Extrusion plant to process recycled thermoplastics with impurities - has leakage flow filter between extruder and die, rotating about central axis and having semi=circular feed chamber, melt inlet and leakage flow outlet

摘要

Plant has a leakage flow filter (6), in between the extruder outlet and the die. Filter unit (6) comprises: i) rotating hollow filtering cylinder (7) which rotates about its own axis; ii) at least one semi-circular feed chamber (8) surrounding the hollow filter cylinder (7) and including both a melt entry (9) and leakage flow outlet gap (10); iii) lips on a sliding shoe at the leakage flow gap (10); and iv) heaters for the leakage flow melt. Quantity of leakage flow melt and cleaning capacity of the filter (6) are controlled by i) rotational speed of the filter cylinder (7); ii) heating the leakage flow melt; iii) using melt pressure; (iv) varying leakage flow outlet gap (10). USE/ADVANTAGE - For extrusion of recycled thermoplastic contg. impurities particles. Removes impurities with low pressure loss, has high efficiency and increases working life of filtering unit before interchange or cleaning.