Hutchinson: Painting and bonding of EPDM seals
The Hutchinson Group is one of the world's leading manufacturers and processors of high-quality elastomer products. Their manufacturing range comprises all natural and synthetic caoutchouc based types of products, except for car tires. The German Hutchinson GmbH, Aachen, started pretreating EPDM profiles with Openair® plasma for the automotive industry as early as in the late 90ies.
Seals can be found everywhere in vehicles, whether in the engine compartments, at the doors, the windows, the battery compartment, in the trunk or at many other locations. At Hutchinson, about 100 different types of EPDM profiles of varied geometries are activated by means of 12 Plasmatreat installations.
Increasing the surface energy is a prerequisite for the subsequent
water-based painting or flocking process of the seals. The primer that
was formerly used as an adhesion promoter for painting, was applied with
a spray gun - a method that experienced a high reject rate when it
came to spray gun failures since paint adhesion was no longer ensured.
Adding to this was that the brushes used for roughening the EPDM surface
before the flocking process or, in other words, before the injection of
finest polyamide fibers into an adhesive, generated a great deal of
dirt. These two methods were completely substituted by converting this
pretreatment process to atmospheric pressure plasma technology. The
result: The reject rate was reduced to a minimum and consistent
environmental protection could be realized for the very first time
through the omission of solvents - and all this with an essential
increase in the production throughput.
Hutchinson's process engineering department in Aachen considers the Openair® plasma technology as optimal for the water-based painting systems in use. The engineers also attribute the increase in production to the well-proven computer control system and the high process safety of the Plasmatreat system. As a spokesman says: "The automatic fault detection and immediate fault notification features allow us to identify any rejects as a function of time. We can therefore react instantly and avoid major production losses."
The plasma systems, mostly equipped with rotary jets, are continuously operated by Hutchinson at a speed of 20 – 25m/min for 24 hours a day on a 3- or 4-shift basis. During this operation, approximately 20 million meters of endless gasket material are activated with Openair® plasma every year. The first plasma installation that was supplied as early as over 10 years ago is still in operation.
Openair® plasma offers the user the following values:
- Reduction of the reject rate
- Increase in production
- High process safety in the pretreatment process
- Contactless process with no generation of contamination
- Pretreatment of varied profile geometries
- Gentle material treatment
- Environmentally friendly production