What are the heat shrinkable films in daily life

What are the heat shrinkable films in daily life? Heat shrinkable films are commonly known as shrink films, which are a kind of film that can shrink greatly after being heated, so that it can tightly wrap objects and maintain its shape for a long time. The heat shrinkable film is designed with the principle of stretching and orientation of polymer molecular chains, and is formed by the method of quenching and setting. The physical principle is: when the plastic raw material is heated and plasticized and extruded into a master film, the polymer is forced to stretch in both vertical and horizontal directions between the glass transition temperature and the drill flow temperature, so that the molecular chain of the polymer is stretched in the direction of stretching. Orientation, and then the polymer is rapidly cooled, and the molecular orientation is frozen. When the film is reheated to the 'thawing' temperature, stress relaxation occurs due to molecular motion, and the molecules return to their original state and shrink. What are the heat-shrinkable films in life? Heat-shrinkable films are things that we rarely know but often come into contact with. The cola, paper drinks, and instant noodles we usually buy are all packaged in heat-shrinkable film, and we are excited about buying mobile phones The film outside the packaging box is also a shrink film. The development of the plastic packaging film industry in my country has mainly experienced more than 20 years, during which a certain scale has been formed. The heat shrinkable film industry occupies an important position in the packaging market, and it also plays a positive role in promoting the national economy. Previous: Analysis of the advantages of PET heat shrinkable film packaging machine technology Next: Classification and use of heat shrinkable film