Products and solutions, 2005-09-12, 10:09 AM
ThyssenKrupp Drauz Nothelfer develops automated roller application system for door seals
Anyone who has anything to do with cars will know that although frequently not recognized as such, door seals are an important part of a car. They compensate for body part tolerances, keep occupants dry and help reduce noise levels inside the car. But that's not all: it's all about the right "clunk", i.e. the sound the door makes when closing. Car manufacturers attach a great deal of importance to this: the right kind of clunk is a sign of good quality.
The quality and positioning of the door seal and the way it is fastened in the vehicle are key to this. Adhesive fastening compares favorably with other methods. For this reason, door seal application equipment is the subject of continuous development. A project team from ThyssenKrupp Drauz Nothelfer has been investigating the area of robot-guided door seal application as an alternative to the proven plate application method. Auto manufacturers apply complex criteria when selecting the application method to be used. The new technique is fundamentally different in that the adhesive-backed seal is not pressed into the door frame, as in the plate method, but is applied by a roller.
There are two equipment variants for this method: one with stationary roller application head where the door is moved by a robot, and one in which the door remains stationary and the roller head is moved by a robot. In both variants, the seal is taken from a magazine as an endless strip and automatically cut to the required length after application.
One of the major challenges in this project was to roll the seal into position without expanding it. Force is applied locally during rolling; expanding the seal would increase stress, with the result that the seal may contract again after a certain time, possibly even falling out of the door. However, pressure distribution measurements have shown that the roller method used by ThyssenKrupp Drauz Nothelfer provides optimum results with no subsequent problems.
The automated door seal application system is highly flexible and can be adapted quickly to changes in component design. It is also possible to apply several derivatives of a seal using the same unit, although the seal profile has to be the same. Given the current trend toward rapid changes in vehicle models on the international automobile market, the flexibility of roller application technology - coupled with continuous optimization of the sealing systems - offers major advantages.