Hot melts adhesives (HMA) are mainly made from thermoplastics that it only can be used if we melt the polymer beyond its melting point.
The main advantage of hot melts over other kinds of adhesives is that they do not require a solvent. Hence, environmental issues are avoided. Furthurmore, they also set rapidly and require a smaller space for storing.
Hot melts are used in packaging, paper laminates, non-wovens, bookbinding, labeling, textiles and other industries.
Hot melt adhesives majorly comprise of three main components: polymer/ blend of polymers, tackifying resin, wax/oil. Apart from these ingredients, hot melts may include an antioxidant, filler, UV stabilizer, pigment and others.
The base polymer is the molecular backbone of the systems, and its duty is to provide the inherent strength and chemical resistance as well as the application characteristics.
Tackifying resin is added to improve initial adhesion and to modify the base polymer.
Processing oils and waxes are used to adjust viscosity and set times.
Fillers helps to adjust certain properties such as melt viscosity, thermal expansion coefficient, set time.