Selection and Manufacturing Technology of Jiangmen Waterborne Resin Material
Although water-borne resins have many special functions to complement superfibers, there are still many key and difficult points in the process of application and combination, which need to be studied and dealt with.
1. Proper selection of resins
Generally speaking, resins should be selected according to different tannery processes and physical properties of synthetic leather.
From the technical point of view, the selection of resin for low sealing must be soft, not rigid after sealing; resin for bonding layer should be selected with strong bonding fastness and high hydrolysis resistance, so as to effectively prevent the occurrence of water degumming or low peeling strength; resin for middle layer should be soft and elastic enough; resin for top layer of surface should be summarized according to the application requirements of synthetic leather. Conduct investigation and selection. If the top resin is not selected properly, the style and characteristics of synthetic leather will be completely changed. Therefore, the selection of resins, focusing on the selection of top resins.
Generally, water-borne high modulus resins are needed for shoe leather. Water-borne resins are required for wear resistance, scratch resistance and folding resistance. When making light or white leather sports shoes, water-borne resins with high modulus and yellowing resistance should be selected. Sofa leather needs to choose water-borne medium modulus resin, which should have anti-wear and scratch resistance, as well as excellent dirty and anti-fouling properties, and have good hand feel, especially the same touch of dermis. Low modulus resin should be selected for garment and soft leather. It is necessary for this kind of resin to have good softness at low temperature, elasticity and a touch similar to dermis. At the same time, it should have the requirement of dry cleaning and washing, i.e. water resistance and solvent resistance.
2. Correct selection of process
Ultra-fibre leather is usually processed by pure drying method. Although the process is single, the selection of processing technology is very important because of the different requirements of leather surface and the different functions of leather.
The process is determined according to the leather texture. Ultra-fibre substrates contain certain loosening fibers on the surface. If these fibers are not sealed or filled properly, they will cause uneven appearance, affect the brightness and visual perception of ultra-fine pattern leather, especially super-fibre mirror leather. Therefore, if fine pattern or mirror leather is produced, it is generally necessary to seal the bottom of the super-fibre base cloth. At the same time, in the dry process, sizing process with more than two knives is generally selected, and the visual effect of leather surface is improved by increasing the thickness of the coating film. Deep pattern super-fibre leather, sizing times and sizing quantity are based on no groove bottom.
Different processes were determined according to different synthetic leather functions. Generally speaking, shoe leather needs a high strength appearance, so the appearance should adhere to a higher thickness, the middle layer can be thinner, sofa leather not only has a better physical properties, but also has a better touch and elasticity, so the top and middle resin selection is equivalent. For garment leather and handbag leather, more attention should be paid to elasticity and handle, so the sizing amount of middle layer should be increased. At the same time, it is necessary to use low modulus and high dosage of adhesive resin.