List of Differences in Adhesive Strength between Hot Melt Adhesive Particle Adhesive Copperplate Paper and Double Adhesive Paper: 6 Influencing Factors Disassembled Item by Item

What is the difference between sticking the same glue to different papers?

Many printing factories have found that the same batchhot melt adhesive pelletsThe double adhesive paper is very firm, but when replaced with copperplate paper, the pages will fall off. This is not a problem with the glue, but rather determined by the surface characteristics of the paper. Here are six key influencing factors.

• 1. Surface coatingCopperplate paper has a coating layer (calcium carbonate+latex) with a smooth and dense surface, making it difficult for the adhesive to penetrate; The surface fibers of the double adhesive paper are exposed and have good permeability.
• 2. Surface energyThe surface energy of the coated layer on copperplate paper is low, the wetting properties of the adhesive solution are poor, and the contact angle is large; Double adhesive paper has high surface energy and good spreading of adhesive solution.
• 3. Water absorptionDouble adhesive paper has strong water absorption, and the polar groups in the hot melt adhesive particles are tightly bound to it; Copperplate paper has low water absorption and weak mechanical anchoring.
• 4. Direction of paper strandsThe fibers are arranged neatly in the longitudinal direction, and the glue solution penetrates evenly; There are multiple fiber fracture surfaces in the transverse direction, but the permeation path is uneven.
• 5. Moisture content of paperThe optimal moisture content is 8-12%. Paper that is too low will become brittle, while fiber expansion that is too high will weaken the adhesion.
• 6. Printing inkThe ink coverage area is equivalent to adding a layer of low surface energy barrier, and UV ink is particularly difficult to stick. Sunlife hot melt adhesive particles with high initial adhesion can be improved.

Frequently Asked Questions (FAQ)

Q: Can only the adhesive be replaced if the copperplate paper falls off?

A: Not necessarily. Increasing the milling depth and raising the coating temperature by 5-10 ° C can usually improve the situation. Only when these measures are ineffective should a higher initial adhesive model be replaced.

Q: Can double adhesive paper stick firmly with any glue?

A: Most of them are, but thin double adhesive paper with a weight of less than 60g requires a low viscosity model to ensure that penetration is not excessive.