1. Raw material leather treatment material.
The treatment of raw material skin includes anticorrosion of fresh skin, preservation of dry skin, and chemical materials used in the process of soaking, degreasing, liming, pickling, depilation and so on. Most of the chemical materials used in the raw material skin treatment process are common chemicals such as acid, alkali, salt surfactant and so on. In addition to general chemical materials, there are also special chemical materials or common chemicals used in a single process, including leather degreasing agent, liming agent, anticorrosion, insecticide and so on.
two。. Tanning material.
Any chemical agent that can increase the shrinkage temperature of rawhide and turn into leather is called tanning agent. Tanning agent is a kind of active substance with multi-functional groups. Tanning agents can form intermolecular bonds with two or more interaction points in collagen structure, and sometimes increase the reaction points on part of the molecular chain of collagen and produce more new intermolecular cross-linking, which has tanning effect. According to the chemical properties, tanning agents can be divided into two categories: inorganic tanning agents and organic tanning agents, and can be divided into main tanning agents, pre-tanning agents and retanning agents according to their uses.
Dyeing is an important process of leather production, which can give leather a variety of bright and firm colors and improve the performance of leather. The dyes used in leather can be divided into leather special dyes and general dyes. Leather special dyes have dip dyes and spray dyes. General dyes are usually used in textile dyeing of direct dyes, acid dyes and so on.
4. Lubricating and fatliquoring material.
Leather fatliquoring (refueling) is an important process in the process of leather production. The chemical material used for leather fatliquoring is lubricating fatliquoring material, which is usually called fatliquoring agent. According to the different raw materials used, fatliquoring agents can be divided into three categories: natural oils (animal and vegetable oils) and their processed products; mineral oils and their processed products; and synthetic oils. According to its role in leather production, it can be divided into general fatliquor and multi-functional fatliquoring agent, such as white leather fatliquoring agent, waterproof retanning fatliquoring agent and so on.
5. Finishing material.
Leather is a processed product of all kinds of animal skins. In order to cover up the original defects of the original leather and enhance the durability, leather finishing materials were developed. The basic components of the finishing agent are film-forming agents (or adhesives) and colorants, as well as thickeners, leveling agents, plasticizers, softeners, cross-linking agents and other auxiliary materials.
6. Functional finishing material.
Functional finishing materials are used to make up for the defects of leather tanning and finishing or to improve or add some characteristics. For example, leather fillers mainly aim at the problems such as poor position and loose surface of leather after tanning, which can make leather plump and elastic, and improve the phenomenon of position difference and loose surface. The main purpose of the hand feeling agent is to improve the handle effect of finishing leather surface. There are many types of finishing materials, which have been included in auxiliaries in the past. According to the development in recent years, functional finishing materials such as fillers, hand-feeling agents and preservatives have become independent systems and become indispensable materials for the production of high-grade leather.
7. Fur material.
Fur production process includes preparation process, tanning process and finishing process. Some chemical materials need to be used in each process, and most of the chemical materials used in fur production are the same as those used in leather making, but the fur needs to be treated to improve the glossiness and use value of the fur.