Simple Solutions That Work! Issue 13

S ince the first castings were poured, foundry men have been working to eliminate scrap castings and improve product quality. This article will concentrate in one area of reducing casting defects and scrap by outlining five important considerations for reliable sand core production. There are many different sand core processes that metal casters can utilize. These can include; cold box (isocure), shell, warm box, inorganic, no-bake, among others. Any of these core processes can be used for just about any alloy. Selection is typically based on the size of the core, the production rate required, casting finish, tooling and capital investment. 1. CORE PROCESS Many times, the process will be defined based on the existing core process the foundry is familiar with, but as foundries add new castings to their portfolio; customer specifications may dictate a new core making process, or any of these considerations may impact the core process choice: REDUCING CORE DEFECTS 4 • What kind of finish is required? • Production rates; high runner or job shop? • Can core off-gas adversely affect the castings? • Is shake out of the cores going to be restrictive in any manner? • What are the environmental impacts? The core cost is usually the main driver to process selection, but all the variables listed above are inputs to cost comparisons. JERRY SENK President EQUIPMENT MANUFACTURERS INTERNATIONAL, INC. ARTICLE TAKEAWAYS: • Better Cores = Better Castings • Five considerations for core quality • Existing equipment improvements can minimize defects • New casting products may require new core production process