Foaming thermoplastic compositions, e.g. melt adhesives.

摘要

Method and apparatus for providing a foamed mass of thermoplastic e.g. a hot melt adhesive on a substrate by introducing a foaming agent to the composition which has been melted by heating in excess of 100 DEG C. The foaming agent is provided by water entrained in a carrier gas and is preferably introduced to the thermoplastic as it is dispensed from an applicator. The invention permits foaming of adhesives using readily available raw materials and simple equipment readily derivable from existing hot melt adhesive applicators.