The method of achieving equilibrium between the peel adhesion and lap adhesion of the wrapping film

The required adhesion of the wrapping film should have both excellent peel adhesion and excellent lap adhesion. The higher the peeling viscosity, the less likely the tray is to break loose, and the better the sealing of the film; The higher the overlap adhesion, the less likely the film is to experience longitudinal displacement. Therefore, in order to obtain a sturdy packaging, it is necessary to achieve a balance between the peel adhesion and overlap adhesion of the wrapped film. So how do we achieve equilibrium? Below, the editor will briefly share with you, hoping to be helpful to you.
1. The effect of molecular weight on the adhesion of entangled films: Different molecular weights result in different adhesion functions. PIB with higher molecular weight gives the film higher ultimate peel adhesion, but as the molecular weight of PIB increases, the lap adhesion will weaken; If the molecular weight is too low, its tendency to evaporate can lead to a short persistence time of viscosity. Therefore, selecting a PIB with a suitable molecular weight is necessary to make the entangled film have high performance. Research has shown that PIB with an average molecular weight of around 1300 is more suitable for increasing the self-adhesiveness of wound films.
2. The effect of increasing the amount on the viscosity of the winding film: The viscosity of the winding film is positively correlated with the amount of PIB participation. However, after the PIB participation exceeds 3%, the progress of the self-adhesiveness of the wrapped film becomes less obvious. If the PIB participation continues to increase, PIB will break up into blocks on the surface of the film, forming uneven self-adhesiveness of the film, and even making it difficult for the film roll to open. In order to ensure the ultimate function of the wrapping film and generally consider the cost of materials, the increase in PIB should be controlled between 1-3%. PIB has an exudation process, which usually takes about three days to wrap around the surface of the film to achieve satisfactory adhesion.
3. The effect of storage temperature on viscosity of wrapped film: The migration speed of PIB is related to the storage temperature. As the ambient temperature increases, the migration speed of PIB increases and the viscosity advances. Therefore, in order to achieve the required viscosity, the wrapped film should be stored at a higher temperature and generally prevented from reaching the application requirements after one week. However, if stored in an environment above 30 ℃ for a long time, PIB will separate a lot and is prone to the phenomenon of large or small ends of the film roll or paper core detachment. Therefore, after reaching the viscosity requirements, it should be stored in an environment between -15 ℃ and 40 ℃ as much as possible.