Patent ID: 8057726

Claim:
A process for melt processing a polyester comprising: a. introducing polyester particles into a melt processing device; b. melting the polyester particles in the melt processing device to produce a molten polyester; and c. forming an article from the molten polyester wherein the polyester particles comprise: (i) a carboxylic acid component comprising at least 80 mole percent of the residues of terephthalic acid, derivatives of terephthalic acid, or mixtures thereof, and (ii) a hydroxyl component comprising at least 80 mole percent of the residues of ethylene glycol, based on 100 mole percent of the carboxylic acid component residues and 100 mole percent of the hydroxyl component residues in the polyester particles and the polyester particles are further characterized by one or more of the following: 1. have at least two melting peaks wherein one of the at least two melting peaks is a low peak melting point with a range from 140Â° C. to 220Â° C. and having a melting endotherm area of at least the absolute value of 1 J/g; 2. have one or more melting peaks at least one of which when measured on a DSC first heating scan, has a heating curve departing from a baseline in the endothermic direction at a temperature of less than or equal to 200Â° C.; 3. have an It.V. at their surface which is less than 0.25 dL/g higher than the It.V. at their center; or 4. have not been solid stated; wherein the melt processing device comprises a screw with a total length, L, a feed zone length in the range from 0.16L and 0.45L, a taper angle, Ï†, in the range from 0.5 degrees and 5.0 degrees, and a compression ratio, CR, in the range from 2.0 and 5.0.