Abstract: A multi-layered thermoplastic polyolefin film having an improved combination of physical characteristics is disclosed. In particular, the multi-layered film evidences an improved combination of elongation, elastic memory, tear resistance and heat shrinkability. Preferred five layer embodiments of the film comprise (1) a core layer of either a low density polyethylene homopolymer or an ethylene vinyl acetate copolymer or a blend of an ethylene vinyl acetate copolymer with a linear low density polyethylene; (2) two adjacent intermediate layers of a linear low density polyethylene and (3) two surface layers of an ethylene vinyl acetate copolymer.

Abstract: The invention relates to a method of forming containers useful in vacuum packaging applications which require that the packaged product be wrapped in an air-impervious enclosure.According to one aspect of the invention, the method comprises a step wherein a substrate of an air pervious, semipervious or impervious material is mold formed, and a subsequent step wherein an impervious film is applied on the molded substrate and adhered thereto to produce an impervious substrate. In another aspect, a product is placed on the impervious substrate and enclosed by an impervious film in a vacuum skin packaging process.

Abstract: The present invention comprises an improvement upon the blown bubble process for forming thin heat sealable films from an extruded tubular structure. The utilization of a spray nozzle, internal to the extruded tubular structure, to provide a thin inner coating of a liquid polyorganosiloxane greatly reduces the internal film welding of extruded tubular polyolefin materials which internally weld at their processing temperature. Additionally, reduction of the internal welding allows films of reduced thickness to be manufactured.

Abstract: A package of imbricated bags is provided that is adapted for dispensing and opening such bags one at a time. The package includes a chain of adhesively imbricated bags in overlying sequence, each bag being adhesively but releasably attached to adjacent bags and having an open mouth end directed toward the leading end of the chain, and a container for the chain having an elongate, constricted opening through which the leading end of the chain is directed. The length of the opening is less than the bag chain width by a selected extent sufficient to cause the mouth of each bag to open in response to transverse constriction as the chain is advanced through the opening, provided that the width of the opening is sufficiently narrow so as to resistively confront the lower edge of the mouth of a bag being pulled through the opening. A method for making the bag package is also provided.

Abstract: A heat-shrinkable thermoplastic film includes a food contact layer; a second layer of propylene homopolymer or copolymer, ethylene copolymer, butylene homopolymer or blends thereof; an adhesive layer; a layer of unplasticized vinylidene chloride copolymer; another adhesive layer; and an optical clarity layer.

Abstract: A method is provided for enhancing yield of a cook-in packaged meat product that includes first providing an adhering cook-in container including a flexible thermoplastic envelope being substantially conformable to a contained meat product and having an inner surface of a selectively irradiated ionomer of a metal salt neutralized copolymer of ethylene and acrylic acid or methacrylic acid, then conforming the container about a selected meat product and cooking the packaged product, whereupon the inner surface of the envelope bonds to the meat product to substantially prevent cook-out of fluids. An associated cook-in container is 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: A machine for packaging articles in continuous tubular material, which may be formed by rolling the marginal edges of a flat web around a succession of the product articles to bring the marginal edges into contact and then sealing them continuously to complete the tube, comprises a pair of transverse sealing jaws 14 and 15 which each include a hemi-cylindrical chamber 24 having gas-pervious walls 16 and defining a cylindrical space 25 initially centrally divided by the film between two successive product articles 1.The film extending diametrically across the space 25 is first of all severed and then suction is applied to the gas-pervious walls 16 to draw the film into contact with the walls 16. To the righthand side of the space 25 is a double impulse sealing system 18, 19 centrally divided by a knife 21 which separates a righthand pack 28 from the film in the space 25, and to the lefthand side of that space 25 is a further double impulse sealing system 18, 20, again with a knife 22 to effect separation.

Abstract: A heat-sterilizable laminate film especially useful for making disposible pouches for sterile injectable compositions comprises an ethylene-vinyl acetate copolymer layer and on either side of the said layer a layer of a propylene-ethylene copolymer which may contain an impact modifier. The laminate may be cross-linked by irradiation.

Abstract: A three layered thermoplastic film having a desired combination of physical characteristics is disclosed. The film may be utilized to form storm windows. A preferred embodiment of the film comprises a core layer consisting essentially of a linear low density polyethylene and two surface layers comprising a four component blend of (1) a linear low density polyethylene, (2) a linear medium density polyethylene (3) a copolymer of ethylene and vinyl acetate and (4) one or more light stabilizers.

Abstract: A vacuum packaging process and apparatus employ the novel step of deliberately at least partially repressurizing the exterior of a flexible packaging receptacle after commencement of the evacuation of the exterior and interior of the receptacle in a chamber. The receptacle is closed after the receptacle has been pressed against the article located in the receptacle by repressurization.

Abstract: The invention provides a process for packaging a product article such as meat, in a plastics bag (1) by injecting a hot gas, in this case steam, into the bag interior from behind the product article (2) using a nozzle (3) to flush air (at 5) from the bag (1) and to impart shrinking heat to the material forming the bag.When using steam, or another vapor capable of condensing at atmospheric pressure above room temperature, the condensing of the vapor effects evacuation of the bag interior.

Abstract: The present invention relates to a food tray for supporting, containing and displaying food products which tend to exude or purge juices or liquids. In particular, the present invention relates to a food tray which comprises a sunken exudate reservoir. The reservoir is formed by adhering a sheet of a liquid impermeable material in a liquid tight manner to a raised shoulder area of a support portion of the tray to form a false bottom. The sheet material is further supported by standoffs rising up from the tray bottom. The sheet material is also perforated so as to allow flow of the exudate or purge through the sheet down into the reservoir where the exudate is trapped and retained out of contact with a food product which is located on top of said supported sheet. Preferably, the sheet material is opaque and the exudate is thereby hidden from view. Even more preferably, the sheet material is of the same color as the tray.

Abstract: The invention relates to laminated films and articles of manufacture based on such films and having improved resistance to heat treatment, wherein said films comprise a heat sealing layer of copolyamide obtained by random copolymerization of precursor monomers of at least two different polyamides. Said laminated films, or the articles of manufacture formed therefrom, such as bags or preformed containers, are useful for packaging applications, particularly in connection with food products.

Abstract: A shrink bag having an integral carrying handle is provided that includes an extended lip bag of a heat shrinkable thermoplastic material and having a carrying hole in the lip with a continuous fused bead around its periphery, the carrying hole being spaced sufficiently below the top of the lip such that upon heat shrinking the bag about a product sealed therein enhanced thickening along the carrying-load bearing portion of the hole periphery occurs relative to the non-load bearing portion of the hole periphery. An associated method for making the bag is also provided.

Abstract: The present invention is directed to a method and apparatus for manufacturing a tray having an integral purge juice trap. A particularly important step in the method is adhering a border area of a perforated thermoplastic sheet to a raised shoulder area of a tray. Preferably, this step is accomplished simultaneously with the step of perforating the thermoplastic sheet. A preferred method for adhering the border area to the shoulder area is heat sealing.

Abstract: A method for vacuum shrink packaging a product is provided that includes the steps of placing the product in a heat shrinkable thermoplastic bag; then shrinking the bag in a heated gaseous medium, while partially constricting the mouth of the bag to cause ballooning of the bag, further provided that the constricting is selected such that shrinkage of the bag overcomes the ballooning to collapse the bag onto the product; and then placing the bag in a vacuum chamber followed by vacuumizing and in-chamber sealing, further provided that the rate of vacuumizing is limited to substantially prevent reballooning of the bag. Associated apparatus for carrying out the method is also provided.

Abstract: A three layered heat shrinkable, heat sealable thermoplastic packaging film having a desired combination of physical characteristics is disclosed. The film may be utilized to package a wide variety of items. A preferred embodiment of the film comprises a core layer consisting essentially of a linear low density polyethylene and two surface layers comprising a three component blend of (1) a linear low density polyethylene, (2) a linear medium density polyethylene and (3) a copolymer of ethylene and vinyl acetate.

Abstract: A plurality of multi-walled bags of flexible plastic material is formed by taking a longitudinally folded flat web of a first flexible plastic film; at least partially separating the superposed plies of said first flexible plastic film at the edge opposite the fold line and moving the film past a corona discharge electrode between the separated plies of the film to pre-treat at least a part of the inwardly facing surface of each of said two plies; taking a longitudinally folded flat web of a second flexible plastic film; corona discharge-treating the outwardly facing surfaces of the two plies of said second flexible plastic film; passing the pre-treated web of said second flexible plastic film over a diverter guide into the space between the two at least partially separated plies of said first flexible plastic film to bring the fold lines of the first and second flexible plastic film webs substantially into register with the two webs moving synchronously in a single direction; and sealing the composite of the

Abstract: Apparatus for packing commodities such as meat or bacon into bags of flexible thermoplastics film material comprises a vacuum chamber and sealing means arranged to hold closely together without application of pressure a band of bag material extending across the neck of the bag and applying heat to fuse the band of bag material and form a fluid tight seal. The vacuum chamber may include heating means so that after sealing the bag may be inflated off the commodity and thereby heated prior to collapse into close engagement with the commodity.