The thermal contraction zone is the abbreviation of the heat shrinkable zone. The heat shrinkable zone is composed of radiation crosslinked polyolefin base material and special sealed hot melt adhesive. The processing technology of the heat shrinkable belt is like the six steps of the heat shrinkable casing, which is mainly divided into granulation, extrusion molding, irradiation, stretch expansion, coating and packing. The only difference between the heat shrinkable strip and the heat shrinkable tube is the shape, the heat shrinkable tube is tubular, the heat shrinkable strip is the ribbon, and the product structure is mainly divided into two parts: the base material and the hot melt adhesive. Heat shrinkable tape in the heating installation, material in radial shrinkage and internal composite layer melting, tightly wrapped in the patch, and the substrate together in the pipeline to form a strong anti-corrosion, good abrasion resistance, excellent corrosion resistance, impact resistance and good anti UV and light aging properties.