Inert gas

A gas or air mixture that has the task of displacing atmospheric oxygen or moisture.

Inert gases are used in melters to avoid undesirable premature chemical reactions when processing PUR / POR hot-melt adhesives. Nitrogen is normally used. This use of inert gas is referred to as inert gas application.

In the case of reactive hot-melt adhesives that are processed from a bag pack, there is no necessity for inert gas to be applied. A pneumatic cylinder presses the bag against a sealing ring, thus protecting the adhesive from humidity. In the HB 4000 bag melters, the hot-melt adhesive is not unpacked from the bag: Only an opening in the bottom of the bag is required before melting.

Inert – very slow to react, involved in only a few chemical reactions.

Inert gases include, for example, nitrogen, carbon dioxide and the noble gases (helium, neon, argon, krypton, xenon and radon).

However, the use of inert gas for hot-melt adhesives is a declining trend. Today, compressed air dryers are increasingly being used for cost reasons.