Feature Test Systems Keeping cool under pressure
A newly developed testing unit is helping injection moulders and mould toolmakers alike to ensure consistent quality in their end products. Based on a simple pressurised water technique, the key to its success is an automated control panel based on Mitsubishi Electric components
T
he portable single-phase testing unit has been developed and refined by Mike Atkin of Atkin Machine Tool Maintenance in Oldham, Manchester, along with con- trol systems expert, George Newton of Newton Tesla (Electric Drives), in nearby Warrington. “We produced a prototype back in 2007,” explained Atkin, “and have progressively improved it through a number of iterations. We now have a growing number of high profile users who are helping us further develop the concept.”
In use, the tester quickly fills the cooling water circuits of plastic injec- tion mould tools and pressurises them to up to an adjustable pressure of up to 12 bar. If the pressure holds steady for a set period of time, the integrity of the circuits is proven. However, if the pressure decays, this indicates that there is a leak.
A second function will then com- pare flow rates at different points in the circuits, with discrepancies indi- cating blockages. The unit can also air purge the water circuit after testing.
Accuracy time after time To achieve a high level of accurate performance, cycle after cycle, a high specification multi-stage stain- less steel pump is fitted with a D720S series 1.5kW Mitsubishi inverter, a Mitsubishi Alpha II (Programmable Logic Controller) and flow and pressure sensors in a
closed loop configuration. In use, an adjustable water pressure of up to 12 bar is maintained throughout the flow stages of the test cycle by means of the inverter’s inbuilt pres- sure control algorithm.
“This worked well on the original designs,” explained Newton, “but Mike quickly realised that users would like the comfort of a display so that they knew what was happening, so rather than just having basic pres- sure/flow indication we upgraded to a Mitsubishi GOT 1020 HMI touch screen which we programmed to pro- vide results derived from analysis as well as the raw data.”
All of the automation equipment is from the more compact end of the Mitsubishi range. Each part is made to an optimised design that ensures that the most popular features are included. This means that high performance sys- tems can be built and that they have the capacity to be easily adapted and reconfigured to suit the evolving needs
Automation NOVEMBER/DECEMBER 2013 23
Above, left and right: an automated control panel based on Mitsubishi Electric
components is key to the accurate operation of a newly developed testing unit
of individual applications.
The testing unit has several other features that are proving popular with users in the field. For instance, the water used for the pressure tests is held in a closed circuit that includes a filter so it can be cleaned and reused. This is particularly useful in hard water areas and where contamination build-up is inherent. Water valves, manifold, flow meter and air purge valve are also included to enhance controllability. These are all monitored by the PLC, for precise control.
Summary
Robustly built to suit workshop envi- ronments and using ergonomic design principles to enhance usabil- ity, the testing unit is proving popu- lar with a range of users. Mould toolmakers have realised that they can speed up simultaneously and improve testing, while fully logging all test data for traceability records. Injection moulders generally start to use it as an offline diagnostic tool in their repair and maintenance depart- ments but many then choose to inte- grate it into their production operations so that moulds can be benchmarked and checked regularly between moulding operations. Mitsubishi Electric Europe, Industrial Automation - UK branch is located in Hatfield. It is a part of the European Factory Automation Business Group based in Ratingen, Germany, which in turn is part of Mitsubishi Electric Europe BV, a wholly owned subsidiary of Mitsubishi Electric Corporation, Japan.
Mitsubishi Electric
www.automation.mitsubishielectric.co.uk T: 01707 288 769
Enter 212
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56