Time advantage by STIR®-coating for lacquer drying of massive steel-components

Reduction of the drying time of approx. 36 hours to 20 minutes by using STIR®-heaters

IR-heater in action

REHAU AG + Co., Feuchtwangen, GERMANY

Drying and polymerization of liquid coatings

  • Absolutely innovative system concept with STIR®-technology for drying of liquid coatings
  • Every, in series manufacturing, on 3D-plastic parts appliqued water-based primer and vehicle colors are going to be dried and cross-linked 100% by infrared
  • Due to the enclosed tunnel construction system, all coated surfaces are irradiated sufficiently
  • Substantial reduction in processing time to less than 60%

Andreas Quellmalz GmbH, Limbach-Oberfrohna, GERMANY


UV-lacquer heating/conditioning

  • Usage of IR-heaters in the field of predrying, usage of a solvent based UV-lacquer
  • Fast heating with subsequent temperature keeping area for the reached temperature
  • Time savings by enforced drying
  • Challenge: heating of the products surface up to approx. 65°C and keeping the temperature up to 3 minutes
  • Usage of STIR®-heaters with an actual power output of 2,2 kW and a voltage of 230 V
  • Due to the usage of solvent based UV-lacquer a forced circulation check rail is occurred
  • The heaters are bathed by safety air

Venjakob Maschinenbau GmbH, Rheda-Wiedenbrück, GERMANY

Venjakob Maschinenbau GmbH

IR-heater in action – lacquer drying

  • Installation of the single element heater into the dryer VEN DRY OIR
  • Single elements are exactly adapted to the equipment according to dimensioning
  • Significant shortening of the drying process
  • Perfect surface quality by gentle drying
  • Lacquer is drying constantly from inside to outside

GTL Knödel GmbH, Leonberg, GERMANY

GTL Knödel GmbH

Successful process engineering by GTL Knödel in cooperation with IBT in the field of drying and hardening of protective lacquers

The protective coatings of electronic modules will still be occurred by liquid lacquer for the most part. After the painting application it is necessary to heat-treat this surface – unless the fact, that if the lacquers are depleted by organic dissolvers, diluted with water or both diluted with water and solvent-based.

author: Peter A. Knödel

The heat treatment of the lacquer coating for protective coatings of electronic modules is occurred by hot air or hot air in combination with infrared. During the hardening process of UV-lacquers a convective air flow is not necessary for the heat transfer, but as a circulation fluid for conveying of gasses arising by the cross-linking reaction. For lacquers, where laminating is caused by expelling the dilutor, a convective heat transfer by hot air is essential and a combination with STIR®-infrared heaters optional. It is essential as the drying process is a transportation-phenomenon and the air is the needed and favorable transportation-medium. For an additional infrared irradiation, STIR®-batwing radiators or rod-shaped emitters, with long- or medium wavelength of IBT are in use. It is fixed in the statutory provisions for dimensioning of drying equipment that “technical ventilation” for this drying process cannot be ruled out.

Combined convection and heater

GTL Knödel offers, with its approved heat treatment system Entuca, the combined heat transfer system Irkon. Thereby standard system modules with 2.000 mm processing length for various working width are available; besides systems for heat transfer by convective nozzle ventilation plus long-wave STIR®-batwing radiators and accordingly medium-wave STIR®-rod-shaped emitters. The ratio of irradiation for the complete heat transferring system is selectable.

Flächenstrahler GTL Knödel.

Ceramic coated metal-heaters are used as batwing radiators for the temperature range of 100 to 250°C. The according wave lengths are between 7.6 and 5.5 µm. Rod-shaped emitters are in use for temperature ranges from 400 to 800°C. They lare lying in the medium-wave irradiation range between 4.2 an 2.6 µm.

The absorption characterisitcs of typical paint resin and diluters in comparison to specified wave lengths will be included to the heater selection.

For the equipment system Knödel Entuca Irkon are available approx. ten various conveyors for the working width between 200 and 480 mm.

Source: magazine “productronic 01-2 / 2011“ page 32 www.productronic.de

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