and molds out of the boxes and erosion and burn-in defects,” Walker said. “But really, we were trying to find the best binder for our product. In turn, that meant dealing with our variables that we had never really addressed before to understand them fully. We challenged ourselves to bring our binders down, for our benefit and for the environment.” Denison invited three binder suppliers to provide a solu-
tion to its requirements but eventually settled on a mixture of its own design with a lower binder percentage. Te metal- caster watched every aspect of the process both in the lab and on the plant floor, running tests for strength and core quality and studying how the binder held up over time and performed at shakeout. “We started out trying to get to at least 0.7% binder and then see what we could do,” said Tim Purcell, Porter Warner Industries, Arlington, Texas, U.S.A., who consulted with Denison during the testing. “Ten we said we’ll keep going until we can’t go any longer.” Operators were consulted to be sure no variables were missed in the testing. Denison performed tests in the lab on test bars and tests in the shop on 272-kg core assemblies. “By testing on the floor, we were able to start working with the high temperatures and moisture ranges that we would see,” Walker said. “All of that has an impact on how the mold sets up and the strength built into the mold.” Based on the results of
a round of tests, Denison separated the chemicals in the binder mixture, weighed them, and mixed a new trial binder by increasing or decreasing the percentage of each chemical. “We repeated the process
over and over, and I charted out the variables from the data to see what was taking place in the process,” Walker said. “After a week’s worth of collection, I’d look back and see how each variable correlated. From there we started developing what the next mix should be.”
到最好的粘结剂。反过来，这意味着处理我们从未接触 的因素以充分了解它们。我们挑战自己，减少使用粘结 剂，这是为了我们自己的利益，也为了环境。“ 丹尼森工业公司要求三家粘结剂供应商都提供解决方 案，但最终采用了自行设计的砂配方
，其中粘结剂比例较低。 铸造人员分别在实验室和 车间观察了自硬过程的每一个方面，进行了强度和砂芯 质量测试，并研究粘结剂保存一段时间后的效果以及落 砂时的表现。
“我们一开始就试图用至少0.7％的粘结剂，然后 看看我们能做些什么，”得克萨斯州阿灵顿市Porter Warner 公司的Tim Purcell说： “然后我们说，我们将 继续做，直到我们不能再继续。”在测试过程中，他咨 询了丹尼森公司。
丹尼森工业公司咨询了操作者，以确保在测试中没有 漏掉该测的参数。在实验室进行了试样测试，在车间对 600磅 （272公斤）的组装砂芯进行了测试。 “通过车间测试，我们开始在我们能想象到的高温 和湿度环境内测试”， Walker说：“所有这些因 素都与砂型装配和砂型强 度有关。”
通过一系列测试，丹尼 森工业公司分离出了粘结 剂中的化学物质，进行了 称量，并且通过降低或提 高每种化学成分混合出新 的粘结剂。
“我们一遍遍地实验， 我将数据制成表格，研究 在这一过程中发生了什 么”， Walker说：“通过 一周的数据收集，我会回 过头来看各变量之间的联 系。根据这些研究我们开 始开发新的混合物。”
Testing each binder mix- ture across a wide range of variables, including how long a core or mold sits before pouring, is necessary to find the optimal recipe.
对每种粘结剂混合物都在大 的变化范围内进行测试，包 括砂芯或砂型浇注前放置时 间的长短，这是找到最佳配 方的前提。
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FOUNDRY-PLANET.COM | MODERN CASTING | CHINA FOUNDRY ASSOCIATION Spring 2012
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