Internal pressure type fiber-reinforced filter membrane and preparation method thereof

Abstract

The invention relates to an internal pressure type fiber-reinforced filter membrane and a preparation method thereof. The internal pressure type fiber-reinforced filter membrane is formed by coating the inner surface of a hollow braided tube with a layer of high-polymer membrane casting liquid and carrying out solidification and water washing under the action of internal and external coagulating bath solutions. By preparing the membrane by virtue of the hollow braided tube, the membrane casting liquid and a spinneret plate coextruded by internal coagulating core liquid, a continuous membrane preparation process is realized; the high-polymer membrane casting liquid contains a hydrophilic agent, and thus the prepared fiber-reinforced filter membrane is high in flux and strong in anti-pollution capacity. The internal pressure type fiber-reinforced filter membrane has the beneficial effects that the filter precision is high, a pore structure of the membrane can be controlled by virtue of process parameters of a membrane casting liquid preparation process and a membrane preparation process, the cross flow of inlet water is realized, the reflux ratio is low, and the water production rate is high; compared with an internal pressure type filter membrane, the internal pressure type fiber-reinforced filter membrane has the advantages that a runner is wide and is unlikely to be blocked, feed liquid with high content of suspended solids can be directly processed, and the pretreatment cost is lowered.

Description

technical field [0001] The invention relates to an internal pressure fiber reinforced filter membrane and a preparation method thereof. Background technique [0002] Hollow fiber membranes are widely used in the field of separation technology due to their high packing density, no need for support materials, and simple production processes. In the preparation of hollow fiber membranes, phase inversion wet spinning, dry spinning, dry-wet spinning and other forming methods are mainly used, as well as melt spinning-stretching, melt spinning-sintering, melt spinning - Dissolution and other methods. The hollow fiber membranes prepared by these preparation methods have been able to meet the requirements for membrane strength in the fields of common chemical separation, enrichment, purification and pure water production. However, the strength of hollow fiber membranes is often unsatisfactory for the treatment of sewage in harsh environments, especially in the application of membra...

AI Technical Summary

Problems solved by technology

[0003] In recent years, the reinforced hollow fiber membranes developed have received attention. For example, the inner support hollow fiber membrane is formed by coating the casting liquid on the outer surface of the braided tube and then solidified and formed. The membrane has a single-layer structure and can be used as External pressure membrane or suction membrane is used; fiber-reinforced hollow fiber membrane uses a spinneret with long fiber channels to introduce long fibers into the fiber channel, pass through the fiber positioning plate, and enter the casting liquid and fiber composite area , the composite long fiber and casting solution are co-extruded, and the film is formed under the action of the core liquid and the outer coagulation bath or cooling bath, or the long fiber and the casting solution are co-extruded with a spinneret, and the long fiber is formed from The material liquid tank is drawn out, passes through the casting liquid pipeline, and is introduced into the spinneret from the casting liquid inlet of the spinneret. After being positioned by the fiber positioning plate, the long fiber and the casting liquid are co-extruded. The film is formed under the action of a coagulation bath, and finally winds up on the winder through the guide wheel. The membrane prepared by this method has a double-skin structure; the external support reinforced hollow fiber membrane is made of filaments with flocculent fibers in the hollow The outer surface of the fiber membrane is woven or crocheted to make it a reinforced hollow fiber membrane with flocculation. This method improves the strength of the hollow fiber membrane through the mesh-like support in the hollow fiber membrane, preventing On the other hand, the floc fibers in the hollow fiber membrane can also improve the structure of the filter cake layer, thereby improving the separation efficiency of mud and water. However, by first preparing the hollow fiber membrane and then weaving the mesh support The method of the body makes the bonding performance between the support body and the membrane filament poor, and the support body will fall off during use.

Images