Views: 106 Author: Site Editor Publish Time: 2022-01-25 Origin: Site
Common PTFE membrane is a microporous membrane produced by premixing, extruding, calendering, biaxial stretching and other special processes using polytetrafluoroethylene dispersed resin. It is divided into clothing membrane, pu micro waterproof membrane, filtration membrane, and purification membrane according their uses. The PTFE membrane has a fibril-like microporous structure with a porosity of more than 85%. There are 1.4 billion micropores per square centimeter, and the pore size ranges from 0.02μm-15μm.
1. The surface morphology of the PTFE microporous film is a spider web-like microporous structure. Pores are formed between the microfibers, and the arrangement direction of the microfibers is basically parallel to the stretching direction; the junction of the fiber bundle is the node, which is formed by many microfibers entangled and connected.
2. Micro-pore structure PTFE membrane is an asymmetric membrane, and the size of the micropores on the front and back of the membrane is different.
3. The cross-sectional micropore size of the extruded ptfe film is larger than the surface micropore size, and the vertical and horizontal micropore sizes are also different, and the longitudinal micropores are larger than the horizontal micropores.
4. The cross-section of the membrane is a network structure. There are very complicated changes in the three-dimensional structure of the pores, such as network connection, hole inserting, and pore bending. There may be multiple micropores forming a channel, or a micropore may be connected to multiple channels.
1. PTFE clothing membrane
Microporous eptfe film was prepared by bidirectional tensile method based on the pore-forming characteristics of polytetrafluoroethylene resin.
The membrane surface can reach more than one billion micropores per square centimeter. The diameter of each micropore (0.1μm-0.5μm) is several hundred times smaller than the diameter of water molecules (20μm-100μm), and it is larger than that of water vapor molecules (0.0003μm-0.0004). μm) , so that water vapor can pass through, but water droplets cannot pass. This kind of microporous structure can achieve excellent waterproof and moisture-permeable functions. In addition, because the holes are extremely small and the longitudinal irregularities are arranged in a curved arrangement, the wind cannot pass through, so it has the characteristics of windproof and warmth retention. After being compounded with other fabrics, it can be widely used in clothing industry.
2. PTFE air filter membrane
Utilizing the unique surface smoothness, chemical resistance, air and water impermeability, large air permeability, flame retardant, high temperature resistance, strong acid and alkali resistance, non-toxic and other characteristics of the PTFE microporous membrane, it can be used for atmospheric dust removal, air purification, etc. It is mainly used for flue gas filtration of various industrial furnaces such as chemical industry, steel, metallurgy, carbon black, power generation, cement, garbage incineration, etc.
3. PTFE air purification membrane
The air purification membrane is made of polytetrafluoroethylene, which is expanded and stretched to form a microporous membrane. This membrane is laminated on various fabrics and substrates with a special process to become a new type of filter material. It is widely used in the fields of pharmacy, biochemistry, microelectronics and laboratory consumables.