| 摘要 |
PURPOSE:To perform precise dimensional control even if an extrusion quantity is varied momentarily, by a method wherein a weight reducing rate of raw materials held into a raw material holding part, a practical extrusion quantity per unit time to an extrusion machine is measured and the extrusion quantity to the extrusion machine is operated by performing smoothing treatment of the practical extrusion quantity. CONSTITUTION:A practical extrusion quantity X per unit time can be measured by detecting a reducing rate of resin within a hopper 2 by a weight detecting sensor 7. The practical extrusion quantity X is applied to a filter part 31, an influence due to variation in a short cycle of the practical extrusion quantity X is eliminated and an extrusion quantity Q is operated. A take-off rate L of a take-off gear 4 is obtained by a film width W through a width sensor 8 applied to a take-off rate operation block 32, a thickness target value Do and the extrusion quantity Q. A CPU6 controls a rotation of a take-off motor driving the take-off gear 4 so that the take-off rate of the take-off gear 4 becomes the take-off rate L. A difference between the film width W and a width target value We is obtained, which is applied to an air pump suction and exhaust quantity operation block 41, suction/exhaust quantities of an air pump 9 are operated, based on a result of which the suction/exhaust quantities are controlled and a filter width W is caused to coincide with the width target value We. |
