Hebei Messi Biology Co., Ltd. stated that in the early stage of leather tanning, in order to allow the tanning agent to penetrate into the bare leather, the pH value is often low. Under these conditions, it is conducive to the penetration of the tanning agent, but it is not conducive to the combination of the tanning agent and collagen to produce sufficient Tanning effect. Therefore, at the end of tanning, alkali raising operations are often required to increase the ph value of the tanning system and promote the combination of tanning agents and collagen. At present, the chemical materials used in the alkali extraction operation in the tanning process are generally weakly alkaline materials such as magnesium oxide.
The solution for modifying magnesium oxide as a leather alkali-enhancing agent: (1) Burn magnesium oxide at high temperature to change its crystal form and increase its bulk density. (2) Its mixed complex is modified to reduce the acid center on the surface. (3) Polymer film-forming coating modification-a layer of organic film is wrapped around the magnesium oxide particles, and the film structure is destroyed through the mechanical action of tanning, so that the magnesium oxide is slowly released, slowing down the reaction rate with acid, and tanning The purpose of slowly increasing the liquid pH value.
The prepared samples were reacted with acid solution, and the speed of reaction with the acid and the ability to neutralize the acid were examined. The optimized samples were subjected to application experiments. The results showed that: The alkali extraction effect of the sample is uniform, so that the pH of the tanning solution will not mutate and remain stable within a range. The sample is added in batches to control the increase in pH, so that blue leather with smooth and plump grains and chromium liquid can be obtained. Good absorption depends on factors such as the preparation of the sample and the properties, dosage, drying temperature, sample grinding degree, and stirring conditions of the polymer membrane.
Hebei Messi Biology Co., Ltd. said that high-purity magnesium oxide is used to extract alkali in chrome tanning, which can make the blue leather grains firm and the color uniform. It is simple to use and can be added directly to the drum. Since magnesium oxide is affected by temperature and dissolves slowly, it is recommended to add the product and then rotate it for 6-8 hours, and the end temperature will rise to 38-40°C.