Abstract: A method and apparatus for monitoring the average cell size of a plastic foam structure continuously emerging from a production extrusion source which include means and process steps for magnifying an image of an area of a cross-section of said foam structure, developing said image and comparing the cell size of the image with a known standard and controlling production process parameters to obtain a foam structure of predetermined average cell size.

Abstract: A flexible film laminate of (a) a polyacrylonitrile film containing a heterized ethylene oxide-propylene oxide copolymer; (b) contacting said film with an adhesive combination layer of a styrene-butadiene block copolymer and a terpolymer of 1,3-pentadiene, a monocyclic terpene and alpha methylstyrene; and (c) a second polyacrylonitrile film or a heat-sealable polyolefin film contacting said adhesive layer; a product pouch made therefrom; and a method of forming said laminate.

Abstract: Polyimide film is manufactured by solvent casting onto a film-supporting surface. A solution of polyimide resin is dissolved in hot organic solvent to provide a casting dope. The film is coagulated by contacting an aqueous medium, substantially replacing the organic solvent in the film with water. Orienting the water-containing film and drying the oriented film to remove water produces a substantially homogeneous polyimide film having high electrical resistance, flexibility and strength.

Abstract: A flexible film laminate of (a) a polyacrylonitrile film containing a polyalkylene glycol ether adhesion promoter; (b) contacting said film with an adhesive combination layer of a styrene-butadiene block copolymer and a terpolymer of 1,3 pentadiene, a monocyclic terpene and alpha methylstyrene; and (c) a second polyacrylonitrile film or a heat sealable polyolefin film contacting said adhesive layer; a product pouch therefrom; and a method of forming said laminate.

Abstract: Polymer powder is dispersed in a combination of an organic solvent for the powder and sufficient water to prevent dissolution of the powder in the organic solvent. The system is heated and the powder is dissolved in the solvent-water system. Water is thereafter removed and the system concentrated.

Abstract: A thermoplastic bag characterized by having handles formed on opposite ends of the bag mouth which is characterized by having structural features immediately adjacent the mouth of the bag to provide stress relief at those positions on the bag mouth where maximum stress is concentrated when such bags are being filled with product and eventually carried by the user. The stress redistribution feature is characterized by an area or areas, immediately adjacent the mouth portion of the bag and the base of the handle members, which are characterized by having a plurality of narrow pleats which are impressed into the bag structure by die members during formation of the individual bag.

Abstract: A flexible film laminate and pouch or tube therefrom comprising two or more layers of polyacrylonitrile homopolymer films adhesively bonded together by means of a layer of a combination of a styrene-butadiene block copolymer and a random terpolymer, said laminate having been subjected to ultraviolet radiation to an extent resulting in a greater bond strength between layers than in the absence of said radiation.

Abstract: A heat sealable film laminate having a first layer of a major amount of high density polyolefin, a minor proportion of an adhesion promoting ionomer and a heat seal promoting proportion of a metal salt of a fatty acid; and a second layer adhering to the first layer, said layer comprising a polyamide. A food storage and heating bag formed from said laminate and a method of heat sealing said laminate.

Abstract: This present invention relates to novel coextruded thermoplastic film and the employment of such multi-layer film as stretch-wrap material for packaging of goods, including relatively large palletized loads of material. More specifically, such coextruded stretch-wrap films comprise three-layer laminations having a relatively thin skin layer and a relatively thicker core layer. Suitable skin layers include highly-branched low-density polyethylene, and suitable core layers include linear low-density polyethylene co-polymers, such as ethylene co-polymerized with a minor amount of at least one C.sub.4 to C.sub.10 alpha-olefin, such as octene-1 and 4-methyl-pentene-1, and butene-1.

Abstract: Acrylonitrile polymer film is treated with non-volatile water-miscible glycol plasticizer to improve toughness and other film properties. In a unique, continuous, steady state process polyacrylonitrile aquagel strip is treated with plasticizer additive in concentrated aqueous solution. Aquagel strip is passed at substantially constant rate through a solution treatment bath. The aquagel strip, which may contain at least about 40 weight % water uniformly dispersed in the polyacrylonitrile, is contacted with the aqueous solution during a predetermined residence time in the bath. After passing the treated aquagel strip from the bath, excess aqueous additive solution is removed. The plasticizer additive can be metered to the aqueous solution at concentration greater than the aqueous additive solution of the bath at a rate substantially proportionate to desired steady state uptake of additive for the aquagel strip.

Abstract: Laminar thermoplastic film constructions comprising a layer of low density polyethylene bonded to a layer of a dissimilar polymer blend comprising high density polyethylene and polyethylene copolymers. In particular such copolymers comprise polyethylene copolymerized with another alpha olefin containing from about 3 up to about 15 carbon atoms. Such copolymers are also characterized by being linear, low density polymers having densities which are below about 0.94 grams/cc.

Abstract: A flexible film laminate and retortable pouch therefrom comprising a first layer of heat-sealable polyolefin film; a first adhesive layer contacting said polyolefin film, said first adhesive being a maleic acid anhydride adduct of an ethylene-propylene copolymer; a second adhesive layer contacting said first adhesive layer, said second adhesive being a combination of a styrene-butadiene block copolymer and a random terpolymer, said second adhesive also contacting; a second layer of a polyacrylonitrile homopolymer film; said laminate having been subjected to ultra violet radiation through said second layer to an extent resulting in a greater bond strength between layers than in the absence of said radiation.

Abstract: A flexible film laminate and retortable pouch therefrom comprising a first layer of heat-sealable polyolefin film; a syndiotactic poly-1,2-butadiene adhesive be bonding said first layer to a second layer of polyacrylonitrile homopolymer film; said laminate having been subjected to conditions sufficient to effect the generation of free radicals in the system to an extent resulting in greater bond strength between layers than in the absence of said conditions.

Abstract: A plasticized polyacrylonitrile composition and a film thereof containing a plasticizing proportion of a liquid polyether prepared by reacting ethylene oxide and propylene oxide with at least one monohydric alcohol active hydrogen compound initiator having about one to about ten aliphatic carbon atoms to yield a heterized copolymer. The invention is also concerned with a continuous process for the introduction of the plasticizing proportion of said liquid polyether into the polyacrylonitrile aquagel film.

Abstract: A system for producing coated, oriented polymer film. Methods and apparatus are provided for forming a continuous film of the polymer with water uniformly dispersed therein and applying an aqueous coating composition to at least one surface of the film. The film is oriented and dried under constraint to remove water from the substrate film and coating.

Abstract: Continuous film production from a high pressure feed stream is achieved in a system which provides methods and means for maintaining pressurized gas in an extrusion zone wherein the extrudate may be cooled to form a solid polymeric film. The product film is withdrawn from the extrusion zone continuously through a standing liquid column in fluid communication with the extrusion zone. The film is passed downwardly into a liquid leg below the extrusion zone and upwardly through the liquid column, which has an upper exit end elevated above the pressurized zone thereby exerting super-atmospheric pressure. The product is recovered from the liquid sealing medium, advantageously water, at ambient pressure. Hot aqueous solutions of polyacrylonitrile may be extruded at elevated pressure onto a cooled casting drum in a gaseous environment wherein flashing of the hot solvent is prevented.

Abstract: Biaxially oriented polyacrylonitrile film is treated with corona discharge and laminated on one or both sides with olefin polymer or copolymer by extrusion coating. The resultant laminate has excellent flexibility as measured by the Gelbo flex test. The laminate is readily heat sealed and is useful in packaging application.

Abstract: The present invention is directed to an opaque, biaxially oriented polymeric film structure of lustrous satin appearance comprising a thermoplastic core matrix having a strata of voids; said voids being created by the inclusion within the matrix material of spherical void-initiating solid particles which are incompatible with the matrix material. The void space occupied by the particle is substantially less than the volume of the void. The polymer matrix material is extruded in the form of a film and positioned on opposite surfaces of the film are void free, transparent thermoplastic skin layers adhering to said surfaces. The structure has excellent opacity and extremely high gloss measurement and a lustrous satin appearance.