The self-adhesiveness of stretch film plays a key role in its packaging applications, directly affecting the convenience of use as well as the effect and stability of packaging.
First of all, the control of self-adhesiveness is closely related to the material formula of stretch film. By adjusting the type and proportions of the base polymer, its viscous properties can be changed. For example, in polyethylene stretch film, appropriately increasing the content of linear low-density polyethylene (LLDPE) can improve the toughness and self-adhesiveness of the film. At the same time, adding an appropriate amount of tackifiers, such as rosin resin, terpene resin, etc., can significantly enhance the adhesion between the film and the packaged items. However, the amount of tackifier must be precisely controlled. Adding too much will cause the stretch film to stick too much during use, causing problems such as stringing and difficulty in unfolding, affecting the convenience of use. Adding too little will not meet the viscosity requirements required for packaging. , may cause the packaging to become loose and the items to scatter easily.
Secondly, the production process is also crucial to control the self-adhesiveness of stretch film. In the manufacturing process of stretch film, parameters such as temperature, blow-up ratio and traction speed of the blown film process will affect the molecular structure and surface properties of the film, thereby affecting the self-adhesiveness. A higher film blowing temperature helps the polymer molecules to fully fuse and distribute evenly, making the film surface smoother and flatter, which is conducive to the uniform development of self-adhesiveness. Reasonable inflation ratio and traction speed can control the thickness and crystallinity of the film. For example, appropriately reducing the inflation ratio and traction speed can increase the thickness of the film and improve its self-adhesiveness and puncture resistance. However, if the process parameters are set improperly, the thickness of the film may be uneven, the self-adhesiveness may be unstable, and local adhesion may be insufficient or excessive during use, causing inconvenience to the packaging operation.
Furthermore, the storage conditions and usage environment of stretch film also have a certain impact on the self-adhesiveness. Temperature and humidity are two key factors. Generally speaking, lower temperatures will make the stretch film harder and reduce its viscosity; while higher humidity may cause the film surface to absorb moisture, affecting its adhesion to the packaged items. Therefore, when storing stretch film, the ambient temperature and humidity should be kept relatively stable. Generally, the suitable storage temperature is between 15℃ and 25℃, and the relative humidity is between 40% and 60%. When using stretch film, you should also try to avoid operating under extreme temperature and humidity conditions to ensure that its self-adhesive properties can function properly and make the packaging process smoother and more efficient.
The control of stretch film's self-adhesiveness requires comprehensive consideration from many aspects such as material formula, production process, storage and use environment. Only through precise control of these factors can the self-adhesiveness of stretch film be optimized. While ensuring the tightness and stability of packaging, it can also improve its convenience of use, meet the needs of different packaging scenarios and users, and promote the use of stretch film in logistics and warehousing. Widely used and developed in many industries.
