Simple Solutions That Work! Issue 13

44 T he proverb, “An ounce of prevention is worth a pound of cure”, applies to defects in the permanent mold casting industry. Defects, as defined by the foundry industry, are variances from a desired outcome. The cost of scrapping a casting is extremely high when compared to preventing the defect. Hence, it is better to take measures to prevent the defect as early as possible. The further down the manufacturing process, the more costly the defect JOHN HALL President CMH MANUFACTURING COMPANY ARTICLE TAKEAWAYS: • Defects are not free • Processes for preventing defects • Understanding all of the variables DEFECT PREVENTION IN PERMANENT MOLD CASTING THROUGH PROCESS CONTROL becomes. Automotive casting defects can be found in the following phases of the casting cycle: • In the dip well • At the casting machine • In the workcell • After heat treatment • During machining • During assembly • By the customer As one can deduce, it is much less costly to detect a defect at the casting machine than for the customer to experience a failure. Defects are not free. When a defect occurs a person was paid to make it. Poor quality begets poor quality and lowers productivity throughout the process and if the defective casting goes to the customer it could lead to loss of the account or even the closing of the foundry. It is always better to prevent a defect rather than detect one. This principle can be expressed graphically: Casting defects can be caused by: • Inadequate training/lack of knowledge • Poor communication • Failure to document the problem/ omission Detection (after event) Prevention (before event) Tolerates Waste Avoids Waste Raises Cost Lowers Cost Destroys Jobs Protects Jobs