The composition and characteristics of hot melt adhesive

What is hot melt adhesive?

Hot melt adhesives are thermoplastic materials composed of stabilizers, additives, pigments and polymers, sold as solid, cylindrical rods or pellets. The sticks are melted and applied using a hot melt spray gun or sprayer.

Volatile Organic Compounds (VOCs)

Volatile organic compounds (VOCs) are organic compounds that are volatilized during production or released into helium. On a global scale, there are more and more regulatory issues regarding VOCs and their impact on health and the environment. A key market advantage of hot melt adhesives is that they are not considered VOCs.

Hot melt component

The hot melt consists of three main components: a high molecular weight polymer, a binder, and a plasticizer.

(1) A polymer as a main adhesive.

(2) Tackifiers or resins provide more adhesion and wetting properties.

(3) The ability of plasticizers (wax or petroleum) to control viscosity and small machinery is easy to dispense.

Polyolefin type

The most common hot melt adhesive is vinyl acetate (EVA). Styrene-butadiene is the second most popular. Other categories include polyamides, thermoplastic polyurethanes and polyolefins (PO).

Solvent based adhesive

Solvent based adhesives have traditionally been used in the automotive, furniture and construction industries. A solvent is used as a base liquid for dissolving the binder-forming polymer. Depending on the type of solvent used, you may need to use a solvent-based adhesive with a brush, roll, spray, or other. Some solvents are flammable, many are toxic, and special precautions are required for cleaning and handling. The solvent evaporates quickly and may require special methods for cleaning after use.

Hot melt adhesive and environmental protection

Hot melt adhesives contain no solvents. Hot melt adhesives use water to dissolve the polymer. This is another reason why many different industries are moving from solvent-based products to hot melt adhesives.

Hot melt adhesives produce little pollution and have no effect on the environment. Unlike solvent-based adhesives, you don't need any special ventilation and are not flammable. The price is very low, so it reduces costs for high-volume industries like construction and packaging.

Therefore, governments, regulators and environmental organizations all support the use of hot melt adhesives on solvent-based products. Preferential policies developed by governments around the world will continue to help increase the use of hot melt adhesives, and the market share of hot melt adhesives is expected to come at the expense of solvent based adhesives.

Other advantages of hot melt adhesive

The excellent combination of hot melt adhesives and fast adhesion applications make hot melt adhesives particularly suitable for multi-purpose packaging applications. The shelf life of hot melts is much longer than solvent adhesives.

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