ER-WE-PA Davis-Standard GmbH, Erkrath (Deutschland)

Published in: Spectrum Kunststoff 2001

United against Folds

Uniform Automation of Coating Lines

Coating lines from ER-WE-PA Davis-Standard GmbH attain pass speeds of up to 1100 m/min. For these lines, Siemens provides not only the control and high-precision drives, but also comprehensive support as well. The manufacturer is, therefore, more flexible and can supply top quality combined with maximum productivity.

ER-WE-PA Davis-Standard from Erkrath, Germany, is the world market leader in the production of coating lines for aseptic packets for liquids (e.g., "Tetra Pak"). Worldwide, this company is at the top in the manufacture of extruders: standard, flat-sheet, plate, wire, cable, pipe and profile extrusion systems.

Quality and Productivity Count

Even just a few years ago, the fully automatic production of rolls of composite materials in marketable condition at such a high speed was unimaginable. It has only become possible due to such innovative advancements as an automatic "Culisse" Winder - a multi-lane slitting and winding machine. This has been furthered decisively by the use of powerful, electronically connected servo-drive technology from Siemens instead of mechanical solutions. Highly precise gravimetric proportioning systems with Siwarex load cells and Masterdrive drives ensure a constant quality of the initial products; the Simatic control technology ensures a smooth functional sequence.

Uniform Drive Systems Available

For years, the standard control has been Simatic, however, Design and Purchasing of ER-WE-PA did not select drives from the Masterdrives series MC/VC (Motion Control, Vector Control) until a year ago. This uniform series with fine stepped power up to 250 kW, which is always available, simplifies the warehousing dramatically, even for the end user. For the head designer, Klaus Pack, quick access to motor data sheets in DXF format was particularly important. Until now, its absence was a true problem that often delayed the start of work by up to three months. A further problem was the coordination of the interfaces between a number of fitters. Now, Mr. Pack and his team can act immediately when the order is received, i.e., configure their systems to correspond to individual requests of the customer.

The electronic connection of all line drives guarantees absolutely synchronous operation because the lines that are up to 50 m long have no gears, cross-arms or other mechanical components that are frequently susceptible to damage. Neither the separately supplied initial products - such as aluminum foil, paper or film as carrier material and up to seven-layer, co-extruded films as a cover layer - nor the ultimate composite material - are excessively elongated, which would necessarily result in quality defects.

The drive concept of the patented "Culisse" Winder is also innovative. In this concept, increasing roll diameters are automatically equalized with the control via the Profibus-DP and interconnected Masterdrive drives via the high-speed fiber-optic bus. This minimizes material movements at the end of the line and enables maximum production speeds. One detail that is not routine: both of the servos in the slitting and winding machine receive their signals via a conventional and an optical slipring rotor.

Further Projects Implemented

With Siemens uniform automation technology, ER-WE-PA Davis-Standard operates better than before and the company is very satisfied with the know-how, the comprehensive support from commissioning to teleservice, especially with the promptness of delivery schedule. These reasons also suffice to equip a stretch film system being introduced at the "K" that has a useful width of 4 m and gravure printing unit with pass speeds of up to 500 m/min with control and drive technology from Siemens.