Method for preparing hollow fiber membranes and tubular membranes with microporous PTFE hybrid flat membrane wrapping method

A technology of polytetrafluoroethylene and flat membrane, applied in chemical instruments and methods, membrane technology, semi-permeable membrane separation, etc., can solve problems such as reducing the thickness of flat membranes, and achieve the effect of increasing hardness and enhancing bond strength

Active Publication Date: 2013-11-13
ZHEJIANG SCI-TECH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In order to achieve a higher water flux for hollow fiber membranes and tubular membranes, it is necessary to reduce the thickness of flat membranes as much as possible. technical bottleneck

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] (1) Microporous polytetrafluoroethylene hybrid flat membrane: the 188 dispersed polytetrafluoroethylene resin of Juhua Group, the FR904 polyvinylidene fluoride resin of Shanghai Sanaifu New Materials Co., Ltd. and liquid paraffin were weighed Percentage 1: 0.02: 0.3 Mix evenly, let stand at 20°C for 96 hours, then stand at 40°C for 10 hours, at 20°C, press into a cylindrical blank on a compactor, pass the blank through The plunger extruder extrudes the rod at a temperature of 60°C, and then is rolled into a base tape by a calender at 40°C, and the base tape is longitudinally stretched once in an oven at 180°C, and then stretched twice. Transverse stretching, and finally sintering at 250°C for 30 seconds to obtain a microporous polytetrafluoroethylene hybrid flat membrane with a pore size of 0.03 microns and a thickness of 50 microns;

[0022] (2) Slitting: cutting the microporous polytetrafluoroethylene hybrid flat film into strip-shaped films with a width of 5 mm;

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Embodiment 2

[0026] (1) Microporous polytetrafluoroethylene hybrid flat membrane: 188 dispersed polytetrafluoroethylene resin of Juhua Group, FR921 polyvinylidene fluoride resin of Shanghai Sanaifu New Materials Co., Ltd. and kerosene by weight percentage 1:0.08:0.2 Mix evenly, let it stand at 40°C for 144 hours, then stand at 80°C for 16 hours, press it into a cylindrical blank at 30°C, pass the blank through the column The plug extruder extrudes rods at a temperature of 40°C, and then is rolled into a base tape by a calender at 60°C, and the base tape is stretched 6 times in the longitudinal direction in an oven at 300°C, and then stretched 5 times in the transverse direction Stretching, and finally sintering at 340°C for 10 seconds to obtain a microporous polytetrafluoroethylene hybrid flat membrane with a pore size of 0.2 microns and a thickness of 5 microns;

[0027] (2) Slitting: cutting the microporous polytetrafluoroethylene hybrid flat film into strip-shaped films with a width of ...

Embodiment 3

[0031] (1) Microporous polytetrafluoroethylene hybrid flat film: F106 dispersed polytetrafluoroethylene resin from Daikin Corporation of Japan, FR921 polyvinylidene fluoride resin from Shanghai Sanaifu New Materials Co., Ltd. and petroleum ether were pressed Weight percentage 1:0.05:0.25 Mix evenly, let stand at 30°C for 100 hours, then stand at 60°C for 15 hours, press into a cylindrical blank on a compactor at 25°C, and press the blank The rod is extruded by a plunger extruder at a temperature of 50°C, and then rolled into a base tape by a calender at a temperature of 50°C, and the base tape is longitudinally stretched 3 times in an oven at 200°C, and then 3 times stretched transversely, and finally sintered at 280°C for 20 seconds to obtain a microporous polytetrafluoroethylene hybrid flat membrane with a pore size of 0.15 microns and a thickness of 20 microns;

[0032] (2) Slitting: cutting the microporous polytetrafluoroethylene hybrid flat membrane into strip-shaped memb...

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Abstract

The invention discloses a method for preparing hollow fiber membranes and tubular membranes with a microporous PTFE hybrid flat membrane wrapping method. Dispersed PTFE resin and polyvinylidene fluoride resin are mixed with a liquid lubricant, and microporous PTFE hybrid flat membranes are prepared from the mixture through extrusion, calendaring, stretching and sintering. Then the microporous PTFE hybrid flat membranes are cut into membrane strips which wrap around supporting tubes, and finally the wrapped supporting tubes are sintered to obtain the hollow fiber membranes and the tubular membranes. The polyvinylidene fluoride resin added into the products of the invention has a melting point around 160 DEG C, fuses while sintered at a temperature between 250 and 340 DEG C, and can largely increase the hardness of the flat membranes after solidification, which facilitates slitting of the flat membranes. During the process of sintering after wrapping, the polyvinylidene fluoride resin contained in the flat membranes fuses again when sintered at a temperature between 260 and 340 DEG C, and thus can be used as overlapping parts between the wrapped flat membranes and as binders between the flat membranes and the microporous supporting tubes, so that the bonding strength is substantially improved.

Description

technical field [0001] The invention relates to a preparation method of a hollow fiber membrane and a tubular membrane, in particular to a method for preparing a hollow fiber membrane and a tubular membrane by wrapping a microporous polytetrafluoroethylene hybrid flat membrane. Background technique [0002] Membrane module forms for membrane separation mainly include plate and frame type, hollow fiber type, roll type and tube type. The hollow fiber membrane occupies a small area, is not suitable for blocking, and is easy to maintain. [0003] PTFE microporous membrane has the characteristics of high porosity, adjustable pore size, high and low temperature resistance, corrosion resistance, microbial attack resistance, etc., and has very important application value in the field of membrane separation. Polytetrafluoroethylene microporous membrane mainly includes flat membrane and hollow fiber membrane. It uses dispersed polytetrafluoroethylene resin. The material can form a "f...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D69/08B01D69/04B01D67/00B01D71/36
Inventor 郭玉海朱海霖王峰张华鹏唐红艳陈建勇
Owner ZHEJIANG SCI-TECH UNIV
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