Under the microscope: seat production - In-house seat production to the highest quality standards

Mar 26, 2013
Mercedes-Benz is one of the few car manufacturers not to have the seats produced by a supplier, rather producing them in-house for the E and S-Class. "If we want to have top quality and durability, and at the same time lead the field in new functions such as the ENERGIZING massage function on the hot-stone principle, we must also have the necessary production know-how," says Henry Wunderlich. The 49 year-old is the production manager for Daimler seat manufacture in Böblingen, near Stuttgart.
This is where around 600 employees produce the seats for the E and S-Class on a two-shift basis. This is no easy task in view of the enormous variation, for in the case of the
E-Class, customers around the world are able to order around 360,000 seat variants. The new S-Class even exceeds this number of available variants by a wide margin. Hardly one S-Class seat is like another, thanks to the wide range of leather and colour combinations, numerous seat models, varying features and country-specific differences.
The production of seating systems is a sophisticated and demanding combination of skilled craftsmanship and the very latest production technology. This is shown, for example, by the great care taken when fastening the seat covers, which are also hand-sewn in the case of "designo" upholstery. Thin metal rods are inserted into special tabs in the seat cover, then clipped in place on the seat structure. This creates the contouring typical of Mercedes, combined with a positive climatic effect and outstanding comfort. "Not everybody can do this," says Wunderlich, and points out that the job profile has changed considerably: "We used to employ mainly upholsterers, but the job description nowadays is 'specialist in automotive interior equipment'. This is because the number of electronic and pneumatic components in seats has increased enormously in recent years, requiring the appropriate specialist knowledge in production."
The electronic components include the restraint systems, the electric seat adjustments and other comfort functions such as seat heating, dynamic multicontour seat or the massage and heating elements. The shopfloor is earthed, and for quality reasons the personnel wear anti-static working shoes.
The overall impression of modern seat manufacture is that of car production in miniature: the seats are not assembled in production bays as previously, but rather "just in sequence" as a line operation. At the four production lines for the S-Class - two for front seats (right- and left-hand drive versions) and two for rear seats (cushion and backrest lines) - there are circulating tables that are movable and ergonomically adjustable. At various stations the personnel complete the seats on these tables. Hydraulic carriers and height-adjustable assembly facilities assist the process, and several changes of station per shift to avoid monotony is a matter of course.
The tightening torque for the bolts of the sidebag is even recorded electronically: "This means that even years later, we can show that the seat left here in perfect condition," says Wunderlich. During the final inspection at the end of the line, the seats must show that they meet the highest visual expectations and that all the functions work perfectly. When the seats finally leave the line, they have passed though up to 50 stations.
On the loading conveyor belt in the middle of the assembly shop, the front and rear seats are "married together" and loaded onto transport pallets, so that they can be delivered to the S-Class production lines just in time and in first-class quality.