SubscribeMartin, specialist manufacturer of equipment for the corrugated industry, is using up to 200 Watson-Marlow Bredel 621F/RE peristaltic pumps per year on its new DRO NT range of rotary diecutters.
Introduced to the European market at Corrugated 2002 in Paris, the DRO NT machines use up to eight 621F/RE pumps for ink feed, helping to provide printers of corrugated board with better print quality through improved colour register, on items such as point-of-sale cartons.
Peristaltic pumps contain the ink within the pumps' tube so there is no possibility of contamination with dust particles. The gentle peristaltic action also prevents the ink from foaming - one of the causes of uneven ink distribution resulting in poor print quality.
Jean-Luc Mion, research and development manager at Martin says: "We've replaced the gears and installed a motor on each of the print units to get the best register between the print cylinders. Each print unit on the DRO NT is now independently driven by a DC motor and has its own 621F/RE peristaltic pump feeding ink directly onto the chamber doctor blades, giving better control and accuracy.
"The smooth pump action keeps the flow of ink constant, eliminating pulsation which can cause a build-up of pressure inside the chamber blades. The flow rate we use is between 2.5 and 3 l/min depending on ink viscosity. We specified peristaltic pumps rather than diaphragm pumps for the new DRO NT because flow rate adjustment on the 621 pump is electronic and only one adjustment is necessary.
Watson-Marlow Bredel peristaltic pumps are also simple to clean. The pumps have a reverse flow feature which can pull the ink back from the chamber blades before cleaning - minimising waste ink and reducing the amount of time taken to clean the machine. Water is then flushed through the tube to wash the chamber blades on each print unit. Unlike diaphragm pumps, peristaltic pumps have no low velocity areas or dead-spots so cleaning is faster and more efficient.
"The DRO NT represents 30% of our product range so it was important that all of the equipment used to develop the machine was the highest quality and provided our customers with the best possible printed result. The Watson-Marlow Bredel 600 series pumps are perfect for the job, not just for the excellent quality printed result, but also because of the crucial reduction in time and cost," concludes Jean-Luc.
Martin looked at a number of other pump types but the Watson-Marlow Bredel pumps provided the most efficient and accurate ink feed and were robust enough to withstand the rigours (shouldn't this be rigors?) of a busy print room.
Maintenance of the 621F/RE pumps involves a quick six-monthly check, with a more detailed annual check. Tube elements are changed at each maintenance check and by knowing the expected life of the tubing (3000 hours), Martin can time maintenance checks so that there is no downtime required for tube changes during print runs. Martin's customers are now able to calculate the running cost of the pump per year.
The DRO NT uses water based inks and varnishes and can print up to eight colours.
Established in 1923 and employing around 750 people, Martin is a Bobst Group subsidiary company which exports its FFG (Flexo Folder Gluer) and RDC (Rotary Diecutter) including flexographic printing equipment worldwide from its base in Villeurbanne just outside Lyon in France.