| 摘要 |
The invention relates to a multi-stage process for unhairing (dehairing) animal hides, starting from soaked hides, comprising a) a hair impregnation stage in an appropriately equipped spatial unit E wherein the soaked hides are moistened with an aqueous-alkaline reducing solution (S-red) of a reducing agent R for 2-30 minutes within the temperature range 20 to 50 degrees Celsius by spraying or pouring, the spatial unit E being constructed in such a way that the hides are hanging or lying and the S-red run-off can be collected and recirculated, and subsequently b) a hair preserving stage in which the hide is treated with a 2 +/- 1.5% strength solution (S-ox) of at least one oxidising agent ox by casting or spraying, the temperature of the solution being within the temperature range 20 to 50 degrees C and the treatment time being from 1 to 30 minutes, depending on the oxidising agent, and subsequently c) a hair loosening stage in which the hide is treated with a dilute alkaline solution (S-alk) by spraying or casting so that the pH rises to 11-13, followed by d) hair removal wherein the hair, which is in a slightly pulped (gelatinised) state, is mechanically removed from the hide and, if necessary after a treatment with an acid solution, separated off.
|
