Hot melt adhesives (HMA, hot melt adhesive) are solvent-free adhesives that become liquid with heat and are then applied to the material in this molten state. To achieve good adhesion, the bonding of the substrates must be within the open time take place. The cooling of the hot melt realizes a fast powerful connection.
Hot melt adhesives form a physical bond, a chemical change does not occur with these thermoplastic systems, but with PUR hot melts. Modern hot melt adhesives offer excellent processing properties, easy applicability in automatic production systems and a wide adhesion range on a wide variety of materials. The short pressing times, colloquially referred to as drying time, enable direct further processing and thus high production speeds.
Types of hot melt adhesives
There is a wide range of different high-performance adhesives, which with their special properties provide an ideal process solution for the respective application - even for specific and complex requirements. There are EVA hot melt adhesives for standard applications, and there are also those for plastics that are difficult to glue polyolefin and PSA hot melts available.
The advantages of a hot melt include:
- 100 % solids content, so also for non-porous materials such as plastics, plastics and metal.
- No dangerous solvents
- No water, good filling capacity.
- High production speeds, adaptable to existing production lines and compact machine construction.
- No drying nozzles.
- No need to flush and seal the adhesive system during longer downtimes
- Adheres to many materials, stone, glass, plastics, PE, PP, PET, EPS, cardboard and wood.
- Also glues and adheres uneven surface.
- Surfaces are not affected and do not expand by water.
- Hot melt can be very elastic.
- Heat seal and pre-coating possible. Can be reactivated by, for example, a hot plate or iron.
- Adhesive bond can be removed and restored by means of heat