What Is The Performance Of Plastic Film?
What is the performance of plastic film?
The share of plastic packaging and plastic packaging products in the market is increasing, especially composite plastic flexible packaging, has been widely used in food, medicine, chemical and other fields, and in which the largest proportion of food packaging, such as beverage packaging , frozen food packaging, cooking food packaging, fast food packaging, etc., these products have brought great convenience to people's lives.
The surface tension of the plastic film depends on the surface free energy of the plastic film, and the surface energy of the film depends on the molecular structure of the film material itself. Most plastic films, such as polyolefin films, are non-polar polymers and have a low surface free energy and a low surface wet tension, typically around 30 dyne/cm. In theory, if the surface tension of the object is lower than 33 dyne/cm, ordinary inks or adhesives cannot adhere firmly, so they must be treated on the surface. Polyesters are polar polymers and have a high surface free energy and a surface wet tension of 40 dyne/cm or more. However, for high-speed color printing or for increasing the bonding force between the vacuum aluminizing layer and the BOPET film surface, it is also necessary to perform surface treatment on the BOPET film to further increase the surface wet tension.