Apparatus for dispensing thermoplastic material from containers

In apparatus for dispensing thermoplastic material from a container which apparatus is of the type including a follower having a shape corresponding to the interior of the container, means for urging the follower toward the thermoplastic material in the container, a heat source carried on the follower, and a pump having an inlet in the follower for removing the material, an improved heat exchanger structure for effecting transfer of heat energy from said heat source to the material adjacent the follower to render the material flowable comprising a plurality of groups of rigid heat conductive fins fixed to the follower in heat conductive relation to said heat source, each said group including a plurality of substantially straight parallelly and equally spaced apart fins that define between each adjacent pair a channel having a first extremity, a second extremity remote from said first extremity and a substantially uniform cross section between said extremities, said groups being sufficient in number and configuration to be substantially coextensive with said follower, said groups being oriented so that said first channel extremities are closer to said pump inlet than said second channel extremities, and means for defining a flow passage in communication with the first extremities of said channels and extending to said pump inlet, said flow passage having a cross-sectional area at least as large as that of the channels, said channels intersecting said passage at obtuse angle so as to avoid restriction of flow from said channels into said passage.