Abstract: A pelletizing system and a method for pelletizing a polymer are disclosed. The method comprises the steps of compressing a quantity of polymer flake of a predetermined size to produce a pellet and heating at least one of the polymer flake and the pellet to remove contaminants therefrom.

Abstract: A process for cooling post solid-stating reactor PET flakes comprises conveying PET flakes from a solid-stating reactor to a first separator in the presence of air and water at an elevated pressure, separating the steam from the partially cooled PET flakes, and conveying the partially cooled PET flakes from the first separator to a second separator in the presence of air at an elevated pressure.

Abstract: A process for cooling post solid-stating reactor PET flakes comprises conveying PET flakes from a solid-stating reactor to a first separator in the presence of air and water at an elevated pressure, separating the steam from the partially cooled PET flakes, and conveying the partially cooled PET flakes from the first separator to a second separator in the presence of air at an elevated pressure.

Abstract: A multilayer plastic perform formed from a combination of virgin and recycled plastic such as PET so that the resultant blow-molded bottle has a reduced tendency for bottom failure in spite of the use of recycled plastic. A first plastic preform for providing the inner layer of the multi-layer preform is provided with spaced channels on the exterior surface of a closed end thereof extending from a central region of that end to the sidewalls. An injection mold cavity is provided with a like plurality of channels formed therein in a closed end thereof communicating with the injection gate of an injection molding apparatus. The first plastic preform is inserted into the injection mold cavity with the respective channels of the preform and the injection mold cavity substantially aligned. A second layer of plastic material is overmolded onto the first layer by injection molding in the cavity. A third layer of plastic material may be overmolded on the second layer to form a three-layer preform.

Abstract: A method of injection molding a multi-layer preform from a combination of virgin and recycled plastic such as PET so that the resultant blow molded bottle has a reduced tendency for bottom failure in spite of the use of the recycled plastic. A mold cavity for injection molding the preform is provided and includes an injection gate located along a sidewall of the cavity rather than at a conventional location in the closed end of the cavity which forms the bottom of the preform. The plastic material is injected through the gate in the sidewall which avoids the presence of crystalline "slugs" in the bottom region of the preform. This creates a preform and resultant blow molded bottle with a much more durable bottom which is not subject to various types of cracking.

Abstract: A method of injection molding a multi-layer preform from a combination of virgin and recycled plastic such as PET so that the resultant blow-molded bottle has a reduced tendency for bottom failure in spite of the use of recycled plastic. A first plastic preform for providing the inner layer of the multi-layer preform is provided with spaced channels on the exterior surface of a closed end thereof extending from a central region of that end to the sidewalls. An injection mold cavity is provided with a like plurality of channels formed therein in a closed end thereof communicating with the injection gate of an injection molding apparatus. The first plastic preform is inserted into the injection mold cavity with the respective channels of the preform and the injection mold cavity substantially aligned. A second layer of plastic material is overmolded onto the first layer by injection molding in the cavity. A third layer of plastic material may be overmolded on the second layer to form a three-layer preform.

Abstract: Degradable compositions of polyesters, polyamides, polystyrenes and polyvinyl chlorides containing effective degradable amounts of CO in the composition.

Abstract: A degradable polymer composition having(a) an ethylene-carbon monoxide copolymer only in an amount sufficient to provide a total of substantially about 0.005 to 0.05 percent by weight of CO in the composition; and(b) a low density polyethylene.

Abstract: A group of degradable polymer compositions including admixtures of ethylene-carbon monoxide copolymer with defined proportions of high density polyethylene, linear low density polyethylene or polypropylene is disclosed. The compositions are useful for forming article carriers, containers, closures, foodtrays and the like, which show excellent mechanical and structural properties and controlled environmental degradability.