Research On The Application Of Fluorine Resin In Special Valves

Special valves are high-end industrial valves developed and produced according to specific specifications,materials,uses,etc.,which can adapt to various strong corrosive media,ultra-high temperature,ultra-low temperature and other special working conditions.Special corrosion-resistant metals are expensive and have limited resources.The pursuit of a valve surface protection material with superior performance and an appropriate price is the goal of the joint efforts of enterprises and researchers.Fluororesin is a special thermoplastic polymer material with superior performance.It has excellent mechanical properties and chemical stability,and is particularly suitable as a special valve anticorrosive material.The topic of this article comes from the Surface Engineering Automation Collaborative Innovation Center of Ningxia University and Wuzhong Instrument Co.,Ltd.This article is based on the feasibility study of the application of fluororesin/valve insert injection molding and the project research of the electrostatic spraying of fluorocarbon powder protective coatings prepared by infrared radiation curing process to explore the application of fluororesin in special valves.The parts after metal insert molding and the cured coating of fluorocarbon powder are the research objects.The research content is the molding and curing quality and mechanical properties of the parts and coatings.The purpose is to explore the feasibility of fluororesin/valve insert injection molding to replace traditional compression molding,and fluorocarbon powder coating infrared radiation curing to replace traditional hot air resistance furnaces.Among the influencing factors of the insert injection molding process and its process conditions,the temperature,pressure and time of the filling stage are the three major factors that determine the molding quality of the part,and the crystalline performance of the fluororesin is an important influencing factor.The physical parameters of five fluororesins were determined through WAXD and DSC tests,and PFA resin was selected as the filling material to perform Moldflow simulation analysis on the injection molding filling process of the designed parts.The design and manufacture of simple hand-cranked horizontal injection molding machines,molds and mechanical test benches for experimental verification are all based on simulation results.By comparing the injection molded parts with the simulation results,the overall polymer part of the parts shrinks about 6%-7%,which is basically consistent with the simulation results;a small amount of weld lines and air pockets appear on the fluororesin molding surface of the sample,and the entire part has no flash and other defects.By comparing the molding quality and shear test of injection molded parts and simple molded parts,a small amount of air pockets,weld lines and shrinkage deformations in injection molded parts can be reduced or eliminated by changing the process parameters;while the flash defect in the molding process of molded parts is inevitable;comprehensive comparison shows that the application of insert injection molding has greater advantages than compression molding.The article explores the coating curing mechanism of the electric heating muffle furnace and three different wavelength infrared radiators,and focuses on the matching absorption principle of the infrared radiation coating curing.The matching absorption principle shows that when the infrared absorption wavelength of the fluorocarbon powder matches the radiation wavelength of the infrared radiator,the molecules in the powder coating will resonate,and the coating will have a better curing effect.The surface finish,bending test,impact resistance test and metal/coating bond strength based on the pull method and the cross-cut method of the four curing equipment at the coating thickness of 3,5,7 and 10 layers In the test,it is found that when the coating thickness is less than 150?m,the 2#far-infrared quartz tube radiator has a better curing effect than other curing equipment,and when the coating thickness is about 150?m?200?m,it is recommended to choose a directional far-infrared radiation heater with a more uniform curing temperature and a wavelength in the range of 5.8?24.4?m.Studies have found that the surface finish of the coating is basically not affected by the thickness of the cured coating.As the thickness increases,the coating's flexural and impact resistance performance deteriorates,and the adhesion of the coating to the metal substrate increases,but it increases to It will drop to a certain extent.Therefore,in actual production,on the one hand,the spray thickness of the powder coating should be set reasonably,and on the other hand,the coating should be cured in accordance with the curing conditions recommended by the process regulations or technical conditions.The experiment also shows that whether fluorocarbon powder is used for surface protection or decoration on the valve,when the coating thickness is not high,around 80?m is the best choice and should not exceed 150?m.Through the above two project researches on fluororesin in special valves,it is preliminarily verified that the two process applications of fluororesin in valves,especially special valves,are feasible.The research methods and ideas in this article are also applicable to research in related fields.