Hot Melt Adhesives
Hotmelt adhesives (HMA), also known as hot glues, are generally 100% solids formulations based on thermoplastic resins. They are solid at room temperature and can be softened, reshaped, and dispensed upon heating above their softening point. Solidification takes only seconds after dispensing, or in other word, these thermoplastic adhesives reach full strength once they cool to room temperature. This minimizes clamp time and allows for rapid assembly. Hot melt adhesives are also easy to clean with low to no toxicity and the application and bonding can easily be automatized. Furthermore, they have excellent gap filling capabilities and bond a wide variety of porous and non-porous substrates including pre-painted steel and polyolefin plastics.
Solvent Based Adhesives
Solvent-borne contact adhesives based on polyurethane (PU or PUR) are characterised by resistance to plasticisers and good adhesion to the most different materials (except bare metal). Therefore they are used for bonding soft PVC to each other as well as to many other materials. Similar to CR adhesives, they can also be reactivated by heat (e.g. in vacuum deep-drawing methods for the lamination of formed parts with flexible top layers).