Hot Melt Adhesive For Express Bag

Express bag sealing with Hot Melt Adhesive, generally used for the sealing of various express bags, some people will feel that the bonding strength is not enough when using, resulting in the opening of the express bag in the middle of the situation. The Hot Melt adhesive material used to seal the express bag has been fixed. If you want to improve its bonding strength, it can be achieved by the following methods:

1, improve the surface roughness of the sticky object

When the hot melt adhesive is well infiltrated on the surface of the bonded material, the roughness of the surface is conducive to improving the infiltration degree of the hot melt adhesive on the surface, increasing the contact point density between the hot melt adhesive and the bonded material, and thus improving the bonding strength.

2. Penetration

The bonded joint, by the role of the environmental atmosphere, is often penetrated into some other low molecules, for example: the joint in a humid environment, the polymer adhesive layer in the machine solvent, the solvent molecules penetrate into the polymer, the penetration of low molecules first deforms the adhesive layer, and then enters the interface between the adhesive layer and the adhesive, so that the strength of the adhesive layer is reduced, resulting in bonding damage.

3. Migration

Due to the poor compatibility of these small molecules with polymer macromolecules, they are easy to migrate from the polymer surface or interface, and the small molecules that migrate out will hinder the hot melt adhesive and the adhesive material if they gather at the interface.

4. Apply pressure to the bonding surface

When bonding, pressure is applied to the bonding surface, so that the hot melt adhesive is more easily filled with pits on the surface of the bonded body, and even flows into deep holes and capillaries, reducing the gas overflow on the surface of the bonded body and reducing the porosity in the bonding area.

5. Thickness of rubber layer

The thicker adhesive layer is easy to produce bubbles, defects and early fracture, so the adhesive layer should be as thin as possible to obtain higher bonding strength, in addition, the thermal stress caused by the thermal expansion of the thick adhesive layer after heating in the interface area is also relatively large, which is more likely to cause joint damage.