EP1726368A1 - Holding device for articles to be coated - Google Patents

Abstract

The bracket (1) has many threads (8) for priming of stripping, where bracket is coated with an anti-adherent material layer (6) loaded by mineral particles (7). The threads are arranged along a post of the framework and along a transversal bar and have thickness between 0.5 and 2 mm. The threads have ends associated to the layer having fluorinated polymer and comprises gripping unit e.g. ring, where the layer has thickness between 20 and 60 microns. Independent claims are also included for the following: (1) a method for stripping a layer of painting deposited on a retaining bracket (2) a stripping equipment for a retaining bracket.

Description

The invention relates to a temporary fixing support for parts, for the painting treatment of said parts, as well as a method for stripping a paint layer deposited on such a support, and a stripping installation for such a support.

In particular, the invention relates to the field of stripping part fixing brackets which are painted, on an industrial scale, dry or wet.

To implement this treatment with paint, the fixing brackets, on which were previously fixed the parts to be painted, are introduced into a paint booth in which the parts are subjected to the action of one or more spray guns. painting. The supports are covered, as and when they are used, successive layers of paint. These paint layers are further subjected to one or more subsequent stages of baking, these steps successively succeeding the painting of parts.

After a few cycles of painting / baking, the number of cycles typically being between 5 and 10, it is essential to subject these media stripping of the deposited paint. Indeed, the layers of paint deposited on the supports can become so thick that it is no longer possible to hang new parts satisfactorily.

Classically, this stripping can be done by pyrolysis, using solvents, which presents significant risks for the user, or by scraping, which causes strong mechanical stresses on these supports which are relatively fragile.

It is also known EP-1 348 490 substrates coated with a non-stick bilayer composition which is intended to facilitate the removal of paint or unwanted contamination deposited on the surface of the supports. However, this non-stick composition must, to properly perform its function, be deposited on the surface to be protected by a complex process, since it consists in successively applying the first, then the layer, and heat them together under precise conditions. The constraints imposed by such a method are not very compatible with its implementation on an industrial scale.

To overcome these drawbacks, the invention proposes a support comprising simple means to facilitate its pickling, these means making it possible to effectively reduce not only the time necessary for pickling, but also the power consumption necessary for this operation.

For this purpose, according to a first aspect, the invention proposes a temporary fixing support for parts, for the painting treatment of said parts, said support comprising at least one attachment surface coated with a layer of an anti-adhesive material. adherent, said layer being intended to limit the adhesion of the paint on said surface and to facilitate its pickling, said support comprising at least one pickling initiation means associated with the layer of release material.

The presence of one or more stripping initiation means allows the operator to locally break the deposited paint layer which, being arranged on a layer of release material, is easily detached from the support.

Stripping, for example by spraying water, compressed air, sand, or by simple manual brushing, is therefore easy and fast.

According to a first embodiment, the pickling initiation means is displaceable at least partially with respect to the layer of release material. It can then be an elongated element disposed on the layer of non-adherent material, parallel thereto.

In particular, the elongated element may be a wire of which at least one of the ends is fixedly associated with the layer of release material. The wire may advantageously be provided with a gripping means intended, by its actuation, to allow said wire to be moved away from the layer of non-stick material.

This embodiment is particularly interesting when the paint used is a painting type powder, which is by nature very mechanically resistant and hardly friable in a simple stripping for example by water jet. In addition, the wire being fixed by at least one of its ends to the layer of release material, it is held in place during pickling, and returns to press against the layer of release material, between this layer and the layer of paint deposited, during the next cycle of painting. The same wire can therefore exert its primer function during many successive stripping and painting cycles.

According to a second embodiment, the pickling initiation means is integrated with the layer of release material. In particular, this pickling initiation means may consist of mineral particles mixed with said release material, so as to impart a rough character to said layer.

This embodiment is useful especially when the paint used is liquid.

The roughness of the release material layer also provides some roughness to the paint layer deposited thereon. The jet used for stripping infiltrates areas of the paint layer that have asperities, and breaks said layer easily in these areas of lesser thickness.

The support according to the invention may advantageously comprise several pickling initiation means, said pickling initiation means being able to consist of mineral particles mixed with said non-stick material, and a plurality of wires arranged on the layer of said material. .

The presence of these different means on the same support further facilitates stripping, especially when the layer of paint deposited is thick, or when the paint used is particularly resistant (case of powder paint).

The release material preferably comprises a fluoropolymer, which may be selected from fluorinated ethylene propylene (FEP) or perfluoroalkoxy resin (PFA).

These fluoropolymers have the advantage of having anti-adherent properties adapted to generally used paints, which are by nature formulated to be very adherent. In addition, these polymers are compatible with the electrostatic processes used for the application of the paint, and are mechanically strong enough to withstand the pickling process.

The thickness of the layer of release material is preferably less than 100 microns, and is typically between 20 and 60 microns. Such a thickness is sufficient to prevent the layer of paint from adhering to the support, and at the same time allows only relatively small amounts of release material to be used, which limits the costs of the support.

According to a second aspect, the subject of the invention is a method for stripping a paint layer deposited on a support according to the invention. This method consists of sending a jet of water at high pressure to a part to be stripped from the fixing surface, starting by directing said jet towards one or more zone (s) of initiation of rupture of the layer of paint, said or said zone (s) of initiation of rupture corresponding to the zones of the part to be stripped comprising a pickling initiation means or means.

The implementation of the method can be facilitated when, prior to sending the jet on the part to be stripped, the support is fixed on a gantry arranged to maintain said support and allow its pivoting during pickling. The use of such a gantry ensures optimal stripping since all areas of the support to be stripped are made easily accessible simply by pivoting the gantry.

According to a third aspect, the invention relates to a stripping installation for a support according to the invention, characterized in that it comprises a high-pressure cleaning device and a vessel inside which a gantry is provided. fixing said support, said vessel comprising a grid for recovering pickled dry extracts, a wastewater treatment tank and a sewage pipe.

This installation has the advantage of being easily transportable and can be placed at a location close to the piece of painting and / or cooking, which helps to limit the time required for stripping operations.

• la figure 1 est une vue schématique de face d'un support selon l'invention, pourvu d'une pluralité de fils destinés à amorcer le décapage ;
• la figure 2 est une vue schématique en perspective partiellement éclatée des couches recouvrant une surface de fixation d'un support selon l'invention, ladite surface étant recouverte d'une couche de matériau anti-adhérent chargé et d'une couche de peinture, ledit support comprenant en outre un fil destiné à amorcer le décapage ;
• les figures 3a et 3b sont des vues schématiques en coupe transversale d'une barre d'un support selon l'invention, respectivement avant et après l'amorçage du décapage, ladite barre étant revêtue d'une couche de matériau anti-adhérent chargé et d'une couche de peinture, un fil destiné à amorcer le décapage étant disposé entre la couche de matériau anti-adhérent et la couche de peinture ;
• la figure 4 est une vue en perspective d'une installation de décapage selon l'invention.

Other objects and advantages will become apparent from the following description, made with reference to the appended drawings in which:

• Figure 1 is a schematic front view of a support according to the invention, provided with a plurality of son for initiating stripping;
• FIG. 2 is a diagrammatic perspective view partially exploded of the layers covering a surface for fixing a support according to the invention, said surface being covered with a layer of charged non-stick material and a layer of paint, said support further comprising a wire for initiating pickling;
• FIGS. 3a and 3b are diagrammatic cross-sectional views of a bar of a support according to the invention, respectively before and after initiation of pickling, said bar being coated with a layer of loaded non-stick material and a paint layer, a wire for initiating pickling being disposed between the layer of release material and the paint layer;
• Figure 4 is a perspective view of a pickling plant according to the invention.

The support 1 shown in Figure 1 is intended to allow the temporary fixing of parts during the painting of these.

This support 1 comprises a frame 2 made of a conductive material such as steel, and preferably a stainless steel. The frame 2 is of substantially parallelepiped shape. It is provided with a plurality of transverse bars 3 on which are fixed the pieces to paint. These parts are fixed for example by means of hooks or clamps distributed along the transverse bars 3.

The armature 2 is suspended on a supporting structure 4 by means of bars 5 integral with the armature 2, but electrically insulated.

The support 1 having a surface as shown diagrammatically in FIG. 2 is described below.

The support 1 is coated with a layer of non-stick material 6 previously loaded with mineral particles 7.

The polymer used is "FEP", for example that marketed by the company AKZO NOBEL under the reference CHEMLON 25P0002 or "PFA", for example that marketed by the company AKZO NOBEL under the reference CHEMLON 25P0000.

The particles used are, for example, PEEK particles (Polyether ether ketone), marketed by VICTREX under the reference PF 450, and are incorporated into the polymer by mixing before application to the support. To facilitate these mixing operations, a charge is selected whose particle size is close to but slightly greater than that of the polymer used; this particle size is for example of the order of 60 microns such that, after melting at high temperatures, there remains a relief caused by this particle size at the surface of the coating. The proportions of filler can be chosen between 20 and 60% of the total weight of the release of non-stick substrate mixture and fillers. Other types of fillers, and in particular fillers based on corundum, glass beads, plastic powder, or metal particles, can be used to produce a fluoropolymer coating with a textured surface having a sufficient roughness to facilitate and / or provoke the phenomena of priming.

• mélange entre le substrat en polymère fluoré et la charge ;
• préparation du support, par exemple par décapage ou dégraissage ;
• application d'un primaire d'accroche ;
• application en une seule couche du revêtement anti-adhérent par projection ou immersion ;
• passage dans un four ou tunnel à température élevée, de l'ordre de 400°C.

The coating of the support 1 by the layer of release material 6 is carried out by implementing the following successive steps:

• mixing the fluoropolymer substrate with the filler;
• preparation of the support, for example by pickling or degreasing;
• application of a primer;
• single-layer application of the release coating by spraying or dipping;
• passage in a furnace or tunnel at high temperature, of the order of 400 ° C.

The support 1 is also provided with several son 8 contributing to the priming pickling. These son 8 are arranged along the uprights of the frame 2, and along a transverse bar 3. They may be formed of metal or an elastic material, and / or be arranged to be able to undergo a lengthening of some percent in relation to their length at rest.

The thickness of each wire 8 is typically between 0.5 and 2 mm, which prevents the wire from tearing or being torn off during the implementation of painting and stripping operations.

The two ends of the wire 8 are fixed to the support 1 by welding, and are therefore associated with the adhesive material layer 6 once it has been deposited on the support 1.

The length of the wire 8 is provided so that it is not stretched to the extreme once fixed on the support 1.

Each wire 8 is provided with a gripping means 9 such as a ring, which allows the operator to easily grasp the wire 8 and to fire on it when it wishes to start stripping.

According to the embodiment shown, in which the two ends of the wire 8 are fixed to the support 1, the gripping means 9 is provided substantially in the center of the wire 8. However, it can also be provided that only one end of the wire 8 is attached to the support 1, and that the other end is provided with the gripping means 9.

Thus, when the support has been covered with a paint layer 10 which requires stripping, as shown in FIGS. 2, 3a and 3b, the wire 8 is situated between the layer of release material 6 and the coating layer. painting 10.

Figure 4 shows a pickling installation 11 for a support 1 as described above.

This installation 11 comprises a high-pressure cleaning device (not shown) such as the one sold by DIMACO under the reference FIMECO-CLEANER-400X. This device can be associated with a filter arranged upstream, intended to protect the motor against any impurities that may come from the water used.

The installation 11 comprises a substantially parallelepipedal vessel 12 inside which is provided a gantry 13 for fixing the support 1. This gantry 13 is in the form of a first rectangular frame 14 fixedly mounted relative to the vessel 12 by means of sleepers 15, and substantially in the center thereof, and a second frame 16 hinged to the first, and pivotally mounted relative thereto. The second frame 16 is arranged to receive the support 1 when it must be stripped.

The sides 17 of the tank 12 are formed of a plasticized tarpaulin, with the exception of the side forming the ground which is constituted by a grid 18 for receiving the stripped solids covering a waste water tank 19, the tank 19 communicating with a conduit 20 for discharging wastewater.

The installation 11 further comprises, in the lower part, a plate 21 provided with rails 22 intended to cooperate with the longitudinal members of a pallet truck, so as to facilitate the transport of the installation 11.

The method of stripping a paint layer 10 deposited on the support 1 is now described.

The support 1 is first detached from its supporting structure 4 and placed on the gantry 13 located in the pickling plant 11.

The operator (or robotic means) pulls on the gripping means 9 of the various threads 8, so as to move them away from the layer 6 of non-stick material. This operation creates several areas of initiation of rupture of the paint layer 10, the paint layer 10 is therefore torn locally by the son 8. This tear of the paint layer 10 is shown schematically in Figure 3b.

After opening the water circuit, the high-pressure water jet is sent to the part to be stripped from the support 1, starting with the areas where the paint layer 10 is torn.

This action, preferably but not necessarily associated with the fact that the layer 6 of non-stick material located under the paint layer 10 to be stripped has a rough character, makes it possible to separate easily and quickly the paint layer 10 relative to the support 1.

For a support 1 of dimensions equal to 2 m ² , the pickling operation is typically carried out in less than 5 minutes, with a water pressure of less than or equal to 350 bars. In particular, when the pickling initiation has taken place, a pressure equal to 150 bar is sufficient to complete the pickling.

To initiate stripping, the nozzle from which the water jet emerges can be placed about 5 cm from the paint layer, then to 20 cm when priming has occurred.

The dry extracts collected on the grid 18 can be treated as sludge and therefore sent to an incinerator or used as a base material for example in the manufacture of road surfaces.

Claims (19)

Support (1) for the temporary fixing of parts, for the painting treatment of said parts, said support comprising at least one fixing surface coated with a layer of non-stick material (6), said layer being intended to limit the adherence of the paint to said surface and to facilitate its pickling, characterized in that it comprises at least one pickling initiation means associated with the layer of release material (6). Support according to claim 1, characterized in that said pickling initiation means is displaceable at least partially relative to the layer of release material (6). Support according to claim 2, characterized in that said pickling initiation means is an elongated element disposed on the layer of non-stick material (6), parallel thereto. Support according to claim 3, characterized in that said elongate element is a wire (8), at least one end of said wire (8) being fixedly associated with the layer of release material (6). Support according to claim 4, characterized in that the wire (8) is provided with a gripping means (9) intended, by its actuation, to allow said wire (8) to be removed from the layer of non-stick material (6). Support according to claim 4 or 5, characterized in that the thickness of the wire (8) is between 0.5 mm and 2 mm. Support according to claim 1, characterized in that said pickling initiation means is integrated with the layer of release material (6). Support according to claim 7, characterized in that said pickling initiation means consists of mineral particles (7) mixed with said release material, so as to give a rough character to said layer (6). Support according to claim 8, characterized in that the mineral particles (7) are particles of polyether ether ketone (PEEK). Support according to claim 8 or 9, characterized in that the proportion of mineral particles (7) is between 20 and 60% of the total weight of the mixture. Support according to one or more of the preceding claims, characterized in that it comprises several pickling initiation means. Support according to claim 11, when it depends on claims 4 and 8, characterized in that said pickling initiation means consist of mineral particles (7) mixed with said release material, and a plurality of wires ( 8) arranged on the layer of release material (6). Support according to any one of the preceding claims, characterized in that the release material comprises a fluoropolymer. Support according to claim 13, characterized in that the fluorinated polymer is selected from fluorinated ethylene propylene (FEP) or perfluoroalkoxy resin (PFA). Support according to claim 13 or 14, characterized in that the thickness of the layer of release material (6) is less than 100 microns. Support according to claim 14, characterized in that the thickness of the layer of release material (6) is between 20 and 60 microns. Process for stripping a layer of paint deposited on a support (1) according to any one of Claims 1 to 16, characterized in that it consists in sending a jet of water at high pressure to a part to be stripped from the fixing surface, starting by directing said jet towards one or more zone (s) of initiation of rupture of the paint layer, said zone (s) of initiation of rupture corresponding to the zones of the part to be stripped comprising one or more pickling initiation means. Process according to claim 17, characterized in that , prior to the sending of the jet on the part to stripping, the support (1) is fixed on a gantry (13) arranged to maintain said support (1) and allow the pivoting of said support (1) during pickling. Pickling plant (11) for a support (1) according to any one of claims 1 to 16, characterized in that it comprises a high-pressure cleaning device and a tank (12) inside which is provided a gantry (13) for fixing said support (1), said vessel (12) comprising a grate (18) for recovery of pickled dry extracts, a tank (19) for the recovery of wastewater and a conduit (20) for sewage disposal.

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