| 摘要 |
PURPOSE:To automatically change the thickness of sheet by a method wherein the gap and rotational speeds of rolls are synchronously changed to desired values. CONSTITUTION:Molten resin, which is extruded from an extruder, is extruded in the form of sheet by means of a die 11. The sheet-like molten resin 12 is rolled with a lower roll 3 and a middle roll 1 so as to smooth the surface of the sheet and to cool the sheet in order to be taken off by take-off rolls 25 and 26 after being passed through the middle roll 1 and an upper roll 2. When the change of the thickness of the sheet-like molten resin is intended, the amount of change and change-over time are inputted in a thickness setter 17. Upon the receipt of signal outputted from an operator 18, a rotational frequency addressing device 19 outputs rotation commands to shift an upper wedge type nip adjusting means 14 and a lower wedge type nip adjusting means 13 to their desired positions respectively to an upper wedge shifting motor controlling board 23 and to a lower wedge shifting motor controlling board 24. Thus, by synchronously changing the rotational frequencies of the respective rolls 1-3 and the respective gaps so as to realize set thicknesses, sheet-like molten resin, which is kept on being continuously supplied from a die 11, can be automatically changed to the desired thickness. |
