Oerlikon Surface Solutions Ag, Pfaffikon

Oerlikon Trading Ag, Trubbach

Unaxis Balzers Limited

Oerlikon Surface Solutions Ag, Trubbach

Udo Rauch

Christian Wohlrab

Wolfgang Kalss

Manfred Wurzer

Kerstin Lasch

Torsten Reyher

Mirco Elias Kostner

Caroline Siebert

Tamara Andreoli

Norbert Froemel

Hanspeter Baertsch

Sven Egger

Mirco Kostner

The invention relates to a process for electrochemically removing a coating from coated workpieces by means of a voltage applied in an electrolyte bath between the workpiece and a counter-electrode. According to the invention, a rising voltage profile is selected during the coating removal process. This has the effect that the voltage applied at the start is low, and therefore the workpieces are not damaged, but nevertheless the rise in the voltage prevents the coating removal process taking an uneconomically long time.

Process for removing a coating from workpieces

A material mixture for dissolving a coating system from a work piece comprises an aqueous, alkaline solution containing between 3 and 8 weight percent KMnOand at the same time having an alkaline fraction of between 6 and 15 weight percent. The alkaline fraction is formed in one embodiment by KOH or NaOH, wherein the pH of the solution is above 13. A method according to the present invention uses the above-described material mixture for wet-chemical delaminating of hard material coatings of the group: metallic AlCr, TiAlCr and other AlCr alloys; nitrides, carbides, borides, oxides thereof and combinations thereof.

Process for the stripping of workpieces and stripping solution

A coupling which is rotatable about a vertical axis of rotation and intended for the mounting of a workpiece support which can be loaded, for example, with incorrectly coated or worn workpieces is arranged in a removable holder above a tank filled with an electrolyte. Said workpiece support is connected via the coupling to a current supply device, to the opposite pole of which an opposite electrode is connected. A heating and cooling device and an ultrasound generator are also arranged in the tank. By current supply and simultaneous rotation, the coating is removed from the workpiece support and/or from the workpieces. After incorrect coating, the workpieces together with the workpiece support and in certain circumstances with the holder can be taken over directly from a coating installation and, after coating removal, transferred to such a coating installation for recoating.

Coating removal installation and method of operating it

A coating is stripped off a work piece by applying a chromous and aluminiforous coat directly on the work piece and stripping the work piece with an alkaline solution containing a strong oxidant. A single-compartment system can be used, which includes a spray chamber including a circulatory spray-cycle system; a support for holding the work piece; and a media container connected to the spray chamber via a media circulation system.

Stripping apparatus and method for removal of coatings on metal surfaces

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Schlins, Austria

Udo Rauch