Definition of Hot Melt Adhesives

Hot melt adhesive (HMA), short for hot melt adhesive, is a significant category of adhesives characterized by 100% solid content, absence of solvents, environmental friendliness, non-toxicity, and rapid curing. Typically solid at room temperature, it melts into a viscous liquid when heated to a specific temperature. After application, wetting the substrates, and pressing, it cools to room temperature and completes the bonding process within seconds.

Hot melt adhesives are widely used in tapes, labels, packaging, hygiene products, medical applications, woodworking and furniture, bookbinding, and automotive components. This type of adhesive is solid at room temperature, solvent-free, environmentally friendly, non-toxic, and capable of bonding various substrates quickly, efficiently, and safely. Consequently, the usage volume of hot melt adhesives is continuously increasing.

Application Methods of Hot Melt Adhesives

Hot melt adhesives are heated and melted in a hot melt adhesive machine until they become a flowable liquid with certain tack. The liquid adhesive is then delivered through hoses and applicators onto the substrate surface. Bonding is completed after application and pressure. The most common application methods include dot application, spray coating, and roller coating.

Hot melt adhesive coating machine

A hot melt adhesive coating machine is electromechanical equipment that melts solid hot melt adhesive and uses a pressure device to deliver the liquefied adhesive to a coating device for substrate application. It integrates precise temperature control, pressurized fluid delivery, and extrusion coating functions. Additionally, it features automatic control and the ability to automatically synchronize with production line speeds.

The hot melt adhesive coating machine primarily consists of: a hot melt adhesive unit, mold temperature control unit, unwinding unit, coating unit, cooling and curing unit, traction and winding unit. Typically, the winding unit includes a lamination section, allowing another substrate to be laminated with the coated substrate.

Hot melt adhesive coating machines are widely used for coating and lamination in industries such as tapes, self-adhesive labels, medical dressings (e.g., medical tapes, infusion securement devices, medicated patches, bandages), hygiene products (e.g., diapers, sanitary napkins, protective clothing), textile fabric lamination, and waterproof roofing materials.