Description
From the very beginnings of radio, plastic has been incorporated into the manufacture of radio cabinets and the internal workings of radios. From knobs to tube bases to platforms for components, plastic was used, not to enhance the looks of a home-brew, but as an electrical insulator. The first totally plastic radio cabinets hit the showroom floors sometime in early 1933. They didn't explode onto the scene as some might expect; instead they were offered as exotic alternatives to the millions of wooden radios already in production. With names like Air King, Colonial and Kadette, these maverick manufacturers took advantage of the latest technologies of the time. Plastic cabinets started out small compared to their wooden cousins but they were big compared to almost all other plastic items being manufactured at the time. In 1932 advertisements, Emerson offered "the world's smallest radio" which was about the size of a smallish cathedral. The very next year when Air King introduced its model 52 (the skyscraper), again about the size of a smallish cathedral, it was the largest molded piece of plastic ever attempted up to that time. These early attempts were successful enough for manufacturers to continue offering plastic cabinets in subsequent years. Then in 1936, Sears, using its radio trade name Silvertone, introduced a plastic radio to its catalog audience. The radio had a such a classic design and low price that it became an instant mail order hit and spawned similar designs that lasted into the late 1940s. In the last few years, pre-war plastic radios have become very desirable additions to radio collections. Frequently, when the topic of radio conversation turns to plastic, it becomes lively in discussing the differences between the types of materials, manufacturers and a confusing array of names used when describing a plastic radio. Hopefully, the information discussed below will help to dispel some rumors, provide some insight and possibly relieve some of the confusion surrounding the plastics of pre-war radios. BAKELITE The first plastic radios were made of a material called bakelite. Bakelite is simply the trade name for a material invented by Leo Baekland. Mr. Baekland was a chemist from Belgium who immigrated to the U.S. around 1900. He soon began to experiment with two coal byproducts: phenol and formaldehyde. He found that when these two chemicals were mixed together under moderate heat the result was a sticky, viscous resin. When this material was then allowed to cool it would harden and in this way could be molded into shapes. Unfortunately, the new product was brittle and would break and crumble with minimal pressure. His next step was to crush the new material into a light brown fluffy powder and then resubmit it to heat and pressure but this time a lot more of both. This step permanently "set" or bonded the molecules of the two chemicals into a stable and hard material. This process became known as thermosetting. The result was a powder that could easily be put into molds to create products. In 1909, Mr. Baekland patented this new material and formed a company called Bakelite.