EP2612710B1 - Painting system component having a modified surface - Google Patents

Description

The invention relates to a Lackieranlagenbauteil, in particular a bell cup for a rotary atomizer, according to the preamble of claim 1. Furthermore, the invention comprises a corresponding manufacturing method.

For painting automotive body components usually rotary atomizers are used, which have a rotating bell cup as the application element. A problem here is the fact that the bell cup is heavily contaminated with the applied paint both on outer surfaces (for example, lateral surface) and on inner surfaces (for example overflow surface) in the painting operation, the paint partially adhering very strongly to the surface of the bell cup. In the case of a coating agent change, therefore, a relatively large amount of rinsing agent must be used to clean the bell cup from the adhering residues of the old coating agent, which also takes a relatively long time. This also applies to so-called short rinsing, which is carried out between the coating of individual coating objects (for example motor vehicle bodies). A disadvantage of the conventional bell plates so the tendency to fouling and unsatisfactory cleaning ability.

In addition, the surfaces, in particular the overflow surfaces, of the conventional bell cup are subject to wear by corrosion and / or abrasion, whereby the surface roughness is increased, which in turn increases the requirements for cleaning the bell cup.

Out DE 101 12 854 A1 It is known to coat the surface of such a bell cup in order to increase the abrasion resistance and thereby reduce wear. However, these known surface coatings do not solve the problem of fouling tendency or the lack of cleaning ability of the bell cup.

Furthermore, it should be noted on the prior art US 5,923,944 A . GB 2 170 226 A . EP 0 435 312 A1 . WO 03/064720 A1 and EP 0 087 836 A1 , However, these documents do not disclose paint shop components and belong to a completely different technical field.

The invention is therefore based on the object to reduce the tendency to foul a bell cup and / or to improve the cleanability of the bell cup.

This object is achieved by a bell plate according to the invention according to the main claim.

Within the scope of the invention, it is provided that a painting installation component (for example, bell cup) has a surface layer which reduces the tendency to fouling and / or improves the cleaning capability.

The main body itself may in the context of the invention, for example, made of aluminum or an aluminum alloy, titanium, steel, stainless steel, non-ferrous metal (copper and its alloys), ceramic, plastic or a combination of these materials.

The surface layer may in the context of the invention contain oxides, nitrides and / or carbides, for example, boron, molybdenum, tantalum, niobium, vanadium, zirconium, silicon, chromium, titanium, carbon, nickel and fluorine compounds as (base) materials for the Surface layer are suitable.

In a preferred embodiment of the invention, the surface layer consists of a material based on Si-O, Si-OH or silicon-organic compounds, in particular in the form of a nano-layer, as will be described in detail.

In addition, it should be noted that the surface layer preferably contains metal oxides, metal nitrides or organometallic compound.

It should also be mentioned that the surface layer may optionally consist of an organic, in particular metal-organic material or of an inorganic material.

Depending on the coating agent to be used, the surface layer may be either hydrophilic or hydrophobic. A hydrophilic surface layer is characterized by a contact angle with respect to water which is less than 90 °, 45 °, 20 °, 10 °, 8 ° or even less than 6 °. In addition, the surface layer may even be superhydrophilic, with the surface layer then being characterized by a contact angle with water of less than 5 °, 3 °, 2 °, or even less than 1 °. By contrast, in the case of a hydrophobic surface layer, the contact angle with respect to water is preferably greater than 90 °, 110 °, 130 ° or 150 °. In the context of the invention, there is even the possibility that the surface layer is superhydrophobic, wherein the contact angle with respect to water is greater than 160 °, 180 °, 200 ° or even 220 °.

Furthermore, it is within the scope of the invention, the possibility that the surface layer is a so-called nano-layer. Such nanosheets are known per se from the prior art and therefore need not be described in detail. At this point, it should merely be mentioned that nanosheets are usually made of nanoparticles with a size of less than 100 nm, which settle in the surface roughness and thereby seal the surface, resulting in a significantly reduced surface roughness. With such a nanosheet, a lotus effect of the component surface can be realized, resulting in a self-cleaning component surface. The term nanolayer used in the context of the invention therefore preferably refers to a surface layer which contains particles whose particle size is in the nanometer range. However, there is also or alternatively the possibility that the nanolayer has a layer thickness which is in the nanometer range.

Furthermore, it is within the scope of the invention, the possibility that the surface layer has a microstructuring in order to reduce the tendency to fouling. For example disclosed WO 96/04123 A1 a self-cleaning component surface that combines a microstructure with a hydrophobic coating to achieve the self-cleaning effect. The content of this patent application is therefore to be fully attributed to the present specification.

In addition, the surface layer according to the invention can fulfill a further technical function in that the surface layer is, for example, wear-reducing, which in itself results from the patent application cited above DE 101 12 854 A1 is known.

In a variant of the invention, the main body and the surface layer consist of the same starting material, wherein the material properties of the surface layer are selectively changed in order to reduce the tendency of the painting component to become soiled reduce and / or improve cleanability. For example, the surface of the base body for this purpose with radiation techniques (eg water jets, ceramic bead jets, glass beads, etc.) are irradiated in order to change the surface properties accordingly. Alternatively, there is the possibility that the surface of the main body is irradiated or etched with a laser to produce the desired material properties. Furthermore, in the context of this variant of the invention there is the possibility that the surface layer is produced by plasma processes, for example by plasma-electrolytic oxidation (PEO technology).

In contrast, in another variant of the invention, the base body and the surface layer consist of different starting materials, the surface layer being applied to the base body as a surface coating. For example, this application of the surface layer can be done by physical vapor deposition (PVD) or by other methods.

Further possible methods for applying or producing the surface layer are chemical vapor deposition (CVD), etching, laser irradiation, ion implantation, blasting techniques (eg water jets, ceramic bead blasting, glass bead blasting) and classical coating methods such as spraying, dipping, sputtering, brushing, which are particularly suitable for applying organic surface layers.

To achieve special surface layers, it may be useful in the context of the invention to apply a plurality of sublayers lying one above the other with different material properties, wherein the sublayers lying one above the other are present For example, with regard to ductility, friction, wettability, roughness, corrosion resistance or wear resistance can differ.

Furthermore, it is within the scope of the invention, the possibility that the surface layer has a plurality of areas which are separated from each other and have different properties. For example, in a mechanically heavily loaded area, the surface layer can be more optimized for the greatest possible abrasion resistance, whereas the good cleanability at such sites is less of a priority. On the other hand, in surface areas which are strongly exposed to the paint and, moreover, poorly accessible, the surface layer can be optimized for the lowest possible tendency to become soiled, whereas the abrasion resistance in these areas is given only a lower priority.

It should also be mentioned that the surface layer may consist of a material with a high, medium or low surface friction.

The same applies mutatis mutandis to the wettability of the surface layer, which may optionally consist of a material with a very good, good or low / poor wettability.

Also in terms of ductility exist within the scope of the invention, various options that can be selected depending on the application. For example, the surface layer may consist of a material with a high ductility, in particular with an elongation at break of more than 5% or 10%. Alternatively, however, it is possible that the surface layer of a material with a middle Ductility, in particular with an elongation at break between 0.5 and 5%. Furthermore, there is also the possibility that the surface layer consists of a material with a low ductility, in particular with an elongation at break of less than 0.5%, 0.3% or 0.1%.

In addition, the surface layer may be made of a material having a large roughness (e.g., Rz> 50μm), average roughness (e.g., Rz = 10pm-50pm) or low roughness (e.g., Rz <10pm).

Also in terms of abrasion resistance, there are various possibilities, so that the surface layer can optionally consist of a material with a high, medium or low abrasion resistance.

Furthermore, there are also various possibilities with regard to the corrosion resistance of the surface layer, depending on the application, so that the surface layer can optionally consist of a material with a high, medium or small corrosion resistance.

Corrosion resistance is particularly important when the paint shop equipment (e.g., bell cup) is made of non-ferrous metal (copper and its alloys) because non-ferrous metals also corrode in combination with demineralized water (DI water). This is important because demineralised water is contained in water-based paints and water-based detergents, so that non-ferrous metal dish plates must be coated with a corrosion-resistant surface layer.

The abovementioned possibilities of material properties can also be combined in a targeted manner in order to achieve certain properties.

For the finest possible atomization of the coating composition, it is advantageous, for example, to combine the following material properties of the surface layer: low interfacial friction, low wettability, high ductility, low roughness, high abrasion resistance and low corrosion resistance.

In order to achieve the best possible cleaning ability, it is advantageous to combine the following material properties with each other: average interfacial friction, high wettability, average ductility, low roughness, low abrasion resistance and very good corrosion resistance.

In order to achieve corrosion protection of aluminum, however, it is advantageous to combine the following material properties: average interfacial friction, low wettability, high ductility, low roughness, low abrasion resistance and very good corrosion resistance.

In a variant of the invention, the cleaning-optimizing surface layer covers the entire surface of the base body.

In another variant of the invention, however, the cleaning-optimizing surface layer covers only outer surfaces of the base body. In a bell cup, the outer surface and / or the rear side of the main body are then preferably coated with the surface layer.

In a further variant of the invention, however, only an inner surface of the base body is coated with the surface layer. For example, a bell cup may be an overflow surface.

In a further variant of the invention, however, the surface layer covers the surface of the base body only on partial areas which require an optimization of the cleaning properties. For example, these may be the areas of the lateral surface and the overflow surface that are directly adjacent to the spray-off edge.

The inventive principle of optimizing the tendency to fouling or cleanability is not only suitable for bell plates of rotary atomizers, but is also suitable for other paint-carrying components, such as valve housing or valve needles. In addition, the invention is also useful for ameliorating other paint shop components that come in contact with a coating agent during operation, such as atomizers (e.g., rotary atomizers), robotic hand axes, robotic arms, or flanges. In general, the invention is useful for improving the cleanability or soiling of components of a paint robot or handling robot (e.g., door opener, hood opener). Finally, the invention is also suitable for reducing the tendency to fouling or for improving the cleanability of components of a paint booth, such as covers, gratings, conveyors, windows, wall panels or exhaust ducts.

In addition, it should be noted that the invention is not limited to a single painting plant component (eg bell cup) which is optimized with regard to its tendency to fouling or cleaning capability. Rather, the invention also includes a rotary atomizer with an inventively optimized bell cup and a complete painting robot with such a rotary atomizer.

Finally, the invention also encompasses a production method for producing a coating plant component (for example bell cup) optimized according to the invention, as already apparent from the above description.

Figur 1

eine Querschnittsansicht eines erfindungsgemäßen Glockentellers an einem Rotationszerstäuber,

Figur 2

eine Querschnittsansicht eines erfindungsgemäßen Glockentellers, bei dem die Oberflächenschicht nur Teile des Glockentellers abdeckt,

Figur 3

eine Querschnittsansicht eines erfindungsgemäßen Glockentellers, bei dem die Oberflächenschicht die äußere Mantelfläche und die Rückseite des Glockentellers überzieht,

Figur 4

eine Querschnittsansicht durch ein anderes Ausführungsbeispiel eines erfindungsgemäßen Glockentellers, wobei die Oberflächenschicht den gesamten Glockenteller überzieht, sowie

Figur 5

eine Querschnittsansicht eines erfindungsgemäßen Glockentellers, bei dem die Oberflächenschicht nur die Innenfläche und die Überströmfläche des Glockentellers überzieht.

Other advantageous developments of the invention are characterized in the subclaims or are explained in more detail below together with the description of the preferred embodiments of the invention with reference to FIGS. Show it:

FIG. 1

a cross-sectional view of a bell cup according to the invention on a rotary atomizer,

FIG. 2

a cross-sectional view of a bell cup according to the invention, wherein the surface layer covers only parts of the bell cup,

FIG. 3

a cross-sectional view of a bell cup according to the invention, in which the surface layer covers the outer surface and the back of the bell cup,

FIG. 4

a cross-sectional view through another embodiment of a bell cup according to the invention, wherein the surface layer covers the entire bell cup, as well as

FIG. 5

a cross-sectional view of a bell cup according to the invention, in which the surface layer covers only the inner surface and the overflow surface of the bell cup.

FIG. 1 shows a largely conventional bell cup 1 for a rotary atomizer 2, wherein the bell cup 1 rotates about a rotation axis 3 in operation.

The paint to be applied is the bell cup 1 in this case fed through a paint tube and then hits axially on a baffle plate 4, which deflects the paint in the radial direction.

The paint then flows along an overflow surface 5 to an annular peripheral spray-off edge 6, at which the paint is sprayed.

In addition, the bell cup 1 on its outer side a conical lateral surface 7, which is also known per se from the prior art.

The invention now provides that the bell cup 1 is coated on its surface with a surface layer which reduces the tendency to fouling and improves the cleaning ability. This surface layer is in this case applied to the overflow surface 5 and the paint-carrying inner surfaces of the bell cup 1 and also extends beyond the entire lateral surface 7. However, it is within the scope of the invention also possible that the entire surface of the bell cup 1 is sealed to the surface coating ,

The surface layer of the invention contains in this embodiment, a nano-layer, which realizes a lotus effect, so that the bell cup 1 is self-cleaning and possibly requires a short cleaning.

The embodiment according to FIG. 2 is largely consistent with the embodiment described above, so in order to avoid repetition, reference is made to the above description, wherein the same reference numerals are used for corresponding details.

A special feature of this embodiment is that the bell cup 1 has a surface layer 8 only in the region of its spray-off edge 6, the surface layer 8 being located both on the overflow surface 5 and on the outer jacket surface 7.

In addition, there is also on the inner surface of the bell cup 1, a region 9, which is provided with a surface layer, which reduces the tendency to fouling and improves the cleaning ability.

The embodiment according to FIG. 3 in turn, is broadly consistent with the embodiments described above, so reference is made to the foregoing description to avoid repetition, with like reference numerals being used for like details.

This embodiment is characterized in that the surface layer covers only the outer circumferential surface 7 and the back of the bell cup 1, whereas the overflow surface 5 and the inner surface of the bell cup 1 remain uncoated.

The embodiment according to FIG. 4 again largely coincides with the embodiments described above, so that reference is made to avoid repetition of the above description.

This embodiment is characterized in that the bell cup 1 complete with the surface layer. 8 is sealed. This means that the entire surface of the bell cup 1 is covered by the surface layer 8.

Also, the embodiment according to FIG. 5 is largely consistent with the embodiments described above, so reference is made to avoid repetition of the above description.

A special feature of this embodiment is that only the overflow surface 5 and the inner surface of the bell cup 1 is coated with the surface layer.

The invention is not limited to the preferred embodiments described above. Rather, a variety of variants and modifications is possible, which also make use of the inventive idea and therefore fall within the scope.

LIST OF REFERENCE NUMBERS

1

A bell plate

2

rotary atomizers

3

axis of rotation

4

baffle plate

5

overflow

6

spray edge

7

lateral surface

8th

surface layer

9

Coated area

Claims (13)

1. Painting installation component, in particular a bell plate (1) for a rotary atomiser, having

   a) a base body (1) and

   b) a surface layer (8) at least on a part of the surface of the base body (1),

   c) wherein the surface layer (8) reduces the tendency to contamination of the painting installation component and/or improves the cleaning capability of the painting installation component,

   characterised in that the surface layer (8) contains at least one of the following materials:

   d) niobium,

   e) vanadium,

   f) tantalum.
2. Painting installation component according to claim 1, characterised in that the surface layer (8) contains at least one of the following materials:

   a) oxides,

   b) carbides,

   c) nitrides.
3. Painting installation component according to claim 1 or 2, characterised in that the surface layer (8) contains at least one of the following materials:

   a) metal oxide,

   b) metal nitride,

   c) an organometallic compound.
4. Painting installation component according to one of the claims 1 to 3, characterised in that the base body (1) consists of one of the following materials or of a combination of the following materials:

   a) aluminium or an aluminium alloy,

   b) titanium,

   c) steel, in particular high grade steel,

   d) non-ferrous metal, in particular copper or a copper alloy,

   e) ceramic material,

   f) plastics.
5. Painting installation component according to one of the preceding claims, characterised in that

   a) the surface layer (8) is hydrophilic, in particular with a contact angle in relation to water of less than 90°, 45°, 20°, 10°, 8° or less than 6°, or

   b) in that the surface layer (8) is superhydrophilic, in particular with a contact angle in relation to water of less than 5°, 3°, 2° or less than 1°, or

   c) in that the surface layer (8) is hydrophobic, in particular with a contact angle in relation to water of more than 90°, 110°, 130° or 150°, or

   d) in that the surface layer (8) is superhydrophobic, in particular with a contact angle in relation to water of more than 160°, 180°, 200° or 220°.
6. Painting installation component according to one of the preceding claims, characterised in that

   a) the surface layer (8) is a nanolayer which contains particles with a particle size in the nanometre range, and/or

   b) in that the surface layer (8) is a nanolayer which has a layer thickness in the nanometre range,

   c) in that the surface layer (8) has a microstructure, and/or

   d) in that the surface layer (8) is wear-reducing.
7. Painting installation component according to one of the preceding claims, characterised in that the surface layer (8) is created by one of the following methods:

   a) plasma methods, in particular plasma-electrolytic oxidation,

   b) jet techniques, in particular water jets, ceramic bead jets, glass bead jets, or

   c) laser irradiation,

   d) etching,

   e) ion implantation,

   f) physical gas phase deposition,

   g) chemical gas phase deposition,

   h) spraying,

   i) dipping,

   j) sputtering,

   k) spreading.
8. Painting installation component according to one of the preceding claims, characterised in that

   a) the surface layer (8) comprises a plurality of sublayers having different properties, lying over one another, and/or

   b) in that the surface layer (8) comprises a plurality of regions that are separate from one another and have different properties.
9. Painting installation component according to one of the preceding claims, characterised in that

   a) the surface layer (8) consists of a material with a high ductility, specifically an elongation at failure of more than 5% or 10%, or

   b) in that the surface layer (8) consists of a material with a medium ductility, specifically an elongation at failure of between 0.5% and 5%, or

   c) in that the surface layer (8) consists of a material with a low ductility, specifically an elongation at failure of less than 0.5%, 0.3%, or 0.1%.
10. Painting installation component according to one of the preceding claims, characterised in that

    a) the surface layer (8) consists of a material with a high level of roughness, specifically with a roughness value of greater than 50µm, or

    b) in that the surface layer (8) consists of a material with a medium level of roughness, specifically with a roughness value of between 10µm and 50µm, or

    c) in that the surface layer (8) consists of a material with a low level of roughness, specifically with a roughness value of less than 10µm.
11. Painting installation component according to one of the preceding claims, characterised in that

    a) the surface layer (8) covers the entire surface of the base body (1), or

    b) in that the surface layer (8) covers only outer surfaces of the base body (1), in particular a lateral surface and/or a rear side of the base body (1), or

    c) in that the surface layer (8) covers only an inner surface of the base body (1), in particular a flow-over surface, or

    d) in that the surface layer (8) covers the surface of the base body (1) only at partial regions.
12. Painting installation component according to one of the preceding claims, characterised in that the painting installation component is one of the following components:

    a) a bell plate (1) of a rotary atomiser,

    b) a paint-guiding component, in particular a valve housing or a valve needle,

    c) a component which comes into contact with the coating medium during operation, in particular an atomiser, a robot hand axis, a robot arm or a flange,

    d) a component of a painting robot or a handling robot,

    e) a component of a paint booth, in particular a cover, a grating, a conveyor, a window pane, a wall element, an exhaust air duct.
13. Manufacturing method for a painting installation component, in particular a bell plate (1), comprising the following steps:

    a) providing a base body (1),

    b) generating a surface layer (8) at least on a part of the surface of the base body (1),

    c) wherein the surface layer (8) reduces the tendency to contamination of the painting installation component and/or improves the cleaning capability,

    characterised in that the surface layer (8) contains at least one of the following materials:

    d) niobium,

    e) vanadium,

    f) tantalum.

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