A traditional hot melt adhesive film is applied to a layer of release paper. A substrate-free hot melt adhesive film refers to a type of hot melt adhesive film product that has no other substrate to attach the hot melt adhesive film. It is only a layer of adhesive film, so it is commonly known as a bare film, and can be directly melted and used as an adhesive.
1. Why is there a hot melt adhesive film without a substrate?
Traditional hot melt adhesive films have a layer of release paper or release film, and their cost is much higher than other adhesive products, so it is an obstacle to the application of hot melt adhesive films in some large-scale lamination fields. In order to reduce the cost of using hot melt adhesive films, substrate-free hot melt adhesive films came into being.
2. How is a substrate-free hot melt adhesive film manufactured?
When a substrate-free hot melt adhesive film is manufactured, the hot-melt adhesive particles are first mixed into the silo, and the casting process is used to directly form a film and roll up, without coating on the release paper or release film. Conventional substrate-free hot melt adhesives are produced using casting machines. Of course, there are also companies that do not have casting equipment and will use the film blowing process to produce substrate-free hot melt adhesive films, and the properties of their products will vary. For some hot melt adhesive formulations that are not suitable for production using the casting process, the process of first coating and then peeling the paper will be used, and the material costs and labor costs of production will be greatly increased.
3. Common materials and applications of substrate-free hot melt adhesive films
Common materials for substrate-free hot melt adhesive films are EVA hot melt adhesive film, TPU hot melt adhesive film, and PO hot melt adhesive film. Substrate-free hot melt adhesive films have great advantages in linked composite processes, and their environmentally friendly and clean characteristics greatly improve the environment of production workshops, which makes them widely used in the shoe industry, automobile industry, and building materials composite fields.
