MANUFACTURE OF SPHERICAL PARTICLES OUT OF A PLASTIC MELT
First Claim
1. A method for manufacturing spherical particles out of plastic, in particular a prepolymer- or polymer melt of a polycondensate, e.g., PET, PBT, PEN, PA or PC, wherein the melt is dripped into droplets by means of an dripping nozzle with numerous melt outlet holes, and the droplets are solidified into particles after falling at least part of a drop distance, characterized in that, at the end of the drop distance, the particles make their way into a receiving area in which at least some of the particles are swirled in such a way as to generate turbulences to move the particles toward the middle of the area and/or area outlet hole.
0 Assignments
0 Petitions
Accused Products
Abstract
The invention relates to a method and a device for producing spherical particles from a melted mass of plastic. According to the invention, said melted mass is transformed into droplets by means of a droplet-forming nozzle (10); after falling a certain distance, the droplets are crystallised at least on the surface thereof; the droplets are then supplied to a crystallisation stage in which they are fully crystallised; and are then supplied to an postcondensation stage wherein solid phase polycondensation takes place. In order to ensure surface crystallisation without the risk of adhesion both among the drops and to parts of the device, the drops fall in a crystallisation stage (45) having a cloth element or a sheet metal element comprising openings or a fluidised bed chamber through which gas flows in order to swirl the drops.
-
Citations
80 Claims
- 1. A method for manufacturing spherical particles out of plastic, in particular a prepolymer- or polymer melt of a polycondensate, e.g., PET, PBT, PEN, PA or PC, wherein the melt is dripped into droplets by means of an dripping nozzle with numerous melt outlet holes, and the droplets are solidified into particles after falling at least part of a drop distance, characterized in that, at the end of the drop distance, the particles make their way into a receiving area in which at least some of the particles are swirled in such a way as to generate turbulences to move the particles toward the middle of the area and/or area outlet hole.
- 49. A device for manufacturing spherical particles out of plastic, in particular a prepolymer- or polymer melt of a polycondensate, e.g., PET, PBT, PEN, PA or PC, with a nozzle array that drips the plastic melt along with a downstream drop distance in a drop tower, characterized in that the drop distance passes over into a receiving area in which at least some of the particles can be swirled in such a way as to generate turbulences to move the particles toward the middle of the area and/or area outlet hole.
-
50. The device for manufacturing spherical particles out of plastic, in particular a prepolymer- or polymer melt of a polycondensate, e.g., PET, PBT, PEN, PA or PC, with a nozzle array that drips the plastic melt along with a downstream drop distance in a drop tower, characterized in that a device for exposing the particles to a liquid is allocated to the drop tower.
Specification