Abstract: There is provided a heat shrinkable, high barrier laminate film which includes a hot blown, melt oriented high oxygen barrier film, of relatively high crystallinity and correspondingly relatively low ultimate elongation, laminated to a stretch oriented base film having a shrink tension substantially greater than that of said barrier film, the extent of orientation of said base film being sufficient such that its ultimate elongation is reduced so as to be commensurate with that of said barrier film. In one preferred mode, the barrier film is a layflat tubular film having its interior layflat surfaces laminated together. Representatively, the high barrier layer of the barrier film is vinylidene chloride copolymer having at least about 85% by weight vinylidene chloride content, preferably at least about 90%. Associated methods for making the laminate films are also provided.

Abstract: There is provided a heat shrinkable, high barrier laminate film which includes a hot blown, melt oriented high oxygen barrier film, of relatively high crystallinity and correspondingly relatively low ultimate elongation, laminated to a stretch oriented base film having a shrink tension substantially greater than that of said barrier film, the extent of orientation of said base film being sufficient such that its ultimate elongation is reduced so as to be commensurate with that of said barrier film. In one preferred mode, the barrier film is a layflat tubular film having its interior layflat surfaces laminated together. Representatively, the high barrier layer of the barrier film is vinylidene chloride copolymer having at least about 85% by weight vinylidene chloride content, preferably at least about 90%. Associated methods for making the laminate films are also provided.

Abstract: The invention comprises an oriented multi-layer film having a different orientation distribution between at least two layers and a novel process for forming oriented multi-layer films having a different orientation distribution between the layers. An important feature is the formation of a first tubular layer which is folded and fed into the interior of a second tubular layer of smaller diameter. Upon inflation of the inner tubular layer of larger diameter to its maximum unstretched diameter the smaller diameter outer tubular layer will be stretched and will also be oriented if the stretching occurs while the temperature of the smaller diameter outer tubular layer is maintained within the orientation temperature range of that material.

Abstract: The invention deals with means for producing a manifold for a strutted film. In particular, the connection of a plastic tubular conduit to a strutted film to form a fluid tight communication between the strut passageway and the interior of the conduit is disclosed. The present method is especially advantageous where the struts of the strutted film, as a result of their method of manufacture, are not readily heat sealable. Where necessary, the method may also be applied to provide a manifold for a group of individual tubes.

Abstract: A pasteurizable and/or cook-in shrink film is provided that includes a first or sealing layer of a nonlipophillic polymeric material having a softening point greater than that of the following shrink layer; a second or shrink controlling layer, melt bonded to the first layer, of an ethylene homopolymer or copolymer; a third or adhesive layer, melt bonded to the second layer, of a chemically modified polyethylene being irradiatively cross-linkable and having functional groups with a relatively strong affinity for the following barrier layer; a fourth or barrier layer, melt bonded to the third layer, of a hydrolyzed ethylene-vinyl acetate copolymer; a fifth or adhesive layer as in said third layer, melt bonded to the fourth layer; and a sixth or abuse layer, melt bonded to the fifth layer. An associated method for making the film is also provided that includes full coextrusion and selective irradiation and orientation.

Abstract: A pasteurizable, cook-in shrink bag is provided that comprises a first or sealing and food contact layer composed of propylene homopolymer or copolymer; a second or heat shrinkable layer composed of a blend of propylene homopolymer or copolymer and butylene homopolymer or copolymer; a third or adhesive layer composed of ethylene methacrylate copolymer; a fourth or barrier layer composed of vinylidene chloride copolymer; a fifth or adhesive layer as in said third layer; and a sixth or optical clarity layer as in said first layer; further provided that the foregoing bag structure is oriented and irradiated to a dose of about 4-12 megarads after orienting or alternatively, though less preferred, to about 6-12 megarads before orienting. Associated method for making said bag is also provided.

Abstract: The invention comprises an oriented multi-layer film having a different orientation distribution between at least two layers and a novel process for forming oriented multi-layer films having a different orientation distribution between the layers. An important feature is the formation of a first tubular layer which is folded and fed into the interior of a second tubular layer of smaller diameter. Upon inflation of the inner tubular layer of larger diameter to its maximum unstretched diameter the smaller diameter outer tubular layer will be stretched and will also be oriented if the stretching occurs while the temperature of the smaller diameter outer tubular layer is maintained within the orientation temperature range of that material.

Abstract: The invention deals with means for producing a manifold for a strutted film. In particular, the connection of a plastic tubular conduit to a strutted film to form a fluid tight communication between the strut passageway and the interior of the conduit is disclosed. The present method is especially advantageous where the struts of the strutted film, as a result of their method of manufacture, are not readily heat sealable. Where necessary, the method may also be applied to provide a manifold for a group of individual tubes.

Abstract: An easily peelable heat seal between two sheets of cross-linkable polyolefin packaging materials is achieved by cross-linking the polyolefin material in each sheet by irradiating the sheets to a dosage level of at least 3 MR prior to heat sealing the sheets together. The easily peelable seal is especially useful where film surfaces in large flange areas are sealed together.

Abstract: A laminated, tubular, thermoplastic film having high tensile strength, shrink energy, and tear resistance is produced by continuously extruding a layer of a first thermoplastic material onto a tubular substrate of a second thermoplastic material and then cooling, heating, and stretch-orienting the resulting laminate. By repeating the process, multiple-layer laminates may be produced.

Abstract: The multi-layer polyester/polyolefin shrink film of this invention provides a combination of shrink tension, hot seal strength, sealability, and shrink temperature range heretofore unobtainable in an oriented, monolayer polyolefin material. The preferred film has five layers in which the middle layer comprises a polyester or copolyester, two inner layers adjacent the middle layer comprise ethylene-vinyl actate copolymer, and the skin or outer layers comprise an ethylene-propylene copolymer.

Abstract: A package and a method of producing a package by forming a pocket in the central portion of a sheet of wrapping material, preferably a thermoplastic film, placing a product within the pocket, folding the flat portions of the film into face-to-face contact and bonding the flat portions together. The package can also be evacuated and hermetically sealed. If the film has been oriented, the pocket may be heat shrunk.

Abstract: To provide a hermetic seal for flexible receptacles such as plastic bags, pouches, or casings, the outside of the mouth of the receptacle is coated with a cold flowing resin so that when the receptacle is filled and its mouth gathered under pressure the resin will cold flow and fill the voids in the gathered folds. Preferably, the end of the gathered mouth is trimmed and then high pressure is applied to cause the resin to exude from the trimmed end. Next, a forming plunger is used to press the exudate into a smooth surface whereby a fused cap of resin is formed hermetically closing the bag's mouth. As an alternative, a clip or band can be placed around the gathered end under sufficient pressure to case cold flow of the resin thereby sealing the voids.

Abstract: The multi-layer polyester/polyolefin shrink film of this invention provides a combination of shrink tension, hot seal strength, sealability, and shrink temperature range heretofore unobtainable in an oriented, monolayer polyolefin material. The preferred film has five layers in which the middle layer comprises a polyester or copolyester, two inner layers adjacent the middle layer comprise ethylene-vinyl acetate copolymer, and the skin or outer layers comprises an ethylene-propylene copolymer.

Abstract: A non-woven rug, or the like, is formed by heat sealing a covering material at spaced intervals to a plastic backing and thereafter shrinking the backing to bulk the facing fabric. The heat sealing of the facing fabric to the backing causes a partial loss of orientation in the seal area therein bringing about a bulking or crinkling of the backing. The backing is preferably of a thermoplastic material having a foaming agent incorporated therein which is foamed after the completion of the heat sealing and heat shrinking procedures. Also included in the disclosure are the features of the backing fabric independently, i.e., incorporation of a foaming agent into a plastic which is extruded and thereafter heat sealed and/or stretch oriented and shrunk prior to the activation of the foaming agent to foam the fabric.

Abstract: An amide/olefin polymeric film laminate suitable for packaging, water cooking, and storing food within the package is prepared by coextruding polyamide and polyolefin layers to form a laminate and then cross-linking the laminate by irradiation. Prior art polyolefin/polyamide laminates delaminate readily when subjected to agitation in hot water, but this tendency is significantly reduced by laminates according to the present invention.

Abstract: A process for producing oriented films and laminates of nylon 66 and of blends of nylon 66 with nylon 6. In the process, moisture is excluded from the nylon preferably by coextruding a nylon layer between layers of polymeric material to form a laminate; and, after quenching the laminate, orientation may be performed after a relatively long time lapse.

Abstract: A heat shrinkable multi-layer packaging film having a layer of a hydrolyzed ethylene-vinyl acetate copolymer. Preferably, the film is formed by coextruding the hydrolyzed ethylene-vinyl acetate copolymer layer between two other polymeric layers, at least one of which is cross-linkable, and thereafter irradiating and orienting the multi-layer structure. The resulting film is heat shrinkable and has very low oxygen permeability.

Abstract: In coextruded or extrusion coated, laminated, polymeric films which have been stretched by the inflated bubble technique, liquid can be entrapped between the collapsed bubble walls and can migrate to an interior layer of the laminate to treat same when the layer adjacent to the entrapped liquid is liquid permeable. For example, in a polyethylene/nylon/ethylene vinyl acetate/entrapped water/ethylene vinyl acetate/nylon/polyethylene laminated film the entrapped water will diffuse through the ethylene vinyl acetate layers to keep the nylon layers plasticized and impact resistant.

Abstract: An amide/olefin polymeric film laminate suitable for packaging, water cooking, and storing food within the package is prepared by coextruding polyamide and polyolefin layers to form a laminate and then cross-linking the laminate by irradiation. Prior art polyolefin/polyamide laminates delaminate readily when subjected to agitation in hot water, but this tendency is significantly reduced by laminates according to the present invention.