In the dry process, fabrics are changed to leather which has similar structure and texture with the grain of leather by artificial means. The dry processing technology can be divided into two types: direct knife coating and indirect knife coating process.
For direct knife coating method, polyurethane size is directly coated on the surface of substrate or semi-finished products. After drying a
dense film is formed. While the indirect knife coating method is also known as release paper method in which polyurethane film is transferred to the surface of base through release paper.
Nowadays, release paper method is the main dry processing. The coating agent is coated on release paper, after drying a continuous and uniform film is formed, and then it sticks with the fabric, after drying and curing, the release paper is peeled and polyurethane film is transferred to the base from the release paper. Coating agent, release paper and base are three integral part of dry transfer-coating. By dry process following purposes can be achieved.
The resin film with certain color, pattern, luster and handle is formed on the surface of base. A surface protection layer is formed to improve the durability of synthetic leather. The aesthetics and varieties are increased so as to meet the character of service.