Abstract: Film coating and biaxial orienting apparatus comprising a first uniaxial stretching unit for machine direction orientation of the film, a coating device to provide a liquid coating composition in a center band on the film, a second uniaxial stretching unit for transversely orienting the coated film and having edge holders for gripping the film, and a heater for curing the coating under constrained conditions during setting of the film.

Abstract: A system for producing a biaxially oriented polymer film of predetermined gauge profile. Methods and apparatus are provided for forming a continuous film of the polymer having substantially uniform gauge by controlling the character of the film in its aquagel form prior to transverse stretching.

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: 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: 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: 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 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: 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: 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 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 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: A novel multilayer film is made by extruding and/or casting at least two layers of resin, such as polyacrylonitrile homopolymer or interpolymers. By co-extruding a continuous multilayer film with contiguous or tandem dies from a first supply of homogeneous resin solution and a second supply of non-homogeneous redissolved resin scrap, a film may be cast onto a smooth cooled drum surface to form substantially continuous adjacent layers from two or more resin supplies. Scrap resin, such as selvage trimmed from stretched film or mill scrap, is comminuted and redissolved in solvent for recycle to the second supply of the extrusion step. The homogeneous layer prevents film disruption by inhomogeneities present in the contiguous layer containing redissolved scrap, which might cause localized stresses in the film and discontinuities during stretching.

Abstract: A flowable polymeric extrusion powder consisting essentially of acrylonitrile polymer particles is provided at low temperature treated with a non-sticking amount of solvent. Sufficient solvent can be added to dissolve the polymer at elevated temperature, for instance, more than 120 parts by weight of dimethyl sulfoxide solvent can be added per hundred parts of dry polymer below ambient temperature.

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: A novel system for producing film by extruding and/or casting at least two layers of resin, such as polyacrylonitrile homopolymer or interpolymers. The system provides for co-extruding a continuous multi-layer film with contiguous or tandem dies from a first supply of homogeneous resin solution and a second supply of non-homogeneous redissolved resin scrap. The film may be cast onto a smooth cooled drum surface to form substantially continuous adjacent layers from two or more resin supplies. By stripping the film from the drum as a continuous film strip and stretching the film an oriented structure is provided. Scrap resin, such as selvage trimmed from the stretched film or mill scrap, is comminuted and redissolved in solvent for recycle to the second supply of the extrusion step. The homogeneous layer prevents film disruption by inhomogeneities present in the contiguous layer containing redissolved scrap, which might cause localized stresses in the film and discontinuities during stretching.

Abstract: Method of preparing films of acrylonitrile polymer exhibiting very high tensile strength, stiffness, optical clarity, and outstanding gas barrier properties. Method entails extruding a hot, concentrated solution of said polymer in a solvent therefor that is water-soluble, e.g., dimethyl sulfoxide, onto a film-supporting surface, e.g., a flat surface, or a drum, which, preferably, has a low energy surface such as provided by wetting the surface with aqueous dimethyl sulfoxide, or coated with polytetrafluoroethylene, or other suitable means to thereby form a film. The resulting film is then contacted with an aqueous medium, e.g., water to remove the solvent (e.g., dimethyl sulfoxide) and partially replace it with water, this treatment being effected under conditions that will prevent the film from curling or puckering. The resulting film is composed essentially of acrylonitrile polymer and water, and is ignition resistant.

Abstract: A method for continuously controlling the internal bubble pressure in a tubular thermoplastic film extrusion process which comprises a pressure sensor device which feeds a signal to a pressure controller. In response to the signal the pressure controller feeds a proportional signal to an air valve member which, dependent upon the signal, either increases or decreases air flow into the bubble. A poppet valve, in direct communication with the air pressure inside the bubble, opens to rapidly exhaust air to the atmosphere when the pressure inside the bubble exceeds a set maximum.

Abstract: Method of preparing films of acrylonitrile polymer exhibiting very high tensile strength, stiffness, optical clarity, and outstanding gas barrier properties. Method entails extruding a hot, concentrated solution of said polymer in a solvent therefor that is water-soluble, e.g., dimethyl sulfoxide, onto a film-supporting surface, e.g., a flat surface, or a drum, which, preferably, has a low energy surface such as provided by wetting the surface with aqueous dimethyl sulfoxide, or coated with polytetrafluoroethylene, or other suitable means to thereby form a film. The resulting film is then contacted with an aqueous medium, e.g., water to remove the solvent (e.g., dimethyl sulfoxide) and partially replace it with water, this treatment being effected under conditions that will prevent the film from curling or puckering. The resulting film is composed essentially of acrylonitrile polymer and water, and is ignition resistant.