| 摘要 |
<p>The treatment is of a chemicophysical nature and is included in the tanning, retanning and finishing operations. During flume tanning of the hides they are treated with a percentage of chromium salts which is lower than normal, pref. about 1.5 to 2.0 percent of the wt. of smoothed skins. Retaining is carried out with three basic tanning agents, i.e. glutaraldehyde, vegetable tannings and urea resins. After tanning the leather is treated with nourishing oils. During the finishing stage, the pre-powdered flesh side of the leather is tooled and patterned to obtain a hair side appearance with the assistance of dyes and pigments. The three basic tanning agents are pref. used in the following percentages Glutaraldehyde 3-6%, Vegetable tannins 12-20%, Urea-Formaldehyde resin 1.5-3%. On the same basis the percentage of nourishing oils is pref. between 2.5 and 6.0. The Glutaraldehyde makes the leather sweat-resistant and facilitated the penetration of vegetable tannings. The tanning agents compact with structure of the leather and the urea-formaldehyde resins are adjusted to obtain a desired leather texture from different skins. Suppleness is increased by use of the nourishing oils. Lower grade hides can now be used in the mfr. of high class leather goods.</p> |
