Apparatus for preparing pellets of poly(trimethylene terephthalate)
View Patent ↗An apparatus is described having an extrusion means for extruding a molten polymer strand; a pelletizer; and a trough disposed to convey a polymer strand from the extrusion means to the pelletizer; the trough has an interior bottom surface; a water dispensing means disposed to provide a layer of water on a first portion of the interior bottom surface that is proximate to the extrusion means; a mesh or perforated surface disposed in the trough downstream from the water dispensing means, disposed to permit the separation of water from a water-immersed strand incident upon it; and a second portion of the interior bottom surface downstream from that mesh or perforated surface, disposed to contain a layer of water.
1. An apparatus comprising
(a) an extrusion means for extruding a molten polymer strand;
(b) a pelletizer; and, disposed between said extrusion means and said pelletizer
c) a single downward inclined trough, said trough having a plurality of regions comprising
i) a first quench region proximate to and downstream from said extrusion means, said first quench region comprising
(A) a first trough segment; and,
(B) a water dispensing means disposed to provide water to said trough segment;
ii) an annealing region downstream from and proximate to said first quench region, said annealing region comprising a mesh or perforated surface disposed just above the water surface to permit the separation of water from a water-immersed polymer strand incident upon it; said mesh or perforated surface disposed such that the water so separated will flow through the mesh or perforated surface back into said trough; said mesh or perforated surface having an adjusted length to provide a strand residence time of 0.3 to 5 seconds upon said mesh or perforated surface. and,
iii) a second quench region downstream from said annealing region, said second quench region comprising a second trough segment disposed to contain a layer of water.
2. The apparatus of claim 1 wherein the extrusion means is a screw-type extruder.
3. The apparatus of claim 1 wherein the extrusion means is a continuous polymerizer.
4. The apparatus of claim 1 wherein the water dispensing means is selected from any one of water spray, water pump, hose and tube.
5. The apparatus of claim 1 wherein the second quench region comprises a second water dispensing means.