Window system solutions Low-Stress Leveling—for stunning prospects

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Flat, low-stress steel strips for high-quality window system solutions.

Companies in the Winkhaus Group develop and produce high-quality system solutions for windows, doors, and the latest in access control. Winkhaus has three sites in Germany: manufacturing plants in Münster and Meiningen as well as a head office in Telgte. An additional factory for window systems is located in Poland (Rydzyna). With its international subsidiaries, Winkhaus is represented across Europe.

Since its foundation in 1854, Aug. Winkhaus GmbH & Co. KG has remained a family-run company that is still 100% owned by the Winkhaus family.Today, the fifth generation of the family leads a team of more than 2,300 people. The innovative window systems developed by Winkhaus are characterized by their intelligent design and excellent performance. Window builders, dealers, architects, clients and users all over the world particularly appreciate the top-quality material and processing provided by the durable Winkhaus technology. Tough surfaces ensure the long-lasting retention of aesthetics and functionality.

New Kohler strip leveling line for producing window fittings

Winkhaus has relied on the leveling expertise of KOHLER Maschinenbau GmbH for more than 40 years. Old systems have been successively replaced by new strip leveling lines, not just to keep pace with the increasingly stringent demands in terms of quality and functionality, but also to ensure the seamless assembly of modules without the need for costly reworking. The new KOHLER strip leveling line at the Telgte site, which was recently commissioned for the leveling of window fittings, meets every criteria with regard to precision and cost-effectiveness.   

Precision and cost-effectiveness open up totally new perspectives

Over 33,000 tons of steel each year—chiefly as coiled material—are processed in three shifts over five days a week. "Leveling the steel strips is an important step in our workflow, as the very fact it has been coiled generates certain stresses in the material, such as curvature, warping, and twisting. This makes the downstream processing more difficult and also adversely affects the quality of the window fittings. The new Kohler leveling machine eliminates these stresses," explains Uwe Birwe, Industrial Engineering Manager-Window Fittings at Aug. Winkhaus GmbH & Co.KG, Telgte.

The double-decoiler, with its hydraulic coiler expansion, pneumatic coiler braking and axially tensioned coil retainers, has a load capacity of 3 tonsper side. The coiler is swiveled through 180 degrees using a three phase A.C.motor."The advantage of the double-decoiler is the huge amount of time it saves. One coil can be changed while the other is being processed,allowing for continuous operation and greater productivity," observes Birwe.

At the heart of the strip leveling line is the precision leveling machine. A high degree of rigidity, 21 hard chrome coated leveling rollers, and a camber leveler unit guarantee perfect leveling quality. Depending on the material being processed, particles of dirt will occasionally adhere to the leveling rollers and supporting rollers. The rollers should therefore be regularly inspected, serviced, and cleaned."The advanced cleaning system from Kohler allows this to be done without any fuss. It's just a simple matter of pulling the top or bottom cassette out manuallyto expose the leveling rollers so that they can be easily cleaned by one person," comments Birwe.

Seamless production process right through to the finished window fitting

The result of the leveling process is a flat, almost stress-free strip that has no saber shapes. The strip eventually enters the loop control—which acts as a buffer designed to compensate for the on/off operation of the feeder — so that the decoiling area can operate at as constant a speed as possible. "The integration of the loop controller for loop guidance requires less space and saves on any unnecessary foundation work. Together with the electronically controlled roller feeder, we can significantly increase the stroke rate of the stamping machine to up to 60 strokes at maximum length," explains Uwe Birwe.

To achieve the required degree of precision of less than 0.1 mm, an additional leveler with 13 leveling rollers, each with a diameter of 40 mm, is connected after the stamping operation. "After leveling, the parts pass directly to the parts ejector. The incoming parts are stopped by the braking system and slide down a chute into the parts container. Kohler has provided an enormous amount of assistance to enable us to create an efficient, extremely precise and almost fully automated production process. The line is controlled by a Siemens TIA CPU and is operated from a modern control panel. We've been working with Kohler for more than 40 years—a period during which we've both grown. Kohler has always been there to help us, even when we had out-of-the-ordinary requirements," concludes Uwe Birwe with satisfaction.

Line and material facts

Strip leveling line:

• Double-decoiler, 180 degree motorized swivel,load capacity 3 tons

• Precision strip leveling machine, 21 hard chrome coated rollers of 30 mm diameter

• Double pinch rollers

• Advanced quick change device

• 5-roller camber leveler unit for correcting saber shapes

• Loop controller for loop guidance

• Roller feeder, passing width 50 mm, roller diameter 100 mm

• Realigning unit with discharge table, 13 rollers of 40 mm diameter

Material to be leveled:

• Materials with thicknesses of 0.5 to 4 mm and 4 to 50 mm wide

• Stainless steel

• Steel