Because the affinity of the hot melt adhesive and different adhered materials is different, in order to make the hot melt adhesive play "stickiness" better, the following factors should be carefully considered in selecting the hot melt adhesive:
First, color. Due to the different colors of the adhesive, the color requirements of hot melt adhesives should be different. If there is no special requirement for the color of the adhered object itself, yellow hot melt adhesive is recommended. In general, the yellow hot melt adhesive has better tackiness than white.
Second, surface treatment of the adhesive. Hot-melt adhesives are less stringent than other adhesives for the surface treatment of adhered materials, but the dust and oil stains on the surface of the adhered materials should also be properly treated so that the hot-melt adhesives can perform better adhesion.
Third, the operating time. Fast job is a major feature of hot melt adhesives. The working time of hot-melt adhesives is generally about 15 seconds. With the wide application of modern production methods, assembly lines, the operating time requirements for hot-melt adhesives are getting shorter and shorter, such as bookbinding and speaker manufacturing for hot-melt adhesives. Requirements to reach about 5 seconds.
Fourth, anti-temperature. Hot melt adhesives are sensitive to temperature. When the temperature reaches a certain level, the hot-melt adhesive begins to soften, and the hot-melt adhesive becomes brittle when the temperature is lower than a certain temperature. Therefore, the hot-melt adhesive must be selected in consideration of the temperature change of the product environment.
Fifth, stickiness. The tackiness of hot melt adhesives is early tack and late tack. Only the early stickiness and the late stickiness can make the hot melt adhesive and the adhered material stable. In the production process of hot melt adhesives, it should be ensured that it has anti-oxidation, anti-halogen, anti-acidity and plasticity.
The viscosity of the hot melt adhesive varies depending on the material of the adhered material. Therefore, different hot melt adhesives should be selected according to different materials.
