The waterproof and oil-proof processing of fabrics mainly involves covering the surface of fabric fibers with waterproof and oil-proof agents. In the waterproof and oil-proof processing using water as the solvent, the surface potential of the fiber surface and emulsion ions has a non-negligible influence on the waterproof and oil-proof effect.
1. The relationship between the ionicity of the waterproofing agent and the fibers of the fabric (taking cotton as an example)
Taking cotton as an example, the Z potential of emulsion particles (waterproof working fluid) is related to the waterproofing treatment effect and the coverage of the fiber surface at each stage. Polyester fibers are less like the picture above. If the waterproof and oil repellent agent used to treat polyester fiber is treated in the same way as cotton, high waterproof performance may not be obtained. This is because the Z potential of the waterproof and oil repellent agent is inappropriate for the polyester fiber.
So in the daily waterproof processing of fabrics, how should we choose the appropriate waterproof and oil-repellent agent, and how to adjust it to obtain high waterproof performance? You can start with the pH value of the working fluid.
2. The relationship between the Z potential of the fabric and the pH value of the solution
Conventional fabrics such as cotton, polyester, and nylon maintain a negative potential of -25~-20mV as the pH changes, and the fluctuation is not too large; as the pH increases, the negative potential of polyester becomes larger and larger. ; Because nylon is an amphoteric fiber, it exhibits a positive potential when pH<4.5, and a negative potential when pH>4.5.
In addition, for amphoteric fibers such as nylon, the relationship between fiber Z potential and pH after dyeing with different dyes is also different. When the pH value of the waterproof and oil-repellent agent is around 3, the potentials of the two nylon fabrics dyed with green fluorescent dye and ordinary red dye show positive and negative values respectively; when the pH value of the waterproof and oil-repellent agent is around 6, the potentials both show negative values. value. This means that using the same cationic waterproof and oil-repellent agent cannot achieve the same waterproof performance when the pH is 3, but when the pH is 6, the stability of the waterproof performance can be guaranteed.
3. Summary
Therefore, when processing waterproof and oil-repellent agents, it must be noted that the value of Z potential changes according to pH, which will affect the final waterproof and oil-repellent performance. Different fabric fibers have different Z potential values and different fiber properties. Therefore, you can directly adjust the pH range from 3-7 to find a process that can ensure stable waterproof performance.
Suzhou Leman Polymer Technology Co., Ltd. focuses on the R&D and production of textile functional finishing agents. It has a senior R&D team and rich application experience. It can customize personalized functional finishing solutions according to fabric characteristics and development needs. For functional development consultation and technical exchange of various textiles, please leave a message via email: info@lemanpolymer.cn
Post time: Jan-03-2024