METHOD OF AND APPARATUS FOR EXTRUSION MOLDING

专利名称：METHOD OF AND APPARATUS FOR

EXTRUSION MOLDING

发明人：ANDO, Yukimasa,KISHINO, Katsutomi申请号：EP94903080.3申请日：19931227公开号：EP0672515B1公开日：20020904

摘要：According to the invention, a preliminary extrusion is performed to find anoptimum back pressure which can provide a predetermined sectional size for respectiveportions of a movement pattern DA of a movable die, which pattern is determined by ashape of a product. It is assumed that the movable die is positioned at a position DA1corresponding to a side portion of a product and a value of a back pressure BP, at which amolded product has a predetermined sectional size while rotations of a screw arevariously changed during molding of a molding material, is made an optimum backpressure BPO. An optimum back pressure for an upper portion of a product isdetermined in a like manner to decide a pattern of the optimum back pressure BPO.Taking into account time lag, a timing, at which an initial set pattern R1 for rotations ofthe screw is changed, is set a period of time T11 to T14 ahead of a timing, at which thepattern DA is changed. In a regular extrusion, an actual take-up speed is measured, andwhen the measured speed is different from that at the time of the preliminary extrusion,the movement pattern DA of the movable die is corrected. When the measured backpressure BP is deviated from the pattern of the optimum back pressure BPO afterseveral cycles of extrusion molding have been executed, the pattern R1 for rotations of

the screw is corrected.

申请人：TOKAI KOGYO CO LTD

地址：JP

国籍：JP

代理机构：Hallybone, Huw George

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