PROCESS FOR MAKING HIGHLY CRYSTALLINE SHAPED PART FROM PET OR PEN

摘要

A process for making a shaped part from a polymer selected from polyethylene terephthalate (PET) and polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) by using a compacting tool comprising a die having a cavity and a punch having an outer surface. The process comprises the steps of: a) placing particles of the polymer in the cavity of the die heated to a compaction temperature, wherein the polymer has an intrinsic viscosity of at least 0.45 dL/g and the particles have an average particle size of 0.5-4000 μm, b) pressing the particles in the die cavity at a pressure of at least 3 MPa for 5-15 minutes while maintaining the temperature of the die at the compaction temperature and c) removing the shaped part from the die cavity. When the polymer is PET, the compaction temperature is 235-259° C. When the polymer is PEN, the compaction temperature is 250-275° C.

主权项

1. A process for making a shaped part from a polymer selected from polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) by using a compacting tool comprising a die having a cavity and a punch having an outer surface corresponding to the cavity, wherein the process comprises the steps of:
a) placing particles of the polymer in the cavity of the die which has been heated to a compaction temperature, wherein the polymer has an intrinsic viscosity of at least 0.45 dL/g and the particles have an average particle size of 0.5-4000 μm, b) pressing the particles in the heated die cavity at a pressure of at least 3 MPa for 5-15 minutes while maintaining the temperature of the die at the compaction temperature to form the shaped part and c) removing the shaped part from the die cavity, wherein when the polymer is PET, the compaction temperature is 235-259° C. and wherein when the polymer is PEN, the compaction temperature is 250-275° C.