hot melt adhesive
Hot melt is usually an adhesive, therefore, known as Hot-Melt-Adhesive or Heat Seal Adhesive. Hot melts were previously always thermoplastic, a plastic that melts every time when it become hot. The appearance is often in granules (granules), but can also be packed in blocks, sheets and the tissues.
The adhesive bond is made by cooling of the molten hot melt glue (most around 160 degrees Celcius). Metals are often too cold and make the hot melt coold own quickly. A kind of shock effect may occur. This may eventually lead to a poor adhesion. Preheating of the metal provides a solution. It is also advisable to judge a hotmelt compound, after 24 hours of application, on strength. Eventhough there are special hotmelts available for extreme cold or hot conditions.
Hot melt adhesives contain no solvents. They can often on the following basis:
EVA
Polyolefin
Metallocene
Polyamide
Polyester
In addition to the thermoplastics products, there are also as hot-melt adhesives based on PUR; polyurethane reactive hot melts. The first initial strength of the adhesive bond is achieved by the cooling of the hot melt, the bond can then still not be fully loaded. Afterwards, due to humidity, further reactive curing (polymerization) takes place.
Fields of application of hot melts are:
Construction Adhesive (automated systems, in the production of countertops, doors, panels, white goods, etc.)
Packaging (sealing boxes, primary and secondary packaging, labeling)
paper industry (production of boxes, printing products, promotions)
Bookbinding
Furniture