Abstract: Compartmentalized chips of at least two chemically similar crystallizable thermoplastic polymers each having a different intrinsic viscosity placed in separate zones are disclosed. These compartmentalized chips exhibit thermal characteristics that are different from the traditional technique of homogeneously combining the two materials into the chip. These compartmentalized chips in their amorphous, crystalline and solid phase polymerized forms exhibit a longer crystallization half time than the homogeneous mixture, thus permitting faster injection cycle times when compared to an equivalent homogenous mixture.

Abstract: Compartmentalized chips of at least two chemically similar crystallizable thermoplastic polymers each having a different intrinsic viscosity placed in separate zones are disclosed. These compartmentalized chips exhibit thermal characteristics that are different from the traditional technique of homogeneously combining the two materials into the chip. These compartmentalized chips in their amorphous, crystalline and solid phase polymerized forms exhibit a longer crystallization half time than the homogeneous mixture, thus permitting faster injection cycle times when compared to an equivalent homogenous mixture.

Abstract: Compartmentalized chips of at least two chemically similar crystallizable thermoplastic polymers each having a different intrinsic viscosity placed in separate zones are disclosed. These compartmentalized chips exhibit thermal characteristics that are different from the traditional technique of homogeneously combining the two materials into the chip. These compartmentalized chips in their amorphous, crystalline and solid phase polymerized forms exhibit a longer crystallization half time than the homogeneous mixture, thus permitting faster injection cycle times.

Abstract: This invention discloses a process for producing a polyester resin having a low acetaldehyde generation rate comprised of the steps of polycondensing the polyester resin in the presence of tin and antimony; wherein the tin is present within the range of 50 to 110 ppm of the polyester resin and the antimony is present from 105 ppm to 265 ppm of the polyester resin, and solid phase polymerizing the polyester resin for sufficient time so as to increase the intrinsic viscosity of the polyester resin by at least 0.15 dl/g.

Abstract: A thermoplastic composition, such as PET, contains an inert iron compound such as FeP, FeSi, or combinations thereof, having no chemical activity in the PET, with or without certain quantities of elemental metals, such as antimony, and a reducing agent or other stabilizer such as phosphite or phosphoric acid. A method for forming this composition is also disclosed. The composition may also optionally contain a color stabilizer, a DEG inhibitor and stress crack inhibiting agents.

Abstract: An improved process for manufacturing highly uniform industrial yarn which exhibits high tenacity, high modulus and very low shrinkage which comprises melt spinning polyethylene terephthalate into spun filaments and subsequently drawing the spun filaments in a heated zone to a draw ratio of at least about 1.05:1; wherein the spun filaments have a birefringence of at least about 0.075 and a crystallinity of at least about 10%; wherein the spun filaments are in the heated zone for a residence time of at least 0.3 seconds; and wherein the yarn in the heated zone is at a temperature which is between the glass transition temperature and the melting temperature of the polyethylene terephthalate.

Abstract: Specific color imparting compounds, including colorants and catalysts are used to produce a polyester resin having an amber color. The compounds are added during the preparation of the polymer and the resins produced can be utilized to make various containers or packages to hold liquids or solids.

Abstract: This invention relates to a method of improving the brightness and color of a polyester resin and reducing the acetaldehyde content by passing the resin through molecular sieves at a temperature of from 230.degree. C. to about 300.degree. C.

Abstract: There is disclosed low carboxyl high molecular weight polyester compositions comprising the product of the reaction of an aziridine compound with the polycondensation product derived from the reaction of a diol and a dicarboxylic acid or C.sub.1 to C.sub.4 alkyl ester thereof and processes for preparing said compositions.