1. The color requirements of the glue should be different. If the object to be bonded has no special requirements for color, it is recommended to use yellow hot melt adhesive. Generally speaking, yellow hot melt adhesive has better viscosity than white hot melt adhesive.
2. Surface treatment of the object to be bonded. The surface treatment of the object to be bonded by hot melt adhesive is not as strict as other adhesives, but the dust and oil on the surface of the object to be bonded should also be properly treated so that the hot melt adhesive can better play the bonding role.
3. Operation time. Fast operation is a major feature of hot melt adhesive. The operation time of hot melt adhesive is generally about 15 seconds. With the widespread application of modern production methods-assembly lines, the operation time requirements for hot melt adhesive are getting shorter and shorter. For example, the operation time requirements for hot melt adhesive in book binding and speaker manufacturing are about 5 seconds.
4. Temperature resistance. Hot melt adhesive is sensitive to temperature. When the temperature reaches a certain level, the hot melt adhesive begins to soften. Below a certain temperature, the hot melt adhesive will become brittle, so the selection of hot melt adhesive must fully consider the temperature changes in the environment where the product is located.
5. Viscosity. The viscosity of hot melt adhesive is divided into early viscosity and late viscosity. Only when the early viscosity and the later viscosity are consistent can the hot melt adhesive and the adherend remain stable. In the production process of hot melt adhesive, it should be guaranteed to have anti-oxidation, anti-halogen, acid and alkali resistance and plasticity. The viscosity of hot melt adhesive varies with the material of the adherend. Therefore, different hot melt adhesives should be selected according to different materials.