Selection of Hot Melt Glue Granule
SWA EVA hot melt glue is a solid fusible polymer which does not require solvent and contains 100% of water; it is solid at normal temperature, and is heated and melted to a certain temperature to become a liquid which can flow and has a certain viscosity. The molten EVA hot melt adhesive is light brown or white. EVA hot melt adhesive consists of basic resin, tackifier, viscosity modifier and antioxidant.
Selection:
First, the color requirements of the glue should be different. If there is no special requirement for the color of the substrate itself, it is recommended to use a yellow hot melt adhesive. Generally, the yellow hot melt adhesive is more viscous than white.
Second, the surface treatment of the substrate. The surface treatment of the hot melt adhesive is not as strict as the other adhesives, but the dust and oil on the surface of the adhesive should be properly treated to make the hot melt adhesive better.
Third, the operation time. Fast work 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--pipeline, the working time requirements of hot-melt adhesives are getting shorter and shorter, such as bookbinding and speaker manufacturing. The requirement is about 5 seconds.
Fourth, temperature resistance. Hot melt adhesives are 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 choice of hot melt adhesive must fully consider the temperature change of the environment in which the product is located.
Five, sticky. The viscosity of hot melt adhesives is divided into early tack and late tack. Only the early viscosity and the late viscosity are consistent, so that the hot melt adhesive and the adherend remain stable. In the production process of hot melt adhesive, it should be guaranteed to have antioxidant, halogen resistance, acid and alkali resistance and plasticity. The viscosity of the hot melt adhesive varies depending on the material of the adhesive. Therefore, different hot melt adhesives should be selected according to different materials.
