Toshiba Kikai Kabushiki Kaisha

Toshiba Machine Co., Ltd.

Kenji Nozawa

Takayoshi Sano

Satoru Nitta

Koji Mizunuma

Katsuhiko Iguchi

Hidemi Wada

Masatsugu Tamura

Hiroshi Serizawa

Provided is a sheet forming die capable of finely controlling the flow rates of the respective divided flows of a molten resin with precision. The sheet forming die is a sheet forming dieconfigured to: receive a first molten resin B; to receive a second molten resin A; and to thus form a sheet-shaped resin-made product by discharging the molten resins A, B from a lip gap. The sheet forming dieincludes: a first passageprovided to flow the supplied first molten resin B up to an upstream end of a lip partlocated upstream of the lip gap; a second passageprovided to flow the supplied second molten resin A up to the lip part, the second passage branching out into a plurality of passagewaysA,B in a midstream portion thereof, downstream ends of these passagewaysA,B being connected to portions in an upstream end of the lip part, respectively; and temperature controllerconfigured to locally control a temperature of a midstream portion of at least one of the passagewaysA,B in order to control a flow rate of the second molten resin A in the passagewaysA,B.

Sheet forming die and sheet forming method

For the purpose of molding a multilayered film/sheet having a highly precise thickness of each layer, movable choker bars () are movably arranged in the middle of molten resin channels (), and a plurality of choker adjustment bolts () are arranged at a predetermined pitch in the die width direction. The choker bars with the choker adjustment bolts are moved so as to adjust the gap in a choker portion. Thermal conductors () are provided with the respective choker adjustment bolts.

Multilayered film/sheet molding die

To form a film or sheet relatively thin and needing a high degree of precision in thickness, such as for an optical use, while suppressing temperature fluctuations at one side opposite to the other side in contact with an outer peripheral surface of a roll (), an outer peripheral surface of the roll is covered, with a necessary gap (t) left, by a windshield () of a double-layered structure having a thermally insulating property.

Film or sheet forming apparatus

In a heat displacing type die adapted to extrude a sheet of molten resin, a heat displacing unit provided with a heater is secured to an upper die block. A lip gap is defined between a flexible lid and a stationary lip respectively provided for the upper and lower die blocks. The lower end of a bolt extending through the heat displacing unit is normally in contact with or secured to the flexible lip while the upper end is secured to the upper portion of the heat displacing unit. In a modified embodiment the bolt is air cooled.

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Numazu, Japan

Kenji Nozawa