CONTROL METHOD FOR SHEET-SHAPED MATERIAL AND MONITORING METHOD FOR CORRESPONDING RELATION BETWEEN THICKNESS DISTRIBUTION AND SHEET-SHAPED MATERIAL AND THICKNESS ADJUSTING MEANS

摘要

PURPOSE:To enhance control accuracy of thickness of a sheet-shaped material by grasping the corresponding relation between a discharged molten material thickness adjusting means of a cap and the thickness distribution of the sheet-shaped material after molding by means of a Karman filter and controlling the thickness of the sheet- shaped material based on said relation. CONSTITUTION:Molten resin 22 discharged in the shape of a sheet from a cap 21 passes through the sheet-shaped material molding process and molded into a film 26 of given thickness. Then, measured data by thickness gages 28, 29 and 30 are put into a CPU 31. On the other hand, a number of adjusting bolts 32 to adjust slit of the cap 21 are disposed by small pitches, and the expansion amount of its Y-Y direc tion is adjusted by the temperature control of a heater 35, based upon which the slit space of a slit-shaped discharge outlet 33 and the thickness of the discharged sheet can be adjusted. As a Karman filter is incorporated in the CPU 31, the thickness distribution of the film can correspond with respective adjusting bolts 32 of the cap 21 after respective processes, and the thickness profile is controlled close to the target value with high accuracy.