2 Surface modification method
2.1 Chemical modification method
PTFE can be surface treated by chemical treatment. These chemicals include sodium-naphthalene tetrahydrofuran solution, metal/sodium ammonia solution, and alkali metal amalgam solution. The chemical treatment mainly involves the reaction of the etching solution with PTFE, destroying the surface C-F bond, and removing some fluorine atoms on the surface. The conveyor belt machine forms a carbonized layer and some polar groups on the surface of the PTFE. Infrared spectroscopy showed that the surface of the modified PTFE was introduced with polar groups such as carbonyl, carbon-carbon double bonds and carboxyl groups, which increased the surface energy, reduced the contact angle, improved the wettability, and improved the bonding performance of the PTFE surface. The chemical modification of sodium-naphthalene complex is currently better in the surface modification method. However, the disadvantages are as follows: (1) The treated PTFE surface is obviously darkened or even brownish black; 2 the long-term exposure to light, the bonding performance will be significantly reduced; 3 need to deal with a large amount of waste liquid, conveyor belt problems, high operational risk, etc.
2.2 High energy radiation grafting method
High energy radiation can initiate graft polymerization, giving the polymer some unique properties, such as improved hydrophilicity, biocompatibility, electrical conductivity, and the like. Radiation sources commonly used in radiation grafting include gamma rays such as cobalt-60, cesium-137 and strontium-90. Lu Tingli et al. used conjugated grafting technology to graft styrene onto PTFE and then sulfonate it. The effects of solvent type, monomer concentration, radiation dose and grafting rate on the grafting reaction were studied. It was found that the monomer concentration and radiation dose were the main influencing factors of the reaction, and the PTFE and water increased with the increase of grafting rate. The contact angle is reduced from 102.4° to 75.6° to improve the adhesion. High energy radiation modification is simple, clean and fast, without the need for initiators and catalysts, and the grafting rate is easy to control. However, the modified surface loses its smoothness, and the matrix is also destroyed at the same time as the radiation grafting, resulting in a significant decrease in its mechanical properties.
PTFE seamless conveyor belt
The PTFE seamless belt is made of high-quality imported glass fiber, which is woven or plain woven into a high-grade fiberglass cloth substrate. The unique process technology, fully immersed, impregnated, coated with imported Teflon resin, to produce a variety of ultra-wide Teflon high temperature resistant varnish.
Main features: 1. Stable size, high strength, elongation coefficient less than 5‰ 2. Good temperature resistance, continuous working temperature -70-260°C 3. Small friction coefficient and good insulation 4. Good anti-adhesive, easy to clean Various oil stains, stains or other attachments attached to the surface 5. Good corrosion resistance, resistance to various strong acid and alkali corrosion, no burning, anti-aging
Main application areas 1. Gaskets for heating food, baking pans, microwave gaskets 2. Anti-adhesive linings, conveyor belts, gaskets, masks, etc. 3. Depending on thickness, used in various drying machines Conveyor belts, adhesive tapes, small conveyor belts, sealing tapes, etc. 4. Used for corrosion protection of various petrochemical pipelines, electrical and electronic insulation, temperature-resistant cladding materials, environmental desulfurization of power plant exhaust gas, etc. 5. Widely used in belt pressing and bonding machinery.
Various food baking, frozen food thawing (rice, rice cake, candy, etc.), tobacco and tea baking processing lines, pharmaceutical machinery microwave drying equipment, heat shrink packaging machinery, plastic carpet equipment, glass varnish for plastic steel doors and windows manufacturing, Wood processing industry paving belt. A variety of food electronic components welding conveyor machinery. Industrial medicines, rubber and plastic sheets, heat treatment products for electrical parts, heat-resistant and non-stick special transport belts.