VERFAHREN ZUR HERSTELLUNG EINES MEHRLAGIGEN FORMKÖRPERS

摘要

A preform for a multi-layered hollow vessel having excellent moldability and productivity and free from the deterioration of the characteristic properties of the vessel even when a recycled material is filled in large quantities and a production process therefor. The bottomed preform for a multi-layered blow molded hollow vessel, wherein the barrel portion and the bottom portion of the preform have a three-layer structure, the outermost layer and the innermost layer of the three-layer structure are made from a first material, the intermediate layer is made from a second material, and the thickness (tc) of the intermediate layer of the bottom portion is smaller (tc < to) than the thickness (to) of the intermediate layer of the barrel portion. This molded product is produced by filling the first material and the second material into the cavity of an injection mold in a single molding step consisting of (i) the substep of injecting the first material, (ii) the substep of injecting the first material and the second material at the same time and (iii) the substep of injecting the first material which are carried out continuously in this order.