Wet Blue/Wet White
Wet blue and wet white are intermediate products used by tanneries that process natural hides and skins into leather. Natural fats and oils need to be largely removed from wet blue and wet white for leather processing to be done properly, but no standard had previously existed to evaluate the effectiveness of such removal.
ASTM International Committee D31 on Leather has now developed such a standard, D7674, Test Method for Hexane/Petroleum Ether Extract in Wet Blue and Wet White. D7674 is under the jurisdiction of Subcommittee D31.02 on Wet Blue.
“In the wet blue and wet white process, chemicals are used purposefully to remove the natural fats and oils contents to a very low level,” says Okey Abara, senior chemist, Tyson Foods, and chairman of D31.02. “It is very important to get accurate information from the lab in order to gauge the effectiveness of the process to remove the natural fats and oils to a defined level.”
Abara notes that ineffective test results can lead to false elevated levels, which will result in the addition of unneeded chemicals into the process and greater expense that ultimately is passed on to consumers.
“Accurate results from fats and oils testing is the key to achieving an effective, efficient process that will prevent these issues,” says Abara.
All interested parties, particularly those from any sector of the leather industry, are invited to join the standards developing activities of D31. Abara says that the committee is now specifically interested in developing standards for nonresiduals (for example, fungicides and valence-based chromium analysis) in wet blue and wet white.
Technical Information: Okey Abara, Tyson Foods Inc., Dakota Dunes, S.D.
ASTM Staff: Ashley Wiand