Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method for controlling micro-pore structure of polytetrafluoroethylene hollow fiber membrane

A polytetrafluoroethylene, microporous structure technology, applied in chemical instruments and methods, membrane technology, semi-permeable membrane separation, etc., can solve the problems of hollow fiber membrane retention performance decline, unfavorable stability, reduced penetration pressure, etc. , to achieve the effect of increasing membrane efficiency, optimizing pore distribution, and improving filtration accuracy

Pending Publication Date: 2018-01-05
DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
View PDF5 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the elongation of the fibrils also leads to the increase of the pore size, which leads to the decline of the retention performance of the hollow fiber membrane and even the occurrence of membrane defects.
In addition, the enlarged pore size will lead to a decrease in the penetration pressure, and the membrane is easily wetted, which is not conducive to its long-term application stability.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for controlling micro-pore structure of polytetrafluoroethylene hollow fiber membrane
  • Method for controlling micro-pore structure of polytetrafluoroethylene hollow fiber membrane
  • Method for controlling micro-pore structure of polytetrafluoroethylene hollow fiber membrane

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] 1000g of polytetrafluoroethylene dispersion resin and 230g of lubricating aid aviation kerosene are fully mixed for later use. Then, the paste was stirred in an oscillating mixer for 15 minutes and left to mature for 24 hours. Sieve the fully matured paste and put it into the billet of the billet making machine. After the billet is extruded, the hollow primary fiber is obtained. The as-spun fiber was stretched 0.3 times at 30°C, and then stretched at 1500°C, the total stretching ratio was 3.0 times. The obtained hollow fiber membrane was heat-treated in a sintering furnace at 360° C. for 4 minutes to solidify its microstructure and obtain certain mechanical properties.

[0026] The obtained polytetrafluoroethylene hollow fiber membrane has a porosity of about 75%, an average pore diameter of about 0.3 μm, and a water contact angle of about 121°.

Embodiment 2

[0028] 1000g of polytetrafluoroethylene dispersion resin and 180g of petroleum ether, a lubricating aid, are fully mixed and set aside. Then, the paste was stirred in an oscillating mixer for 10 min and then left to mature for 36 h. Sieve the fully matured paste and put it into the billet of the billet making machine. After the billet is extruded, the hollow primary fiber is obtained. The as-spun fiber was stretched 0.6 times at 80°C, and then stretched at 280°C, the total stretching ratio was 2.5 times. The obtained hollow fiber membrane was heat-treated in a sintering furnace at 370° C. for 2 minutes to solidify its microstructure and obtain certain mechanical properties.

[0029] The obtained polytetrafluoroethylene hollow fiber membrane has a porosity of about 70%, an average pore diameter of about 0.25 μm, and a water contact angle of about 125°.

Embodiment 3

[0031] 1000g of polytetrafluoroethylene dispersion resin and 200g of lubricating aid isoparaffin are fully mixed for later use. Then, the paste was stirred in an oscillating mixer for 10 min and then left to mature for 48 h. Sieve the fully matured paste and put it into the billet of the billet making machine. After the billet is extruded, the hollow primary fiber is obtained. The as-spun fiber was stretched 0.5 times at 50°C, and then stretched at 200°C, the total stretching ratio was 2.0 times. The obtained hollow fiber membrane was heat-treated in a sintering furnace at 380° C. for 3 minutes to solidify its microstructure and obtain certain mechanical properties. The obtained polytetrafluoroethylene hollow fiber membrane has a porosity of about 65%, an average pore diameter of about 0.18 μm, and a water contact angle of about 118°. In addition, the as-spun fiber was stretched 2.0 times "one-stage" at 200°C, and other preparation parameters were the same as above, as a com...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
Average pore sizeaaaaaaaaaa
Static water contact angleaaaaaaaaaa
Average pore sizeaaaaaaaaaa
Login to View More

Abstract

The invention relates to a method for producing a polytetrafluoroethylene hollow fiber membrane and a method for controlling the micro-pore structure of the polytetrafluoroethylene membrane. A paste mixture is prepared from polytetrafluoroethylene dispersion resin and a lubricating additive, the hollow fiber membrane is produced through an extrusion technology, and the pore structure of the membrane is controlled and optimized through a two-stage variable temperature stretching technology. The polytetrafluoroethylene hollow fiber membrane produced through the methods has a uniform micro-pore structure and uniform pore distribution.

Description

technical field [0001] The invention relates to a method for controlling the micropore structure of a polytetrafluoroethylene hollow fiber membrane. Background technique [0002] Polytetrafluoroethylene material (PTFE) is an important variety of engineering plastics, known as the "King of Plastics". Because of its excellent corrosion resistance, high and low temperature resistance, self-lubrication, surface non-stickiness, and weather resistance, porous PTFE hollow fiber membranes have broad application prospects. [0003] PTFE is insoluble in organic solvents and has high melt viscosity, so it cannot be prepared by traditional phase inversion method for hollow fiber membranes. At present, the widely used PTFE hollow fiber membrane processing method is the paste extrusion method. Generally, polytetrafluoroethylene resin and lubricating additives are mixed first, then pre-pressed into a blank, and then extruded to make a hollow fiber nascent membrane. In the case of heatin...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): B01D71/36B01D69/08B01D67/00
Inventor 曹义鸣贾静璇康国栋王付杉李萌周美青
Owner DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com