Abstract: Relates to plastic material molding machines and to a unitary assembly of parts installable between the hopper and the plastic pellet material inlet opening of the molding machine for providing bodily translatable movement of the hopper to one side of the machine where the remaining contents of the hopper may be discharged into a drainage collector for possible re-use at a later time. The translatable movement of the hopper is usually performed when the hopper content is to be changed and is carried out by moving or sliding the hopper while in upright position along a track extending laterally of the machine. The track occupies the upper position of a gas-tight conduit, preferably rectangular in cross section, which serves to deliver a gaseous medium to the contents of the hopper, such as hot dry air for the purpose of removing moisture from the plastic pellets in the hopper.