Wet White - Pretanning with the 'Derugan' System

摘要

This paper briefly reviews the history of the "wet white" principle and lays out Schill and Seilacher's criteria for the production of commercially viable leathers using the patented Derugan pretanning products. General principles of application are discussed for both split and unsplit bovine hides, as well as for small skins such as sheep, pig, and goat. Details of environmental advantages and by-product utilization are given. These include reduction/elimination of chrome-containing waste such as shavings and trimmings, increased efficiency of subsequent chrome tannage and easier degreasing of small skins such as sheep or pig. A summary of by-product studies are covered, reporting on the use of shavings for fertilizer and protein supplements for animal feed. Commercial aspects are also discussed. Reports from production experiences demonstrate yield increases and chemical savings when compared with blue splitting and shaving. Observations on quality improvement and the ability to make non-chrome leathers, if desired, are also noted.