Explanation

It refers to the man-made fiber with tubular cavity in the axial direction, which can be divided into two categories according to its different functions: ① for ordinary wadding, the requirements for hollowness are not high, and the main pursuit is light and the thermal fiber material is polyester or acrylic fiber. The elastic modulus of polyester fiber is high. In order to improve its resilience, it is often made into eccentric core, which can form a permanent three-dimensional roll after heat treatment, which can improve the warmth retention and wearing comfort; Acrylic fiber, commonly known as artificial wool, has good warmth retention properties For separation membranes, the requirements for porosity and cross-sectional roundness are high, and there are also certain requirements for membrane wall micropores and their distribution. Some fibers also need to be coated with one or two different ultra-thin separation layers on the surface to improve separation efficiency and selectivity. The preparation method of hollow fiber is that the first type of fiber can be made by melt spinning (polyester, etc.) or solvent spinning (acrylic, etc.) with hollow, C-shaped or eccentric hollow spinneret; The second type of fiber is mostly dry wet spinning, and the spinneret is mainly hollow. In the process of fiber forming, air or coagulants of different compositions are required to be introduced into the hollow part. There are many kinds of polymer prepared, including cellulose, cellulose, polyethylene, polypropylene, polyacrylonitrile, polyvinyl alcohol, ethylene vinyl acetate copolymer, polysulfone, polyethersulfone, polycarbonate, polyvinylidene fluoride Polymethyl methacrylate, ammonia crosslinking polyphenylene oxide, polyimide, polyisophthaloylmphenylenediamine, polybenzimidazole, poly (4-methyl-1-pentene), cuprammonium cellulose, glass and even hollow carbon fiber, etc. Its main uses can be divided into two categories: one is mainly used as wadding, bedding and padding for winter clothing (including sportswear); the second is mainly used as microfiltration, ultrafiltration, dialysis, reverse osmosis and evaporative osmosis devices. There are also various bioreactor, which are respectively used in water treatment, environmental protection, comprehensive utilization of waste gas, medical treatment, chemical industry, petrochemical, biological engineering and food engineering.

Classification