Preparation method for coating-free and environmental-friendly full grain shoe upper leather

Abstract

The invention discloses a preparation method for coating-free and environmental-friendly full grain shoe upper leather. The preparation method comprises the following steps: (1) tanning: rotationally tanning pickled skin after being depilated in a rotary drum, adding saline, sodium formate, a tanning agent, a degreaser, tear-resistance oil, a pickling auxiliary and macerating enzyme in the tanning process, and carrying out tanning, wherein the tanning agent is a TWS chrome-free tanning agent; (2) sequentially carrying out leather stacking and squeezing and shaving treatment on wet-white leather after being tanned; (3) carrying out retanning and staining; and (4) sequentially carrying out secondary leather stacking, spreading, squeezing, vacuum drying, hang drying, water spraying, standing, soft vibration, toggling, oil wax spraying, polishing, top oil feeling agent spraying and ironing to obtain a finished product. The preparation method is simple and environmental friendly; and in addition, with adoption of the preparation method, the obtained full grain shoe upper leather is compact and plump and accords with the idea of modern ecological leather making.

Description

technical field [0001] The invention belongs to the technical field of tanning, and in particular relates to a method for preparing full-grain uncoated environmental-friendly shoe upper leather. Background technique [0002] Full-grain leather refers to the leather that retains and uses the original surface of animal leather, also called front leather. The grain layer of the leather remains intact, and the unique pores and grain characteristics of animal leather can be clearly seen. Full-grain leather is the main variety of leather, representing the mainstream and technological level of the tanning industry, especially full-grain shoe upper leather. [0003] When the surface of full-grain leather is not painted, it can maintain the softness, elasticity and good air permeability of the leather. The finished product has good comfort, but there are problems of poor appearance quality and unclear grain surface. The full-grain leather of the prior art is less directly used witho...

AI Technical Summary

Problems solved by technology

[0003] When the surface of full-grain leather is not painted, it can maintain the softness, elasticity and good air permeability of the leather. The finished product has good comfort, but there are problems of poor appearance quality and unclear grain surface

The full-grain leather of the prior art is less directly used without surface coating, and most of them are beautified and finished, which brings environmental protection problems and cost increases.

[0004] In addition, the current tanning process generally has great environmental protection problems: the hexavalent chromium in the tanning agent is very harmful to the human body; the use of organic phosphorus has strong tanning properties and good fullness, but there is a large amount of APEO in the sewage discharge. Causes great environmental damage to water quality; formaldehyde is produced during the production process of aldehyde-tannin compound tanning, and the firmness cannot meet the requirements of shoe upper leather

[0005] In recent years, large chemical companies such as Klein and Lanxess have introduced new chrome-free tanning agents and pickling-free tanning, which have played a very good role in promoting the development of ecological leather, but there are still plump leather after tanning. Poor hardness, stiffness, insufficient firmness and fullness of finished leather. Although it solves the environmental protection problem during tanning, it cannot meet the processing requirements of uncoated full-grain shoe upper leather.