Abstract: The invention relates to an environment-protecting method for the liming of raw hides, wherein, after an optional mechanical degreasing step, the hides are subjected to presoaking, chemical degreasing, washing, alkaline swelling and collapsing, enzymatic unhairing, plucking and liming, and the sulfide ions remaining in the liquor after liming are deactivated. According to the invention the raw hides are treated, prior to liming, with 0.05 to 0.50% by weight of a proteolytic enzyme with an Anson-activity of 1.2 to 1.5 in a bath of a temperature not exceeding 35.degree. C. and a pH value not exceeding 12, thereafter the hides are subjected to hair-destruction liming with a lime liquor containing not more than 2.0% by weight of disodium sulfide and/or sodium hydrogen sulfide, calculated for the weight of the raw hide, and the sulfide ions remaining in the lime liquor are oxidized directly in the liming vessel so that 100% by weight of water and at least 0.

Abstract: A process for the production of chemically bonded non-woven material, such as synthetic leather, is disclosed wherein a fiber fleece is impregnated with a heat sensitized polymer dispersion and the composition is destabilized to form a porous gel structure. Finally, the polymer is crosslinked at below 150.degree. C. and is dehydrated. Additionally, cut fibers of polyester of polyamide are formed into a fleece and an aqueous dispersion of butadiene-styrene coagulant and a curing composition is impregnated through the fleece. The binder is gelled and cured in superheated steam. The products obtained are soft and possess excellent physical and mechanical properties as well as superior dynamic stressability.

Abstract: The specification describes water vapor-permeability sheet materials, particularly useful in the footwear industry. The production of sheet materials which are water permeable, highly resistant to wear, water resistant and mechanically stressable occurs by mechanically foaming a polymeric dispersion, the mechanical foaming being carried out in the presence of a surfactant, the density of the film being adjusted by the mechanical foaming to 0.55-0.85 g/cm.sup.3, gelling the foamed dispersion at a temperature of 120.degree. to 220.degree. C., for at most 10 minutes, and finishing the sheet material by spraying and/or rastering.