The heat shrink tube has the function of "shape memory". It is widely used in electric power, communication, petroleum, chemical industry, computer, light industry, medicine, food, aviation and aerospace. The commercialization of heat-shrinking tubes began in the late 1950s abroad, In China, it began in the late 1960 s. With the polymer processing technology, the performance of heat shrinkable products continues to improve.  Heat shrink tubes pose a great challenge to traditional insulation, connection, anticorrosion and protection processes due to their excellent performance and economy. Raychem of the United States is the world's largest manufacturer of heat-shrink tubes, which had a production value of $171 million in 1976 and output value reached US $630 million in 1984.  Japan has more than six large manufacturers of heat-shrinkable materials, such as Ridong Electric and Mitsui Petrochemical Industries, which reached 6 billion yen annually in the early 1980s and tens of billions of yen in the early 1990s. There are dozens of enterprises producing heat shrink tube in China. Most of them adopt radiation cross-linking technology to produce heat shrink tube. It is estimated that the annual output value of domestic heat-shrinkable products in recent years is about 700 million RMB, and more than 50 million dollars of heat-shrinkable tubes are imported from abroad every year.