The challenge
An 8-cavity hot-runner mold making water connectors for residential PEX lines kept producing underfilled cavities. Process engineers had worked on it for two years. The mold was repeatedly torn down and checked with no lasting fix.
How we investigated
Bob moved the investigation from the process to the hot-runner manifold. He had the manifold sent to a specialist in Northern Illinois for cleaning, and when several cleaning cycles did not fix it, he had the channels inspected with a video scope.
What we found
A ceramic insulator, left in the channels during a cleaning two years earlier, was blocking the flow.
The result
With the obstruction removed, all 8 cavities ran at full capacity. Two years of recurring tear-downs ended.
The lesson
When process changes keep failing, stop adjusting the process and inspect the tool. Thorough investigation beats repeated tear-downs.
Dealing with something similar?
Cycle time, scrap, mold downtime and bottlenecks on tools that are already running.