The Purpose of this study was to obtain suitable bench time by measuring Comperssive strength and surface stability of new sand and return sand of furan resin pattern. The results obtained in this study are summarized as follows.
(1) SuitabIe bench t...
The Purpose of this study was to obtain suitable bench time by measuring Comperssive strength and surface stability of new sand and return sand of furan resin pattern. The results obtained in this study are summarized as follows.
(1) SuitabIe bench time of new sand and return sand by the mixing ratio of resin and hardening agent was 25 to 38 minutes in new sand and 6 to 12 minutes in return sand.
(2) In the return sand system the amount of resin addition wasenough to about 1/2 of new sand and was vcry economical.
(3) Hardening velocity of return sand was very quick, therefore molding shonld quickly be done because bench time is short.