December 03, 2017
Labor.Never rule out the machine operator as the cause of process failures. Defects can sometimes appear to be process-related, but eventually part handling/operator procedure becomes the true cause of process change. Step back and take the time to evaluate precisely where the defect occurs. Don’t be afraid to run a press in semi-automatic and to inspect the part as it is removed from the mold, even prior to removal in a post-ejection state.
- Quality system. Make sure that quality failures are not misdiagnosed. Check part dimensions and aesthetics to print and customer requirements. Make comparisons between the last shot previous run and first shot from the new run. Utilize the “fit-to-function principle,” making sure that components meet the needs of your customer to ensure functions meet part requirements. Remember, unnecessary process changes can be just as detrimental as taking the “good Samaritan approach,” trying to adjust for false defects.
- Setup. Standardized setup is fundamental to strong start up and production runs. Poorly executed and/or inconsistent mold and process setups quickly lead to large scrap rates and unplanned down time. Develop the changeover during the process engineering stage to ensure that changeovers are precise and easily repeatable. Make sure that all personnel involved in changeovers are consistently performing setup duties and not using multiple approaches to accomplish the same task. Establish clear changeover guidelines, and enforce their implementation.
- Robotics. Never rule out a robot as a potential cause of part defects. Programming and even end-of-arm tooling can cause defects such as drag, pull, scratches and so forth. Inspect parts prior to robot extraction to verify that the scrap event isn’t robot-based. Damaged cups, pneumatic cylinder failures and even poorly cleaned/serviced end-of-arm tooling can lead to unexpected defects.
- Automation. Similar to robotics, never assume that automation can’t be the root cause of a defect event. Inspect parts prior to and post assembly to verify that scrap issues aren’t being caused by poorly performing or maladjusted automation equipment. Look for damaged components, poorly performed automated actions and review that the equipment has been properly cleaned and serviced.
- Material handling. Inspect all aspects of the material-handling operation. Make sure filters are being cleaned, loaders are functioning properly and products are not being moved improperly causing damage. Inspect product just packed by operators and prior to removal from press to ensure adherence to proper handling procedures.