Effects of furan resin sand hardening speed factor

Furan resin hardening speed in the production process is particularly important for sand box size, filling sand and small sectional area of the mold, can improve the rate of hardening resin sand box; the size of filling sand and a large cross-sectional area cast, in order to guarantee the use time, prevent sand mud layer, then to control the rate of hardening. A plant resin sand hardening speed control quality, directly affects the production proceed smoothly. Usually affect the resin sand hardened factors include the following aspects.

1, furan resin in water is relatively high, will inhibit the polycondensation reaction, reduce the rate of hardening; resin pH value is too high, will consume more curing agent, also reduces the rate of hardening.

Curing agent2, total acidity and free acid content was measured in curing agent activity are important indicators, generally with the total acidity and free fatty acid content increased, the prepared resin self hardening hardening speed, conversely, is hardening speed slow down; in addition, the curing agent dosage must be strictly controlled, in 20% to50%, adding more faster, hardening.

3, the temperature and humidity of environment is the impact of hardening speed of important factors, the higher the temperature, curing agent on grease catalysis and more intense, hardening faster; environment with high humidity can affect the moisture evaporation rate, the hardening rate slows down, especially in a long time in the environment humidity is too high or too low, hardening speed very obvious.

In 4, the sand temperature than the air temperature can affect the rate of hardening resin sand, as long as there are sand temperature, solid velocity is accelerated apparently; if the sand temperature greater than 40 DEG C, then mixing the resin sand can use time can not satisfy the need of production.

In 5, the new sand moisture in high and new sand and used sand in the acid consumption value, one can reduce the curing agent for the resin catalysis, on the other hand will consume part of curing agent, from infants to lead hardening speed slows down.

In 6, mixed resin sand equipment after years of use, the components of friction is large, big mixing process will produce heat, and the hardening speed.

7, using the correct sequence of feeding and appropriate mixing time contribute to obtain high quality resin sand, general sand mixing process: sand + curing agent, mixing - about 1 minutes, and resin, mixing - around 0.5 points out of the sand.

The order can not be reversed, or bureau will radically curing reaction, shorten the time of resin can be used; after adding the mixing time can not be too short ( too short mixing unevenly ) and long ( long sand temperature rise, can use a shorter time ).

ZHUHAI DOUMEN FULIAN MOLDING MATERIALS INDUSTRY CO., LTD
Add: Xinqing 6Rd, Xinqing Ind. Zone, Doumen District,

Zhuhai City, Guangdong Province , China (519180)

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