Abstract: The invention is a method for the late introduction of additives into polyethylene terephthalate. The method employs a reactive carrier that functions as a delivery vehicle for one or more additives. The reactive carrier reacts with the polyethylene terephthalate, thereby binding the reactive carrier in the polyethylene terephthalate resin and preventing the emergence of the reactive carrier and additives from the polyethylene terephthalate during subsequent thermal processing.

Abstract: The present invention relates to slow-crystallizing polyethylene terephthalate resins that possess a significantly higher heating crystallization exotherm peak temperature (TCH) as compared with those of conventional antimony-catalyzed polyethylene terephthalate resins. The polyethylene terephthalate resins of the present invention are especially useful for making hot-fill bottles having exceptional clarity.

Abstract: The present invention relates to slow-crystallizing polyethylene terephthalate resins that possess a significantly higher heating crystallization exotherm peak temperature (TCH) as compared with those of conventional antimony-catalyzed polyethylene terephthalate resins. The polyethylene terephthalate preforms of the present invention, which possess improved reheating profiles, are especially useful for making polyester bottles that have exceptional clarity and that retain acceptable dimensional stability upon being hot-filled with product at temperatures between about 195° F. and 205° F.

Abstract: The present invention relates to slow-crystallizing polyethylene terephthalate resins that possess a significantly higher heating crystallization exotherm peak temperature (TCH) as compared with those of conventional antimony-catalyzed polyethylene terephthalate resins. The polyethylene terephthalate resins of the present invention are especially useful for making hot-fill bottles having exceptional clarity.

Abstract: A polyester composition is disclosed that is particularly suitable for filament. The composition is formed of polyethylene terephthalate; polyethylene glycol in an amount sufficient to increase the wetting and wicking properties of a filament made from the composition to a level substantially similar to the wetting and wicking properties of cotton and other cellulosic fibers (natural or synthetic) but less than the amount that would reduce the favorable elastic memory properties of the polyester composition; and a chain branching agent selected from the group consisting of trifunctional alcohols and acids and tetrafunctional alcohols and acids that will copolymerize with polyethylene terephthalate, the chain branching agent being present in an amount sufficient to raise the melt viscosity of the polyester composition to a level that permits filament manufacture under conditions that are substantially the same as those under which filament can be formed from unmodified polyethylene terephthalate.

Abstract: The invention relates to a method for using spinel pigments to increase the infrared heat-up rates of thermoplastic resins and specifically polyester bottle resins. In particular, the method comprises adding spinel pigments to polymerized resins to increase the reheat rates of the resulting polyester pre-forms. When uniformly distributed, these spinel pigments absorb applied energy and thereupon transfer the energy to the polyester.

Abstract: The invention relates to a method for using spinel pigments to increase the infrared heat-up rates of thermoplastic resins and specifically polyester bottle resins. In particular, the method comprises adding spinel pigments to polymerized resins to increase the reheat rates of the resulting polyester pre-forms. When uniformly distributed, these spinel pigments absorb applied energy and thereupon transfer the energy to the polyester.

Abstract: The invention relates to a method for using spinel pigments to increase the infrared heat-up rates of thermoplastic resins and specifically polyester bottle resins. In particular, the method comprises adding spinel pigments to polymerized resins to increase the reheat rates of the resulting polyester pre-forms. When uniformly distributed, these spinel pigments absorb applied energy and thereupon transfer the energy to the polyester.

Abstract: A polyester composition is disclosed that is particularly suitable for filament. The composition is formed of polyethylene terephthalate; polyethylene glycol in an amount sufficient to increase the wetting and wicking properties of a filament made from the composition to a level substantially similar to the wetting and wicking properties of cotton and other cellulosic fibers (natural or synthetic) but less than the amount that would reduce the favorable elastic memory properties of the polyester composition; and a chain branching agent selected from the group consisting of trifunctional alcohols and acids and tetrafunctional alcohols and acids that will copolymerize with polyethylene terephthalate, the chain branching agent being present in an amount sufficient to raise the melt viscosity of the polyester composition to a level that permits filament manufacture under conditions that are substantially the same as those under which filament can be formed from unmodified polyethylene terephthalate.

Abstract: A polyester composition is disclosed that is particularly suitable for filament. The composition is formed of polyethylene terephthalate; polyethylene glycol in an amount sufficient to increase the wetting and wicking properties of a filament made from the composition to a level substantially similar to the wetting and wicking properties of cotton and other cellulosic fibers (natural or synthetic) but less than the amount that would reduce the favorable elastic memory properties of the polyester composition; and a chain branching agent selected from the group consisting of trifunctional alcohols and acids and tetrafunctional alcohols and acids that will copolymerize with polyethylene terephthalate, the chain branching agent being present in an amount sufficient to raise the melt viscosity of the polyester composition to a level that permits filament manufacture under conditions that are substantially the same as those under which filament can be formed from unmodified polyethylene terephthalate.

Abstract: A method is disclosed of producing a blended fabric of polyester and cotton with superior low pilling characteristics. The method comprises polymerizing a melt consisting essentially of terephthalic acid, ethylene glycol and at least about 1300 parts per million of pentaerythritol to an intrinsic viscosity of at least about 0.55 dl/g. The resulting polymer can be spun into filament, textured, cut into staple, spun into yarn, and formed into fabric. The method and resulting polyester also have advantages in the production of polyester bottle resin and the resulting bottles.

Abstract: A method is disclosed of producing a blended fabric of polyester and cotton with superior low pilling characteristics. The method comprises polymerizing a melt consisting essentially of terephthalic acid, ethlyene glycol and at least about 1300 parts per million of pentaerythritol to an intrinsic viscosity of at least about 0.55 dl/g. The resulting polymer can be spun into filament, textured, cut into staple, spun into yarn, and formed into fabric. The method and resulting polyester also have advantages in the production of polyester bottle resin and the resulting bottles.

Abstract: A method is disclosed of producing a copolymer of polyethylene terephthalate and polyethylene naphthalate. The method comprises esterifying a combination of a diester of naphthalene, terephthalic acid, and ethylene glycol to produce an esterification reaction mixture that includes the alcohol byproduct of the naphthalene diester, distilling the reaction mixture to remove at least a portion of the esterification byproducts from the reaction mixture in the form of a vapor stream of which the majority component is water vapor and which includes the alcohol byproduct of the naphthalate ester in the vapor state, and combusting at least a portion of the vapor stream under conditions sufficient to decompose at least a portion of the alcohol byproduct present in the vapor stream.

Abstract: A continuous process for producing polyethylene terephthalate polyester from terephthalic acid and ethylene glycol uses a stabilizer, preferably containing phosphorous, to produce a high quality polyethylene terephthalate polyester which is relatively free of the acetaldehyde and discoloration which are associated with the post-polymerization activity of a polymerization catalyst. The stabilizer is preferably added at or after the end of the polymerization reaction prior to polymer processing to deactivate the polymerization catalyst and can increase the throughput of the polyester without adversely affecting the thermal stability of the polyethylene terephthalate polyester. Alternatively, the late addition of the stabilizer can increase the thermal stability of the polyester without adversely affecting the throughput of the polyethylene terephthalate polyester.

Abstract: A method of recycling post-consumer polyester to obtain recycled polyester of sufficiently high purity to meet food packaging requirements is disclosed. The method includes cleaning comminuted pieces of post-consumer polyester to remove surface contaminants; melting the surface-cleaned post-consumer polyester pieces; extruding the post-consumer melt; blending the melt of post-consumer polyester with a melt of virgin polyester prepolymer; solidifying and pelletizing the blended melt while the virgin polyester prepolymer remains as prepolymer; and polymerizing the solid blended pellets in the solid state.

Abstract: Spent photographic film having at least a polyester base, blue dye, and a polyvinylidene binder layer, and from which the photographic emulsion has been removed, is treated to recover usable polyester. The spent photographic film is heated in cyclohexanone at a temperature sufficient and for a time sufficient to remove both polyvinylidene and dye compounds from the polyester base. The recovered polyester may then be mixed with virgin polyester and extruded to produce a polyester product comprising in part recovered polyester and in part virgin polyester.

Abstract: Spent photographic film having at least a polyester base, blue dye, and a polyvinylidene binder layer, and from which the photographic emulsion has been removed, is treated to recover usable polyester. The spent photographic film is heated in cyclohexanone at a temperature sufficient and for a time sufficient to remove both polyvinylidene and dye compounds from the polyester base. The recovered polyester may then be mixed with virgin polyester and extruded to produce a polyester product comprising in part recovered polyester and in part virgin polyester.

Abstract: A repair method for filter elements such as those used to filter polyester during the later stages of polyester manufacture in which the filter media is a particulate solid media arranged in a desired shape and maintained in that shape by a surrounding porous container that has filtration openings of a desired size. The method fills undesirably large openings in the surrounding porous container that result from damage to the container and through which enlarged openings the particulate solid media would otherwise escape with a polymeric resin. The polymeric resin is a resin with a glass transition temperature when cured that is at least greater than the melting point of polyester, and that has an absence of any chemical functional groups at temperatures at least as great as the melting point of polyester that would substantially react with polyester, the glycol precursors of polyester, the acid precursors of polyester, or the solvents useful in cleaning polyester from such filter elements.

Abstract: A repair method for filter elements such as those used to filter polyester during the later stages of polyester manufacture in which the filter media is a particulate solid media arranged in a desired shape and maintained in that shape by a surrounding porous container that has filtration openings of a desired size. The method fills undesirably large openings in the surrounding porous container that result from damage to the container and through which enlarged openings the particulate solid media would otherwise escape with a polymeric resin. The polymeric resin is a resin with a glass transition temperature when cured that is at least greater than the melting point of polyester, and that has an absence of any chemical functional groups at temperatures at least as great as the melting point of polyester that would substantially react with polyester, the glycol precursors of polyester, the acid precursors of polyester, or the solvents useful in cleaning polyester from such filter elements.

Abstract: A novel catalyst system, a process for using the novel catalyst system, and a product made from the process is described. The novel catalyst system is specific for producing polyethylene terephthalate made from reacting terephthalic acid and ethylene glycol, wherein the catalyst system includes antimony; cobalt and/or zinc, and at least one of zinc, magnesium, manganese or calcium. The antimony is generally present from about 150 ppm to about 650 ppm. The cobalt and/or zinc is usually present from about 5 ppm to about 60 ppm, and the zinc, magnesium, manganese or calcium, as the third component, is generally present from about 10 ppm to about 150 ppm. The amounts of all catalyst components are based on the theoretical yield of the polymer. Using the novel catalyst system to produce PET drastically reduces the polymerization time without sacrificing color and clarity of the polymer produced.