Abstract: Polymer molding processes, such as injection-molding processes, include use of a viscosity-reducing supercritical fluid additive resulting in less breakage of reinforcing fibers upon introduction into the mold.

Abstract: Polymer molding processes, such as injection-molding processes, include use of a viscosity-reducing supercritical fluid additive resulting in less breakage of reinforcing fibers upon introduction into the mold.

Abstract: Injection molding and blow molding systems that include screws having low L:D ratios are provided. The systems are capable of producing microcellular polymeric materials. In some cases, the systems may be formed by retrofitting conventional polymer processing systems. Retrofitting may involve changing (e.g., machining or replacing) existing components of the conventional system, as well as, adding new components to the system. For example, retrofitting generally involves replacing the conventional polymer processing screw with a new screw designed to satisfy conditions needed for processing microcellular materials. In other cases, the systems may be newly manufactured. The retrofitted or newly manufactured systems of the invention are considerably less expensive than newly manufactured microcellular processing systems having higher L:D ratios.

Abstract: The invention provides systems, methods, and articles useful in the production of foams, and, in particular microcellular foams. The systems include a restriction element that reduces the backflow of polymer melt in an extruder while polymeric material is injected into a mold or ejected from a die. The restriction element is positioned upstream of a blowing agent injection port to maintain the solution of polymer and blowing agent in the extruder above a minimum pressure throughout an injection or ejection cycle, and preferably above the critical pressure required for the maintenance of a single-phase solution of polymer and blowing agent. The systems can be used in injection molding, blow molding, or in any other processing techniques that include injection or ejection cycles. In some embodiments, the systems utilize reciprocating screws for injection or ejection.

Abstract: An injection molding screw for metal injection molding includes a first end, a second end, a longitudinal body with a first stage and a second stage extending axially along a length of the screw between the ends, a pressure retention device, and optionally, a screw tip. The pressure retention element minimizes loss of pressure in the second stage portion.

Abstract: An injection molding screw for metal injection molding includes a first end, a second end, a longitudinal body with a first stage and a second stage extending axially along a length of the screw between the ends, a pressure retention device, and optionally, a screw tip. The pressure retention element minimizes loss of pressure in the second stage portion.

Abstract: Injection molding and blow molding systems that include screws having low L:D ratios are provided. The systems are capable of producing microcellular polymeric materials. In some cases, the systems may be formed by retrofitting conventional polymer processing systems. Retrofitting may involve changing (e.g., machining or replacing) existing components of the conventional system, as well as, adding new components to the system. For example, retrofitting generally involves replacing the conventional polymer processing screw with a new screw designed to satisfy conditions needed for processing microcellular materials. In other cases, the systems may be newly manufactured. The retrofitted or newly manufactured systems of the invention are considerably less expensive than newly manufactured microcellular processing systems having higher L:D ratios.

Abstract: Polymer molding processes, such as injection-molding processes, include use of a viscosity-reducing supercritical fluid additive resulting in less breakage of reinforcing fibers upon introduction into the mold.

Abstract: The invention provides systems, methods, and articles useful in the production of foams, and, in particular microcellular foams. The systems include a restriction element that reduces the backflow of polymer melt in an extruder while polymeric material is injected into a mold or ejected from a die. The restriction element is positioned upstream of a blowing agent injection port to maintain the solution of polymer and blowing agent in the extruder above a minimum pressure throughout an injection or ejection cycle, and preferably above the critical pressure required for the maintenance of a single-phase solution of polymer and blowing agent. The systems can be used in injection molding, blow molding, or in any other processing techniques that include injection or ejection cycles. In some embodiments, the systems utilize reciprocating screws for injection or ejection.

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: An injection molding screw for metal injection molding includes a first end, a second end, a longitudinal body with a first stage and a second stage extending axially along a length of the screw between the ends, a pressure retention device, and optionally, a screw tip. The pressure retention element minimizes loss of pressure in the second stage portion.

Abstract: Injection molding and blow molding systems that include screws having low L:D ratios are provided. The systems are capable of producing microcellular polymeric materials. In some cases, the systems may be formed by retrofitting conventional polymer processing systems. Retrofitting may involve changing (e.g., machining or replacing) existing components of the conventional system, as well as, adding new components to the system. For example, retrofitting generally involves replacing the conventional polymer processing screw with a new screw designed to satisfy conditions needed for processing microcellular materials. In other cases, the systems may be newly manufactured. The retrofitted or newly manufactured systems of the invention are considerably less expensive than newly manufactured microcellular processing systems having higher L:D ratios.

Abstract: The invention provides systems, methods, and articles useful in the production of foams, and, in particular microcellular foams. The systems include a restriction element that reduces the backflow of polymer melt in an extruder while polymeric material is injected into a mold or ejected from a die. The restriction element is positioned upstream of a blowing agent injection port to maintain the solution of polymer and blowing agent in the extruder above a minimum pressure throughout an injection or ejection cycle, and preferably above the critical pressure required for the maintenance of a single-phase solution of polymer and blowing agent. The systems can be used in injection molding, blow molding, or in any other processing techniques that include injection or ejection cycles. In some embodiments, the systems utilize reciprocating screws for injection or ejection.

Abstract: The invention provides systems, methods, and articles useful in the production of foams, and, in particular microcellular foams. The systems include a restriction element that reduces the backflow of polymer melt in an extruder while polymeric material is injected into a mold or ejected from a die. The restriction element is positioned upstream of a blowing agent injection port to maintain the solution of polymer and blowing agent in the extruder above a minimum pressure throughout an injection or ejection cycle, and preferably above the critical pressure required for the maintenance of a single-phase solution of polymer and blowing agent. The systems can be used in injection molding, blow molding, or in any other processing techniques that include injection or ejection cycles. In some embodiments, the systems utilize reciprocating screws for injection or ejection.

Abstract: The invention provides systems, methods, and articles useful in the production of foams, and, in particular microcellular foams. The systems include a restriction element that reduces the backflow of polymer melt in an extruder while polymeric material is injected into a mold or ejected from a die. The restriction element is positioned upstream of a blowing agent injection port to maintain the solution of polymer and blowing agent in the extruder above a minimum pressure throughout an injection or ejection cycle, and preferably above the critical pressure required for the maintenance of a single-phase solution of polymer and blowing agent. The systems can be used in injection molding, blow molding, or in any other processing techniques that include injection or ejection cycles. In some embodiments, the systems utilize reciprocating screws for injection or ejection.