The self-adhesiveness of stretch film is mainly achieved through its specific material and production process. The following is a detailed explanation of how the self-adhesiveness of stretch film is achieved:
1. Material selection
The self-adhesiveness of stretch film mainly depends on the selection of its substrate and additives. Common stretch film materials include polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), etc. These materials themselves have a certain degree of adhesion, but in the actual production process, it is necessary to add specific additives to enhance their self-adhesiveness.
2. The role of additives
In order to enhance the self-adhesiveness of stretch film, some special additives are usually added during the production process, such as PIB (polyisobutylene) or its masterbatch, and VLDPE (ethylene-vinyl acetate copolymer). These additives can react chemically with the substrate of stretch film to form a film with strong adhesion.
PIB: PIB is a translucent viscous liquid. Directly adding it to stretch film requires special equipment or modification of the equipment. The viscosity of PIB is affected by temperature. It is more viscous when the temperature is high and weaker when the temperature is low. Therefore, when using PIB as an additive, the temperature of the production environment needs to be controlled.
VLDPE: Unlike PIB, VLDPE has no special requirements for equipment, and its viscosity is relatively stable and not controlled by time. But it is also affected by temperature. It is relatively sticky when the temperature is above 30℃, and slightly less sticky when it is below 15℃. By adjusting the amount of LLDPE in the sticky layer, the required viscosity can be achieved.
3. Production process
In the production process of Stretch film, the additives and the base material are fully mixed and evenly distributed in the film by precisely controlling the process parameters such as temperature, pressure and speed. In this way, when the Stretch film is stretched and wrapped around an object, the adhesive film on its surface can adhere tightly to the surface of the object to achieve a self-adhesive effect.
In summary, the self-adhesiveness of Stretch film is achieved by selecting suitable materials and additives, as well as precisely controlling the production process. This self-adhesiveness makes Stretch film have a wide range of application prospects in packaging, protection, and fixation.
