| 摘要 |
PROBLEM TO BE SOLVED: To prevent the generation of liquid sagging during the stop of discharge in a casting machine. SOLUTION: The feed of a liquid raw material to a mixing chamber 2 by feed valves 11a, 11b is stopped, and linking with the stopping operation, compressed air is fed to an air chamber 6 of a rubber valve 4 in a mixing chamber 3 of a head part. After the internal volume of the mixing chamber 3 is reduced by the contraction of the diameter of the rubber valve 4, it is restored to the original internal volume, thus its discharge is stopped, and liquid sagging during the stop of the discharge is prevented. In this way, a polyurethane molding free from defects caused by liquid sagging upon the exchange of a molding die after casting and a molding die before casting can be produced. COPYRIGHT: (C)2009,JPO&INPIT
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