Abstract: Apparatus for forming plastic melts into strands or filaments wherein molten plastic material is delivered by a pump from a container through a feed line to a distributor means which has a first outlet for the molten plastic material to be processed and a second outlet to a return line leading back to the container, and a control valve is located in the return line to regulate the return of flow of the plastic material to the container, the return flow of the plastic material to the container, the return line and associated controls functioning to avoid undesirable plugging of the apparatus or damage to the plastic materials during interruptions in operations, and the like.

Abstract: A method of and apparatus for continuously and controllably proportioning the components of a vulcanizable mixture in a screw extruding machine having at least one screw shaft and comprising a first inlet and at least one second inlet to the working region of the screw shaft or shafts, the screw shaft or shafts being rotated at constant speed and a back-pressure generating stage being arranged in the said working region, the features of the method being (1) that one component (preferably the main bulk component) of the feed that is to be mixed is introduced into the first inlet in an undosable condition (for instance in the form of plates, slabs or of a non-flowable bulk form) but at a rate controlled by the back pressure produced by the back-pressure generating stage, the latter being located at a given distance away from, and on the down-stream side of, the first inlet as well as upstream in relation to the second or a further inlet, through which an additive material is preferably fed in measured quantity

Abstract: Apparatus for filtering molten plastics and for extruding plastic strands has a filter combined with a die head into an interchangeable unit. Plastics strands are discharged from the die head. The interchangeable unit is movable transverse to the direction of flow of plastics material.

Abstract: Apparatus for use in processing molten plastics is connected to a polymerisation vessel and has an outlet, a pump and three-way gate valve downstream of the pump. The three-way valve has an inlet connected to the pump, an outlet connected to the vessel and an outlet connected to the outlet of the apparatus.

Abstract: In order to dry wet strands of plastics which have been passed through a cooling bath during the manufacture of plastics granules, we provide an apparatus and a process in which the strands are fed through a gap and a current of air is passed through the gap in order to dry the strands.