PREFORM HAVING INNER PARTITION WALL AND PROCESS OF MAKING PLASTIC VESSEL HAVING INNER PARTITION WALL

摘要

PCT No. PCT/JP92/00129 Sec. 371 Date Oct. 5, 1992 Sec. 102(e) Date Oct. 5, 1992 PCT Filed Feb. 10, 1992 PCT Pub. No. WO92/13702 PCT Pub. Date Aug. 20, 1992.A preform (70) has an open top portion (72), a cylindrical barrel portion (74) and a bottom portion (76) formed to close the barrel portion (74) at the end opposite to the open top portion (72). The preform (70) also has an internal partition wall (78) formed to extend across the interior of the barrel portion and from the bottom portion (76). In the transverse direction relative to the longitudinal center axis of the preform (70), the internal partition wall (78) has the maximum wall thickness (a2) at the connection (84) between the inner wall of the barrel portion (74) and the internal partition wall (78), the maximum wall thickness of the internal partition wall being gradually reduced toward the longitudinal center axis of the preform with the minimum wall thickness (a1) at a position (82) near the longitudinal center axis of the preform.