Waterproof finishing can make textiles waterproof. Fabric waterproof finishing is divided into water repellent finishing and hydrostatic pressure resistant finishing.
After the water-repellent finishing, the surface tension of the water-repellent finishing fabric changes, and the fabric changes from hydrophilic to hydrophobic. The water droplets on it, like dripping on a lotus leaf, can roll but cannot be wetted.
The surface of the hydrostatic pressure-resistant finishing fabric is coated with a layer of impermeable continuous film, which blocks the voids of the fabric tissue and prevents the passage of water droplets. This method is also called coating finishing. From the moisture permeability of the fabric after waterproof finishing, it can be divided into moisture-permeable waterproof finishing and moisture-impermeable waterproof finishing.
The moisture-permeable and waterproof finishing hydrophobic substance forms a continuous film on the surface of the fabric, which can prevent the penetration of water and can withstand long-term rain and certain water pressure. Clothing usually adopts moisture-permeable and waterproof finishing, so that it has a certain degree of waterproof performance without reducing the moisture permeability of the fabric, and it is comfortable to wear and not stuffy.
Moisture-impermeable, waterproof and water-impermeable fabrics are usually used for waterproof canvas, tents and packaging.