The present invention provides a multilayer packaging film characterized by an improved sealability even through contamination with excellent shrinkability good optics and strength without using internal layers of stiff resins and cross-linking, to flexible containers made therefrom, such as bags, pouches and the like, useful for packaging articles, in particular food items.

A film forming apparatus includes a die device which extrudes a molten resin in a tube shape to form a film and a controller which controls the die device. The die device includes an inner peripheral member which defines an inner periphery of an annular discharge port, an outer peripheral member which surrounds the inner peripheral member and defines an outer periphery of the discharge port, and an adjustment portion which applies a load to at least one of the inner peripheral member and the outer peripheral member to elastically deform the at least one of the inner peripheral member and the outer peripheral member and change a radial width of the discharge port. The controller controls a thickness of the film with the load applied by the adjustment portion.

A film forming apparatus includes a die device which extrudes a molten resin in a tube shape to form a film and a controller which controls the die device. The die device includes an inner peripheral member which defines an inner periphery of an annular discharge port, an outer peripheral member which surrounds the inner peripheral member and defines an outer periphery of the discharge port, and an adjustment portion which applies a load to at least one of the inner peripheral member and the outer peripheral member to elastically deform the at least one of the inner peripheral member and the outer peripheral member and change a radial width of the discharge port. The controller controls a thickness of the film with the load applied by the adjustment portion.

A blown film coextrusion line includes a support frame, a plurality of extruders each mounted to the support frame and extending upward at an angle, and a downward facing blown film coextrusion die connected to distal ends of each of the plurality of extruders and receiving individual polymer streams from them. The blown film coextrusion line is compact and sturdy and eliminates much of the floor space and towered mounting structure that was required for conventional blown film coextrusion lines.

A blown film coextrusion line includes a support frame, a plurality of extruders each mounted to the support frame and extending upward at an angle, and a downward facing blown film coextrusion die connected to distal ends of each of the plurality of extruders and receiving individual polymer streams from them. The blown film coextrusion line is compact and sturdy and eliminates much of the floor space and towered mounting structure that was required for conventional blown film coextrusion lines.

In one example embodiment, disclosed is a biaxially oriented multilayer film, which may include a first tie layer and a second tie layer, wherein each has an inside surface and an outside surface. The film's core layer may consist of: (i) at least 50 wt. % high-crystalline polypropylene; (ii) both cyclic olefin copolymer and polypropylene homopolymer, or, polypropylene heterophasic copolymer; (iii) and, optionally, additives, wherein the core layer is between the inside surface of the first tie layer and the inside surface of the second tie layer. The film may also include a first skin layer on the outside surface of the first tie layer and a second skin layer on the outside surface of the second tie layer, wherein shrinkage is less than 3.5% in a transverse direction for the biaxially oriented multilayer film after subjecting the biaxially oriented multilayer film to 135° C. for 7 min at 1 atm.

An inflation molding device includes a viscosity estimation unit that estimates a viscosity of a bubble discharged in a substantially cylindrical shape from a die, a temperature identification unit that identifies a temperature of the bubble, and a parameter estimation unit that estimates a viscosity parameter of the bubble based on the viscosity of the bubble estimated by the viscosity estimation unit and the temperature of the bubble identified by the temperature identification unit.

An inflation molding device includes a viscosity estimation unit that estimates a viscosity of a bubble discharged in a substantially cylindrical shape from a die, a temperature identification unit that identifies a temperature of the bubble, and a parameter estimation unit that estimates a viscosity parameter of the bubble based on the viscosity of the bubble estimated by the viscosity estimation unit and the temperature of the bubble identified by the temperature identification unit.

A film molding device includes: a cooling unit that cools a molding material discharged from a mold; and a rectifying unit that rectifies cooling air blown out from the cooling unit. The rectifying unit includes a suction portion that suctions the cooling air.

Aspects of the disclosure relate to manufacturing a balloon envelope for use in a stratospheric balloon system. For instance, a stream of polyethylene mixture us extruded through an extruder in order to orient molecules of polymer chains of polyethylene and to provide an oriented film. The oriented film is passed through an electron beam and thereby crosslinking the polymer chains to provide a cross-linked film. The cross-linked film is heat sealed to form the balloon envelope.