Manufacturing method of inner pressure pipe type multilayer composite film

Abstract

The invention discloses a manufacturing method of an inner pressure pipe type multilayer composite film. The manufacturing method comprises: a, uniformly mixing a film forming polymer, a film forming diluent, a film forming penetrant, a film forming pore forming agent and a film forming additive according to a certain mass percentage ratio, heating to a temperature of 130-390 DEG C with an extrusion molding machine through a thermally induced phase separation method, melting, uniformly mixing, extruding with a pipe type film inner film mold, and cooling to obtain the inner layer film of a pipe type film; b, weaving a warp and weft mesh pipe outside the inner layer film by using a warp and weft weaving machine, wherein it is ensured that the warp and weft mesh pipe is tightly attached to the surface of the inner layer film; c, coating the inner layer film outer layer attached to the warp and weft mesh pipe with a layer of an outer layer film; and d, extracting the prepared inner pressure pipe type multilayer composite film semi-finished product by using ethanol or isopropanol to obtain the inner pressure pipe type multilayer composite film finished product. According to the present invention, the inner pressure pipe type multilayer composite film has advantages of good separation performance, good compounding fastness and good mechanical property, the area of the effective filtration membrane can be increased, and the breaking of the film pipe and the damage caused by the separating and the layering between the filtration membrane layer and the support layer can be effectively avoided, such that the use efficiency and the service life of the film can be improved.

Description

technical field [0001] The invention relates to a method for manufacturing a composite membrane, in particular to a method for manufacturing an internal pressure tube type multilayer composite membrane. Background technique [0002] Tubular membrane, as a high-efficiency separation material, has been widely used in various fields such as water treatment and material separation. According to the requirements of use, the tubular membrane whose outer surface is used as the separation functional layer is usually called the external pressure tubular membrane; the tubular membrane whose inner surface is used as the separation functional layer is called the inner pressure tubular membrane. For the internal pressure tubular membrane, in order to ensure the smooth flow of the liquid in the tube, it is necessary to maintain a high support of the membrane body; since internal pressure filtration is often used in occasions with high system viscosity, it is necessary to increase the inte...

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Problems solved by technology

[0003] The existing internal pressure tubular membrane is mainly a composite membrane prepared by the solvent-induced phase separation (LIPS) method of non-woven welded pipe coating. The internal pressure tubular membrane obtained by this method has a dense layer of small pores on the inner surface, and the separation The precision is high, but the disadvantage is that the coating composite fastness is low. In the actual application process, it is easy to cause the separation layer to separate from the non-woven fabric layer due to poor fastness, resulting in a decrease in its service life; at the same time, due to the use of non-woven The cloth is welded into a tube, and the welding part has no filtering function, which reduces the effective filtration area of ​​the membrane, thereby reducing the filtration flux

In addition, due to the limitation of the preparation method, only materials suitable for the solvent-induced phase separation (LIPS) method can be selected, so the selection of membrane materials is also subject to greater restrictions.

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