树脂芯砂的混入对湿型砂质量的影响

论述了在用湿型砂生产铸铁件的型砂系统中混入大量树脂砂时,对型砂粒度、膨润土有效含量、抗粘砂性能的影响,并提出了相应的措施.针对铸造一厂的型砂系统,详细介绍了灰铸铁型砂系统物料的变化情况、混入树脂砂对型砂发气量的影响,并成功实施了将灰铸铁型砂系统的旧砂代替新砂使用在球墨铸铁型砂中的工艺,这一工艺的实施不仅降低了成本和铸件缺陷,而且使型砂的性能更稳定.实践证明:在用湿型砂生产有芯铸件时,芯砂的粒度要与型砂的粒度基本一致；混入树脂砂中的树脂膜可以起到一定的防止铸铁件粘砂作用,应当加以利用；适当地往型砂系统中补充旧砂对型砂系统的稳定是有利的；控制好型砂的有效膨润土含量和有效添加剂含量是大量树脂砂混入型砂系统情况下稳定型砂系统的有效途径.

Intermixed Resin Core Sand on Quality of Green Sand

The influence of a great deal of intermixed resin sand in molding sand system for cast iron on molding sand granularity,effective bentonite content,and burning-on resistance were discussed in this paper,and some responsive methods were brought forward.In term of molding sand systems in First Foundry of our company,the change of materials in molding sand system for gray cast iron and influence of intermixed resin sand on gas evolution for molding sand were introduced in detail.A technical innovative method for molding sand treatment process was brought into effect successfully,in which new sand in molding sand system for ductile iron were replaced by used sand frommolding sand systemfor gray cast iron.This innovativemethodmade not only the cost and casting defects decrease,but molding sand properties to be more stable.Our experiences in practices have proved that the granularity of core sand should be conformity with that of molding sand;the resin membrane of intermixed resin sand can play a role of preventing cast iron castings fromburning-on in some degree;supplement of a proper amount of used sand to molding sand system is favorable to stabilizing molding sand system;it is an effective way to stabilize molding sand system to control effective bentonite content and effective additives contentwell inmolding sandwhen a great deal of resin sandwere intermixed tomolding sand system.