A hundred needles sew patterns in the soft fabric in white thread at breathtaking speed. What sounds like the buzzing of a swarm of bees soon turns into something on which people spend around one third of their lives: a mattress, or to be more precise, a mattress cover.
These days, a mattress is more than simply something to sleep on. The quality concealed on the inside should also be visible on the outside – in softly curved lines, elegant diamond shapes, perfect circles and an almost infinite number of freehand patterns. Since millions of people want to sleep as comfortably as possible, the production of mattress covers depends on high speed and increasingly also on a high degree of flexible pattern design. Emil Stutznäcker GmbH & Co. KG uses new cylinder/valve combinations with ASI technology from Festo in their latest multi-needle quilting machines in order to be able to quickly switch from one pattern to the next.
Textures in seconds
Industrial multi-needle quilting machines – like those by Stutznäcker – sew up to 10 m of stitched pattern a minute. This is the case with the latest addition to Stutznäcker’s range, a quilting machine with two rows of up to 96 needles each, each needle capable of an impressive 1600 strokes a minute. Distinctive and impressive textures can be added to mattresses within seconds. However, the increasing variety of options brings with it a new challenge: diminishing batch sizes. This means that the multi-needle quilting machines have to switch to new patterns more and more often. Stutznäcker achieves a high level of flexibility through the automatic variation of the needle configuration, meaning the various arrangements of the needles required for different patterns. Needles that are not required for the new configuration are pushed away from the drive axis by pneumatic cylinders, while needles that are required are pushed back on. This allows program-controlled variation of the needle configuration from one pattern to the next in a matter of seconds and customised selection of individual sewing positions from a bank of sewing units.
Less burdensome upgrades
Until recently, the stumbling block to fast and flexible assembly of the machines was the complexity of the tubing between the valve terminals and the pneumatic cylinders. The technical complexity involved in an upgrade or change in the position of switchable needles was also immense. Three experts in the field of innovative automation met in 2011 to solve the problem: Burkhard Feige, Head of Design at Nähmaschinenfabrik Emil Stutznäcker GmbH + Co. KG, Michael Dahl, Technical Consultant at Festo in the Cologne region, and Ulrich Beck, Head of Project Engineering for Sensors and Connection Technology at Festo in Esslingen. The solution was soon found: a cylinder/valve combination with ASI bus technology and integrated AND gate. The latter is required so that the thread wiper can pull the thread out of the active sewing process during changeovers. The old machines needed their own pneumatic AND gate manifold to realise this function.
Nähmaschinenfabrik Emil Stutznäcker GmbH + Co. KG
Max-Planck-Straße 3
50858 Cologne
Germany
Area of business: Production of high-quality quilting machines for industrial stitching