Will hot melt melt in a microwave?
In the end it will. But as microwaves are designed to make substances hot that contain water, a microwave is probably not the best option to melt hot melt. An oven set at the provided application temperature of the hot melt adhesive, is probably a better option.
For commercial purposes professional heated glue systems such as Nordson and Robatech are probably the beste solution. For small applications and research purposes, there are manual hot melt glue guns available, also for bulk/granule hot melt adhesives
Will a hot melt sealed tray or box pop open in a microwave?
That depends on the amount of heat, the construction of the packaging and the formulation of the hot melt, mostly on the end temperature. It is a reasonable risk to take into account if boxes and trays are glued with hot melt.
Can I prevent boxes and trays will pop open?
For food purposes, our single hot melt products are Hotpack 65 and Hotpack 95, as pictured above. The most reliable solution is to make a combination gluing of a hot melt for the fast setting in the machine, and a waterbased adhesive for the durable, microwave resistant bond. We can advice in machine equipment and integration as well.
Polyurethane hot melt
Polyurethane hot melt adhesives can withstand very high temperatures and offer a high green strength for fast processing in production. Polyurethane hot melts are mostly not food safe, but more applied in furniture applications and non-food packaging.