Fig. 312 -Dr. Leo Baekleland the inventor of the Phenol-Formaldehyde resin as known as Bakelite.
Fig. 313 - Radio receiver cabinet made with Bakelite resin.
Major development of synthetic resins improved certainly creative and imaginative designers to produce innovative types of works including the domestic radio receiver.
For historical allocation purpose the plastic age started with the invention of the Bakelite resin, whose chemical componsition the Phenol-Formaldehyde, was invented by the Belgian-born Dr. Leo Baekeland. Fig 312
In the beginning it was used as lacquer and an impregnating fluid, Bakelite was later combined with various fillers becoming a large application industrial molding material since it was capable of being used to turn out exact copies of great different types of articles.
Fig. 314 – Several types of radio receivers cabinets made with resin Durez.
Magazine Communication
Thus, the bakelite resin must have seemed the answer to the electronic industry’s long searching for a material to replace the old, expensive, labour-intensive processes previously required to construct radio cabinets. Fig 313
Soon other types of synthetic resins appeared in the market. Among them are the ones sold under the trade name of: Catalin and Durez.
Fig. 313A - Advertisement of Bakelite resin.
Magazine Communication
The Catalin resin required no pressue to form, as the syroup without fillers required no pressure to form the cast, being simply poured into moulds, and then, oven-baked to harden it. Fig. 314
The manufacturers developed innovative types of radios just rang the changes on basic designs by casting cabinets in a multi sections cast in contrasting colors that could be mixed and matched to produce a large range of combined patterns in a handmade appeal.
While the wood and steel were responsible for the radio cabinet’ shape, the plastic material together with new technological developments as: the 1,4 V thermionic valves, electrical components smaller in size as well as the AC-DC circuit topology arose the miniaturization as a new trend in radio manufacturing reaching the top in 1960 with the launching in the market of the first type of solid-state receiver. Fig 315

Fig. 315A - Brazilian made crystal radio receiver in plastic cabinet circa 1950. Fig. 315 - The lauching in the Italian market one of the first solid state radios made by the German company NordMend circa 1958.
Radio Industria Televisione Magazine
Fig 314A -Radio receiver’s cabinet made with resin “Catalin”.