Abstract: A foam composition comprising about 50 to about 95 parts by weight of at least one polypropylene polymer having a density of about 85 to about 125 kg/m3, wherein the composition has blister rating of 1-2, an unaged peel tear strength of at least about 34 N and a heat aged peel tear strength of at least about 28 N when laminated to a support layer.

Abstract: A thermoplastic laminate suitable for long-term storage of food products includes a first substrate having a core layer of ethylene vinyl alcohol copolymer, two interior adhesive layers, and two surface layers each comprising a blend of a linear ethylene alpha olefin copolymer and an ethylene unsaturated ester copolymer; and a second substrate comprising an olefinic material of monolayer or multilayer construction, and preferably of substantiallly the same composition as the first substrate; and the second substrate bonded to the first substrate preferably by means of a conventional lamination adhesive.

Abstract: A thermoplastic bag with a separably integral draw strip which is extruded concurrently with the thermoplastic film of the bag body and has a thicker dimension than the thermoplastic film. The draw strip is confined within a tubular channel defining an open mouth for the bag.

Abstract: A seal bar including a clamped seal element for rotary side seal machines and, more particularly, to a thin ribbon-like seal element constituted of a metallic high-temperature resistant material for the concurrent heat sealing and cutting through of superimposed layers of a thermoplastic film material.

Abstract: A container constituted of a microwave transparent material for the heating or cooking of foods or comestibles through the intermediary of microwaves at a high degree of efficiency and with an enhanced temperature uniformity. The container base is configured in a manner to produce generally wavilinear or undulating bottom wall and side wall configurations which will disperse the food or comestible within the container to an optimum extent so as to increase the heating and cooking efficiency thereof, and to provide a more uniform temperature distribution throughout the container contents, thereby enabling the rapid and even heating and/or cooking of the food by microwave energy.

Abstract: An apparatus for cooling a tubular polymer film material which is being extruded, and more particularly, an apparatus for extruding tubular thermoplastic films including two tandem spaced air rings for controlling the cooling rate and production speeds of the thermoplastic films during extrusion thereof. Moreover, there is also disclosed a method for the cooling of an extruded tubular thermoplastic film material through the utilization of a tandem air ring cooling structure.

Abstract: Disclosed is a single lip tubular extrusion die in which a plurality of separate melt streams passing through respective annular flow paths are fed to a common annular flow passage extending axially to and terminating at a die orifice. The annular flow passage is connected to the annular flow paths through respective groups of holes spaced annularly about the die axis. Each group of holes has its openings to the common annular flow passage spaced a different radial distance from the die axis to allow the separate melt streams to be layered in the common annular flow passage and co-extruded. One of the die lips is rotatable so that each melt stream produces a uniform layer of polymer in the extruded film while imparting a molecular orientation to the extruded film in the transverse direction (TD). An extruder-type seal may be provided adjacent a gap between a rotating and stationary part of the die to force melt attempting to penetrate the gap into the annular flow passage.

Abstract: An improved method for the production of polyolefin film by extruding molten film from an annular die in a tubular form into an extrusion zone is disclosed wherein physical properties are enhanced by controlling polymeric crystalline growth. The method includes providing a liquid quench medium maintained at a constant temperature range in the extrusion zone immediately adjacent the annular die, extruding the molten film directly into the liquid quench medium, and then orienting the quenched film in a tubular bubble whereby the size and amount of crystalline growth is controlled.

Abstract: A resin composition is disclosed which comprises a blend of from about 40 to about 95 percent by weight thereof of a first polymeric component and from about 50 to about 5 percent by weight thereof of a second polymeric component, the blend being characterized by an interior region containing a disproportionately higher content of first polymeric component and an exterior region containing a disproportionately higher content of second polymeric component, the first polymeric component being selected from the group consisting of amorphous homopolymer of styrene or lower alkyl substituted styrene and amorphous copolymer of styrene and/or alkyl substituted styrene containing up to about 40 weight percent thereof of at least one other olefinic monomer copolymerized therewith and the second polymeric component being selected from the group consisting of crystalline homopolymer of propylene and crystalline copolymer of propylene containing up to about 30 weight percent thereof of at least one other olefinic monomer

Abstract: Disclosed is a composite laminated film suitable for use in constructing trash and other bags, in which at least one layer of a non-woven fabric material of a density in the range of 0.125 oz. to 1.5 oz. per square yard is secured to at least one layer of a plastic film. A method of continuous manufacturing of the laminate film is also disclosed.

Abstract: Disclosed is a method and apparatus for separately coextruding dissimilar polymer melts through a die, expanding the polymer melts to different degrees and then contacting and adhering the polymer melts together at or near the frost line to produce a laminated film where the various polymer layers thereof can be optimally molecularly oriented in the completed film. The invention is particularly useful in producing a film where one of the extruded layers therein is a polymer foam.

Abstract: Disclosed is plastics film containing a tear strip and a method for producing it in which the film is co-extruded with a bead which adheres to the film surface. Because of the heat retained by the bead, blown expansion of the film following extrusion causes the film to undergo a gauge reduction along and adjacent to the bead which provides a preferential tear line for the film.

Abstract: A method and an apparatus for the production of a composite plastic material consisting of oriented polymer filaments and a polymer film web, and more particularly, the production of a composite material which possesses an improved physical strength and higher tear resistance in comparison with plastic film materials which are not reinforced. An extrusion die is used for example, a conventional tubular extrusion die for extruding a continuous blown tubular plastic film web and wherein the die orifice is encompassed by spinerette apertures through which there are concurrently extruded a plurality of polymer filaments which are oriented and initially conveyed along a path substantially parallel to but not in adherence with the blown tubular plastic film web.

Abstract: A method is disclosed for forming a blocked cross-plied polymer film by extruding a polymer melt through a tubular rotary die to impart a molecular orientation of the polymer in the transverse (TD) direction during extrusion, expanding the film, and then blocking it by pressing opposing walls together to produce a film in which at lease two layers thereof have transverse molecular orientations which cross to form a balanced cross-plied film.

Abstract: Disclosed are an apparatus and method for cutting and sealing a plastic film. The plastics film is conveyed to a sealing area which contains a sealing wire in a housing over which the plastics film is draped out of contact with the wire. The wire is preheated to a first temperature and is then heated to a second higher temperature while a differential pressure is applied to the film biasing it towards and into contact with the wire which cuts and heat seals it. By providing the heat sealing area in the outer periphery of a rotatable drum to which a continuous film is conveyed, a continuous cutting and heat sealing process can be achieved.