METHOD AND APPARATUS FOR FORMING PARISON PARTIALLY DIFFERENT IN COMPOSITION

摘要

PURPOSE:To provide a parison different in compsn. in its circumferential direction along at least a part of its longitudinal axis. CONSTITUTION:A first passage 3a receiving the supply of a first plastic substance communicates with an annular discharge port 2c and can be selectively closed over an angle alpha by a projection 3c and a second passage 3b receiving the supply of a second plastic substance communicates with the discharge port 2c over the angle alpha. When the first passage is allowed to communicate with the discharge port 2c over its entire periphery, the supply of the second plastic substance to the second passage 3b is temporarily stopped.