Hotmelts

Hotmelts are solvent-free and water-free adhesives based on thermoplastic polymers. On cooling to room temperature, they solidify reversibly while developing bond strength (setting).

The adhesive then rapidly bonds substrates with high initial strength, allowing easy downstream processing of the substrates to be bonded. Hotmelt adhesives are 100 percent adhesives. This means that no application agent, such as water or solvent, is added to the formulation which would subsequently escape during the setting process.

Formulations are with base polymers, resins (up to 40 percent), plasticizers, and waxes (up to 40 percent) or fillers (up to 50 percent), and additives (usually < 5 percent). Hotmelt adhesives now have a market share of about 30 percent, which is steadily rising.

Advantages

Free of solvent and water
Stable in storage
Short bonding times
High initial strength

Applications

Hygiene industry (diapers, sanitary napkins)
Wood and fashion industry (edge-banding)
Packaging industry (paper, cardboard, food packaging)
Bookbinding (spines of paperbacks)
Textile industry (men’s and women’s apparel)
Automotive industry (car carpeting and seat covers, lamination of headlining)
Shoe industry (e.g., toecaps for sports shoes)
Construction industry (only as sealant, e.g., in production of insulation glass)