Preparation method of melt spun high-strength high-modulus polyvinyl alcohol fibers

Abstract

The invention relates to a preparation method of melt spun high-strength high-modulus polyvinyl alcohol fibers. The method comprises the following steps of: mixing polyvinyl alcohol and water uniformly for fully swelling; adding the fully swollen polyvinyl alcohol to a double screw extruder for full fusion and then extrusion, and the fused mass trickle is subjected to air blast cooling to form nascent fibers; and the obtained nascent fibers are subjected to drying by a hot-air oven, multistage drawing and tension heat setting to form polyvinyl alcohol fibers. The preparation method of polyvinyl alcohol fibers provided by the invention has the beneficial effect that as only water is used for plasticization, through hydrogen bond complex formed between water molecules and polyvinyl alcohol molecules, melt spinning and high stretching of polyvinyl alcohol are achieved; the polyvinyl alcohol fibers with excellent mechanical property are prepared from general-grade polyvinyl alcohol; relevant complex process steps of coagulating bath and the like in the traditional wet spinning method are not needed, the production process is simple, and environmental pollution is small, and the production cost is low. The polyvinyl alcohol fiber prepared by the method has the advantages of controllable fiber number, high strength and high modulus, and the fibers can be widely applied to the field of civil work concrete.

Description

technical field [0001] The invention relates to a method for preparing melt-spun high-strength and high-modulus polyvinyl alcohol fibers, in particular to a method for preparing high-strength and high-modulus polyvinyl alcohol fibers used in civil engineering, specifically a high-strength and high-modulus polyvinyl alcohol (PVA) coarse denier Process for producing fibers by melt spinning. Background technique [0002] In order to improve the shortcomings of concrete such as poor tensile performance, crack resistance and poor ductility, the research on adding synthetic fibers to concrete to improve concrete performance has developed quite rapidly. At present, there are more researches on polypropylene fiber, polyethylene fiber, nylon fiber, polyester fiber, carbon fiber, aramid fiber, polyvinyl alcohol fiber, etc. Among them, polypropylene monofilament fiber is currently widely used in the market because of its low price, high chemical corrosion resistance, and wide source. ...

AI Technical Summary

Problems solved by technology

Therefore, in order to realize the coarse denier of polyvinyl alcohol fibers, there are also certain research results in the melt spinning of polyvinyl alcohol: Chinese patent CN101899722A swells polyvinyl alcohol with water, extrudes after dissolving by a single screw, and passes through the freezing liquid Coagulation forms polyvinyl alcohol fibers, but there are still the disadvantages of long production process and high cost through the coagulation bath into filaments; the plasticized melt-spun coarse denier fibers are detailed in the Chinese invention patent publication authorized announcement number CN1786302A "a A method for preparing high-performance polyvinyl alcohol fibers", by adding small molecule modifiers and polyvinyl alcohol to form intermolecular composites for melt spinning, but there are many kinds of small molecule additives, complex extraction, and high cost.