First of all, what is water-repellent finishing? Water-repellent finishing: changes the hydrophilicity of the fiber surface to hydrophobicity, making the fabric breathable and not easily wetted by water.
The main principles of water repellency are:
1. Adhesion
2. Wetting pull force
3. Critical surface tension
Conclusion: It is ideal to use substances with larger contact angles and smaller critical surface tension as water-repellent finishing agents.
4. Contact angle of liquid on a rough surface with small holes
After the water-repellent finishing agent is applied to the fabric, the contact angle is larger than the contact angle of the smooth plane composed of the finishing agent itself, and the looser the structure of the fabric within a certain range, the better the water repellency (but the looser the fabric, the more prone to water permeability).
For cotton fabrics, fortunately, they have larger pores in the dry state and become denser through swelling after wetting.
Extended reading: https://www. alltextile.cn/product/product-16-130.html
Extended reading: https ://www.china-fire-retardant.com/post/9382.html
Extended reading: https://www.china-fire-retardant.com/post/9392.html
Extended reading: https://www.yingjietex.com/product/Two-way-stretch-satin-Printing-fabric.html
Extended reading: https://www.yingjietex.com/product/Full-dull- Nylon-Taslon-Oxford-Breathable-Fabric.htm
