Product category:
Drives, motors and power transmission, couplings, clutches
News Release from: Hoerbiger-Origa | Subject: Electric drives
Edited by the Manufacturingtalk Editorial
Team on 15 March 2004
Electric drive slashes paper slitter
downtimes
Swapping from pneumatic power to an electric cylinder, coupled with a bit of imaginative engineering redesign, has slashed maintenance time on a paper slitter positioning system.
Swapping from pneumatic power to an electric cylinder supplied by Hoerbiger-Origa, coupled with a bit of imaginative engineering redesign has slashed maintenance time on a slitter positioning system for one of the country's most successful paper mills St Regis Kemsley near Maidstone in Kent produces packing paper in a variety of widths by slitting and rewinding from giant 6m wide stock reels
This article was originally published on Manufacturingtalk on 18 Jun 2002 at 8.00am (UK)
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Because compressed air was already being supplied to the slitting system, it was decided originally to use a pneumatic solution to provide the flying motion that positions the sensors and knives in relation to the width of the paper web, even though the dusty atmosphere around the machine had the potential to compromise the seals of the air cylinder.
"We organised a maintenance schedule and the system served us well for eight to ten years," recalls plant engineer Adrian Collins.
"But, as is common in most industries, we gradually increased the output of the machine over the years in order to increase productivity.
A side effect of this was that we were having to remove the cylinder every six months as part of a refit and rebuild programme; additionally the number of unscheduled stoppages increased as more dust was being generated by the increased amount of slitting." The design of the system was such that removing the 6m long cylinder was a major task, taking 8-10 hours and requiring up to five men.
So Collins began to explore possibilities for a redesign.
"We considered all sorts of ideas, such as completely redesigning the whole measuring system, enclosing the cylinder in a box to protect it from air-bourn dust particles, and even installing a powerful vacuum system around it so keep the dust at bay.
In the end the most appropriate solution seemed to be a straight swap from air power to an electric linear cylinder." St Regis called in engineers from Hoerbiger-Origa to look at the detailed design, and was pleased to hear that a 6m-stroke unit was not going to be a problem, as Hoerbiger-Origa regularly supplies them up to 10m.
In fact Hoerbiger-Origa suggested a standard 25mm bore BHD belt drive unit would be ideal for the job.
By watching a cylinder changeover procedure, it was realised that vast improvements could be made to the way in which the cylinder is mounted onto the machine.
Hoerbiger-Origa suggested that a rail be built onto the machine and its Special GDLF External Guide carriages mounted onto this, which would allow the cylinder to slide into and out of position.
This would reduce the mounting/demounting task to a two-man, one-hour operation and represent a massive saving in downtime from what is essentially a continuous slitting operation.
Collins was amazed to see that the GDLF guide is based on the bearings used internally in the BHD cylinders, and equally pleased to find out that Hoerbiger-Origa intended specifying a Control Techniques' UNI SP servomotor as the prime mover.
"Both Control Techniques and Hoerbiger-Origa have always given us great back up services - and its very comforting to know that they will be on hand as we push our productivity levels ever-higher," says Collins.
He reports that the new system gives smooth operation and has completely eliminated stick-slip, even after long stationary periods.
The vastly improved changeover routine is of course much appreciated by Adrian and his colleagues and they are now planning to simulate an encoder output from the servo so that they can dispense with the need to have a delicate digital ruler used as a fast-moving field device in an aggressive environment. Request a free brochure from Hoerbiger-Origa ...
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