hotmmelts

Hot melts, also known as hot melt adhesives, are thermoplastic polymers that are solid at room temperature and become flowable when melted. They bond substrates by wetting and then cooling to form a solid bond without curing chemistry.

Most common is EVA-based (ethylene-vinyl acetate) adhesives, often with tackifiers to adjust viscosity and bond performance. Other families include polyolefin-based hot melts for higher temperature resistance, and polyamide or polyurethane hot melts for specialized performance. Additives such as waxes, tackifiers, and plasticizers tailor setting speed, flexibility, and heat resistance.

Hot melts are applied using dedicated equipment: handheld glue guns, cartridge or cartridge-indexed systems, and industrial extruders. The material is heated to processing temperature and dispensed as a molten adhesive, which rapidly cools. Processing temperatures vary by formulation, with EVA-based systems typically melting in the 120 to 180 C range and some polyolefin-based systems running higher.

Used in packaging, carton sealing, bookbinding, woodworking, furniture assembly, footwear, textiles, electronics assembly, and automotive interiors, hot melts are valued for fast setting and strong initial tack. They are often chosen for solvent-free bonding and automation-friendly production.

Advantages include fast bonding, good gap-filling, and compatibility with automated lines. Limitations include performance loss at elevated temperatures, sensitivity to moisture or UV exposure in some formulations, and difficulty bonding certain substrates without surface preparation.

Many hot melts are formulated to be low in odors and VOCs, but disposal and recycling can be challenging where adhesives must be removed. They are generally stable in storage when kept in cool, dry conditions.