What are the classifications of waterproof fabrics? What are the characteristics of various types of waterproof fabrics?

Classification according to different processing techniques

1 Tight and waterproof
Microfiber thermal insulation cotton is an early representative of waterproof fabrics. The Ventel fabric designed by the British is the earliest waterproof and breathable fabric. It is woven into a fabric from high-count, low-twist pure cotton yarn of Egyptian long-staple cotton. When the fabric is in a dry state, the gap between the warp and weft yarns is about 10 microns. When water wets the fabric, the cotton yarn automatically expands, and the gap between the warp and weft yarns is reduced to 3 to 4 microns. This closed-cell mechanism is combined with the water-repellent finishing to make the fabric waterproof. At present, this type of fabric has been replaced by other waterproof and breathable fabrics.

2 Coating waterproofing
Use dry coating, transfer coating, foam coating and other methods to apply waterproofing agent to the surface of the textile. The pores on the surface of the fabric are closed to make it waterproof. According to the different coating materials, it is divided into polyurethane coating, semi-polyurethane coating and polyvinyl chloride coating.

3 Finishing and waterproofing
The resin-based additives are used in textiles to change the surface tension of the textile, and water droplets form bead-like shapes on the surface without penetrating or diffusing, and slide down on the surface to achieve a waterproof effect. For example, waterproof Oxford cloth has a very good waterproof effect and is usually used to make products such as bags and tents.
4 Paste the film for waterproofing
The waterproof film and other fabrics are pasted together to form a composite fabric. Under the protection of the waterproof film, even if the surface of the composite fabric is soaked by water, the inner layer is dry.