JPS6469312A - Method and apparatus for processing trimmed edge in calendering - Google Patents

Abstract

PURPOSE:To reduce the energy for replasticization and the cost of equipment for grinding, pneumatic conveying and the like and obtain a high quality product by a method wherein plasticized resin, which is extruded with an extruder, is formed in the shape of sheet at a calender roll section and the edge parts of the sheet are trimmed and sent back to the extruder so as to be deaerated in the extruder and fed again to the calender roll section. CONSTITUTION:Resin, which is prepared by kneading end plasticizing raw material fed from a hopper 2 with a kneader 3, is extruded from the die 13 of an extruder 4 in the form of bar and fed through a conveyer 15 to a calender roll section 14. The edge parts of a formed sheet 24 are trimmed with cutters 17. The trimmed edges 25 are taken out by a lateral conveyer 19 and further sent back by a longitudinal conveyer 20 to the feeding port 8 of the extruder 4 again. The trimmed edges 25 are heated with the infrared burner 23 of a heating device 21 and sent back to the extruder 4 under the heated state. The trimmed edges 25 are mixed with new material sent from the kneader 3 and extruded again from the die 13. Since vacuum deaeration is done through the vent hole 11 of a cylinder section 10 in order to prevent bubbles from mixing, a high quality sheet is manufactured.