The selection of hot melt adhesive directly affects edge banding quality. It is essential to focus on key indicators including viscosity, open time, softening point, and bonding strength, while making a comprehensive evaluation combined with process conditions and substrate characteristics.
Viscosity determines the fluidity and coating uniformity of hot melt adhesive, with different viscosity requirements at varying temperatures. For example, high-temperature adhesives usually have a viscosity of 45,000–120,000 mPa·s at 200°C. Medium to high viscosity products are recommended for high-speed edge banding machines.
Open time refers to the effective interval from adhesive application to pressing. Hot melt adhesives with high initial bonding strength feature a shorter open time and require a faster edge banding speed. In low-temperature environments, products with a longer open time should be selected to avoid curing before adequate pressing.
The softening point defines the heat resistance of hot melt adhesive; the higher the softening point, the better the heat resistance. For high-temperature scenarios such as kitchen cabinets, adhesives with a softening point of ≥120°C are preferred.
Bonding strength is a core performance indicator, which can be verified via tear tests or peel strength tests. Under the same conditions, high-temperature hot melt adhesives generally deliver higher strength than medium and low-temperature types.
In addition, the wettability of the adhesive to the substrate should be considered. Especially for difficult-to-bond materials such as melamine paper and wood veneer, products with good substrate affinity are required.
