With formula made of various raw materials and radiation, cross linking and other process techniques, Heat shrinkable wraparound sleeve of various size for various purpose are manufactured. They are widely used in joint corrosion prevention , leakage prevention ,protection of petroleum, naural gas (coal gas), communication and heat insulation pipelines , water supply and drainage pipelines , etc. They are predominant in high mechanical strength , strong anti-aging capability , good sealing property, corrosion resistance ,convenient construction , etc.