Benefits ‘pile up’ thanks to Siemens technology

With the carpet industry notoriously influenced by fluctuations in fashion, modern tufting machinery has to be suitably flexible to cope with dramatic changes in demand regarding pattern and pile height. With this in mind, carpet manufacturer WS Graham Ltd of Dewsbury, placed an order for a tufting machine with Blackburn-based Danley Engineering Services on the proviso that it would be able to cope with all the demands of a fickle consumer-led carpet industry. To meet the specification, Danley used the assistance of engineers from Siemens Automation & Drives, who duly supplied standard Siemens hardware fitted with special control programs designed specifically to meet the requirements of the end user.

“WS Graham was a new customer and this was an entirely new project for us,” says Danley’s managing director Graham Wolstenholme. “Previously we had employed traditional mechanical methods using gearboxes, AC ‘squirrel cage’ motors, cams and belt or drive chains. However, by using Siemens electronic servo equipment and CNC controls we knew we could offer our customers enormous improvements in efficiency and quality of end product, particularly on patterns because of the instantaneous response to control commands that simply can’t be achieved using mechanical drives.”

Some of Danley’s competitors had started to use alternative suppliers, all of which were considered even though none could eventually compare to Siemens, for a number of reasons: “Because of the decline in the UK carpet manufacturing industry, up to 70 per cent of our machines are exported,” says Mr Wolstenholme. “We therefore required an automation partner that could service our needs wherever they may be across the globe. Siemens has a wonderful warranty policy where the company guarantees 48-hour call-out cover regardless of location. Add to this factor the quality of Siemens products and the confidence we had in Siemens engineers to adapt the equipment to our application, and our choice was made.”

Danley contracted Siemens to develop servo motor drive systems for carpet tufting machinery that would normally be used on CNC machine tools. The company realised that the benefits of enhanced speed, accuracy and reliability would accelerate Danley to the forefront of tufting technology. The project for WS Graham included a SINUMERIK 840D CNC control with NCU572.4, 611D digital drives and four 1FK7 series servomotors. All of these are off-the-shelf items, however, Siemens technicians developed special software that controls the drives to suit the different functions of the tufting machine. Using the PC-based operator interface, Danley was then able to develop a special suite of screens especially for tufting applications. Changing from one pattern to another now takes a matter of seconds rather than hours, and each pattern design can be stored and retrieved for use whenever necessary. Keeping the hardware standard ensures replacement spares are widely available the world over.

The technology was tested initially on a rig developed by Siemens. Danley then introduced Electron Engineering Services as a partner that, together with Siemens, applied the technology to the production machine destined for WS Graham, where it was installed in May 2005. Now in full production the machine is currently manufacturing a textured loop carpet, which is a multifunction of varying pile heights – apparently the next big fashion in carpets!

Danley and Electron are now moving forwards with further projects in the retrofit market, where there are considerable opportunities. The flexibility of the Sinumerik control s ystem has allowed Danley to target a wide range of machine configurations from a common software platform, together with the usual high standard of service and support that is provided by Siemens. In fact, the equipment is so adaptable that it has also been applied to machines manufactured by Danley for the production of synthetic football pitches and ski slope matting.