Factors affecting the bonding strength of aluminum foil bags

What are the physical factors affecting the bonding strength of round bottom aluminum foil bags

① The viscosity of the adhesive.

The actual infiltration of adhesive on round bottom aluminum foil bag materials is closely related to viscosity, with low viscosity and good flowability, which is beneficial for actual infiltration.

② Surface treatment of adhesive composite film.

The manufacturer of round bottom aluminum foil bags introduces that the surface of any composite film substrate has adsorption properties. In order to achieve the best bonding effect, the surface of any substrate must be treated. In the composite process of round bottom aluminum foil bags, it is generally believed that only corona treatment is needed for the film, but in reality, it should include surface cleanliness, surface roughness, etc.

③ Internal stress.

The internal stress generated during the composite bonding process is one of the important factors affecting the bonding strength and durability. Therefore, effective measures must be taken to reduce the internal stress during the composite process of round bottom aluminum foil bags. However, as it is difficult to implement in specific operations, please choose adhesives with low internal stress. Stress includes shrinkage stress and thermal stress.

④ The thickness of the rubber layer.

The thickness of the adhesive layer is closely related to the composite strength. The general rule is that, while ensuring insufficient adhesive, the composite strength increases as the thickness of the adhesive layer decreases. If the adhesive layer is too thick or too thin, the probability of bubbles or adhesive defects forming inside the layer will increase. The thickness of the rubber layer, due to the different thermal expansion coefficients between the adhesive and the bonding substrate, results in high thermal stress and a decrease in the composite strength of the round bottom aluminum foil bag manufacturer. Of course, a thin rubber layer can also lead to a decrease in composite strength due to insufficient rubber.