In the 1910s Henry Ford experimented with using agricultural materials in the manufacture of automobiles. Ford was partly motivated by a desire to find nonfood applications for agricultural surpluses, which existed then as they do now. He tried out many agricultural crops, including wheat.
In the following few years, uses were found for soy oil in automobile paints and enamels, and in the production of glycerol for shock absorbers. Coil cases for the 1915 Model T Ford were made from a wheat gluten resin reinforced with asbestos fibres. Eventually he focused on soybeans, and in the 1920s began promoting soybean products at every opportunity. He recruited Robert Boyer, a young chemist, to lead the research.In the following few years, uses were found for soy oil in automobile paints and enamels, in rubber substitutes, and in the production of glycerol for shock absorbers. Viscous solutions of soy protein were extruded and "set" in formaldehyde bath to form fibers for upholstery cloth. But Ford's special interest was in converting soy meal into plastics. Soy meal is what is left after soy-beans are crushed or ground into flakes and the soy oil extracted with a hydrocarbon solvent. Soy meal is about 50 percent protein and 50 percent carbohydrate- mainly cellulose.The compositions of Ford's soy plastics, and the methods of their processing, evolved over time and varied according to the application. In general the resin core was made of soy meal reacted with formaldehyde to produce cross-linked protein (reminiscent of casein plastics and animal horn), but for added strength and resistance to moisture, phenol or urea was cocondensed with the protein. The resulting resin was part phenol formaldehyde (or urea formaldehyde) and part cross-linked soy protein; the soy meal was not merely a filler.
The condensation took place in the presence of the cellulose and other carbohydrates that were part of the soy meal. Fillers, up to 50 to 60 percent, provided additional cellulose fibres, from HEMP, wood flour or pulp from sprice or pine, cotton, flax, ramie even wheat. The final mix was about 70 percent cellulose and 10 to 20 percent soy meal. When additional strength became necessary, glass fiber was also used. Relatively low pressures and temperatures were used in the moulding process.Soy meal plastics were used for a steadily increasing number of automobile parts- glove-box doors, gear-shift knobs, horn buttons, accelerator pedals, distributor heads, interior trim, steering wheels, dashboard panels, and eventually a prototype exterior rear-deck lid. Finally Ford gave the go-ahead to produce a completely prototype "plastic car," including an entire plastic body. The body consisted of fourteen plastic panels fixed to a welded tubular frame (instead of the customary parallel I-beam frame). The panels and frame each weighed about 250 pounds. The total weight of the automobile was 2,300 pounds, roughly two-thirds the weight of a steel model of comparable size.
Ford, a master at generating publicity, exhibited the prototype with great fanfare in 1941. But then, by late 1941, Ford no longer publicized the "plastic car". The reasons for this are unknown, but his media contacts, the strength of the DuPont organisation and World War II are likely to have played a role. Also, technology was not yet well developed and limited options. Plastics have become more common, but plastics from renewable resources got sidetracked. This is where Hemp Plastics have continued with research projects and collaborations to re-visit and re-new the use of plant based plastics.
Picture of Henry Ford smashing a plant fibre bodied car with an axe is here.