Abstract: 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.

Abstract: A T-die adapted for extrusion molding of a plastic material such as plastic film is constituted by a lower stationary half and an upper movable half. The stationary half is integrally provided with a steady lip portion and a movable half is provided with a base portion and flexible lip portion so as to form a gap in slit form between the steady and flexible lip portions. The gap is adjusted partially by a plurality of adjusting bolts screwed to the upper portion of the movable half extending to cover the flexible lip portion with space, the bolts being arranged in a line along the longitudinal direction of the T-die and spaced equally with each other. Each bolt has such a length that the front end thereof downwardly presses the flexible lip portion when the bolt is driven downwardly. The flexible lip portion is provided with a plurality of U-shaped grooves each disposed between the adjacent two bolts and having a width of an opening substantially equal to the distance between the adjacent two bolts.

Abstract: An apparatus for adjusting die clearance for an extruder producing a sheet in a die having an adjusting device for adjusting the die clearance between an upper die and a lower die, a measuring device for measuring thicknesses of the sheet at a plurality of positions in the direction of width on the sheet, a setting device for setting desirable thicknesses at the positions, an adjusting data producing device for producing data with respect to die displacement to be adjusted from the measured data and the desirable thicknesses, and control device for controlling the adjusting device in order that the die clearance coincides with the desirable thickness. Rough adjustment can be effected by tightening or loosening the bolts while fine adjustment is achieved by heating the bolts with an electrical heater disposed thereabout.