In-line treatment of Automotive Sealing Products

Top quality adhesion of printing inks, adhesives or coatings on polymer materials, such as PE, PP, PS, EPDM-rubber and other substrates, is a common requirement throughout the plastic and rubber processing industry. All polymer materials exhibit by nature a low surface energy, resulting poor adhesion and wetting properties. To cope with such difficulties Tantec offers customized and standard units with integrated corona systems.

Ten years ago Tantec developed their first customized station for surface treatment of EPDM profiles. We have advanced our surface treating technology with our ProfileTEC – a plasma treating system for EPDM profiles. It is now possible to treat multiple surfaces and difficult configurations with superior one-pass coverage, consistency and convenience.

In practice, plasma pre-treatment has become one of the most common processes used for surface refinement. The method increases the surface tension of plastics before they are printed, laminated or coated. This surface treatment improves inter-layer adhesion and promotes adhesion of the spread coating compound or printing ink. The final effect achieved by the treatment depends on various parameters, including electrode efficiency, duration of the corona discharge, the type of material being treated, the temperature and moisture, any contamination, the surface morphology and similar factors.

Corona treatment eliminates the inefficiencies, safety hazards, and product damage potential of open flame treatment, chemical surface preparation and sanding techniques, while offering improved bonding results as well.

To improve the adhesion qualities, the surface is modified using potential free discharges. Using plasma enables the treatment of a broad range of materials without having to change treatment heads. A simple, yet highly effective pro-cess for sponge dense and TPV materials.

We design customer-oriented solutions for in-line production. Our ProfileTEC offers sustained conti-nuous operation with first-class results. It ensures that the further processing can occur in the most optimal way. The ProfileTEC completely replaces processes such as roughening up, fluoride treatments with gas or the use of primers.ProfileTEC consumes less energy in comparison with the industry average, and this makes itself apparent not only during the initial investment stage, but also in reduced long-term running costs. ProfileTEC includes a modular electrode system made in non-corrosive materials, featuring a minimum of wearing parts and a compact design.

A customised ProfileTEC usually consists of 4-16 treating units (heads) and is capable of handling high line speeds (20-25 meters per minute depending on the type of profile) and complex parts made of conductive and non-conductive rubber. The system increases the surface tension from 34 to 50 mN/m – which is the tension level required for the best adhesion possible today. The system can be used both in the extrusion line and in fabrication.

Operation of the treatment system could not be made simpler. The well thought out concept for our generators and treatment stations ensure operation with the best results. With the ProfileTEC it is possible to save energy, increase productivity and improve the quality of EPDM profiles.

ProfileTEC can treat all kinds of profiles,
including:
• Door weatherstrips
• Inner and outer beltstrips
• Secondary seals
• Quarter window weatherstrips
• Decklid seals
• Roof rail weatherstrips
• Glass run weatherstrips
• Windshield moldings
• Hood-to-cowl weatherstrips

The advantages of using this technology with EPDM applications are as follows:
• High processing speeds (up to 25 m/min, depending on the die), higher on request
• Area pre-treatment using homogenous corona discharge
• Gentle pre-treatment process (no surface burns)
• Large process window (important with groove geometry, because surface and groove floor are
treated evenly)
• Low energy consumption, max 2000W
• Flexible electrode set-up, for quick change and adjustment
• Pre-produceable treatment process with microprocessor controlled generator technology