热缩管的 原理（The principle of heat shrinkable tube）.docVIP

热缩管的 原理（The principle of heat shrinkable tube） High polymer materials should experience glassy state and high elastic state as the temperature is from low to high. The performance of glass is close to that of plastic, and its performance is close to that of rubber in high elastic state. The material used in the heat shrinkable tube is glassy at room temperature and becomes a high elastic state after heating. When the product is heated, the heat shrinkable tube is heated to a high elastic state, the load is applied to expand, and the cooling state is rapidly cooled in the condition of expanding so as to enter the glass state, and the state is fixed. In use, when heated, it will return to high elastic state, but when the load is gone, it will retract. To put it simply, its like stretching the rubber band and freezing it. The next time it heats up, he shrinks back. But this kind of rubber band is only like rubber band at high temperature, and it freezes as soon as it reaches the room temperature. Design of polymer molecular chain stretching oriented principle of POF heat shrinkable film POF heat shrinkable film system is designed by the principle of polymer molecular chain stretching and orientating. It is formed by the method of rapid cooling and shaping. The physical principle is: when the polymer in high elastic state, the tensile orientation, then the following polymer quenched to glass transition temperature, molecular orientation is frozen, when the goods in the packaging process of the heating, the stress relaxation due to thermal motion of molecules, the restoration of the original state, shrinkage. The heat shrinkable film market common PE shrink film, PVC shrink film, PP heat shrinkable film, shrink film and POF co extrusion, the heat shrink packaging film of this family, POF three layer heat shrinkable film (POF - C3) is a new generation of products for the rise gradually and accepted by the people in recent years. POF - C3 heat shrinkable packaging film is