What is the principle of heat shrinking?

For polyolefin materials, under the action of high energy electron beam, the linear molecular structure is transformed into a three-dimensional network structure, and crosslinking is made. The polymer materials after crosslinking have got great improvement in performance in mechanical strength, heat resistance, resistance to chemical solvents, heat oxygen aging, etc. When the crystallization polymer materials after crosslinking are heated to above the melting point, they become rubber elastomers, and under the action of external force, are expanded or stretched and rapid cooled, and the state will be preserved. When they are reheated to the temperature above the melting point, they also can be restored to the state before the action of the external force.