| 摘要 |
PURPOSE:To manufacture a cap assembly at low cost by eliminating the assembling work of the cap assembly by a method wherein an upper cap is fitted to a lower cap by injecting second synthetic resin, which is incompatible with first synthetic resin, between the lower cap, which has been molded of the first synthetic resin, and a mold opposing to the lower cap. CONSTITUTION:Firstly, a lower cap 2 is obtained by injecting synthetic resin P1, between a core 7 and a first cavity die 9. Secondly, synthetic resin P2, which is incompatible with the resin P1, is injected through a gate 17 between the lower cap 2 and a second cavity die 10 under the state that the cavity die 10 is faced to the lower cap 2 in such a manner as to cover the outside of the lower cap 2. Thirdly, the resins P1 and P2 are cooled down for the predetermined period of time in order to harden themselves. Fourthly, the cavity die 10 is removed. Finally, the lower cap 2 is released from the core 7 by raising a stripper 8 in order to obtain a cap assembly, in which the upper cap 4 is molded in the state air-tightly fitted to the lower cap 1. |
