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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.
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%.
Misconception 1: Increasing the amount of glue applied can make it stick Many operators find that the BOPP film surface cannot stick, and their first reaction is to add glue. In fact, increasing the adhesive amount from 40g/m ² to 80g/m ² does not increase the bonding strength by less than 20%, but instead causes […]
Hot melt adhesive is a type of plastic polymer adhesive. Within a certain temperature range, its physical state will change with the temperature. EVA hot melt adhesive is an environmentally friendly chemical product. During use, sometimes hot melt adhesive may be pulled out after melting. What is the reason for drawing hot melt adhesive after […]
hot melt adhesive pelletsAre you afraid of ultraviolet rays? Hot melt adhesive particles are based on high molecular weight materials such as EVA, PO, PA, etc. These materials undergo photo oxidative degradation under long-term UV irradiation – molecular chain breakage, decreased cross-linking degree, resulting in yellowing and brittleness of the adhesive layer, and decreased bonding […]
The correct sequence for carbonization of residual glue in the glue can is:First, cool down to the softening range where the glue can still flow (about 120-140); Drain the remaining adhesive (℃), then use specialized cleaning adhesive or high flash point cleaning agent to circulate and soften the carbon residue, and finally use a copper […]
