Keywords: Fluorinated Ethylene Propylene Plastics; valve; the biggest characteristic lining process 1 overview the fluorine plastic lined valves is the flow surface by fluorine plastic shielding cover, to directly contact the isolate iron and steel and strong corrosive medium. This not only solved PTFE Adhesive Tape the intensity of low fluorine plastic, can not withstand high pressure, but also solve the corrosion of steel materials intolerance, and rational use PTFE Fabric of resources, in accordance with national energy industry policy, thus obtains the rapid development. In the production of fluorine plastic lined valves, the most important is the choice of fluoroplastics materials suitable for lining technology and die design and reasonable, this article will talk about the view of shallow. 2 fluorinated ethylene propylene plastic properties in the fluorine plastic lined valves, fluorine plastic is the largest amount of FEP, fluorinated ethylene propylene copolymers of tetrafluoroethylene and hexafluoropropylene is six, also known as fluorine plastic 46, referred to as FEP. Usually tetrafluoroethylene hexafluoropropylene accounted for 83%, six accounted for 17%. FEP is a fully fluorinated polymer, which is a modified model of fluorine plastic developed to overcome PTFE molding difficult. The structure of the form: FEP synthesis by three chloro acetyl peroxide as catalyst, copolymerization of tetrafluoroethylene and six of hexafluoropropene; also by ammonium sulfate, sodium pyrophosphate as catalyst, at 55 ~ 64 ℃ by suspension polymerization. FEP is a kind of macromolecular compounds with straight chain, can be regarded as a part of the fluorine atoms connected with main chain carbon atoms in PTFE is three methyl fluoride (CF3) substitution, molecular arrangement is very irregular, crystallization speed is slow, the crystallinity of at most 40% ~ 47%. It can be regarded as random copolymer. The melt viscosity is low, the available general methods of thermoplastic plastics on the molding processing, which overcomes the shortcomings of PTFE molding difficult?. But FEP molecules are composed of two elements and fluorocarbon by covalent bond, so its performance with
PTFE is basically the same.

FEP look and feel similar to polyethylene, but the relative density more than doubled; properties and applications like PTFE, temperature is 50 ℃ lower than PTFE; the hardness and strength higher than PTFE, is the standard of thermoplastic plastics. FEP relative PTFE Coated Fiberglass density is 2.14 ~ 2.17, the crystallinity with the heat treatment temperature differences, if six HFP accounted for 15% ~ 16% of FEP, its melting temperature is 288 ℃, Tg at 130 ℃, long-term use temperature of 88 ~ 250 ℃, brittle temperature of - 90 DEG C, the decomposition temperature of over 400 DEG C.

Fluorinated Ethylene Propylene Plastics (FEP) performance and the valve lining process is introduced for polyperfluoroethylene Propylene Plastics (FEP) performance, molding process, summarizes some problems easily occurred in the process of fluorine plastic lining, and puts forward the corresponding solutions.