Plastic Furs (Apr, 1946)
MAKING mink and other precious furs
from sheepskin is the latest miracle to come out of the chemist’s laboratory. Fabulous furs, hitherto within the reach of only the wealthiest women, will come clown in price to the point (about $160) at which almost every woman can satisfy her yearning for a luxurious coat.
The Cinderella-izing of the humble sheepskin is brought about by the Calva process, which effects a chemical change in the components of the coarse, kinky fibers, which take on the softness, luster and body, found, for example, in natural beaver.
Wool fibers are composed chiefly of a complex protein substance called keratin, which exists in a chain-like structure consisting of separate links of “polypeptide linkages.” In the first stage of the Calva process, the sheared sheepskin is put into an acid medium to activate the keratin, with the result that the molecular chains slide over one another freely. The wool is then much more flexible. Its individual polypeptide chains are no longer kinky, and their strength is enough for further processing.
Formaldehyde and a member of the phenol family, in a remarkable reaction involving the chemistry of plastics, produce a plastic within the fibers, which remain permanently changed.