The performance characteristics of PTFE
PTFE is a tetrafluoroethylene polymer plastics products by polymerization, is similar to a transparent or opaque PE wax having a density of 2.2g/cm3, clear plastic box water absorption is less than 0.01%. Its plastic trays chemical structure and PE similar, but in all of the hydrogen atoms of polyethylene are replaced by fluorine atoms. Since CF bond can be high, stable performance, and thus its excellent chemical resistance to withstand in addition to molten alkali metals, fluoride, medium, and higher than 300 everything except acid sodium hydroxide (including aqua regia), and strong oxidizing packaging design agents, reducing agents and the role of various organic solvents; PTFE molecular symmetry of F atoms, CF plastic box bond of two elements in the covalent bond in the molecule no free electrons, so that the whole molecule is neutral, so it has excellent dielectric properties, and the electrical insulation from the environment and frequency. Its volume resistivity greater than 1017 health m, dielectric loss, high breakdown voltage, arc resistance, electrical energy at 250 under long-term work; due to the molecular structure of PTFE is not hydrogen, the structure symmetry.
So its high crystallinity (crystallinity of usually 55% to 75%, sometimes plastic packaging up to 94%), excellent heat resistance of PTFE, its melting temperature is 324 , decomposition temperature of 415 , the maximum plastic case temperature of 250 , brittle transition temperature of -190 , heat distortion temperature (0.46MPa conditions) to 120 . Good mechanical properties of PTFE, a tensile strength of 21 ~ 28MPa, the bending strength of 11 ~ 14MPa, elongation of 250% to 300%, and the static friction coefficient of steel 0.04, nylon, POM, PET small friction coefficient of plastic.
Pure PTFE low intensity, poor wear resistance and good creep resistance, the PTFE polymer usually add some inorganic particles, such as graphite, molybdenum disulfide, aluminum oxide, glass fiber, carbon fiber, etc. to improve the mechanical properties ; also be used with other polymers such as polyphenylene ester (PHB), polyphenylene packaging company sulfide (PPS), polyether ether ketone (PEEK), perfluoro poly (ethylene / propylene) copolymer (PFEP), etc. The plastic package clamshell packaging method of blending to its damping temperature range, to improve their creep resistance.
Use of PTFE
PTFE’s unique properties make it in the chemical, petroleum, textile, food, paper, medicine, electronics, and machinery and other industrial and marine operations fields have a wide range of applications.