Abstract: A layer sequence repeater module for a co-extrusion die includes a cell formed of a plurality of thin annular disks stacked on top of each other in an axial direction of the co-extrusion die. Each disk includes a plurality of openings aligned with openings in the adjacent disks, thus forming multiple inner and outer melt passages. At least one of the layer sequence repeater module includes at least one first cap disk, at least one second cap disk, at least one distribution disk, at least one repeater disk and at least one spreader disk. The layer sequence repeater module may be a separately assembled and individually removable module of the co-extrusion die. Alternatively or additionally, the layer sequence repeater module may be incorporated into a module of the co-extrusion die.

Abstract: Cellular thin films include a first side separated from a second side, the separation of which defines the thickness of the thin film; at least one layer of a polymeric material arranged along the thickness of the thin film, wherein the polymeric material includes cells and the first and second sides of the thin film have exterior surfaces that have substantially the same thickness as the interior walls forming the cells. The surfaces of the thin films have bumps caused by the cells. The thin exterior surfaces of the thin films is advantageous to allow the films to be flexible.

Abstract: A layer sequence repeater module for a co-extrusion die includes a cell formed of a plurality of thin annular disks stacked on top of each other in an axial direction of the co-extrusion die. Each disk includes a plurality of openings aligned with openings in the adjacent disks, thus forming multiple inner and outer melt passages. At least one of the layer sequence repeater module includes at least one first cap disk, at least one second cap disk, at least one distribution disk, at least one repeater disk and at least one spreader disk. The layer sequence repeater module may be a separately assembled and individually removable module of the co-extrusion die. Alternatively or additionally, the layer sequence repeater module may be incorporated into a module of the co-extrusion die.

Abstract: A layer sequence repeater module for a co-extrusion die includes a cell formed of a plurality of thin annular disks stacked on top of each other in an axial direction of the co-extrusion die. Each disk includes a plurality of openings aligned with openings in the adjacent disks, thus forming multiple inner and outer melt passages. At least one of the layer sequence repeater module includes at least one first cap disk, at least one second cap disk, at least one distribution disk, at least one repeater disk and at least one spreader disk. The layer sequence repeater module may be a separately assembled and individually removable module of the co-extrusion die. Alternatively or additionally, the layer sequence repeater module may be incorporated into a module of the co-extrusion die.

Abstract: A layer sequence repeater module for a co-extrusion die includes a cell formed of a plurality of thin annular disks stacked on top of each other in an axial direction of the co-extrusion die. Each disk includes a plurality of openings aligned with openings in the adjacent disks, thus forming multiple inner and outer melt passages. At least one of the layer sequence repeater module includes at least one first cap disk, at least one second cap disk, at least one distribution disk, at least one repeater disk and at least one spreader disk. The layer sequence repeater module may be a separately assembled and individually removable module of the co-extrusion die. Alternatively or additionally, the layer sequence repeater module may be incorporated into a module of the co-extrusion die.

Abstract: Cellular thin films include a first side separated from a second side, the separation of which defines the thickness of the thin film; at least one layer of a polymeric material arranged along the thickness of the thin film, wherein the polymeric material includes cells and the first and second sides of the thin film have exterior surfaces that have substantially the same thickness as the interior walls forming the cells. The surfaces of the thin films have bumps caused by the cells. The thin exterior surfaces of the thin films is advantageous to allow the films to be flexible.

Abstract: A coextrusion die includes a plurality of annular cells stacked on top of each other. Each annular cell includes a plurality of openings aligned with openings in the adjacent cell, thus forming multiple streams. Plastic melt may be supplied to the die coplanarly. Stacks of annular disks may be joined to form the annular cells through which plastic melt can be axially directed.

Abstract: An apparatus and process for chopping and mixing a polymeric material having an elongated hollow barrel element with a material inlet end and a material outlet end and housing a rotatable extruder screw. The rotatable extruder screw includes at least one flightless screw section and at least one stationary tube element made from a bearing material and forming a plurality of serrations at at least one end, the stationary tube element being disposed around the flightless screw section within the elongated hollow barrel element and fixed against rotation with respect to the elongated hollow barrel element. The flightless screw section forms at least one material melt recess in a region corresponding to the serrations of the stationary tube element. Extruded products requiring, and characterized by, low shear, uniform dispersive mixing are made in one process step in a single screw extruder employing this invention.

Abstract: A coextrusion die includes a plurality of annular cells stacked on top of each other. Each annular cell includes a plurality of openings aligned with openings in the adjacent cell, thus forming multiple streams. Plastic melt may be supplied to the die coplanarly. Stacks of annular disks may be joined to form the annular cells through which plastic melt can be axially directed.

Abstract: The present invention provides a process for producing thermoplastic foam, including:(a) melting a thermoplastic polymer to produce a polymer melt;(b) introducing a carbon dioxide blowing agent into the polymer melt;(c) adding to the polymer melt one or more additives selected from the group consisting of(1) polysiloxane, and(2) mineral oil; and(d) extruding and foaming the melted polymer melt, blowing agent, and one or more additives to produce thermoplastic foam.The resultant thermoplastic foam can be thermoformed into various foamed articles, such as foam packaging trays. The quality of foams made from a carbon dioxide blowing agent, and particularly 100% carbon dioxide, has been found to be substantially improved by adding one or more of the foregoing additives, i.e., polysiloxane, mineral oil and, optionally, polyolefin to the polymer melt during the extrusion and foaming process.

Abstract: A coextrusion die includes a plurality of thin annular disks stacked on top of each other. Each annular disk includes a plurality of openings aligned with openings in the adjacent disk, thus forming multiple streams. Plastic melt may be supplied to the die coplanarly. Stacks of annular disks may be used to form modules through which plastic melt can be axially directed.

Abstract: The present invention provides a method for the semi-continuous production of microcellular foam articles. In a preferred embodiment, a roll of polymer sheet is provided with a gas channelling means interleaved between the layers of polymer. The roll is exposed to a non-reacting gas at elevated pressure for a period of time sufficient to achieve a desired concentration of gas within the polymer. The saturated polymer sheet is then separated from the gas channelling means and bubble nucleation and growth is initiated by heating the polymer sheet. After foaming, bubble nucleation and growth is quenched by cooling the foamed polymer sheet.

Abstract: Polymeric, thin oriented films can be made by use of a combination of a hot blown process and a blown bubble process, i.e. a double bubble process. The resulting film has use in replacing PVC for in store stretch wrap applications. Very low density polyethylene, VLDPE, is an especially preferred material for this process. It may be used as a monolayer, or as one layer of a multilayer structure. In practicing the invention, the polymer is extruded and hot blown, and heated to a temperature above its orientation temperature. This heating can be accomplished by the use of a heated liquid reservoir or sock disposed at the lower end of the primary bubble, inside the bubble. The hot blown heated film is then passed through a first set of pinch rolls, re-inflated into a blown bubble, and collapsed at a second set of pinch rolls. Thin, tough and elastic packaging materials are obtained by this process.

Abstract: Polymeric, thin oriented films can be made by use of a combination of a hot blown process and a blown bubble process, i.e. a double bubble process. The resulting film has use in replacing PVC for in store stretch wrap applications. Very low density polyethylene, VLDPE, is an especially preferred material for this process. It may be used as a monolayer, or as one layer of a multilayer structure. In practicing the invention, the polymer is extruded and hot blown, and heated to a temperature above its orientation temperature. This heating can be accomplished by the use of a heated liquid reservoir or sock disposed at the lower end of the primary bubble, inside the bubble. The hot blown heated film is then passed through a first set of pinch rolls, re-inflated into a blown bubble, and collapsed at a second set of pinch rolls. Thin, tough and elastic packaging materials are obtained by this process.

Abstract: The present invention provides a process for producing thermoplastic foam, including:(a) melting a thermoplastic polymer to produce a polymer melt;(b) introducing a carbon dioxide blowing agent into the polymer melt;(c) adding to the polymer melt one or more additives selected from the group consisting of(1) polysiloxane, and(2) mineral oil; and(d) extruding and foaming the melted polymer melt, blowing agent, and one or more additives to produce thermoplastic foam.The resultant thermoplastic foam can be thermoformed into various foamed articles, such as foam packaging trays. The quality of foams made from a carbon dioxide blowing agent, and particularly 100% carbon dioxide, has been found to be substantially improved by adding one or more of the foregoing additives, i.e., polysiloxane, mineral oil and, optionally, polyolefin to the polymer melt during the extrusion and foaming process.

Abstract: A multilayer film is disclosed in which at least one layer thereof comprises a blend of:a first styrene butadiene copolymer having a butadiene content of 50 weight percent or more; anda second styrene butadiene copolymer having a butadiene content of 50 weight percent or less, wherein, the total butadiene content of the blend ranges from about 30 weight percent to about 50 weight percent. When used as an outer layer of an overwrap material, such blend provides provides an improved overlap heat seal.

Abstract: A cross-linkable, preferably stretch oriented film comprising a blend of a polyolefin and a diene polymer and a transition metal catalyst, wherein the blend cross-links in the presence of oxygen without irradiation to provide a film with high heat resistance.

Abstract: Polymeric, thin oriented films can be made by use of a combination of a hot blown process and a blown bubble process, i.e. a double bubble process. The resulting film has use in replacing PVC for in store stretch wrap applications. Very low density polyethylene, VLDPE, is an especially preferred material for this process. It may be used as a monolayer, or as one layer of a multilayer structure. In practicing the invention, the polymer is extruded and hot blown, and heated to a temperature above its orientation temperature. This heating can be accomplished by the use of a heated liquid reservoir or sock disposed at the lower end of the primary bubble, inside the bubble. The hot blown heated film is then passed through a first set of pinch rolls, re-inflated into a blown bubble, and collapsed at a second set of pinch rolls. Thin, tough and elastic packaging materials are obtained by this process.

Abstract: A composition of matter comprises a blend of propylene homopolymer or copolymer, and ethylene copolymer. Ethylene vinyl acetate copolymer (EVA), very low density polyethylene (VLDPE), and ethylene alpha olefin copolymer are preferred ethylene copolymers. VLDPE with a high molecular weight (low melt index), and with a broad molecular weight distribution (high flow rate ratio) is preferred. A multilayer film comprises a first layer comprising a propylene homopolymer or copolymer, or blend, and at least one outer sealable layer.

Abstract: A barrier foam tray contains recycled reclaim of barrier foam. The tray comprises a sheet of foamed polystyrene (PS) having laminated to it a flexible barrier film. The foamed polystyrene part can have admixed therein from 0.0001% up to 30% by weight of the flexible barrier film. The barrier film contains a barrier polymer such as ethylene vinyl alcohol copolymer (EVOH). The tray is made by grinding laminate scrap and extruding reclaim therefrom with virgin polystyrene.