wide veloped in 1929, together reached a production frequency range, excellent insulation resistance level in 1967 of approximately 740,000,000 lbs. and arc resistance. Unmatched ability to retain its excellent electrical properties under condi- TYPICAL USES tions of high humidity with rapid and full re- covery of properties on drying. Melamine Familiar in colorful tableware, melamine also finds wide use indistributor Staining, and Heat,Moisture, Chemical, heads, buttons and hearing aid cases.It is also Weather Resistance Ally lic plastics can be produced to withstand constant use at up to used in laminate surfaces, like table tops, as a plywood adhesive, for baking enamel finishes, 350° F. and colored products have excellent and as a textile and paper treatment. color stability at high temperatures. These plastics have practically no moisture ab- Urea Representative molded urea products sorption and are highly resistant to decomposi- are closures, scale housings, lamp reflectors, tion by practically all chemicals. Consequently, radio cabinets, electrical devices, buttons, appli- allylicplasticsarehighlystainresistant. ance housings, stove knobs and handles.In Allylics have superior resistance to the adverse resin form it is used as baking enamel coatings, effects of weathering, and even thin overlays plywood adhesives, and paper and textile treat- will greatly improve the weathering ability of ment. other materials such as polyester glass fiber sheet. PROPERTIES Odorless, Tasteless, Insoluble. Colorful Both melamine and urea offer a full Unusual DimensionalStabilityDuring and range of translucent and opaque colors, colors After Molding. which have the advantage of being lightfast. They give a glossy surface. Color Ally lic plastics can be produced in a fullrange of opaque and transparent colors Strength Both melamine and urea are very which are stable under the most adverse con- hard,scratch-resistantmaterials.They are ditions. strong but not unbreakable, and should be guarded against hard blows. There are special FORMS AND METHODS OF FORMING high shock-resistant and tl'ipact-resistant types. Allylics are available in the form of Chemical resistanceBoth melamine and urea and prepolymers. Also available are ready -to- are unaffected by detergents, cleaning fluids

12THE STORY OF THE PLASTICS INDUSTRY (like carbon tetrachloride and gasoline), nail Chemical resistance Casein products with- polish and remover, alcohol, oils, grease. stand dry cleaning and are not adversely af- Heat and weather resistance Melamine and fected by contact with such liquids as gasoline, urea perform satisfactorily over a wide tem- nail polish, organic solvents and chemicals. perature range from as low as 70°F. for both Weathering and water resistance Casein is plastics to a continuous operating temperature adversely affected by humidity and tempera- of 170°F. for urea and 210°F. for melamine. ture changes.Immersion in liquids for long They maintain their dimensions well and, for periods at room temperatureorshort periods at most indoor uses, may be considered complete- boiling temperature will cause casein to absorb ly permanent. Neither material should be used Water, swell, soften and break easily.It be- in an oven or over a flame, as discoloration or comes more brittle as the temperature drops be -. charring may occur. However, neither will burn low freezing, and withstands only moderately or soften in contact with aflame. elevated temperatures without becoming pliable Electrical characteristics Both melamine and or discoloring. It is not recommended for con- urea have good electrical qualities. tinuous outdoor exposure. FORMS AND METHODS OF FORMING FORMS AND METHODS OF FORMING The amino plastics (melamine and urea) are Casein isavailable in rigid sheets, rods and available as molding powders or granules, as tubes, as a powder and liquid. a foamed material, in solution and as resins. Finished products are made by of Finished products can be made by compres- the sheets, rods and tubes. sion, transfer, plunger molding and laminating with wood, paper.

CELLULOSICS CASEIN There are five types of cellulosics, all thermo- plastic. Cellulose nitrate was developedin1868, Casein, the product of the protein of skim milk cellulose acetate in 1927, cellulose acetate bu- reacted with formaldehyde, is a thermosetting tyrate in1938, ethyl cellulose in 1935 and material developed in 1919. cellulose propionate in 1945. They reached a TYPICAL USES volume of approximately 195,000,000 lbs. in Buttons and buckles, beads, game counters, 1967. knitting needles, atthesives, toys and novelty- TYPICAL USES - counter items are all typical applications for Cellulose acetateis used for rigid packaging casein plastic. and is familiar as recording tape, photographic PROPERTIES film, as a lamination for book covers, in spec- tacle frames, toys, lamp shades, vacuum cleaner Color and appearance Casein takes a brilliant surface polish and has a wide color range of parts, combs, shoe heels. near transparent and opaque colors.Many Cellulose acetate butyrateis used for packaging extremely interesting and unusual variegated and in steering wheels, portable radio cases, patterned color effects can be achieved with pipe and tubing, tool handles. this thermosettingmaterial. Cellulose propionateis used In packaging, ap- Strength Casein is a strong, rigid plastic.It pliance housings, telephone hand sets, pens. resists the effects of both blows and flexing. continued on page 15

13 1.Electrically heated compart- mented baby food dish is molded of melamine which resists attack from food, juices and detergents, and is break resistant.

2.Facewide sun shade is made ofcolorfullyprintedcellulose acetate sheet. Shade is personal wind-and-sunshieldthatlets wearerlookatworldthrough new Op eyes. Flipped up, it be- comes a bonnet; flipped down, a protective veil to cut glare and wind.

3. Transparent cellulose acetate butyrate pipeis used to Wow cups several hundred feet from the manufacturing area to the packing and shipping department.

4.Crystal-clear flowmeter col- umn made from extruded cel- lulose propionate plastic.Four- sided column on rotatable base permits direct and instant read {' ing of flow rate for any of four inert industrial welding gases.

5. Cold molded plastics are used for electrical appliance connec- tors and plugs, wiring devices, heat resisting ferrules, adapters where precision tolerances and heat resistance are prime factors.

6.Epoxy/glass filament wound externallyreinforced pressure vessel, showing the combination helical winding and circumferen tial winding to attain design re- quirements.

7. Epoxy-based surface coatings curerapidly,withstandshock and exposure to chemicals, oil, grease and severe weathering.

3. One-use sanitary medical syr inge eliminates costly steriliza- tion. Syringeisblow-molded from ethylene-vinyl acetate, im- mediately packaged, and remains sterile and ready for use. Resin combines toughness,flexibility and clarity. Ethyl celluloseis favored for edge moldings on cabinets, electrical parts, flashlights. Cellulose, nitrate is familiarin shoe heel covers, and as a fabric coating. PROPERTIES Strong and durable Cellulosics are among the toughest of plastics. Normal rough usage will not break cellulose parts. They retain a lus- trous finish under normal conditions though abrasives 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 the cellulosics will withstand moderate heat.Ex- cept for cellulose acetate butyrate and cellulose propionate which are suitable for outdoor use, cellulosics should not be exposed to continuous outdoor Weathering. Electrical characteristics All the cellulosics have good electrical properties and are suitable insulators against usual domestic and industrial currents. TYPES Cellulose acetate (C/A) This cellulosic is resistant to most household chemicals, oil, gascr line and cleaning fluids but should be kept away from alcohol, alkalies. This plastic is odorless, and tasteless.It is unaffected by normal mois- ture and moderate heat and will withstand normal usage at below freezing temperatures. Water resistance and dimensional stability are improved in high acetyl C/A. Cellulose acetate butyrate (CAB) and Cellu- lose propionate (CP) Special weather-re- sistant formulations of these cellulosics alone are suitable for outdoor use. Some types may be used in water approaching boiling, and all types cara stand quite rough usage at sub-zero temperatures.Their moisture absorption rate is low. CAB and CP are resistant to most household chemicals, but are adversely affected by 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 good tiles, furnace covers, jigs and dies, in game dimensional stability over a wide range of tem- markers and toy building blocks. peratures and humidity conditions.Itis un- affected by alkalies, weak acids, but should be PROPERTIES kept away from cleaning fluids, oils, solvents. Cold molded plastics possess resistance to high Cellulose nitrate (C/N) This is made only heat, most alkalis and solvents, water and oils. as sheet, film, rod and tube and in solution for They also exhibit good arc resistance. coating because it is flammable and cannot be FORMS AND METHODS OF FORMING subjected to molding. C/N offers a wide range Cold molded plastic materials are available as of colors and variegated color effects.It is re- compounds. sistant to most acids and alkalies. Finished articles are produced by molding FORMS AND METHODS OF FORMING using heavy pressure in a rapid cycle, and by subsequent curing. Cellulose acetate is available as pellets, sheets, The bitumin and phenolic types of cold film, rods, tubes, strips, coated cord.It can be molded materials are cured either in ovens or made into finished products by injection, com- at room temperature. pression molding; extrusion; blow-molding and The cement-asbestos type of cold molded ma- vacuum forming of sheets; laminating; ma- terial is first cured in the presence of moisture chining; coating. and it is then baked. 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 blowing and drawing of sheet; laminating; machining; EPDXY coating. Cellulose propionate is available in pelicts for injection, extrusion, or compression molding. Epoxy resins are thermosetting and were first manufactured in the United States about 1947. Ethyl cellulose is available as granules, flake, Production totalled approximately 145,000,000 sheet, rod, tube, film and foil.It can be made lbs. in 1967. into finished products by injection, compression molding; extrusion; drawing; machining. TYPICAL USES Cellulose nitrateisavailable as rods, tubes, Protective coatings for appliances, plant struc- film, sheets for machining and eas a coating. ture' and equipment, automobiles, pipe, cans and drums, gymnasium floors and other hard-to- protect surfaces. They firmly bond metals, ceramics, glass, plas- tics, hard rubber and are used in combination with glassfibersto manufacture reinforced COLD MOLDED plastics products. Other products are: Printed circuits, laminated tools and jigs, ducts and liquid storage tanks. Epoxies are employed most Cold molded plastics are thermosetting mate- commonly in casting, potting, laminating, coat- rials developed in 1909. There are three types: ing and adhesive-bonding applications. bitumin, phenolic, and cement-asbestos. PROPERTIES TYPICAL USES Electrical qualities Epoxies have good elec- Cold molded plastics find use in switch bases trical properties. and plugs, arc barriers and shoots, 3rd rail in- Water and weather resistance Epoxy base ad- sulators, in small gears, handles and knobs, hesives, due to their resistance to various chemi-

16THE STORY OF THE PLASTICS INDUSTRY cals and weathering, may be used where cor- rosion resistant joints are required. FLUOROCARBONS Chemical resistance Epoxies are resistant to many chemicals. They have found widespread use for surface coating due to their excellent adhesion, durability and chemical resistance. Fluorocarbons are thermoplastic materials intro- duced in 1943. They include tetrafluoroethylene Strength Epoxies have good flexibility. (TFE), chlorotrifluoroethylene (CTFE), vinyli- FORMS AND METHODS OF FORMING dene fluoride (PVF2), and fluorinated ethylene- polypropylene (FEP). Epoxies are available as molding compounds, resins, foamed blocks, liquid solutions, adhe- TYPICAL USES sives, coatings, sealants. Fluorocarbonresinsare used inindustrial applications such as:gaskets and packings, seals, piston rings, and sealants(i.e. thread sealant tape), linings for vessels, valves, pumps, pipe and fittings, hose, etc., bearing pads, slip ETHYLENE-VINYL joints, pipe slides, expansion plates, anti-stick ACETATE surfaces (in form of films, sheeting and coat- ings), electrical wire insulation and compo- nents; and other miscellaneous items (i.e. bel- Ethylene-vinyl acetate (EVA) copolymers are lows, filters, pipe, tubing, and laboratory ware). flexible thermoplastic resins. Moldable grades They are used in consumer and household were develop; d in 1964. applications as coatings for frying pans, cooking utensils, rolling pins. TYPICAL USES Present and potential uses for these new rub- PROPERTIES ber-like plastics cover a variety of products, Chemical resistance Fluorocarbon resins have such as molded mechanical goodsmilk dis- unmatched chemical resistance to most indus- penser tubing, syringe bulbs, hospital sheeting trial chemicals and solvents. and similar hospital and pharmaceutical items. Others include shower curtains,greenhouse Thermal stability Fluorocarbon reins retain covers, disposable gloves, inflatable toys, and useful properties from cryogenic to elevated pool liners. Some grades meet Food and Drug temperatures, exceeding the temperature range Administration requirements for food pack- of all other plastics. aging. Low coefficient of friction and anti-stick prop- erties a Fluorocarbon resins have one of the PROPERTIES lowest coefficients of friction known for solids Flexibility Flexible without over and exhibit unmatched anti-stick characteristics. a wide range of low and medium temperatures, includingbetterlow temperatureflexibility FORMS AND METHODS OF FABRICATION when compared to vinyls. Fluorocarbon resins are applied as powders, Impact strength High, even at extremely low granules or dispersions. They can be molded, temperatures. extruded, hot or cold formed, machined, and Resilience Excellent "snap-back.' are also applied as 'coatings. Flex life High resistance to flex cracking or environmental stress cracking. FORMS :AND METHODS OF FORMING EVA molding compounds are formed by injec- tion molding, extrusion and .

17 1.Miniature, subminiature and microminiature terminals, molded andfabricatedfromfluorocar- bons, are used for components for circuitry in TV, UHF micro- wave computers and other criti- cal electronic circuits.

2. Plasticsheet compression- molded from ionomer resin has high transparency and flexibility. Quarter-inch sheetis easily flexed by girl, indicating use as faceprotectionforindustrial safety equipment.

3.lonomer can be tailored for skin packaging of hardware items and other consumer products.

4.Auxiliary gasoline fuel tank for utility automobile is molded of nylon.Irregular in shape and made without seams or joints, the nylon tank is designed to fit into compact space below driv- er's seat. Using nylon, engineers were able to design tank to meet unusual space requirements.

5. Woven fabric of nylon mono- filamentis used for handbags and shoes in matching colors. Nylon fabric resjsts attack and staining by oil, grease and com- mon chemicals.

6. Parylenecoated lithiummetal granules atleftdo not react with water on which they float. Unprotected granules at right re- act instantly and violently. IONOMER NYLON (POLYAMIDE)

The ionomers are a new family of thermoplas- Nylon, the generic name for a family of polya- tic resins developed in 1964. The term ionomer midc resins with related but not identical chemi- was coined to indicate that the polymer con- cal compositions, is a thermoplastic material tains inorganic as well as organic materials developed in 1938. linked by both covalent and ionic bonds. TYPICAL USES TYPICAL USES Nylon is a familiar material for tumblers, slide Ionomers can he tailored for a very wide va- fasteners, faucet washers, gears. As a filament riety of end uses; skin packaging applications, it is used as brush bristles, fishing lines. extrusion coatings and for , molded items for housewares, toys, PROPERTIES tool handles, bottles, closures and , wire Resistant :o extremes of temperature Nylon and cable insulation, extruded shapes, tubing can be safely boiled and steam sterilized. Also, and sheeting.Flat sheeting can he thermo- freezing temperatures do not adversely effect it. formed info covers, trays and irregular shapes. However, nylon is not recommended for contin- uous outdoor exposure. It is self-extinguishing. PROPERTIES Strong and long wearing Nylon is tough, Transparent and tough Ionomers combine having high tensile, impact and flexural strength. transparency with toughness, especially at low In part, its resistance to hard blows is due to its temperatures and are more resilient than poly- resiliency, allowing it to give a little when hit. ethylene. Though the hard, glossy surface of nylon is very Chemical resistance Ionomers arc virtually resistant to abrasion, scouring powders and steel unaffected by oils and greases. irhey are re- wool should not be usedincleaning. sistanttobases, diluteacids, hydrocarbons, Chemical resistance Nylon is unaffected by ketones,alcohols and esters.Resistanceto all common work-a-day chemicals, greases and liquid absorption is high by comparison with solvents except mineral acids.It is fairly e.isily many plastic materials of comparable trans- stained by coffee, tea and colored foods. gradesofionomersare parency.Certain Electrical characteristicsVery good. recommended for food packaging; meeting the requirements of food additives resulations. Cojor Nylon varies from transparent to opaque depending on the thinne'ss of the article. Exceptional corona resistance in electricalin- It comes in a range of soft colors. sulation. Tasteless, odorless. FORMS AND METHODS OF FORMING Color In the natural state it is crystal clear. Nylon is available as a molding powder and as This new resin can be readily colored with sheets, rods, tubes and filaments. complete uniformity and has a high capacity Finished products can be made by injection, level for fillers while retaining serviceable prop- compression, molding, blow molding, and ex- erties. trusion. Adhesion Ionomers can be heat sealed and can provide adhesion from a molten state to substrates, including metals. FORMS AND METHODS OF FORMING This plastic is injection molded, blow molded, extruded as shapes, film, substrate coatings and wire insulation, and thermoformed.

19 PARYLENE PHENOLIC

Parylene is a family of thermoplastic materials Thermosetting phenolics were developed in 1909. introduced in 1965. Production was approximately 1.1 billion lbs. in 1967. TYPICAL USES Sophisticated applications include: insulating TYPICAL USES and protective coatings for paper, fabric, ce- Automobile distributor heads and insulation, ramics, metals, and electronic parts such as telephone handsets, radio and television cabinets, photo cells, micro-circuits, memory units, and electrical insulation, washing machine agitators, capacitors; encapsulation of reactive materials; appliance parts, molded drawers, tube bases, and ultra-thin pellicles. bonds for abrasives, brake linings, protective coatings, juke housing parts,novelties, PROPERTIES jewelry, pulleys, handles, dials, knobs, lami- nated wood frame members. High-temperature resistance Parylenes have high melting points (500°F.-750°F.) Thermal PROPERTIES endurance in air is moderate, but for short term (1000 hr.) use, temperatures of about 200°F. Strong and hard Phenolics are hard, rigid, to 240°F. are practical.For long term (10 strong. The average phenolic will withstand yr.), data indicates that temperatures in the knocks, such as are common with camera hous- range of 140°F to 175°F. are optimum. ings. Special impact-resistant molding phenolics can be employed where useiseven more Cryogenic Steel panels coated with parylene rigorous. Their smooth, lustrous surface will and chilled in liquid nitrogen to 320°F. with give excellent service under severe conditions. stand impacts of more than 100 in.-lb. in a Heat and cold resistant Phenolics have good modified falling ball impacttest. heat resistance up to 300°F. and some above. Dimensional stability Parylene shows out- Mineral and glass reinforced phenolics will per- standing dimensional stability with respect to form up to 400°F. continuously.Moreover, changes in relative humidity. they are poor conductors of heat, being cool to Chemical resistance Parylenes resist attack the touch when used as handles for cooking and are insoluble in all organic solvents up to utensils. They do not support combustion or 300°F. They are unaffected by stress-cracking undergo change from freezing temperatures. agents and are also resistant to permeation by Electrical characteristics Phenolics are excel- all solvents with the exception of aromatic lent insulators.Special low-loss electrical in- hydrocarbons. Gas and moisture vapor barrier sulating materials are available. properties are excellent. Chemical and water resistance Water,al- Electrical Dielectric properties of parylenes cohol, oils, greases and mild acids and common are extremely good. Near absolute zero, one solvents do not adversely affect phenolic parts. type of parylene provides the best electrical in- Where extreme chemical resistance is required sulation of any known plastic. a special chemical resistant type is available. Phenolics, as a whole, do not absorb water and FORMS AND METHODS OF FABRICATION retain their luster, strength and rigidity. Parylene can be deposited as a uniform, con- Color As molding materials they are opaque tinuous, adherent film or formed on a surface and are produced in black, brown, mottled wal- treated with a release agent and then stripped nut and dark colors. They tend to yellow upon free. Any material that can withstand relatively exposure tolight.Colorability distinguishes high vacuum can be coated. cast from molded phenolic. Cast phenolics are

20THE STORY OP THE PLASTICS INDUSTRY produced in transparent, translucent and opaque colors, and in variegated effects. PH EN OXY TYPES Phenol-formaldehyde Molding materials are considered the "work horses" of the plastics in- Phenoxies are thermoplastic materials intro- dustry, They are combined with various fillers duced in 1962. woodflour, chopped fabric, paper pulp, as- bestos, micadepending upon the ultimate use TYPICAL USES for which they are intended. These plastics are End uses for phenoxy compounds include clear also produced as bonding resins, resins for pro- blow-molded bottles, cosmetic, drug and food tective coatings, adhesives.Finished products and other packaging applications: are made by compression. transfer, plunger molded electronic parts for computers, electri- molding; casting; laminating; coatings. cal appliance housings: sporting goods and bat- Cast phenolic These are resins cast to form tery cases; extruded pipe; and in adhesives :And and are usually machined into finished products. coatings. They are strong, rigid and dimensionally stable, PROPERTIES heat resistant, hard to scratch, water and chemi- calresistant.They are produced in a wide Optical Crystal-clear, water-white phenoxy range of colors and variegated patterns, like resins can be colored with dyes or pigments onyx and marble. They are produced as sheets, through the full range from delicate transpawnt rods, tubes and in special forms. tints to opaque colors. Phenol-furfural This type has most of the Mechanical Phenoxy exhibits an excellent properties of phenol-formaldehyde resins and balance of high rigidity, strength, hardness, and plastics.It offers high strength, durability, di- toughness, and is a practical engineering mate- mensional stability and good electrical charac- rial,Parts can be economically and rapidly teristics. Dark in color. Molding advantage is produced to meet tight tolerances and to hold extended flow at low temperatures, fast cure at their shape and size. high temperatures.It is available as molding Thermal Phenoxy retainsitshigh tensile compounds, liquidresins,varnishes and ce- strength and rigidity right up to its heat dis- ments. Phenol-furfurals are made into finished tortion point, Fabricated parts can he used in products by compression, transfer and injection load bearing applications at temperatures as molding; low-pressure molding; coatings; im- high as 160°F. to 170°F. pregnating; laminates. Barrier The permeability of phenoxy, par- Resorcinol This type is used primarily as ticularly to oxygen, is the lowest of any melt- room-setting adhesives in laminated gear blanks processable polymer. Oxygen permeability is and laminated wood frame members. Outdoor 1/20 that of high density polyethylene. exposure is good. Low temperature curing is Chemical Phenoxy is resistant to attack by an advantage in the lamination of heavy struc- acids and alkalies, but swells and ultimately tures with thick sections. Resorcinols come as dissolves in solvents.Itisalso resistantto solids and liquids and are made into products hydrocarbons, and most household cleaning by laminating; impregnating; coating; foaming. compounds. FORMS AND METHODS OF FORMING FORMS AND METHODS OF FORMING Phenolics are available as a molding compound Phenoxy pellets may he blow-molded, injection to which different fillers may be added; as pre- molded or extruded with ease. Finished parts forms, boards and blanks; for impregnants, are readily joined by conventional methods. bonding agents, coatings, foams. Finished prod- Phenoxy is also supplied as resins for adhesives ucts are made by: injection, compression, trans- and as resins or in solution form for surface fer, plunger molding; casting; laminating. coatings.

21 POLYALLOMER POLYCARBONATE

Polyallomers are a class of crystalline polyole- are developed fin polymers prepared from at least two mono- commercially in 1957. mers by copolymerization. The resulting poly- mer chains comprise polymerized segments of TYPICAL USES each of the monomers used Polycarbonates are used to provide frameless Thermoplastic, piopylene-ethylene polyallo- design, where a combination of structural rigid- mer was developed and introduced in the United ity and outer housing are necessary in one part; States in 1962. and double insulation where a secondary outer housing is necessary to protect the operator TYPICAL USES when using an electrically operated device. Air conditioner housings; handles of electric Automobile windlace and cowl panels, pipe tools:powerdrills,saws,routers,impact fittings, self-hinged cases and containers, note- wrenches, hedge clippers; home appliances: book binders, closures, toys, shoe lasts, film and electric can openers and shavers; street light sheet for packaging and vacuum forming. globes; lighting diffusion panels; lamp coatings; sunglass lenses and frames; telephone finger PROPERTIES wheels;fishingreels; covers for baby food Propylene-ethylene polyallomer combines many warmers and baby bottles; glazing; coffee pots; of the best characteristics of crystalline poly- electric.] connectors; blood oxygenators; rocket propylene and linear polyethylene. launcher handles; water pump impellers; elec- Compared with general-purpose polypropyl- tric knife handles. ene,itofferslowerbrittlenesstemperature, PROPERTIES higher impact strength, less notch sensitivity, and greater melt strength. Mechanical Exceptionallyhighimpact It offers better color, lower susceptability to strength, heat resistance, rigidity, dimensional blushing, and better moldability than impact- stability. Parts made from poiycarbonate resin grade polypropylene.It also possesses superior can take hammer blows without shattering and resistance to fatigue from flexing ... the "built- can withstand small caliber bullet force without in" hinge property. being pierced or shattered. Polycarbonates can also be reinforced with glass fibers for even Compared with linear polyethylene, it offers greater dimensional stability and rigidity. superior processability, a higher softening point, greater dimensional stability and surface hard- Heat resistance Polycarbonates maintain ness, lower and more uniform shrinkages, and their stability at operating temperatures up to lower mold density.It possesses the outstand- 240°F. Self extinguishing. ing dielectric properties common to the poly- ElectricalGood, olefin plastics. Chemical resistance Resistant to oil.Stain resistant. Non-corrosive. FORMS AND METHODS OF FORMING Color Transparent. Good colorability and Propylene-ethylene polyallomer can be proc- gloss. essed by injection molding and extrusion on conventional thermoplastic equipment.Sheet FORMS ANT) METHODS OF FABRICATION made of polyallomer is generally superior to Polycarbonate resin is primarily a molding ma- sheet made of other polyolefins for vacuum terial.It may also take the form of film, ex- forming. trusions, coatings, fibers or elastomers.

22THE STORY OF THE PLASTICS INDUSTRY 1. A heavy metal frame for this Braille typewriter has been re- placed with a one-piece, multi- partframe moldedofhigh strengthphenolic. Frameis molded to tolerances as accu- rate as .003 to permit carriage and other moving parts to func- tion with fingertip ease.

2. Durablecarryingcaseof polyallomer provides portability for industrial gas mask.Light- weight 2 lb. Is molded in one pieceand includesback, front, hinges, handles and snap clasps. Case is strong enough to holdmarsweight, resilient enoughtoresistimpact and tracking.Integral tinges have been tested 12 milliontimes without cracking. it 3.Low shrinkage and dimen- sional stability give phenoxy the edge in molding the precision frames necessary in these elec- tronic sub-assemblies, known as diode sticks.

4.Visor cl polycarbonate pro- vides excellentopticalproper- ties and high strength protection forastronautduringwalkIn space. Polycarbonate plastic was strongesttransparentmaterial 3 tested.

5. Polyesterreinforcedfiber glass canoe Is of sandwich con- struction with high strength and low weight.A layer ofpoly- urethane foam gives 150 pound flotation in excess of hull weight. POLYESTER POLYETHYLENE

Polyesters are thermosetting materials. Devel- Polyethylene is a thermoplastic material. De- oped in 1942, they reached a production level veloped in 1942, this plastic reached a produc- of about 495,000,000 lbs. in 1967. tion level of about 3.8 billion lbs. in 1967.

TYPICAL USES TYPICAL USES Polyester resins are used to impregnate cloth Polyethyleneisfamiliar as the material for or mats of glass fibers, paper, synthetic fibers, flexible ice cube trays, tumblers, dishes, car- cotton and other fibers in the making of rein- boys and rigid and squeezable bottles, pipe and forced plastics for use in boats, automobile tubing, for candy and food products, rain bodies, pipe, luggage, aircraft components, in- capes, meteorological balloons, dry cleaners' terior partitions and skylights or translucent bags for clothing, artificial flowers, greenhouses, roofs for buildings, scuff plates, film developing silo covers, insulation, freezer bags, toys, mois- trays. They are used in cast form for jewels ture barriers under concrete and in walls, and and lenses, and are combined with acrylics to coated paper for freezer wrap. Many of these produce peatlescent buttons that resist heat. products can be made with low, medium, or PROPERTIES high density polyethylene, depending on the Adaptability to large parts Products up to flexibility or rigidity required. 500 sq. ft. in area are practicable because they Some formulations are specifically approved can be formed under low or no pressure and at by U. S. Food and Drug Administration regu- low or room temperatures. lations. Semi-conductive and vulcanizable poly- ethylene has recently been developed for outer Strength These plastics are strong and tough. The strength, rigidity or flexibility of laminates jacketing on communications and power cables. and moldings may be varied through the QP1eC" Copolymers such as ethylene-vinyl acetate and tion of the reinforcing material. ethylene acrylate are also available. have a superior surface hardness. PROPERTIES Chemical and water resistant Polyesters are highly resistant to most solvents, acids, bases Strong and flexible Depending on density, and salts. They also offer a low water absorp- polyethylene is flexible or rigid. Either form is tion rate and good weathering qualities. very resistant to breakage.Its surface is hard enough to withstand normal use but abrasive Electrical properties These plastics have high cleaners should be avoided. dielectric qualities. Colorability These plastics can be made in a Heat and cold resistant This plastic can range of bright and pastel colors. withstand temperatures down to 100°F. with- out becoming stiff and brittle.Also, some for- FORMS AND METHODS OF FORMING mulations may be subjected to boiling water Polyesters are produced as liquids, dry pow- and sterilization.It should not be used over an ders, premix molding compounds, and as cast open flame or in a hot oven. sheets, rods and tubes. A special fire-retardant Electrical characteristics Polyethylene offers grade is available. Premix compounds are made excellent insulating properties. from these basic resins to produce compression and transfer molded parts for automobiles, Odorless, tasteless. householdutensils,electricalappliances,fix- Resistant to water and weathering Polyethyl- tures and tools. ene ismoistureproof, but allows passage of They are formed by reinforcing, molding, oxygen. Recommended for some outdoor ap- casting, impregnating, premixing. plications.

24THE STORY OF THE PLASTICS INDUSTRY Chemical resistant This plastic is highly re- Other properties possess excellent sistant to chemicals and is unaffected by food bearing qualities, resist radiation, exhibit low acids, household solvents and by short contact out-gassing in high vacuum, and maintain their with cleaning fluids. excellent properties at cryogenic temperatures. Color and appearance This wax-like plastic is available as a clear transparent, translucent FORMS AND METHODS OF FABRICATION or opaque material. Made in a range of colors. Polyimides are supplied in the form of finished precision parts, as wire enamel, laminates, ad- FORMS AND METHODS OF FORMING hesives, film, and as the resin bond in diamond Polyethylene is available in pellet form, pow- abrasive products. Because polyimides do not der, sheet, film, filament, rod, tube and foamed. melt, fabricated parts are made by machining, It may be made into finished articles by in- punching or by direct forming techniques. jection, compression, blow molding; extrusion, calendering, coating, casting, vacuum forming.

POLYPHENYLENE OXIDE

POLYIMIDE Polyphenylene oxide resins are thermoplastics developed in 1964. Polyimides, a new class of non-melting plastics, were announced in 1962. They share the linear TYPICAL USES structure of the thermoplastics, yet, like ther- mosetting plastics, they have no measurable Polyphenylene oxides have a wide range of ap- melting point. plications as electrical insulating partsbattery cases, coil forms, computer modulessteriliz- TYPICAL USES able medical and surgical instruments, house. hold appliances exposed to Polyimides are used in a wide range of appli- hot water and plumbing equipment, including valves, pumps cations in extreme environments at both high and plumber's brass goods. and low temperatures. Examples are aerospace parts, valve seats, bearings, seals and retainer PROPERTIES rings.Industrial applications include compres- sor vanes, piston rings, bearing separators, con- Color Presently opaque, beige. nector inserts, and relay actuators. A Impact strength Excellent. filmis produced for cable wrap, motor slot Tensile strength Polyphenylene oxide main- liners, formed coil wrap, flexible circuits, tapes, tains a high level of strength and rigidity over hose and tubing. A polyimide enamel is pro- a broad temperature range. duced for wire insulation, and polyimide lami- nates and adhesives are also available. Dimensional stability Parts molded of poly- phenylene oxide withstand large loads for long PROPERTIES periods of time without significant change in Heatresistance Excellent. Polyimides retain dimension.Parts possess high modulus and a significant portion of their room temperature low creep. mechanical properties up to at least 750°F. and Thermal Polyphenylene oxide has a wide can be used continuously in air at 500°F. with- temperature range, a brittle point of approxi- out any loss of properties. mately 275°F. and a heat distortion point of Electrical Very good. 375°F. at 264 psi, Wearresistance Excellent frictional charac- Electrical Polyphenylene oxide has excellent teristics and very good wear resistance. continued on page 27 25 1. Blow-molded polyethylene bot- tlesforindustrial,automotive and chemicalspecialties are colorful, easy to handle, chemi- cally resistant and often serve as self-dispensers.

2. High voltage submarine cable is protected with extruded poly- 1 ethyleneinsulation,whichen- sureshighdielectricstrength, low dielectric loss, and excellent stability of electrical and physi- cal properties when incontact with sea water.

3. Gears made of polyimide in two different aircraftanti-colli- sion lighting assemblies operate satisfactorily at very high ambi- ent temperatures.These gears are strong enough for the high toads encountered, while oper- ating continuously at 300°F. and higher.

4.Sterilizablemediolequip- ment made from polyphenylene oxide is autoclavable and low in cost.

5.Enlarger printer for amateur photographersismolded from asbestos - reinforced polypropy- lene, a stiffer, more heat resist- ant material without sacrificing polypropylene's surface hard- ness, resistance to flexuralfa- tigue,impact strength andre- sistance to chemicals and stress cracking.

B.Refrigerator door liners are thermoformedfrom a single sheetofhighimpactstyrene. Theywithstand slam-bangim- pacts of clay-in and day-out serv- ice at refrigerator temperatures.

7.Animated toys benefit from the unusual toughness of extra high impact polystyrene.

B.Subminiature printed circuit card-edge connector at left, and rack-and-panel connector at right are precision mulded from poly- sulfone. dielectric properties maintained over a wide temperature and frequency range. Hydrolytic stability Polyphenylene oxide re- sists steam, aqueous chemicals, acids and bases.

FORMS AND METHODS OF FABRICATION Polyphenylene oxide resins are fabricated by all conventionaltechniquesincludingextrusion and molding.

POLYPROPYLENE

Polypropylenes are thermoplastic materials first introduced if:: the United States in 1957. Pro- duction of polypropylenein1967 reached 620,000,000 lbs. TYPICAL USES Safety helmets, pipes and fittings, valves, pack- aging film and sheets, sterilizable bottles, wire and cable insulation, battery boxes, refrigerator parts, waste baskets, tubs for washing machines, flexible hinges, housewares and household ap- pliance parts. PROPERTIES Flex life have excellent flex life. Mechanical In general, polypropylene is an outstanding electrical insulation material. It has very low dielectric constant, essentially unaf- fected by frequency or temperature over ranges tested. It shows a low loss factor. Surface hardness The surface hardness and scratch and abrasion resistance of polypropy- lene are superior to other low-cost polymers. FORMS AND METHODS OF FORMING Polypropylene can be processed by injection molding, blow molding and extruded on con- ventional thermoplastic equipment. Films made of polypropylene may be heat-sealed with the same equipment used for polyethylene and can be laminated to paper, cloth or aluminum. Polypropylene isalso produced as a foam plastic. serae impact or flexing. Abrasives should be avoided when cleaning.For higher strength POLYSTYRENE OR STYRENE aml impact resistance,glass-filled types are a wail able.

Polystyrene is a thermoplastic.Developed in YORMS AND METHODS OF FORMING 1938,itsproductiontotaledanestimated Polystyrene or styrene is available as molding 2,550,000,000 lbs. in 1967. powder and granules, sheets, rods and other shapes, foamed blocks, as liquid solutions and TYPICAL USES adhesives, coatings. Kitchenitems,refrigerator food containers, Finished products may be made from poly- toys, battery cases, instrument panels, wall tile, styrene or styrene by injection, compression portable radio housings, premiums, are typical molding and by extrusion, laminating and ma- products made from polystyrene or styrene. chining. Styrenecopolymers andterpolymersare available which offer greater toughness and im- pact properties, higher heat resistance, or other special qualities. POLYSULFONE PROPERTIES Optical qualities, color, texture Polystyrene or styrene is available as a clear transparent, are thermoplastic materials de- translucent or opaque material in a rainbow of veloped in 1965. colors.It can be produced with a smooth satiny surface or a special texture. TYPICAL USES Tasteless, odorless. Polysulfone finds wide use in appliance hous- Polystyrene or styrene has ings; "under-the-hood" automotive components; Electrical qualities hand power toolhousings; computer parts; very good all-round dielectric properties. switches; circuit breakers; extruded pipe, sheet- Water and weather resistanceArticles made of ing, and wire coatings; and in structural bond- polystyrene or styrene hold their dimensions well ing and laminating formulations. under conditions of normal use.It should not be exposed to continued outdoor use. The ma- PROPERTIES terial's water absorption rate is low. Resistant to extremes of temperature Poly- Resistance to heat and cold Polystyrene or sulfone possesses the highest use temperature of styrene is not harmed by continuous use at food any melt processable thermoplastic and very freezer temperatures.It can be subjected, for low creep under toad.Itisinherently self- short periods, to heat approaching the boiling extinguishing. It maintains a high degree of its mechanical and electrical properties in con- point of water.If greater heat resistanceis desired, a special type may be used. This plastic tinuous service at temperatures ranging from will burn slowly if subjected to a direct flame. 150°F. to over 300°F. ColorSupplied in a variety of transparent and Chemical resistant Most foods, drinks and usual household acids, oils,alcohol, vinegar, opaque colors, polysulfone can be dry-colored with certain dyes. have no effect on polystyrene or styrene. This is not true, however, of citrus fruit rind oil, Mechanical strengthPolysulfone has high ten- cleaning fluids, gasoline, turpentine, nail polish sile strength and modulus and a good stress- and remover, which will harm the material. strain behavior pattern typical of rigid ductile materials. Strength Polystyrene or styrene is hard and rigid and withstands ordinary household use. Chemical and solvent resistance Polysulfone It is not recommended for articles subject to is highly resistant to mineral acid, alkali, and

28THE STORY OF THE PLASTICS INDUSTRY salt solutions.Resistance to detergents, oils PROPERTIES and alcohols is good even at elevated tempera- SOLID MATERIALS: tit:AN under moderate levels of stress. Tough and shock resistant Elastomeric types Electrical properties Electrical properties of have unusual abrasion and tear resistance. polysulfone are excellent over a wide tempera- ture range and even after immersion in water Adhesion Isocyanates are among the few or exposure to high humidity. substances effective for adhering synthetic rub- ber to synthetic fibers in the manufacture of FORMS AND METHODS OF FORMING tires, and for uniting rubber with metals and Polysulfone resins may be used as adhesives ceramics. Urethanes are used as adhesives for and can be fabricated by extrusion, injection bonding leather to leather, foams to various molding, blow molding and . substrates, etc. Formed parts can be processed by all standard Resistance to chemicals and other agentsThe machining methods, joined by solvent or heat cured plastics are remarkably resistant to a wide sealing techniques, and surface decorated with variety a deteriorating agents, such as common ease. chemicals, including organic solvents, and pe- troleum products. Water-, moisture-, rot- and vermin-proof.Special polymers can be com- .1 pounded to be flame - resistant. FOAMED MATERIALS: POLYURETHANE OR URETHANE Flexible foams can be made in a broad range of firmness and resilience and in varying densi- Industrial interest in urethane plastics in this ties. These foams have properties suitable for country has grown rapidly in recent years. cushioning, shock- and sound-absorption, and Urethanes were introduced commercially in heat insulation. Rigid foams are beginning to find large use as thermal insulation. Because 1954. urethanes can be foamed-in-place, their areas of use are greatly enhanced. TYPICAL USES These versatile materials have been used for FORMS AND METHODS OF FORMING some time abroad for a variety of purposesand in many different forms, such as flexible to rigid SOLID TYPE: foams, solid elastomers and plastics, coatings Fabrication isgenerally carried out starting for wood, metal, wire and textiles, adhesives, with two reactants; polyisocyanate and polyol. bristles. These raw materials are supplied as liquid or Urethane foams are favored for cushioning, solid organic di-isocyanates, to be combined mattresses, insulated clothing, padding, toys, with special polyesters or polyethers or as pre- packing, rug underlays, sponges, mats, crash polymers (partially reacted). Final articles can pads, lightweight structural parts and appliance be extruded, molded, calendered, or cast in insulation. shapes as desired. They are then cured to final Solid articles formed by molding, extrusion or form. casting include elastic rolls, abrasive FOAMED TYPE: wheels, cable insulation, automotive parts, bris- tles, tire treads, and airplane structures. The raw materials are polyols, polyisocyanates, Urethane coatings impart outstanding protec- water and catalyst mixtures. Foams can be tive and decorative effects to wood, metals, rub- made by either a prepolymer or one-shot proc- ber, textiles, concrete, paper, leather, plastics ess, in both slab stock and also in molded and many other products. forms. 29 SILICONE VINYL

Silicones were commercialized inthe early The vinyls, which are thermoplastic materials, 1940's. are produced in seven major types. Introduced in1927,all the vinyls were estimated as totaling 2.8 billion lbs. in1967. TYPICAL USES TYPICAL USES The big outlets for silicones are in the elec- The vinylsare produced inseveral forms: trical industry where they are used for coil flexible or elastomeric, inflexible or rigid, cellu- forms, switch parts, induction heating appa- lar or foam. ratus, as insulation for motors and generator They are familiar as raincoats, garment bags, coils, and in power cables. inflatable water toys, shower curtains, uphol- Inthermoplastic and thermosettingresin stery, draperies, garden hose, wire and cable in- systems silicone coupling agents are used to sulation, phonograph records, clear blow-Mold- strengthen the bond between glass fibers or min- ed packaging containers, gaskets, weatherstrip, eral fillers and resins. As little as 0.001% sili- electric plugs,floor and wall covering and cone (based on total weight) can double the coated materials. strength of glass/reinforced thermoplastics. PROPERTIES PROPERTIES Strong and abrasion resistant All types of Heat resistant Silicones exhibit high heat vinyls are tough and strong, though only the stability.Silicone insulation has shown itself flexible types can be bent back and forth with- highly stable up to350°Fto590°F.depending out weakening or tearing. The surface of all on whether itis used with glass fiber, mica, vinyls resists the abrasion of normal use and or asbestos. special types are available with very high wear resistance.Abrasive cleaners should not be Electrical qualities Silicones have very good used. dielectric properties, particularly after exposure Chemical and water resistant to moisture and elevated temperatures. They Vinyls, with the exception of some non-rigid types, are un- offer a low power factor over a wide frequency affected by prolonged contact with water, oils, range. foods, common chemicals and cleaning fluids Chemical and water resistant Silicones are such as gasoline and naphtha. They should all water repellent, weather resistant and highly re- be kept away from chlorinated solvents, nail sistant to mineral acids, and also corrosive salt polish and remover, and moth repellents. Vinyls solutions. enjoy a very slow rate of water absorption. Resistance to heat and coldVinyls in general FORMS AND METHODS OF FORMING withstand continuous exposure to temperatures Silicones are available as molding compounds, up to130°F.,the range usually encountered in household operation. resins, coatings, greases, fluids and as silicone Flexible types and fila- ments are unaffected by higher temperatures. rubber. On the cold side, vinyls perform satisfactorily They may be made into finished articles by: at food freezing temperatures. Vinyls are slow compression and , extrusion, burning; certain types self-extinguishing. They coating, calendering, impregnating, laminating, should be kept from contact with direct heat. foaming, casting. Wide color range Vinyls are produced in clear form and in a wide range of colors which

30THE STORYOF THEPLASTICS INDUSTRY 1. Trim straight lines of modern furniture are assured by use of long-lastingpolyurethanefoam cushions, which will retain their shape despite long wear, while offering exceptional seatinw com- fort.

2.Flexible "concrote"a new construction material that looks like concrete, but can be bent like rubber. The base compound isaspacedevelopedsilicone rubber. The material is used as a topping for highways, patios, swimming pools.It withstands the ravages of weather, water, freezing and cracking.

3. Lightweight, weather resistant polyvinylchlorideisusedIn modern homes for gutters, down spouts, leaders and siding.

4.Vinyl-chloride acetate sheet- ing finds use as liners for ponds, reservoirs and irrigation ditches, effectivelypreventinglossof water due to seepage.

5. Exterior vinylmetal laminates decorate thislaboratorybuild- ing.Applicationinvolvesvinyl laminated to aluminum with a sandwich of polyurethane foam and gypsum board.This board Is,in turn, laminated with in. tenor vinyl which becomes the interior wall.

6.j Young traveler rides in lux- urious comfort on a padded car seat made from soft vinyl foam. may be clear, translucent or opaque. They may plications.Itisalso produced as film and be printed or embossed. shoring. Weathering Vinylsaregenerally recom- Polyvinyl chloride-acetate Available in rigid mended for indoor use, though special types and flexible form. It is familiar in shower cur- are made for use out-of-doors. tains, rainwear, phonograph records, shoe sol- Electrical qualities Vinyls generally have ex- ing, wire insulation, coatedfabrics, surface cellent electrical properties. coatings. Polyvinylidene chloride This vinyl may be TYPES made into both flexible and rigid form.It is Polyvinyl acetal This type vinyl falls into familiar as an extruded monofilarnent which is three groups: polyvinyl formal, polyvinyl acetal woven into upholstery fabric and screening. It and . Polyvinyl butyral is fa- is also used as pipe and tubing. miliar as the interlayer for safety glass. FORMS AND METHODS OF FORMING Polyvinyl acetateThis, vinyl material is odor- less and tasteless, slow-burning, colorless, in- Polyvinyl acetal is available asmolding pow- soluble in water, fats, tvaxes and aliphatic hy- der; sheet, rod and tube.It can be formed by: drocarbons.It is used for heat-sealing films, molding, extruding, casting, calendering. flashbulb linings, paints, adhesives. Polyvinyl acetate is availableas granules, film- forming emulsions, adhesives. Polyvinyl alcohol This vinyl is characterized by its imperviousness to all water insoluble sol- Polyvinyl alcohol is availableas molding pow- vents and gases, animal and vegetable oils.It is der, sheets, film, tube and rod. It. can be formed strong and abrasion resistant. It is used in paper by: molding, extrusion, casting. coating and sizing.Cast polyvinyl aloe ofis Polyvinyl carbazoleisavailableas powder, usedas amold release in molding polyester lumps, film.It can be made into articles by_ : resins with glass fiber for airplane parts, boats, compression and injection molding, casting. etc.Internally plasticized polyvinyl alcohol is Polyvinyl chloride is availableas resins, latices, used as a water soluble film for packaging soaps, coatings, organosols, plastisols, compounds. It detergents, dyes. can be made into finished products by molding, Polyvinyl carbazole This vinyl is character- extrusion, calendering. ized by its combination of desirable electrical Polyvinyl chloride-acetate is availableas mold- properties. Typical applications are structural ing powders, organosols, plastisols, sheets, rods, components for low-loss electrical assemblies. tubes.It can be made into finished products Polyvinyl chloride This vinyl can be made by compression, injection and slush molding, in a wide range of flexibility.It offers unlimited calendering, casting, extrusion and as coatings. colors, toughness and high resistance to acids, Polyvinylidene chloride is availableas molding alkalies and alcohol.It has wide use as pipe powder, sheets, rods, tubes.It can be made and extruded profiles, wire and cable insulation, into products by injection, compression, trans- work gloves, flooring, upholstery and foam ap- fer molding, extrusion, casting.

32 THE.STORY OF THE PLASTICS INDUSTRY Processing Plastics

PLASTIC

BLOW MOLDING

!MUM PA ISON. MOLD CLOSEDa fINISNIO KITTLE Blow molding is a method of forming used with MOLD CORN $OME BLOWN111140100 PROM MOLD thermoplastic materials. Basically, blow molding consists of stretch- ing and then hardening a plastic against a mold. There are two general methods of doing this BLOW MOLDING type of thermoplastic molding:thedirect method and the indirect method, encompassing several variations of each. In the direct method, a gob of molten ther- moplastic material is formed into the rough shape of the desired finished product. This shape is then inserted in a female mold and air blown into the plastic, as into a balloon, to force it against the sides of the mold. The formed material is then cooled before removal from the mold. PLASTIC In the indirect method, a thermoplastic sheet or special shape is first heated, then clamped between a die and cover. Mr pressure forced between the plastic and the cover forces the material into contact with the die, which has CALINDIRTD PLASTIC UNITING the contour desired in the finished product. The OR FILM plastic is cooled before removal from contact TARP 00 with the die. /00

SMELTING SOUL/

CALENDERING CALENDERING Calendering can be used to process thermo- plastics into film and sheeting, and to apply a plastic coating to textiles or other supporting materials. Film refers to thicknesses up to and

33 including 10 mils, while sheeting includes thick- nesses over 10 mils. COATING In calendering film and sheeting, the plastic compound is passed between a series of three /11, or four large, heated, revolving rollers which squeeze the material between them into a sheet Thermosetting and thermoplastic materials may or film. The thickness of the finished material both be used as a coating. The materials to be is controlled by the space between the rolls. The coated may be metal, wood, paper, fabric, surface of the or sheeting may be leather,glass,concrete,ceramics orother smooth or matted, depending on the surfacing plastics. on the rollers. Methods of coating are varied and include In applying a plastic coating to a fabric or knife or spread coating, spraying, roller coat- other material by the calendering process, the ing, dipping, and brushing. Calendering of a coating compound is passed through two top film to a supporting material, described under horizontal rollers on a calender, while the un- calendering, is also a form of coating. A new coated material is passed through two bottom method for applying plastics to metals is called rollers, emerging as a smooth film which is an- the fluidized bed process. chored to the fabric when fabric and.film pass In spread coating, the material to be coated between the same rolls. passes over a roller and under a long blade or knife. The plastic coating compound is placed on the material just in front of the knife, and is spread out over the material. The thickness of the coating is regulated by the speed at which the material is drawn under the knife, and the CASTING position of the knife. In roller coating, two horizontal rollers are used. One roller picks up the plastic coating Casting may be employed for both thermo- solution on its surface Sand deposits it on the plastic and thermosetting materials in making second roller which, in turn, deposits the coat- special shapes, rigid sheets, film and sheeting, ing solution on the supporting material. rods and tubes. A plastic coating may also be applied by The essential difference between casting and spraying it through a spray gun or by brushing molding is that no pressure is used in casting it over the material to be coated as in silk as it is in molding. screen work. Articles to be coated may also be In casting, the plastic material is heated to a dipped into a solution of plastics until the de- fluid mass, poured into either open or closed sired thickness of coating is achieved, and then molds, cured at varying temperatures depend- dried. ing on the plastic used, and removed from the molds, Casting of film (and some sheeting) is done on a wheel or belt, or by precipitation in a chemical bath. COMPRESSION MOLDING In the case of wheel or belt casting, the plastic is spread to the desired thickness on the wheel or belt as it revolves or moves and as the temperature is increased. The film is then dried Compression moldingisthe most common It and stripped off. method of forming thermosetting materials. is 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 material in a mold.

34 THE STORY OF THE PLASTICS INDUSTRY 1 Plastic molding powder, mixed with such materials or fillers as woodflour, cellulose and asbestos to strengthen or give other added qual- COMING ities to the finished product, is put directly into COATING I KNiff COMPOUND the open mold cavity. The mold is then closed, COATED WEI pressing down on the plastic and causing it to SHUT TO SE flow throughout the mold. It is while the heated COATED mold is closed that the thermosetting material undergoes a chemical change which perma- MTN nently hardens it into the shape of the mold. 110U The three compression molding factors pres- sure, temperature and time the mold is closed SUPPORT SUPPORTING vary with the design of the finished article and CHANNEL IOWA the material being molded. COATING

EXTRUSION MOLD PlUNGIR

Extrusion molding is the method employed to GUIDE PIN form thermoplastic materials into continuous sheeting, film, tubes, rods, profile shapes, fil3- ments, and to coat wire, cable and cord. MOLDED PLASTIC In extrusion, dry plastic materialisfirst loaded into a hopper, then fed into -a long beat- ing chamber through which it is moved by the action of a continuously revolving screw. At the end of the heating.- chamber the molten MOW CAVIET plastic is forced out through a small opening or die with the shape desired in the finished COMPRESSION MOLDING product. As the comes from the die, it is fed onto a conveyor belt where it is cooled, most frequently by blowers or by im- mersion in water. In the case of wire and cable coating, the MINDING POWDIP thermoplastic is extruded around a continuing length of wire or cable which, like the plastic, passes through the extruder die. The coated wire is wound on drums after cooling. In producing wide film or sheeting, the plas- tic is extruded in the form of a tube. This tube may be split as it comes from the die and then stretched and thinned to the dimensions desired AMCNAN,C1 SC./ W in the finished film. In a different process, the extruded tubing is EXTRUSION MOLDING inflated as it comes from the die, the degree of inflation of the tubing regulating the thickness of the final film.

35 In addition, rigid sheets can be fabricated into finished products by welding them together FABRICATING as in thermoplastic structural products. These items include hoods, veining systems,duct work, tank linerr4. -storage tanks, machinery Fabricating covers operations on sheet, rod, covers, and other allied products. tube, sheeting, film and special shapes to make The welding torch itself is perhaps the most them into finished products. The materials may important piece of equipment used inthis be thermosetting cz thermoplastic. process. There arc t.vo basic types of torches Fabricating divides into three broad catego- available which accomplish this procedure sat- ries machining; cutting, sewing and sealing of isfactorily. The first and more popular is the Elm and sheeting; and forming. torch which heats the welding gases electrically. Machining: The second type uses an open flame of either acetylene or propane gas which transfers its Machining is used on rigid sheets, rods, tubes heat to a coil through which the welding gas and special shapes. The various operations in- is passed. clude grinding, turning on a lathe, sawing, Standard procedures as established by the in- reaming, milling, routing, , tapping. dustry should be utilized to evaluate welding Cutting, sewing, sealing of film and sheeting: performance of thermoplastic structures. In this category of fabricating fall all the op- erations involved in fashioning plastic film and sheeting into finished articleslikeinflatable toys, garment bags, aprons, raincoats, luggage. FINISHING For all these articles, the film or sheeting must first be cut to pattern. This cutting may be done in a press by a power-driven hand- The finishing of plastics includes the different operated knife or by other methods. methods of adding either decorative or func- It remains to join the various pieces of film. tional surface effects to a plastic product. This may be done by sewing or heat sealing. Film, sheeting and coated materials: Cements are rarely used in fabricating film. These forms of plastics may have the texture Forming: of their surface changed, either during process- In working with flexible thermoplastic sheets, ing or after, by being pressed against a heated the first step is usually the cutting or blanking roller or mold that is embossed with a pattern. out of sections roughly approximating the di- Colorful patterns may also be printed on the mensions of the finished article.This blank surface of film, sheeting and coated material may be beaded for added strength, creased and either by letter press, gravure or silk screening. folded into final form a box, for example. Rigid plastics: Or deep drawing may be employed, using male There are a wide variety of methods of add- and female molds to shape the plastic blank. ing decorative effects to the surface of rigid Rigid sheet may also be molded to final form. There are a number of methods of thus shap- plastic parts. One is metal plating, accomplished ing a sheet. In vacuum forming or molding, through metal spraying, vacuum deposition or the heated sheet is damped to the top of a metal dusting and painting. female mold and either drawn down into the Other means of decorating involve stamping mold by vacuum or forced down by air pres- the finished product, printing by silk-screen or sure. In snapback forming, the heated sheet is offset, engraving, etching or air blasting. drawn into a vacuum pot and a male mold low- Molded Products: ered inside the bubble formed by the sheet. As Decorative textures on molded products are the vacuum is released the hot sheet snaps back often achieved by incorporating them into the against the male mold. molds.

36THE STORY OF THE PLASTICS INDUSTRY/ HIGH-PRESSURE LAMINATING

Thermosetting plastics are most generally used in high-pressure laminating which isdistin- guished by the use of high heat and pressure. These plastics are used to hold together the re- HEAD inforcing materials that comprise the body of tutu.,ccc stivdtrili tttttttttttttttttttttt the finished product. The reinforcing materials nr NEMEC PLATENS may be cloth, paper, wood, fibers of glass. PLIES ITS Of The end product of high-pressure laminating tAIIIINff SUPS may be plain flat sheets, decorative sheets as in ,,,pylvwsissi counter tops; rods, tubes or formed shapes. SEE Whatever the final shape, the first step in high-pressure laminating is the impregnating of -1141 the reinforcing materials with plastics. UPWARD /SETS USE t :100 PEll In producing a flat surface, impregnated sheets are stacked between two highly polished steel plates and subjected to heat and high pres- sure in an hydraulic press which cures the plas- HIGHPRESSURE LAMINATING tic and presses the plies of material into a single piece of the desired thickness. In making high- pressure tubing, resin-treated reinforcing sheets are wrapped, under tension and/or pressure, around a heated rod. The assembly is then cured in an oven. In producing formed shapes, the reinforcing material is cut into pieces that conform to the contour of the product, fitted into the mold and cured under heat and pressure.

MO MOPPED

MOLDED PIECE

GATE INJECTION MOLDING 'PRUE

Injection is the principal method of forming NOZZLE PLUNGIR thermoplastic materials.Modifications of the (Mina injection process art sometimes used for ther- mosetting plastics. In injection molding, plastic material is put into a hopper which feeds into a heating cham- ber. A plunger pushes the plastic through this INJECTION MOLDING long heating chamber where the material is softened to a fluid state. At the end of this chamber there is a nozzle which abuts firmly against an opening into a cool, closed mold. The fluid plastic is forced at high pressure through this nozzle into the cold mold. As soon 37 as the plastic cools to a solid state, the mold Reinforced plastics offer exceptionally high opens and the finished plastic piece is ejected strength with low weight. Also, they lend them- from the press. selves to easy, economical fabrication, requir- The problem with injection molding of ther- ing relatively little pressure and heat for curing, mosetting materials is that, under heat, these and employing types of molds and other equip- plastics will first soften, then harden to an in- ment that represent a fraction of the investment fusible state. Thus it is essential that no soft- cost for metal fabricating dies and machinery. ened thermosetting materialintheheating Thus, they make possible considerably larger chamber be allowedto remain there long plastics products. enough to set. A number of different techniques may be em- Jet molding, offset molding and molding ployed in the production of reinforced plastics. using a screw-type machine overcome this prob- In making formed shapes, impregnated rein- lem by liquefying the thermosetting plastic ma- forcing material is cut in accordance with the terial just as it goes through the injection nozzle shape of the finished product into one piece or into the mold, but not before. a number of pieces. The pattern or patterns are placed on a male mold in enough volume to give the final thickness and form. Molding is completed in heated, mated dies. A single mold may be used. The impregnated reinforcing ma- PULP MOLDING terial may be laid up on a male mold, inserted in a rubber from which all air is withdrawn so the bag presses around the layup, and cured in an oven.If a female mold is used, a dia- Thermosetting plastics are used in pulp molding. phragm is placed over the end of the mold so In this process a porous form, approximating that when airis withdrawn from within the the shape of a finished article, is lowered into a mold, the diaphragm is drawn down inside the tank containing a mixture of pulp, plastic resins mold to press against the layup of resin im- and water. The water is drawn off through the pregnated materials. porous form by a vacuum. This causes the pulp In producing a continuous laminate, a web and resin. mixture to be drawn to the form of reinforcing material passes through a bath and adhere to it. When a sufficient thickness of plastic resin, between rolls or under wiper of pulp has been drawn onto the form, it is bars that remove excess resin, and then between removed and then molded into final shape. sheets of cellophane or coated paper. Thus protected, top and bottom, the material goes through the curing oven. After curing, the cel- lophane or paper is stripped off. REINFORCING

Reinforced plastics mostly employ thermoset plastics, though some thermoplastics are used. Reinforced plastics differ from high-pressure laminates ia that very low or no pressure is This technique is used to fabricate hollow, one- used in the processing. The two methods are piece flexible parts from vinyl plastisols or alike in that in both, the plastic is used to bind from polyethylene powders. together the cloth, paper or glass fibers rein- Essentially,rotational molding consists of forcing material used for the body of the prod- charging a measured amount of resin into a uct. The reinforcing materials may be in sheet warm mold which is rotated in an oven about or mat form, and their selection depends on the two axes.Centrifugal force distributes the qualities desired in the end product. plastic evenly throughout the mold and the heat

38THE STORY OF THE PLASTICS INDUSTRY melts and fuses the charge to the shape of the cavity. After removing and cooling the mold, the finished part is extracted. Rotational mold- ing is particularly suited to the production of very large parts, size being limited only by the capacity of the oven. The advantages of this type of molding are:

ACKUP PLATES SEALING HEATING CHANNELS low mold cost, strain-free parts, and uniform wall thickness.

IND MOLDING SURFACES ANTICS REINEORC,ED PLASTIC MATERIAL. SOLVENT MOLDING

SACKUP PLATESSLALOM HEATINGCHANNELS Thermoplastic materials are used in this proc- ess of forming. Solvent molding is based on the fact that REINFORCING when a mold is immersed in a solution and withdrawn, or when it is filled with a liquid plastic and then emptied, a layer of plastic film adheres to the sides of the mold. Some articles thus formed, like a bathing cap or , are removed from the molds. Other solvent moldings remain permanently on the form as, for example, a plastic coating on a metal tube.

COMPRESSED AIR THERMOFORMING

Thermoforming of plastic sheet has developed rapidly in recent years. Basically, this process consists of heating thermoplastic sheet to a formable plastic state and then applying air and/or mechanical assists to shape it to the contours of a mold. Air pressure may range from almost zero to several hundred psi. Up to approximately 14 psi (atmospheric pressure), the pressure is ob- SHEET FORMING tained by evacuating the space between the sheet and the mold in order to utilize this at- mospheric pressure.This range, known as vacuum forming, will give satisfactory repro- duction of the mold configuration in the ma- jority of forming applications.

39 "When higher pressures are required, they are obtained by sealing a chamber to the top side of the sheet and building pressure within by compressed air. This system is known aspres- sure forming. Essentially, vacuum and pressure forming are variations of the same basic technique, even though the difference in the formed parts may be significant. Variations of thermoforming include: straight forming; drape forming; plug and ring forming; slip forming; snap-back forming; reverse-draw forming; air slip forming; plug-assist forming; plug-assist-air-slip forming; and machine die forming.

TRANSFER MOLDING

CAVITY

Transfer molding is most generally used for thermosetting plastics.

KNOCIOU? PINS This method is like compression molding in that the plastic is cured into an infusible state in a mold undcr heat and pressure.It differs from compression molding in that the plastic isheated to a point of plasticity beforeit reaches the mold and is forced into a closed mold by means of an hydraulically-operated TRANSFER MOLDING plunger, Transfer molding was developed to facilitate the molding of intricate products with small deep holes or numerous metal inserts. The dry molding compound used in compression mold- ing sometimes disturbs the position of the metal inserts and the pins which form the holes. The liquefied plastic material in transfer molding flows around these metal parts without causing them to shift position.

40THE STORY OF THE PLASTICS INDUSTRY Educational Facilities

Each year more schools, colleges and uni- versities are adding instructions in plastics to their curricula. As interest grows, new courses are added, old courses realigned to better prepare students for the needs of the plastics industry.

MI==iMilMME Trade Publications and Books

A wealth of information is contained in trade and technical magazines and technical books for and about the plastics industry. A listing of these publications is available.

Films About Plastics For these lists write to THE SOCIETY OF THE PLASTICS INDUSTRY, INC. The Society of the Plastics Industry, Inc., Public Relations Department has a list of motion picture films, film strips 250 Park Avenue and slides that are available from various or- New York, N. Y. 10017 ganizations for showing. The list describes the subject of each slide or film. Printed in U.S.A.