Thermoplastic waterproof non-woven fabric plays a key role in the transformation of building waterproof materials

Waterproof non-woven fabrics have been widely used in new waterproof membranes. Among them, polyester and polypropylene fiber spunbond fabrics, recycled fiber non-woven fabrics, and non-woven fabrics composed of recycled fibers and woven glass fibers are used in large quantities. Weaving cloth etc. This type of product improves the shortcomings of traditional asphalt felts of single variety, short service life, and poor technical application performance. In the transformation of building waterproof materials, thermoplastic waterproof finishing technology has played a key role.　　 The public raw materials and finishing effects of waterproof and water-repellent finishing are different. Water-repellent finishing mainly uses low surface tension materials to make the surface tension of the non-woven fabric far lower than that of water, so that the surface of the non-woven fabric has a water-repellent effect, and the air permeability of the non-woven fabric is not affected in this process performance. The waterproof finishing of non-woven fabrics usually refers to the use of padding, baking, coating, lamination and other means to combine the surface of the cloth with a layer of non-permeable and impermeable polymer film materials to achieve the purpose of waterproofing. At present, this method is mainly used in the processing of industrial waterproof materials.　　 Various processing methods have been developed in terms of waterproof finishing, such as porous film bonding method, polyurethane wet coating method, dry coating method, etc. The products processed by the above method are not only waterproof, moisture permeable and breathable, and can be used as clothing materials, it is a better non-woven fabric waterproof processing method currently. Regardless of whether the water-repellent agent used in waterproof finishing is hydrophobic or hydrophilic, it is used to block the gap of the fabric to achieve the purpose of waterproofing. The former is such as grease, wax, paraffin, etc., and the latter is a variety of rubber or thermoplastic resins. .　　 1. Grease, wax, and paraffin. The method of applying certain greases for airtight finishing still occupies a certain market, such as tent cloths. The quick-drying oil in fats and oils is coated with a metal desiccant on the surface of the non-woven fabric. After air oxidation and sufficient drying, a soft, impermeable transparent film is formed. To prevent the fabric from adhering to other objects, it can be re-coated Put a layer of dilute ammonia solution. However, the disadvantage of using this method is slow drying and unpleasant odor. The disadvantage of the paraffin coating is its low melting point. The paraffin will melt at 56°C to 60°C.　　 2. Rubber. The rubber currently used includes neoprene, nitrile rubber, styrene butadiene rubber, etc., which can be selected according to different requirements. Because polyisobutylene has no double bond structure and is difficult to vulcanize, it is necessary to add a small amount of isoprene for copolymerization to form butyl rubber. This rubber is the least permeable and breathable. Recently, it has been widely used in waterproof rubber; the price of styrene-butadiene rubber is relatively low. However, the adhesion to non-woven fabrics is poor; the chlorinated vulcanized polyethylene can be colored arbitrarily and has excellent light resistance, especially for the rubber coating of waterproof canvas.　　 3. Thermoplastic resin. Ethylene resin can be made into solution type or emulsion type, with large output, low price and convenient processing. It occupies a large part of the market, and the most popular is polyvinyl chloride resin. When using polyvinyl chloride, three issues should be paid attention to: the plasticizing temperature should be adapted to the product variety and fiber properties; the paste viscosity should be matched with the processing technology and equipment; the appropriate plasticizer should be selected.