Patent ID: 8079158

Claim:
A process comprising providing a pressurized slurry comprising thermoplastic synthetic polymer particles in combination with a liquid at a liquid temperature greater than the normal boiling point of the liquid and at a pressure equal to or greater than the vapor pressure of the liquid at the liquid temperature, feeding the pressurized slurry to a separation zone, and within the separation zone: a. separating the liquid from the particles, b. drying the particles, while under a high pressure equal to or greater than the vapor pressure of the liquid; and c. decoupling the particles from the separation zone to produce decoupled particles by depressurizing the particles to a low pressure below the vapor pressure of the liquid at the liquid temperature within the separation zone while maintaining the high pressure on the particles prior to depressurization at above the vapor pressure of the liquid at the liquid temperature; and wherein the particles comprise a condensation polymer comprising a polyester polymer comprising: i. a carboxylic acid component comprising at least 80 mole% of the residues of terephthalic acid, derivates of terephthalic acid, naphthalene-2,6-dicarboxylic acid, derivatives of naphthalene-2,6-dicarboxylic acid, or mixtures thereof, and ii. a hydroxyl component comprising at least 60 mole% of the residues of ethylene glycol or propane diol, based on 100 mole percent of carboxylic acid component residues and 100 mole percent of hydroxyl component residues in the polyester polymer, wherein the temrerature of the decoupled rarticles urjon the decourling is within 60° C. of the temperature of the liquid entering the seraration zone.