Extrusion plant for production of strand-like products, in particular cosmetic crayon refills, involves cutting extrudate with knives which move in conveying direction and transverse to this direction

摘要

An extrusion head(2) is followed by a pair of knives symmetrically arranged relative to a continuous extrudate moving in a first conveying direction(R1). Each knife(4) is guided by a eccentric guide(5) which produces a cutting movement of the knife transverse to the first conveying direction and an overlapping feed movement in the conveying direction. During operation each knife(4) forms an angle of not less than80[deg] with the first conveying direction(R1). Guidance for each knife is effected by a slot moving on a peg and knife movement is controled by a sensor unit(12) which detects extrudate emerging from the extrusion die. The sensor unit moves relative to the extrusion head(2) in the first conveying direction and comprises two light boxes(13,14), one behind the other in the movement direction, for extrudate detection. Spacing of the light boxes and between the sensor unit and extrusion head(2) can be adjusted by a motor drive system. A diverter(19) removes faulty products from a conveyer belt(3) following the knives. A transporting roll(20) following the conveyer moves the cut sections of extrudate into a second conveying direction(R2) transverse to the first direction. Movement of the knife in the conveying direction exceeds the output speed of extrudate by not less than5%. The conveyer belt speed exceeds the extrudate output speed by not less than50% and maximum speed of the knife in the first conveying direction by not less than30%. An independent claim is included for a process for manufacturing a strand-like product involving: a) extrusion of a continuous product in a first conveying direction(R1); b) cutting of the extrudate with a pair of knives, one on each side of the extrudate, and moving in both the conveying direction and transverse to it where the speed in the conveying direction exceeds the speed of the extruded product on emerging from the extrusion head.