Chinese Again Break Technological Blockade In Developed Countries

High performance polytetrafluoroethylene (PTFE) fiber materials have been widely used in many fields of national economy due to their excellent high and low temperature stability, chemical stability, electrical insulation, non adhesion, weather resistance, flame retardance and self lubrication. They have become the preferred materials for environmental protection, filtration, construction, aerospace and other fields.

Due to the nature of polytetrafluoroethylene, the manufacture of PTFE fibers can not simply be made of general thermoplastic polymers.

Breaking technological blockade in developed countries

According to Dr. Hao Xinmin, senior engineer of the general military equipment research institute, who participated in the research and development, PTFE is not soluble in any solvent, and the macromolecule chain is arranged in a straight line, with large rigidity and large viscosity above the melting point. Therefore, it is impossible to use traditional solution or melt spinning. This has become a major technical problem in the field of PTFE material deep processing, and has become a technical bottleneck for the application of PTFE materials in China.

At present, only a few companies in the world have mastered.

Starting from the analysis of only a few samples of foreign production, a long years of hard exploration and hard work began.

據悉，由企業、科研單位和用戶組成的課題組研究設計了PTFE膜裂法長短纖維生產工藝流程，研發了溫度梯度控制的非等速、變幅寬、多次拉伸PTFE纖維的生產工藝，研制了高強異型PTFE長纖維和短纖維，解決了PTFE短纖維“併絲”問題;研制了多棱角型膜裂長纖維切刀、耐磨金剛石短纖維分切針輥、牙線膜裂切片成型等關鍵裝置，設計加工了螺旋式擠壓機、二輥壓延機、非等速拉伸機、梯度溫控變幅寬拉伸機、膜裂長纖維分切機、短纖維分切機、纖維擠壓牽伸機、卷曲機等系列成套生產設備，并建立了規模化生產線;研發生產了“ひ”形PTFE牙線、高強純PTFE梯度覆膜過濾材料，所有這些工藝技術、系列產品及生產設備，在國內外未見相似或相同文獻報道，具有新穎性和創新性。

The product novelty search further proves that the PTFE fiber produced has filled the domestic blank. The PTFE fiber performance is at the international leading level, and the PTFE fiber application product is in the international advanced, the domestic leading level.

Production capacity of 1000 ton class has been formed.

The expert appraisal committee of the appraisal activities is a strong lineup. The director and deputy director of the appraisal committee are three academicians of Sun Jinliang, Jiang Shicheng and Zhang Yaoming respectively, from chemical fiber materials, industrial textiles,

In the opinion of experts, experts believe that the project has invented PTFE uniform solid processing and membrane making technology, and the PTFE film and fiber integrated production equipment with independent research and development and integrated innovation have been running steadily, and the production capacity has reached 1000 tons.

The research results have 10 independent intellectual property rights, applied for invention patents, and have authorized 4 items. The social and economic benefits are significant, and the market has broad application prospects.

Ye Yongmao, consultant and senior professor of the China Chemical Fiber Industry Association, told reporters: "the national development and Reform Commission has clearly listed the development and production of PTFE fiber and products in this year's guidance catalogue for industrial restructuring." in the year 12th Five-Year, we can see that the series of fruitful achievements of project completion units is exciting. "

PTFE fiber as an excellent skeleton material, its mass production can promote the application of high performance fiber such as aramid fiber 1313, polysulfonamide fiber and polyphenylene sulfide fiber on filter material. It can accelerate the pformation of China's chemical fiber industry's economic development mode, promote the chemical fiber industry structure adjustment and optimization and upgrading, and improve and develop the modern industrial system.

Ye Yongmao introduced the production of PTFE fiber by membrane cracking and its application products, mainly including polytetrafluoroethylene long fiber and PTFE short fiber. The products developed by PTFE long fiber include: long fiber yarn, PTFE sewing thread, polytetrafluoroethylene dental floss, polytetrafluoroethylene long fiber reinforced polytetrafluoroethylene network reinforced by chlor alkali engineering, polytetrafluoroethylene fabric produced by PTFE fiber, PTFE film coated needle felt filter material and so on.

The technology of Teflon long and short fiber produced in this project is at the international advanced level. The price of the product is about 35% of the foreign similar products, which greatly reduces the production cost of the domestic users, laying the foundation for the batch application of high-performance PTFE fiber in China's environmental protection.

Ideal material for dedusting filter material

Fang Aimin, director and senior professorship engineer of the dust removal and ash removal Research Institute of Guodian Environmental Protection Research Institute, said: "a major breakthrough in the production technology of domestic PTFE fiber has successfully broken the monopoly and technology blockade of foreign products over the years, which will lead to the upgrading of environmental technology and materials. It is of great social significance and important economic benefits in the key stage of the" blue sky project "in 12th Five-Year.

According to Fang Aimin, the important application of PTFE fiber in the project is to prepare PTFE filter material for high temperature corrosive flue gas dedusting.

At present, the domestic PTFE filter has been widely used in waste incineration, coal-fired power plants, steel and other industries. It is one of the key materials for energy saving and emission reduction in China. At the same time, PTFE filter material can also be used in the gas-solid two phase separation field under corrosive high temperature environment as filtration separation material.

At present, there are about more than 40 municipal solid waste incinerators and hazardous solid waste incinerators in China, all of which are made of PTFE long and short fiber products developed by this project. The total filtration area is above about 700000 square meters, and the total amount of PTFE fiber used is about 595.31 tons. In, the total amount of fiber used in our country is about 595.31 tons.

For example, in the whole year of 2009, the PTFE long fiber used in the filter material used for producing garbage incinerator is 40 tons, and the amount of short fiber reaches 240 tons, which accounts for more than 91% of the total waste incineration industry.

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In the power industry, 9 household electrical appliances factories have used the PTFE long fiber filter bag foundation cloth produced by this project, with a total area of 24.

50 thousand square meters, the total weight of PTFE fiber is about 36.75 tons.

Teflon base cloth provides key support for the 30000 hour filter material life in China's power industry. The market share is over 50%.

The continuous use of pure PTFE fiber membrane filter material is as high as 250 degrees centigrade, and the instantaneous working temperature reaches 280 degrees.

The service life is as long as 4 years, far exceeding that of ordinary membrane filter media.

According to the introduction, PM2.5 refers to particles in the atmosphere whose diameters are less than or equal to 2.5 microns, also known as particulates, which have important effects on air quality and visibility.

Compared with the coarser atmospheric particles, PM2.5 has a small particle size, rich in toxic and harmful substances, and has a long residence time and a long distance in the atmosphere. Therefore, it has a greater impact on human health and atmospheric environmental quality.

In most parts of China, especially in North China where industrial concentration is concentrated, PM2.5 accounts for more than half of the total weight of airborne particulate matter.

PM2.5 is also the main cause of haze weather, but in the past, there was no PM2.5 in China's air quality standards.

The Ministry of environmental protection recently issued the "weight method" for determining PM10 and PM2.5 in ambient air. For the first time, the determination of PM2.5 in suspended particles in air with diameters less than or equal to 2.5 microns was standardized.

The filtration efficiency of PM2.5 using polytetrafluoroethylene and its coated filter media is as high as 99.99%.

All of these have made great contributions to the implementation of the policies and guidelines for energy conservation and emission reduction in China, making our country in the key area of PTFE filter material no longer controlled by others and saving the cost of environmental protection investment for the country.