铬复鞣对TWLZ鞣制白湿革染色性能的影响
Effect of Rechroming on the Dyeing Performance of Wet White Leather Tanned by TWLZ
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摘要: 采用几种常见的含铬复鞣剂对TWLZ鞣制白湿革进行铬复鞣,以不经铬复鞣的白湿革作为空白对照,考察了不同铬复鞣方式对白湿革染色性能的影响,并探究了染色不匀的可能原因。标准铬粉或含铬单宁复鞣不会对染色均匀性产生不利影响,而铬-锆-铝多金属复鞣剂复鞣会导致染色不均匀。该染色坯革的粒面层金属分布较均匀,染整材料吸收率也与其他组相当。造成染色不匀的主要原因是多金属复鞣剂会使白湿革的等电点提高,阳电性增强,染料易发生表面结合。Abstract: Wet white leather tanned by TWLZ was rechromed by several chrome-containing retanning agents, respectively. The effect of rechroming method on the dyeing performance of wet white was investigated, and the possible causes of uneven dyeing were explored. The wet white without rechroming was used as control. The results showed that rechroming with chrome powder or chrome-containing syntan did not have any detrimental effects on dyeing levelness. Rechroming with chromium-zirconium-aluminum multi-metal retanning agent led to uneven dyeing performance. The metal distribution on the grain layer of the dyed leather retanned by the multi-metal retanning agent was relatively uniform, and the uptake rate of post-tanning chemicals was comparable to other groups. The main cause of uneven dyeing should be attributed to the fact that retanning by the multi-metal retanning agent increased the isoelectric point and the electropositivity of wet white leather, thereby resulting in the surface binding of dyestuff.