what are pressure sensitive (psa) hot melt adhesives?
Pressure-sensitive adhesives are adhesives which forms a bond when contact or pressure is applied to merge the adhesive with the substrate. No solvent, or heat is needed to activate the adhesion. PSA hot melts can be used to produce (e.g. coating of a plastic laminate) pressure-sensitive tapes, labels, glue dots, and a variety of other products.
The degree of bond is often influenced by the amount of pressure to e.g. the self adhesive tape.
Substrates or laminates with a low surface energy may be difficult to coat, partly because of the "Wetting" of the surface.
PSA hot melt adhesives are usually designed to form a quick and very sticky bond and keep a bond in a wide temperature range, from deepfreeze to hot circumstances. Hot-melts PSAs typically lose their tack at low temperatures (The Tg Temperature, glass transition temperature) and higher temperatures there is a Shear Adhesivon Fail Temperature (SAFT). Intercol has a range of special hot melt psa adhesives to function at high or low temperatures. It is important to select the proper adhesive for the end application for which it's intended to use.