Is the cover of the kraft paper board book firmly adhered by hot melt adhesive particles? Choose the right model, it will be firm and not peel off the shell

Kraft paper board book coverhot melt adhesive pelletsCan it stick?

Many hardcover book and magazine factories are most concerned about weak adhesion and cracked book covers when making kraft paper covers. Hot melt adhesive particles, as the mainstream adhesive material for book binding, are fully capable of bonding kraft paper and cover paper. The key lies in selecting the right model and controlling the adhesive coating process.

The surface of cowhide cardboard is relatively rough and the fibers are loose, making it more permeable compared to copperplate paper. The medium to high viscosity EVA model in Sunlife hot melt adhesive particles has a moderate opening time and can fully penetrate the gaps between cardboard fibers to form mechanical anchoring. The bonding strength far exceeds the national standard requirement of ≥ 2.5N/cm.

Key selection points

• Viscosity recommendation: 2000-4000 mPa · s (medium to high viscosity), low viscosity models that penetrate too quickly are prone to missing glue
• Open time: 8-15 seconds is preferred. If it is too short, the adhesive will solidify before wetting, and if it is too long, production efficiency will be low
• Operating temperature: 160-180 ° C, excessive temperature will accelerate the aging of the adhesive solution

Frequently Asked Questions (FAQ)

Q: Is the delamination of cowhide cardboard book shells a problem of glue or a process issue?

A: Both are possible. First, check if the glue application is uniform (recommended 80-120g/m ²), and then confirm if the milling depth meets the standard. If the process is normal and still debonding, using a higher viscosity Sunlife hot melt adhesive particle model can improve the situation.

Q: Is there any special requirement for bonding the cover paper with kraft paper, which is matte powder paper?

A: The surface of the matte paper has a coating and slightly poor wettability. It is recommended to choose hot melt adhesive particles with high initial adhesion and increase the coating temperature by 5-10 ° C to enhance penetration.

Q: Does high environmental humidity have an impact on bonding?

A: Has an impact. After moisture absorption, the moisture content of cowhide cardboard increases, which will reduce the bonding strength. It is recommended to control the humidity in the workshop at 40-65% RH, and the moisture content of the cardboard should be 8-12%.