The customer approached Andrews-Cooper with a need to convert their manual pressure decay leak testing process to an automated system that would increase production and reduce product damage. The leak testing process required precise and consistent product sealing that was difficult to achieve using manual methods. One challenging customer desire was a solution where a single system would enable testing of multiple products, which would reduce the required system footprint as well as downtime between product changeovers. An experienced design team was needed capable of creating an automated tool that met these tough requirements.
Andrews-Cooper participated from the beginning of process development through the delivery and on-site qualification of the tool. During the design phase, the engineering team presented a number of potential solutions to meet the client’s needs. Thinking beyond just the performance requirements, Andrews-Cooper added extra value by delivering the system with features to reduce cycle time, improve uptime, reduce scrap, and improve ergonomics. A two-position rotary dial was used for the part nests. This reduced the cycle time by 15 seconds since part unloading and loading could occur while a part was being processed. This dial positioned the part nest in an easy to load/unload, ergonomic position for the operator which also reduced scrap from damage caused by misloads.
This tool required frequent access for loading and unloading parts. To ensure operator safety, light curtains were used rather than interlocking doors. To reduce the risk of accidental trips of the light curtains, Andrews-Cooper added LED strips to illuminate the loading and unloading zone different colors to communicate the state of the light curtain: green = light curtain inactive (free to access), red = light curtain active (access will interrupt cycle). This became very intuitive the tool operators a reduced accidental trips of the light curtain, leading to greater throughput and less downtime.
This product was designed to process multiple products thus requiring changeover in the manufacturing line. Our approach to design for change-over includes the following:
Minimize time – by including product-specific adjustments in the modules. Adjustments are made once at the initial setup and do not need to be repeated at change-over. A good example is a sub-assembly that requires precise XY alignment; all XY adjustments are made within the module and the entire module is pinned on the system. The adjusted XY location stays with the module on change-out and returns to the same location when re-installed.
Minimize error – reduce manual system adjustments. We accomplish this by either including product-specific adjustment mechanisms in the modules, using software to control adjustments, or verifying settings with recipes. A good example is an air cylinder that must be operated at different pressures for each product. Counting on an operator to adjust an air regulator introduces risk as it may not be set correctly. To mitigate this risk, a digital pressure gage with software to verify pressure is installed with an operator prompt if further adjustment is needed.
Utilizing this approach, Andrews-Cooper delivered a manufacturing test systems capable of processing up to four different products with simple, robust, and rapid change-over schemes.