WO1998009828A1 - Method and device to remove paint from covering and/or support elements in a paint installation - Google Patents

Abstract

Method to remove paint from covering and/or elements (1) in a paint installation, preferably from hooks. With a view to achieving inexpensive and environmentally friendly paint stripping of covering and/or support elements (1) and no need for repair of damaged elements said method is characterized by initial selection (3) of covering and/or support elements (1) that are to be stripped of paint. This is followed by inductive heating (4) of the covering and/or support elements at a temperature (1) allowing the paint to be removed, and the existing coat of paint is mechanically (5) removed. The stripped covering and/or support elements (1) is finally returned (7, 8) to the painting process or to a store. A device to remove paint from covering and/or support elements (1) in a paint installation, preferably from hooks, is disclosed and characterized in that a chamber fitted with an induction heating device is used for inductive heating of the covering and/or support elements (1) and that said chamber is assigned to the paint installation or designed as a mobile unit.

Description

Method and an apparatus for stripping paint from cover and / or carrier elements of a painting installation

The invention relates to a method and a device for stripping paint from cover and / or support elements of a painting installation, preferably from hangers.

A wide variety of painting systems are known from practice. On the one hand, the known painting systems are individually adapted to the workpieces to be painted and, on the other hand, they allow a wide variety of coating processes to be carried out. The immersion bath process, in which the workpiece to be coated is immersed in a paint bath, for example, and the coating by spraying on a liquid, viscous or powdery coating medium - in the latter cases it is classic spray painting - are of particular importance.

In all of the aforementioned methods, it is necessary that the workpiece to be coated or painted is appropriately positioned by carrier elements and / or, if necessary, supplied with the coating to cover areas of the workpiece that are not to be painted. In this context, the term "hangers" is used in particular, to which workpieces to be painted, such as complete rear axles for cars, can be hung.

Excess paint, which is referred to as overspray in the spraying process, collects on such covering and / or carrier elements both in the immersion bathing process and in the spraying process. Excess paint material of this type can, after multiple use of the same cover and / or support element for painting several workpieces in succession and after a reaction of the paint layer or layers, form a several centimeter thick paint layer on the cover and / or support elements.

Cover and / or support elements with such a thick layer of lacquer are often no longer functional, for example since suspension eyes or the like are closed by lacquer, and must therefore be subjected to cleaning in which the lacquer layer is removed. For this purpose, the cover and / or support elements must be removed from the painting system and transported to a cleaning company that specializes in stripping. With such a transport, bending or even mechanical damage to the cover and / or support elements often occurs. A subsequent repair of the damaged elements required for reuse is associated with incalculable costs. Furthermore, the mostly chemical cleaning processes used by cleaning companies are extremely expensive and polluting.

The present invention is therefore based on the object of specifying a method and a device for stripping the cover and / or carrier elements of a painting installation, according to which a cheaper and more environmentally friendly stripping of the cover and / or carrier elements is possible without reworking damaged elements.

The above-mentioned object is achieved by a method and a device with the features of claims 1 and 20. According to this, a method for stripping paint from cover and / or carrier elements of a painting system of the type in question is characterized by the following method steps:

First, the covering and / or carrier element to be stripped is selected. The selected cover and / or carrier element is then inductively heated to a paint stripping temperature. As a result of this inductive heating according to the invention, the element to be stripped is heated in a particularly energetically advantageous manner. Eddy currents are generated in the element by direct coupling to the electrically conductive element, which lead to heating of the element due to the electrical resistance of the element material. Energy losses from heating a boiler room are largely excluded here - apart from the radiation of the element. Due to the inductive heating, the covering and / or carrier material is heated from the inside, with the innermost lacquer layer being heated accordingly. The heating takes place until a stripping process which is favorable for stripping is reached temperature, which is usually well above ambient or room temperature.

In the subsequent process step, the lacquer layer on the cover and / or carrier element is mechanically removed. Such removal can also be done by a single person in any conceivable way. Finally, the cover and / or carrier element is returned to the painting process or to a bearing after the paint layer has been removed.

In the method according to the invention, it is essential that the paint stripping can be carried out at the place of use of the cover and / or support elements and that an expensive and possibly damaging transport of the elements for cleaning purposes is no longer necessary. Furthermore, the use of chemical cleaning or paint stripping processes, which can lead to high environmental pollution, can be dispensed with entirely.

In a further advantageous manner, the method according to the invention enables a considerable reduction in the cost of paint stripping, since cost-intensive transport to external cleaning companies and subsequent post-processing of damaged elements that may be necessary afterwards are avoided.

Consequently, the method according to the invention provides a method for stripping the cover and / or carrier elements of a painting installation of the type in question, in which a cheaper and more environmentally friendly stripping of the cover and / or carrier elements is possible without reworking damaged elements.

With regard to a particularly simple removal of the paint layer present, the paint stripping temperature could be the temperature at which the boundary layer of the paint to be removed adhering to the cover and / or carrier element burns or detaches from the element. The lacquer layer can then be easily scraped off or peeled off. In this context, it is further advantageous if the removal of the lacquer layer while it has not yet cooled to ambient temperature Cover and / or support element takes place. Ultimately, the less the element has cooled, the better it is possible to detach or remove the lacquer layer.

The entire stripping process could now be carried out with the covering and / or carrier element left inside the painting area or a painting line. This would have the advantage that no additional removal areas of the elements would be required. A corresponding induction heating device could be led directly to the cover and / or support element and heat the element. Furthermore, a special heating station could be provided in a painting line, through which the elements routinely run after each painting operation. A paint removal could then take place in each case.

As an alternative to the method example described last, the covering and / or carrier element could be removed from the painting area or a painting line for stripping. This would have the advantage that the painting process itself is ultimately not hindered and can be continued without stripping to remove paint from an element.

The cover and / or support element could be brought to a separate chamber from the painting area or the painting line for heating after being discharged for heating. This could prevent heat loss. The subsequent removal of the lacquer layer could then take place outside the chamber, which on the one hand would allow any positioning of the elements to be stripped without restriction by the chamber shape and, on the other hand, would allow simultaneous heating of another element in the chamber.

The chamber could be permanently installed in a homogeneous arrangement with the painting system at a predetermined location of the painting system and possibly integrally connected to the painting system. Depending on the size of the painting system, several chambers could also be provided at predetermined locations. With a view to retrofitting existing painting systems and with regard to universal use of the chamber, the chamber could be designed as a mobile unit. It would be conceivable to design the chamber as a mobile container or to design it in a mobile container.

With regard to a problem-free operation of the chamber, the chamber could have connections for energy and / or water and / or exhaust air. This would enable both the energy supply to the induction heating device, its cooling and the discharge of exhaust air.

With a view to the most effective possible selection process for the covering and / or carrier element to be stripped, the selection could take place according to predeterminable stripping cycles. It would be conceivable to remove paint after a predeterminable number of passes of the respective element. In a further advantageous manner, the selection could take place automatically depending on the thickness of the lacquer layer to be removed. A wide variety of non-contact thickness measurement methods known from the prior art could be used for this. Depending on the required application, a selection could also be made manually - for example after a visual inspection.

To ensure that the painting process within a painting line is as unimpeded and continuous as possible, the covering and / or carrier elements could remain connected to a conveyor system that may be provided during the stripping process. With such a configuration, the elements to be stripped could be manipulated in an unproblematic manner by means of the existing conveyor system. A cumbersome and complex positioning of the elements on additional holding devices would be avoided.

With a view to heating the elements as effectively as possible, they could be hung in induction coils during the heating. Such induction coils or induction heating devices could be individually adapted to the respective outer shape of the elements. The mechanical removal of the lacquer layer could be carried out in a particularly simple manner by means of a spatula and / or a wire brush, with other suitable tools also being conceivable for this purpose.

In any case, the paint residues removed from the cover and / or support elements can be disposed of in a targeted manner due to their easy and unproblematic handling consistency. Chemical dissolving or burning on site is not necessary. The only small amount of gases generated during the combustion of the boundary layer can be fed to the ventilation system of the paint shop without additional precautions. Overloading the ventilation system of the painting system is excluded. Overall, the disposal costs are reduced to about 20 percent of the conventional costs when using the method according to the invention.

In accordance with the foregoing, the aforementioned object with regard to the device according to the invention for removing paint from cover and / or support elements of a painting installation, preferably from hangers, is achieved by the features of patent claim 20. A corresponding device is then designed such that a chamber with an induction heating device arranged therein is provided for inductive heating of the cover and / or support elements and that the chamber is assigned to the painting system or is designed as a mobile unit. The chamber could be integrated directly into a painting system or painting line, so that it is not necessary to remove covering and / or carrier elements to be stripped. Alternatively, the chamber could serve as a mobile unit for retrofitting an existing painting system or for use at different locations on the painting line.

In an embodiment which is advantageous with regard to the operation of the chamber, the chamber could have connections for energy and / or water and / or exhaust air. On the one hand, this would ensure the energy supply and possibly cooling of the induction heating device and, on the other hand, would allow exhaust air to be discharged.

There are now various possibilities for designing and developing the teaching of the present invention in an advantageous manner. This is on the one hand on the subordinate claims, on the other hand to refer to the following explanation of an embodiment of the method according to the invention with reference to the drawing. In connection with the explanation of the preferred exemplary embodiment of the method according to the invention with reference to the drawing, generally preferred configurations and developments of the teaching are also explained. In the drawing, the

only figure in the context of a block diagram the exemplary sequence of a method according to the invention for stripping the covering and / or carrier elements of a painting installation.

The single figure shows a schematic representation of the sequence of an exemplary method according to the invention for removing paint from cover and / or support elements 1 of a painting system, preferably from hangers. With the reference number 1 three cover and / or support elements 1 are shown schematically as a section of a painting line. The running direction of the painting line is marked with the reference number 2.

The first method step of the method according to the invention consists in the selection of the covering and / or carrier element 1 to be stripped. This station is identified by the reference number 3. The selection can be made according to a wide variety of criteria, for example the paint thickness on the cover and / or support elements 1.

In the next step, identified by reference number 4, the cover and / or carrier element 1 is inductively heated to a stripping temperature. The paint stripping temperature is a temperature at or in which the subsequent removal of a paint layer is particularly favored. The heating can take place in a chamber separate from the painting area or the painting line.

The subsequent removal of the lacquer layer, identified by the reference number 5, can then take place outside the chamber, specifically to mechanical ones Wise. Any suitable tool can be used for this, in particular a spatula and wire brush. In the last process step, which is identified by reference number 6, the stripped cover and / or carrier element 1 is returned to the painting process - arrow direction 8 - or to a bearing - arrow direction 7. In this way, either continuous use of the stripped cover and / or carrier element 1 in the painting process or storage until the next use is possible.

With regard to further advantageous refinements of the method according to the invention and the device according to the invention, reference is made to the general part of the description and to the appended claims in order to avoid repetition.

Finally, it should be expressly pointed out that the exemplary embodiment of the method according to the invention discussed above only serves to discuss the claimed teaching, but does not restrict it to the exemplary embodiment.

Claims

Patent claims 1. Process for removing paint from cover and / or support elements (1) of a painting system, preferably from hangers, g e k e n n e e i c h n e t d u r c h following process steps: Selection of the covering and / or carrier element (1) to be stripped; Induction heating of the cover and / or support element (1) to a stripping temperature; mechanical removal of the lacquer layer present on the cover and / or carrier element (1); Returning the stripped cover and / or carrier element (1) in the painting process or in a warehouse. 2. The method according to claim 1, characterized in that the paint stripping temperature is the temperature at which the boundary layer of the lacquer to be removed, which adheres to the cover and / or carrier element (1), burns. 3. The method according to claim 1 or 2, characterized in that the removal of the lacquer layer is carried out with the cover and / or carrier element (1) not yet cooled to ambient temperature. 4. The method according to any one of claims 1 to 3, characterized in that the entire stripping process is carried out with the covering and / or carrier element (1) left within the painting area or a painting line. 5. The method according to any one of claims 1 to 3, characterized in that the covering and / or carrier element (1) is removed for stripping from the painting area or a painting line. 6. The method according to claim 5, characterized in that the cover and / or support element (1) is brought for heating in a separate from the painting area or the painting line chamber. 7. The method according to claim 6, characterized in that the removal of the lacquer layer is carried out outside the chamber. 8. The method according to claim 6 or 7, characterized in that the chamber or, if appropriate, a plurality of chambers is or are permanently installed at predetermined locations in the painting installation. 9. The method according to claim 6 or 7, characterized in that the chamber is designed as a mobile unit. 10. The method according to claim 9, characterized in that the chamber is designed or arranged as a mobile or in a mobile container. 11. The method according to any one of claims 6 to 10, characterized in that the chamber has connections for energy and / or water and / or exhaust air. 12. The method according to any one of claims 1 to 11, characterized in that the selection is made according to predeterminable stripping cycles. 13. The method according to any one of claims 1 to 12, characterized in that the selection is carried out automatically depending on the thickness of the lacquer layer to be removed. 14. The method according to any one of claims 1 to 13, characterized in that the selection is carried out manually. 15. The method according to any one of claims 1 to 14, characterized in that the cover and / or support elements (1) remain connected during the stripping with an optionally provided conveyor system. 16. The method according to any one of claims 1 to 15, characterized in that the cover and / or support elements (1) are hung in induction coils during heating. 17. The method according to any one of claims 1 to 16, characterized in that the mechanical removal of the lacquer layer is carried out by means of a spatula and / or wire brush. 18. The method according to any one of claims 1 to 17, characterized in that the paint residues removed from the cover and / or support elements (1) are fed to a targeted disposal. 19. The method according to any one of claims 2 to 18, characterized in that the gases formed during the combustion of the boundary layer are supplied to the ventilation system of the painting system. 20. Device for stripping the cover and / or support elements (1) of a painting system, preferably hangers, characterized in that a chamber with an induction heating device arranged therein is provided for inductive heating of the cover and / or support elements and that Chamber is assigned to the painting system or is designed as a mobile unit. 21. The apparatus according to claim 20, characterized in that the chamber has connections for energy and / or water and / or exhaust air.