Apparatus for liquefying a thermoplastic plastic

Abstract

An apparatus for liquefying a polyurethane based thermoplastic adhesive which includes a heatable sealed supply container having an upper portion for receiving a downwardly open transport container for the adhesive and a lower portion serving as a buffer volume. A base portion is arranged below the supply container and includes a collecting trough leading to an outlet passage. A cover is provided at the upper end of the supply container and a conduit supplies an inert gas to the interior of the supply container. The conduit also opens into the interior of the transport container. A mandrel having a tip is provided at the inner side of the cover and the tip penetrates the transport container when the cover is closed. The inert gas is provided through an outlet opening located in the side wall of the tip of the mandrel. The gas supply through the conduit is periodically interrupted by a magnetic valve operated by a timer which only opens the valve for short periods, which provides an appreciable gas saving.

Dependencies are inferred from the claim text.