Hot melt adhesives exist in solid form and are classified by different types of raw materials. Polyurethane (Polyurethane Hot Melt Adhesive) is a reactive type of hot melt adhesive for the base material. After cooling, there will be a chemical cross-linking reaction. Rubber-based pressure-sensitive hot melt adhesives are mainly used in packaging, labels ,metal back stickers and so on. https://www.deepmaterialcn.com/hot-melt-adhesive.html https://www.pinterest.com/hotmeltadhesive552 https://www.linkedin.com/in/hotmeltadhesive5/ https://www.jigsawplanet.com/waterproofadhesi?viewas=036d5b3a78f3 https://app.roll20.net/users/10639849/hot-melt-adhesive https://www.metal-archives.com/users/hotmeltadhesive5 https://os.mbed.com/users/hotmeltadhesive5/ https://app.lookbook.nu/hotmeltadhesive5 https://artistecard.com/hotmeltadhesive5