POF heat shrink film is the abbreviation of biaxially oriented polyolefin shrink film, due to the POF heat shrink film’s high shrinkage, high transparency, high heat sealing performance, green environmental protection, low-temperature resistance and other properties, so that the rapid development of its global use of a very wide range of new environmentally friendly shrink film. So what is the principle of POF heat shrink film?

What is POF heat shrink film?

POF is heat shrink film, the full name of multi-layer co-extruded polyolefin heat shrink film, POF heat shrink film is a linear low-density polyethylene as the intermediate layer (LLDPE), a total of polypropylene (pp) as the inner and outer layers, through the plasticization of the three extruder extrusion, and then by the die molding, film bubble blowing and other special processes and become a kind of the world is now very widely used, the development of a new type of rapid development of the new environmental protection shrink film.

POF Heat Shrink Film

The principle of POF heat shrinkable film

The film is preheated, stretched, cooled and shaped (as long as it does not go through the heat-setting process) to get the heat-shrinkable film. Near the resin Tf, the resin casting sheet through the transverse and longitudinal stretching, and then sudden cooling, so that the resin molecular chain in the state of orientation is frozen, the formation of the heat shrink film.

What is the principle of POF heat shrink film heating to produce shrinkage?

The macromolecules of ordinary plastic films are in a natural state of curling and generally do not shrink when heated. Shrink film is different, its film formation has undergone two steps, raw materials are melted at the specified temperature, and under the action of external forces to make the film stretch, the macromolecules can not slip each other, not the natural state that is frozen up.

POF heat shrink film principle is introduced roughly this, heat shrink film shrinkage, generally up to 75%, good flexibility, can be packaged for any shape of the goods, and after a special process of three-layer co-extruded film shrinkage force can be controlled to meet the requirements of the contraction force of different commodity packaging.