A preparation method of melt spinning of polyvinylidene fluoride hollow fiber filter membrane

Abstract

A method for preparing polyvinylidene fluoride hollow fiber filter membrane by melt spinning, comprising the following steps: S1, the following parts by weight of 18-35 parts of polyvinylidene fluoride, 10-30 parts of solvent, and 40-60 parts of inorganic particles , 1~3 parts of coupling agent and 2~6 parts of hydrophilic polymer are mixed at room temperature at high speed to form a uniform mixed powder, which is extruded by a twin-screw extruder at 170~220°C Uniform granules; the advantages of the present invention are: this method uses inorganic fillers, organic solvents, coupling agents, and polymer pore-forming agents to form uniform granules through high-mixing and twin-screw extruder blending and kneading, and then through single-screw extruders. Extruder annular spinneret to make filaments. The fiber filaments are stretched, soaked in acid solution, and washed with water to make a hollow fiber filter membrane. The membrane silk produced by the method has the characteristics of simple production process, low price, high throughput and uniform hole formation.

Description

technical field [0001] The invention relates to the field of preparation of hollow fiber microfiltration membranes, in particular to a method for preparing polyvinylidene fluoride hollow fiber filtration membranes by melt spinning. Background technique [0002] Membrane separation technology has been extensively researched and developed rapidly in the past 20 years, and various forms of membrane modules have been developed, among which hollow fiber membranes have attracted more and more attention because of their special advantages. It has been maturely used in sewage treatment, petrochemical industry, medicine, food, steel, electric power and many other fields. [0003] At present, the preparation technology of hollow fiber filter membrane mainly includes solution spinning method and melt spinning method. Melt spinning methods include thermally induced phase separation and melt spinning-drawing methods. The thermotropic phase method, as described in ZL98807444.3, is to bl...

AI Technical Summary

Problems solved by technology

Since no suitable coupling agent is added in this method, the added inorganic powder cannot be uniformly dispersed in the membrane-forming system, so the hollow fiber porous membrane produced has a relatively large pore size, and it is necessary to coat a layer on the surface of the fiber membrane. Feed solution for solvent spinning to obtain smaller membrane pores, the spinning process is more cumbersome

And because the bubble cavity is relatively large, a higher concentration of glycerin aqueous solution (55%) is required to maintain the water flux of the membrane filament, which results in a relatively high requirement for the preservation of the membrane filament and the production environment of the membrane module.