Abstract: The influence of the environment humidity on the curing strength of the rosin sand (furne phenols, phonelic-arethane, polyel-urethane resin) in the curing and storage process has been invest-agate. By using the infrared spectrum analysis and S.E.M. observation, the rupture mechanism of the humidity to the blading bridge of the rosin sand was presented and the tm proving method was found. The blading characteristics between the blading bridge and the sand particles surfaces were improved by adding the addition agents of Kil-550, Si400 or Si400 and effect of the anti-humidity of the resin sand was strengthened.

Key words: 化学降解, 解吸, 湿度, 树脂砂, 粘结桥