Flow gap control in planetary extruder - by flow restrictor(s) attached to radial rotors distributed uniformly round circumference of gap and adjustable in their angle to flow

摘要

In the annular gap between two parts of the planetary rollers (or between the front ring of planetary extruders) the flow section for melt is varied by an arrangement which consists of a retaining ring and at least one ring running on it. The restrictor element has a number of radial rotors disposed uniformly round the circumference; each such rotor has a restrictor strip located diametrically in the flow gap between the successive planetary roller members or between the member and the front ring after it (in the direction of extrusion); the width of each such strip is at least equal to the dia. of the rotor. The thickness of each strip is small compared with its width; the rotors with their restrictor strips can be adjusted (at least over an angle of 90 deg.C) between one position at right angles to the longitudinal axis of the planetary roller parts and cylinders and another position which is parallel. ADVANTAGE - The flow restrictor is simple to install. It allows the section of flow to be adjusted continuously or in stages.