Abstract: The present invention provides blowing agent introduction systems and methods for introducing blowing agent into polymeric foam processing systems. The methods may involve introducing one or more doses of blowing agent into polymeric material in an extruder during a plastication period of a molding cycle. Prior to introduction, a dose is confined in an accumulator which, for example, has a volume defined between an inlet valve and an outlet valve. A control system may receive inputs related to system parameters (e.g., pressure of polymeric material in extruder, axial position of screw in barrel, whether screw is rotating, and the like) and based on the inputs coordinates operation of the valves to confine and introduce the blowing agent dose(s). The introduction systems may be used in discontinuous plasticating processes, such as injection molding and blow molding, and can be particularly useful in processes that use precise quantities of blowing agent.

Abstract: Systems and methods of processing polymer foam materials are provided. The methods involve introducing blowing agent downstream of an extruder. For example, the blowing agent may be introduced into a static mixing device positioned between the extruder and a mold. The methods may be used in connection with injection molding systems to produce high quality injection molded polymer foam articles.

Abstract: The present invention provides blowing agent introduction systems and methods for introducing blowing agent into polymeric foam processing systems. The methods may involve introducing one or more doses of blowing agent into polymeric material in an extruder during a plastication period of a molding cycle. Prior to introduction, a dose is confined in an accumulator which, for example, has a volume defined between an inlet valve and an outlet valve. A control system may receive inputs related to system parameters (e.g., pressure of polymeric material in extruder, axial position of screw in barrel, whether screw is rotating, and the like) and based on the inputs coordinates operation of the valves to confine and introduce the blowing agent dose(s). The introduction systems may be used in discontinuous plasticating processes, such as injection molding and blow molding, and can be particularly useful in processes that use precise quantities of blowing agent.

Abstract: The present invention provides blowing agent introduction systems and methods for introducing blowing agent into polymeric foam processing systems. The methods may involve introducing one or more doses of blowing agent into polymeric material in an extruder during a plastication period of a molding cycle. Prior to introduction, a dose is confined in an accumulator which, for example, has a volume defined between an inlet valve and an outlet valve. A control system may receive inputs related to system parameters (e.g., pressure of polymeric material in extruder, axial position of screw in barrel, whether screw is rotating, and the like) and based on the inputs coordinates operation of the valves to confine and introduce the blowing agent dose(s). The introduction systems may be used in discontinuous plasticating processes, such as injection molding and blow molding, and can be particularly useful in processes that use precise quantities of blowing agent.

Abstract: The present invention provides blowing agent introduction systems and methods for introducing blowing agent into polymeric foam processing systems. The methods may involve introducing one or more doses of blowing agent into polymeric material in an extruder during a plastication period of a molding cycle. Prior to introduction, a dose is confined in an accumulator which, for example, has a volume defined between an inlet valve and an outlet valve. A control system may receive inputs related to system parameters (e.g., pressure of polymeric material in extruder, axial position of screw in barrel, whether screw is rotating, and the like) and based on the inputs coordinates operation of the valves to confine and introduce the blowing agent dose(s). The introduction systems may be used in discontinuous plasticating processes, such as injection molding and blow molding, and can be particularly useful in processes that use precise quantities of blowing agent.

Abstract: The invention provides a blowing agent delivery system for introducing a blowing agent into a polymeric foam processing system. The delivery system is designed to discontinuously introduce blowing agent from a continuous source into polymeric material within an extruder. The system, thus, may improve control over blowing agent delivery in discontinuous polymer processing systems such as injection molding or blow molding. In some embodiments, the blowing agent delivery system selectively directs blowing agent flow from the source to the extruder barrel, or through a bypassing passageway. In this manner, blowing agent may be continuously supplied by the source but discontinuously injected into the extruder barrel. During use, the delivery system may cause blowing agent to flow through the bypassing passageway, for example, when the screw stops plasticating polymeric material.

Abstract: Continuous polymeric extrusion nucleation systems and methods useful for making polymeric microcellular foamed materials, including crystalline and semi-crystalline polymeric microcellular materials, are provided. Pressure drop rate is an important feature in some embodiments, and the invention provides systems for controlling these and other parameters. One aspect involves a multiple-pathway nucleator that is separated from a shaping die by a residence chamber. Another aspect involves a die for making advantageously thick articles, including a multiple-pathway nucleation section. Microcellular material can be continuously extruded onto wire, resulting in a very thin, essentially closed-cell microcellular insulating coating secured to a wire. Other very thin microcellular products can be fabricated as well.

Abstract: Systems and methods for injection molding polymeric materials are provided. The systems and methods use a supercritical fluid additive. In some cases, the use of supercritical fluid additive enables formation of molded articles with low clamping forces and/or low injection pressures. Low clamping forces and/or low injection pressures may reduce the cost of a system designed to form a particular molded article. In some embodiments, the systems may include a control system that controls the operation of one or more components of the system (e.g., the extruder or the supercritical fluid additive introduction system). The systems and methods are suitable for forming polymeric foam articles including microcellular material articles.

Abstract: The present invention provides blowing agent introduction systems and methods for introducing blowing agent into polymeric foam processing systems. The methods may involve introducing one or more doses of blowing agent into polymeric material in an extruder during a plastication period of a molding cycle. Prior to introduction, a dose is confined in an accumulator which, for example, has a volume defined between an inlet valve and an outlet valve. A control system may receive inputs related to system parameters (e.g., pressure of polymeric material in extruder, axial position of screw in barrel, whether screw is rotating, and the like) and based on the inputs coordinates operation of the valves to confine and introduce the blowing agent dose(s). The introduction systems may be used in discontinuous plasticating processes, such as injection molding and blow molding, and can be particularly useful in processes that use precise quantities of blowing agent.

Abstract: A valve for controlling the flow of a high pressure fluid is provided. The valve provides a reliable way of controlling the flow of high pressure fluids in applications requiring multiple cycles where equipment may be exposed to environmentally harsh conditions, such as high temperatures and pressures.

Abstract: A valve for controlling the flow of a high pressure fluid is provided. The valve provides a reliable way of controlling the flow of high pressure fluids in applications requiring multiple cycles where equipment may be exposed to environmentally harsh conditions, such as high temperatures and pressures.

Abstract: An injection molding system is provided. The system includes a source of polymeric material, and an extruder including a screw rotatable within a barrel to convey polymeric material from the source in a downstream direction towards an outlet of the extruder. The system further includes an injection mold defining a cavity connectable to the outlet of the extruder, and an article positioned in the cavity. The article is to be molded along with the polymeric material in the injection mold.

Abstract: A method and apparatus for controlling foam processing. The method includes acts of receiving a first input indicative of an amount of a polymeric material to be provided to a polymer processing space of a polymer processing apparatus, and automatically determining an amount of a blowing agent to be provided to the polymer processing space to form a foamed product based upon the amount of polymeric material. Additional acts may include automatically configuring a blowing agent delivery system to provide the determined amount of the blowing agent to the polymer processing space to form the foamed product. The method and apparatus may be used to produce microcellular foamed products as well as non-microcellular foamed products, and can be used with a variety of foam processing equipment, such as injection molders, blow molders, and extruders.

Abstract: Molding, including injection molding, of crystalline or semicrystalline polymeric material is described. Microcellular polymeric material is preferred. The invention involves use of a viscosity-reducing additive in molding that results in relatively better crystallinity at relatively lower mold temperatures, and lower aging time.

Abstract: A process for the extrusion of microcellular polymeric material onto data communications material such as wire and optical fiber is described. Electrical conductors and optical fibers coated with microcellular polymeric material exhibit unexpected strength sufficient to pass certain industry tests necessary for use in a variety of applications, even without an exterior coating of structurally-supporting polymeric material. Polymeric microcellular materials provided in contact with the electrical connectors for a variety of purposes are described where the strength of microcellular material provides required structural support.

Abstract: Continuous polymeric extrusion nucleation systems and methods useful for making polymeric microcellular foamed materials, including crystalline and semi-crystalline polymeric microcellular materials, are provided. Pressure drop rate is an important feature in some embodiments, and the invention provides systems for controlling these and other parameters. One aspect involves a multiple-pathway nucleator that is separated from a shaping die by a residence chamber. Another aspect involves a die for making advantageously thick articles, including a multiple-pathway nucleation section. Microcellular material can be continuously extruded onto wire, resulting in a very thin, essentially closed-cell microcellular insulating coating secured to a wire. Other very thin microcellular products can be fabricated as well.

Abstract: A process for the extrusion of microcellular polymeric material onto data communications material such as wire and optical fiber is described. Electrical conductors and optical fibers coated with microcellular polymeric material exhibit unexpected strength sufficient to pass certain industry tests necessary for use in a variety of applications, even without an exterior coating of structurally-supporting polymeric material. Polymeric microcellular materials provided in contact with the electrical connectors for a variety of purposes are described where the strength of microcellular material provides required structural support.