being molded or cast. And all go through the chemical process known as polymerization, in which the molecules of the substance combine by enlargement of molecular structure.
After Dr. Leo Baekeland discovered Bakelite almost by accident in 1909 when he was trying to make a fusible synthetic resin, the creation of new plastics slumped. For years Bakelite and Celluloid were the only important ones used in America, and each had definite limitations. Celluloid, admirable as it was for many uses, was highly inflammable; and Bakelite, despite its utilitarian , excellence, could not then come into popular use because of its cost and blackness.
America needed a popular plasticâ€”a substance cheap, fire-resistant, and capable of taking on beautiful colors so that it could be used in the drawing-room as well as the telephone exchange. Not until the last decade did such a product appear.
Beetle, Catalin, Durez, Plaskon, Tenite, Resinox, Unyte, and many othersâ€”all are new names, all trade names of brilliant plastics made for thousands of uses. Outwardly similar, they are chemically different. Lustrous, vari-colored Catalin, for instance, cannot take the place of Bakelite in telephone and radio; nor can black Bakelite replace Catalin in the construction of toilet articles and chessmen, where beauty is needed and dialectricity is not. Roughly, plastic can be divided into three groups: Those made from vegetables, from animal, and from mineral matter.
Celluloseâ€”the fiber forming the cell wall of all plants, but found in its purest form in cottonâ€”is the old and the new titan in plastics. From this cheap and plentiful vegetable base came the earlier Celluloid; and it now makes Pyralin, Tenite and cellulose acetate. Though it will burn slowly, cellulose acetate is not highly inflammable as was the older Celluloid. Buyers of Cord, Auburn and Hudson cars this year have steering wheels made of this newest plastic. Sheets of Pyralin one-fiftieth of an inch thick are sandwiched between two thin panes of glass to make modern automobile safety glass. And tough, gleaming Tenite now makes thousands of fountain pen barrels, as well as many other semi-transparent things.
It seems a far cry from cow’s milk to buttons, yet chemistry has hurdled the distance. America’s button industryâ€”a large producer concentrating on a small but vital productâ€”relies largely on milk for its basic material. Casein, made from milk, is chemically combined with formaldehyde to form a lustrous plastic that is giving buttons a more prominent place in wearing apparel.
Mineral plastics are composed chiefly of phenol (carbolic acid) combined with formaldehyde. Of these the well-known Bakelite and a few others are molded into desired shapes, are black in color, and therefore are largely restricted for indus-trial use. Others such as Catalin are made from similar basic materials but are cast into sheets, rods and tubes of brilliant colors. This bulk stock can be fabricated by cutting or by turning on an ordinary lathe, resulting in colorful cutlery handles, knobs and novelties.
Among the most useful of the phenol plastics is the laminated type, such as Formica, in which canvas or other fabric is pressed into the material for greater strength and insulation. Modern motor cars can thank laminated phenolic formaldehyde for a large degree of their quietness. Gears of this substance have widely supplanted steel because they wear remarkably and do not clatter. In the new ocean giant, Queen Mary, too, is $100,000 worth of decorative material made from fire-resistant American Formica.
One of the newest compounds to startle the market is the urea plastic, a mixture of nitrogenâ€”snatched from the airâ€”with carbon dioxide and formaldehyde. Unlike the others this is manufactured first as a powder and is then molded. Grocery scales made by the Toledo Scale Company used to be housed in cumbrous metal that made them weigh 160 pounds. The company substituted Plaskon, a urea plastic, for its metal housings; in so doing it reduced the weight of the scales to 55 pounds and trebled its sa