JPH05345347

PURPOSE:To enable the distribution of thickness to be controlled in the direction of width during operation by permitting one end part in the peripheral direction of the outer peripheral surface of flow rate control pins rotatably disposed at the expansion chamber side of a lip block, to be opposite to the flow path of molten resin, and forming a control recession and protrusion on its outer peripheral surface, which have different cross-sections in the direction of periphery and in the direction of axis. CONSTITUTION:Both end shafts of cylindrical flow quantity control pins 21A-21C rotatably mounted on cylindrical insertion grooves are rotatably supported on the support holes of a field block 1, and layer thickness control actuators (layer thickness control driving mechanisms) 14A-14C for rotating the flow rate control pins 21A-21C are provided on each one end shaft part. On inlet resin paths, curved flow paths 25A-25C being projectingly curved with a set clearance with respect to the flow quantity control pins 21A-21C are formed, and each recession 33a for central increased thickness is formed on the central increased thickness parts 33 of the flow quantity control pins 21A-21C. By the recession 33a for central increased thickness, resin resistance in the central side at the curved flow paths 25A-25C is made small, so that the quantity of resin supply at the central side can be increased relative to both the end parts thereof.