1940: Plastics

Production.

The use of plastics throughout the world is constantly increasing and doubtless will continue to do so, on a sharply ascending scale, as more and more large chemical companies take up plastics research and manufacture.

Because of the war it is impossible to obtain even approximate figures as to the volume of plastics produced in Europe, but it is well known that plastics in great variety and volume are being utilized in all of the belligerent countries. We can safely estimate that the 1939 world production of all plastics was upwards of 425,000,000 pounds.

In the United States production of cellulose derivative plastics during 1939 was 34,170,000 pounds. Production of synthetic resins, excluding alkyds, was 136,560,000 pounds, the percentage of distribution being approximately as follows: phenol formaldehyde, 29; cellulose acetate, 26; cellulose nitrate, 20; urea formaldehyde, 11; vinyls, 7; casein, 5; acrylic and methacrylic, 2; and styrene, 0.30.

Military Uses.

In 1940, much plastic material was used for military purposes, some of the applications being as follows: Cellulose acetate: transparent windows, flexible tubing, gunstocks, gas mask windows and visors, aircraft fairings, ammunition chutes, in airplanes and helmets; Methyl methacrylate: transparent windows for airplanes and gas masks; Styrene and Styroflex: electrical insulation; Polyvinyl chloride: (mostly in Germany) radio dials, pipes for corrosive liquids, impregnant for gas mask fabrics and gaskets; Phenol formaldehyde: for gas mask containers and mouth pieces, small propellers, substitute for aluminum, automobile doors, helmets and heavy-duty bearings. Doubtless there were other uses in Germany, about which we can only guess.

Great Britain and Germany have instituted government control over the sale and use of plastics while even in the United States the Government has established licensing requirements for the export of optically clear transparents.

Cellulose Acetate and Butyrate.

Cellulose acetate molding powder and sheeting continues to replace cellulose nitrate plastics, the ratio being now about three to two. Marked advances in molding technique of both the compression and injection types contributed to the increased use of cellulose acetate and other molding powders. Complete instrument panels can now be injected at the rate of one per minute. The use of cellulose acetate, as well as other plastics, in automobiles continued to progress, plastics being used in eighty-nine separate places in one make of car.

The new cellulose derivate, cellulose acetate butyrate, introduced in 1939, has been increasingly used, its advantage being relative water insensitivity, which decreases warpage. It has found application in tail light lenses, horn buttons, instrument panels with or without metal inlay, substitute for reed seating in furniture, for arch supports in shoes and many other uses.

Methyl Methacrylate.

Methyl methacrylate, as mentioned above, was almost universally substituted for glass in both commercial and military airplanes. Other new uses are molded toilet sets, door knobs, furniture, pipe stems, cosmetic boxes, jewelry boxes, refrigerator hardware, gasoline pump dials, cutlery handles, novelty jewelry and display fixtures and signs.

Nylon.

Nylon continued to enjoy a growing market in hair brushes and tooth brushes, and found new application in industrial brushes where its great wear-resistance presents a real economy. (See also CHEMISTRY.)

Other Resins.

Phenol formaldehyde, especially laminated, was used in many new places and in larger volume in old fields, such as heavy bearings, ball bearing containers, kitchen utensils, radio cabinets, window sills in railroad cars, refrigerator doors and sliding door frames and rails in large commercial refrigerators. A new development not yet ready for commercial production was that of laminated automobile trunk doors.

Styrene found use in door knobs, toilet sets, bottle closures and refrigerator fittings. Styroflex (thin oriented styrene) was used as packaging material and for electrical insulation.

Vinylite, a copolymer of vinyl chloride and vinyl acetate, found application as house numbers, battery separators, radio dials, bottle cap liners and rain coats. In a soft elastic form, it was used as a leather substitute, belts, suspenders, garters and shoe trimmings.

Vinylidene chloride, a new plastic, has been used experimentally in the form of filament or strands as seats in cars and household furniture and for rope.

Castphenol formaldehyde in bright colors had a new lease of life as a material for automatic phonograph record players (juke boxes).

Polyvinyl butyral continues as the preferred plastic interlayer for safety glass, receiving practically universal acceptance.

Polyvinyl formal was used for tank linings and, when combined with ethyl cellulose, as an insulating wire coating.

Urea formaldehyde was used in larger volume for lighting fixtures and in a new type of light which throws the illumination directly below the fixture but shades the eyes of one at a little distance. Very large fixtures, twenty-six inches in diameter, have been made. Other applications are cosmetic containers, sanitary appliances, refrigerator door linings and plywood adhesives.

Finally it may be said that the consuming public have become increasingly plastic-minded, even although about fifty per cent of plastic production goes into industrial uses where it is not always evident to the consumer. Such uses are machine parts, factory and electrical equipment. (See also CHEMISTRY.)