| 摘要 |
PURPOSE:To reduce tab loss and achieve the material cost reduce and embody effective utilization of resources by suppressing the fluctuations of the width of a sheet. CONSTITUTION:A foamable thermoplastic resin 10 is passed through a heating oven 12 to be foamed to produce a foamed sheet 13 having predetermined width. In this method, the taking-up speed and width of the foamed sheet 13 are detected by a speed sensor 15 and a sheet width sensor 16. The taking-up base speed of the foamed sheet is renewed corresponding to the fluctuations of the detected width of the sheet with the elapse of time in an operation part 17 and the taking-up speed of the foamed sheet 13 is changed in a pulsated state cetering around the taking-up base speed and, on the basis of the totalized quantity of the taking-up base speed and pulses, the optimum taking-up speed is calculated and, corresponding to the detected taking-up speed and the detected optimum taking-up base speed, the taking-up speed of the foamed sheet 13 is controlled by a controller 20 to always make the passing position of the foamed sheet in the heating oven constant. |
