HMI solution boosts production for plastic recycling extruders

Paul Boughton

Plasmac, based in Aylesbury, England, manufactures recycling extruders that are designed to meet with the varying demands of the thermoplastic industry to convert plastic scrap into a high quality reusable granule.

For the plastic manufacturing sector, which is being crippled by rocketing prices for resin and polymers, recycling waste material is becoming critical for survival.
Plasmac's technical team looked at various turnkey solutions that met its requirements. In the end, it opted for a bespoke design route with a control system that includes human machine interfaces (HMIs) as standard on all machines -- unlike any of the company's competitors.
A Siemens solution was chosen due to its flexibility and ability to supply a competitively priced system with improved diagnostics, remote monitoring, simple integration and world wide back-up service. Using WinCC Flexible HMI software, Plasmac achieved high functionality on a low-cost HMI Touch Panel.
Creighton Varney, technical manager at Plasmac, was then charged with the task of integrating the system into the complete machinery range.
The original combination of relay logic controls and standard switchgear provided limited control functionality and resulted in extended build time. The integrated Siemens solution has revolutionised the way Plasmac manufactures and in turn, the way the company's customers recycle.
The seamless package has been applied to the whole range, with machine control systems sharing one generic configuration rather than multiple platforms, increasing standardisation. This was made possible because the TP170M HMI has no footprint, enabling Plasmac to incorporate an innovative backplate design that spreads across the width of the control panel. With just one cable to plug in, using a single standard facia, wiring on one example system has been reduced from five days down to three and a half.
Commissioning has also seen significant improvements: with most of the parameters established within the PLC, very little manual input is necessary. Operator training, so often a time consuming process, is greatly improved due to the multi language format that the TP170M supports.
The benefits to end users are numerous. A password protected user operation system with limited access to specific control areas simplifies operation, while increased diagnostic functionality provides specific locations to a fault within the machine, saving both time and money.


The Siemens solution is based around the
S7-200 PLC and an EM231 Thermocouple Module. MicroMaster 440 inverters are controlled over an RS-485 network (USS) and are connected via Profibus cabling.
Working with Siemens gives us the benefits associated with the commonality of componentssystems integration with SCADA systemsand increased security of sensitive parameters xplained Varney.
Remote diagnostics is available through the installation of a modem module. The plug in and play capabilities of the HMI screen means that in the case of a catastrophic failure, replacement components can simply be shipped to location and connected without the requirement of a service engineer.
With customers across the other side of the globe in countries such as Australia, flying an engineer onto site to resolve a problem can prove highly expensive.
Ninety eight per cent of our sales are exported to companies across the worldso having global support and remote diagnostic capabilities was a big plus point for us he concluded.

For more information on Siemens Automation and Drives, please visit or call 44 161 446 6645. For more information about Plasmac please visit or call
44 1902 373699.


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