Abstract: A shrink tunnel for use in shrink packaging of articles with shrinkable films comprises a gaseous return flow, having a working section along which gas passes from an inlet to an outlet in a substantially rectilinier direction, and a return section around which the gas is recirculated for heat and velocity boosting prior to the next cycle through the working section.

Abstract: A molded plastic article having either a transparent window or a mirror insert therein is produced by molding a plastic mass around the insert with a layer of insulation or parting material interposed between the plastic mass and the insert.

Abstract: The multi-layer polyolefin shrink film of this invention provides shrink tensions, optical clarity, cuttability, sealability, shrink temperature range, and tear resistance heretofore unobtainable in an oriented, monolayer polyolefin material. The preferred film has three layers in which the core layer comprises a blend of ethylene-vinyl acetate copolymer with ethylene-butylene copolymer and each skin layer comprises ethylene-propylene copolymer.

Abstract: Microwave energy is used for sealing polymeric film material particularly the sealing of film material in the form of flexible containers.

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: This invention is a process for making a self-welding packaging film by blending at least two ethylene polymers, one of the polymers having a melt flow substantially greater than any of the other polymers in the blend, and thereafter extruding a film from the blend. The film may be self-supporting or it may be an inner layer in a multi-ply film. Preferred ethylene polymers for the blend are the ethylene-vinyl acetate copolymers wherein one copolymer has a melt flow of less than 5.0 and the other has a melt flow greater than 28.0.

Abstract: A device for separating from a continuous strip having score lines defining individual sheets or bags wherein a plate and a pressure bar justapositioned to the plate and spaced apart therefrom to permit the strip to pass therebetween is provided. A bearing or prong projects outwardly from the center portion of the plate in order to facilitate separation sections of the strip along the score lines and display the next succeeding section for easy grasp by an operator.

Abstract: Irradiated film having substantial uniformity in the radiation dosage profile is produced by irradiating the film within a trough having lateral deflection blocks disposed adjacent the film edges for deflecting electrons toward the surface of the trough bottom for further deflecting the electrons toward the film edge.

Abstract: This invention is a self-welding packaging film made by blending at least two ethylene polymers, one of the polymers having a melt flow substantially greater than any of the other polymers in the blend, and thereafter extruding a film from the blend. The film may be self-supporting or it may be an inner layer in a multi-ply film. Preferred ethylene polymers for the blend are the ethylene-vinyl acetate copolymers wherein one copolymer has a melt flow of less than 5.0 and the other has a melt flow greater than 28.0.

Abstract: The opening of a flexible container is closed by gathering the portion defining the opening into a bunch, surrounding the opening with an adhesive and allowing the adhesive to harden.

Abstract: A film useful as a packaging material having a self-adhering layer on the interior thereof has improved optical and adhesion characteristics. The self-adhering layer is composed of a terpolymer of ethylene, a vinyl ester and an alkenoic acid. The saran layer is plasticized with a polyester to synergistically improve both the optical and adhesive characteristics of the composite laminate.

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: A tear and puncture resistant container for use in packaging meat products having protruding bone sections. The container is multilayer having an outer body portion of a flexible packaging material and an inner layer of puncture resistant material disposed between the meat product and the outer layer.

Abstract: When carrying out continuous biologically catalyzed reactions with anaerobic microorganisms attached to a support in an upflow packed bed column, growth of the microorganisms is restricted to prevent the microorganisms from plugging the column by limiting the availability of an essential nutrient and/or by the presence of predatory protozoa which consume the anaerobic microorganisms. A membrane disruptive detergent may be provided in the column to lyse dead microorganisms to make them available as nutrients for live microorganisms.

Abstract: The strength of a heat seal which bonds irradiatively cross-linkable thermoplastic materials together can be significantly improved by irradiating the seal area after sealing is completed. This technique is especially effective for improving the seal strength of packaging film laminates such as those having a layer of saran and a layer of ethylene vinyl acetate copolymer.

Abstract: Plastics bags are formed by welding a continuous tube or a pair of continuous films or a continuous folded film, and the finished bags are marked by attachment of pre-printed panels of plastics material using adhesion by corona-discharge irradiation of both the bag material and the printed panel material.

Abstract: A resilient flexible wall comprising plastic composition has an inner portion and a second portion connected to and disposed at least partially about the inner portion. The second portion extends radially outwardly relative to the inner portion and includes one or more resilient flexible segments of plastic composition. Also disclosed is a container including the wall as a component thereof. In a preferred embodiment the second portion of the wall extends radially in sinuous configuration, and the wall is prepared by blow molding a preform against a mold surface having a corresponding sinuous configuration.The wall is useful for supporting articles thereon with improved resistance to article damage resulting from impact forces which may be developed on the wall.

Abstract: A generally cylindrical core for winding a web of sheetlike material has portions with a lesser diameter than other portions such that otherwise baggy areas of the web overlie the lesser diameter area of the core. The core particularly solves the problem of elongated edges on a wound film of heat shrinkable thermoplastic material caused by differential shrinkage about a core.

Abstract: A chain of imbricated bags connected and supported by a carrier removably secured to the closed end of each of the bags is used for individually dispensing the leading bag when the carrier is moved in a direction which advances the sealed end of the bag ahead of the open end. A method and apparatus for dispensing such bags are also included.

Abstract: In the prior art, vacuum skin packaging processes are performed by placing the product to be packaged on an impervious backing board; placing the product and board in a vacuum chamber; positioning a sheet of thermoplastic film above the product and backing board in the chamber; evacuating the chamber; then, either pulling the film down over the product or pushing the product up into the film; and, thereafter sealing the film to the board. In the present invention, a portion of the film is drawn by differential air pressure against the concave interior surface of the upper portion of a vacuum chamber; the film is then heated by surface contact; and then, after evacuation of the chamber, air pressure is used to blow the film down over the product and against the backing board. Thus, in the present invention, the film is shaped in a concave fashion surrounding the upper portion of the product and it is not necessary for the product to move.