Abstract: A film forming apparatus includes a die device which extrudes a molten resin in a tube shape to form a film, a measurement unit which measures a thickness profile of a film in a circumferential direction, a plurality of adjustment portions which change the thickness profile of the film, and a controller which controls the plurality of adjustment portions such that the thickness profile approaches a target thickness profile. The controller changes the target thickness profile based on the measured thickness profile.

Abstract: Provide is a blown film forming apparatus including a die including a columnar inner peripheral member and a cylindrical outer peripheral member that surrounds the inner peripheral member, and extruding a resin from a lip formed between the inner peripheral member and the outer peripheral member, and a plurality of die lip drive mechanisms including a fluid pressure actuator as a drive source and adjusting a lip width by applying a radial load to the outer peripheral member, in which the outer peripheral member includes a plurality of load receiving portions to which a load is applied by the die lip drive mechanism, and a stiffness reducing portion that is provided between the plurality of load receiving portions.

Abstract: 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.

Abstract: Provided is a die lip driving structure for adjusting a gap between a first lip and a second lip by applying a pressing load or a tensile load to a flexible lip portion which forms at least one of the first lip and the second lip provided in a die body, the die lip driving structure including: a lever supported by a rotating shaft as a fulcrum; and an operating rod which is supported to be displaced in an axial direction by the die body. A rotational force of the lever is converted into a force in the axial direction of the operating rod, and the force in the axial direction becomes a pressing load or a tensile load exerted on the flexible lip portion. The lever directly applies a force to the operating rod at the point of action of the lever.

Abstract: A lip drive part for a T-die that adjusts a gap between first and second lips includes an actuator acts on a flexible lip part forming at least one of the first and second lips of a T-die body, includes a lever that acts on the flexible lip part, a first bellows that narrow the gap by acting on the lever when being expanded, and a second bellows that widen the gap by acting on the lever when being expanded.

Abstract: A lip drive part for a T-die that adjusts a gap between first and second lips includes an actuator acts on a flexible lip part forming at least one of the first and second lips of a T-die body, includes a lever that acts on the flexible lip part, a first bellows that narrow the gap by acting on the lever when being expanded, and a second bellows that widen the gap by acting on the lever when being expanded.