| 摘要 |
PROBLEM TO BE SOLVED: To provide a mold for a preform of a multilayer container, which can accurately control so as for a core layer located in the center part to take a predetermined position. SOLUTION: In the mold for the preform of the multilayer container which molds the preform 1 by successively injecting molten resins for forming the core layer 1a and the outside and inside skin layers 1b, 1c into the cavity through the gate 5 while opening/closing the gate 5 by the operation of the valve stem 6, the gate length (L) is set in the range of 15-30 mm. It is preferable to make the draft of the gate 5 to be 3°or smaller. Further, it is preferable to set both of the arc diameter (A) of the gate root portion and the arc diameter (B) passing the three points of the bottom center portion of the preform and the gate root portion to 5 mm or smaller. COPYRIGHT: (C)2006,JPO&NCIPI |
