我们是一个成批生产中型铣床的铸铁车间。由于生产的迅速发展,出现了制芯能力的不足。一九七○年底在车间党总支的领导下,成立了以老工人为主体的三结合技术革新小组,开始研究制芯的新工艺。最初我们试验用呋喃树脂砂热芯盒射芯,收到了一些效果。但 We are a mass production of medium-sized milling machine cast iron workshop. Due to the rapid development of production, there has been a shortage of core making capacity. At the end of 1970, under the leadership of the party branch chief of the workshop, a three-pronged technical innovation group with old workers as the main body was established and started to study the new technology of making cores. Initially we experimented with a core of furan resin sand hot core shot, received some results. but