EP4059617A1 - Coating method with printed mask and printing apparatus - Google Patents

Abstract

In order to improve the complex painting process of large three-dimensionally shaped components (10), preferably aircraft components, it is proposed to automate the masking step (S14). This can be achieved by inkjet printing a masking agent (16) onto the component (10), the masking agent (16) forming a masking film (18). The masking film (18) masks the desired surface area (24) and can be removed after painting is complete. Spray foils, functional printing inks or mold release agents are preferably used as masking agents (16).

Description

The invention relates to a painting method and a printing device for use in such a method.

Until now, aircraft components have been masked by hand before painting, not least because of their curved surfaces. The masking effort for aircraft is particularly high, for example, on the door and window areas and on the surfaces provided with letters or logos.

There is therefore a need to automate the masking process as much as possible.

The object of the invention is to improve painting methods for components, preferably with a view to further automation.

The object is solved by the subject matter of the independent claims. Preferred developments are the subject matter of the dependent claims.

1.1

Bereitstellen des Bauteils;

1.2

bereichsweises Aufbringen eines filmbildenden Maskiermittels durch Drucken des Maskiermittels mittels eines Druckkopfes auf das Bauteil, um wenigstens einen maskierten Oberflächenbereich zu schaffen;

1.3

Ausbildenlassen oder Ausbilden eines Maskierfilmes aus dem Maskiermittel

1.4

Lackieren des Bauteils mit einem Lackierungsmittel; und

1.5

Entfernen des Maskierfilmes von dem Bauteil zum Freilegen des maskierten Oberflächenbereichs.

The invention provides a painting method for painting a component, preferably an aircraft component, with the steps:

1.1

providing the component;

1.2

regionally applying a film-forming masking agent by printing the masking agent onto the component with a printhead to create at least one masked surface area;

1.3

allowing the masking agent to be formed or forming a masking film

1.4

painting the component with a paint composition; and

1.5

removing the masking film from the component to expose the masked surface area.

It is preferred that in step 1.1 the component is or will be provided with a substrate.

It is preferred that in step 1.1 a further layer is applied to the component material or to the substrate.

It is preferred that the masking agent printed in step 1.2 is a liquid film-forming masking agent. The masking agent is preferably a spray film liquid, a printing ink, or a liquid mold release agent.

It is preferred that in step 1.3 the masking film is formed by evaporating solvent from the masking agent or by activating the masking agent by heating or by irradiation, preferably by irradiation with (UV) light.

It is preferred that in step 1.5 the masking film is removed by mechanical removal, preferably by mechanical peeling. It is preferred that in step 1.5 the masking film is weakened, for example by cutting or lasering. It is preferred that in step 1.5 the masking film is removed with the aid of compressed air, preferably blown away. It is preferred that in step 1.5 the masking film is removed by means of a suction device, preferably sucked off. It is preferred that the mechanical removal is by a gripping device. It is preferred that the masking film has a starting point for removal, the starting point being formed by a strip element embedded in the masking film, e.g. It is preferred that in step 1.5 the masking film is removed by brushing, rubbing, erasing, a water jet and/or a high-pressure cleaner.

It is preferred that in step 1.5 a top coat layer is applied to reduce the adhesion of the masking film and then the masking film is detached from the component by mechanical removal.

The invention also provides a printing device for printing components, preferably aircraft components, the printing device having a print head that can be moved relative to the component and a reservoir that is fluidly connected to the print head and supplies the print head with material to be printed, the reservoir containing a liquid masking agent . The masking agent is preferably a spray film liquid, a printing ink, or a mold release liquid.

The invention also creates a use of such a pressure device when carrying out a painting method as described above.

One idea of the invention is to apply the masking agent or the masking film to the component using an inkjet method. This can be a fully automated process, eliminating the need for manual masking of the component prior to painting. Inkjet methods for printing three-dimensional objects are known as such (for example Heidelberger Omnifire printing machines).

The method proposed here is a new application for inkjet methods, in which the material applied is used as a masking film for later painting. In contrast to the conventional method, the masking film printed in this way can simply be removed after painting. The printing ink can, for example, be a UV ink which hardens into a finished masking film by exposure to UV light.

Tests by the applicant have shown that conventional printing inks are functionally suitable as a masking agent on a paint substrate or another paint layer that is usual in aviation. The functional printing ink is covering, but not necessarily coloring and only slightly adheres and can therefore be removed from the component manually, using a gripper or other methods.

It is also possible to print a spray film liquid as a masking agent, as long as it has approximately the same viscosity as functional printing inks. Furthermore, it is also conceivable that a liquid mold release agent, such as is used in the production of fiber composite components in a mold, can be printed as a masking agent. The mold release agent preferably has a viscosity similar to that of the functional printing ink.

Furthermore, the applicant's tests have shown that the application of a top coat layer (clear coat or the like) can support the detachment of the masking agent.

With the ideas described here, a printable masking film is made possible, which can eliminate manual work on the component. Printing preferably enables precise and targeted dosing on the component, so that less waste material is produced and the quality of the result can be increased. Furthermore, printing enables the masking process to be fully automated, so that ultimately the entire painting process can be automated. Overall, this also allows the entire process time for painting to be reduced.

Fig. 1

ein Ausführungsbeispiel eines Lackierverfahrens;

Fig. 2

ein Ausführungsbeispiel einer Druckvorrichtung;

Fig. 3

eine Ansicht der Druckvorrichtung beim Maskieren; und

Fig. 4

eine Ansicht vom Entfernen des Maskierfilms aus einem Versuch der Anmelderin.

Exemplary embodiments are explained in more detail with reference to the accompanying schematic drawings. It shows:

1

an embodiment of a painting process;

2

an embodiment of a printing device;

3

a view of the printing device during masking; and

4

a view of removing the masking film from an experiment by the applicant.

1 shows schematically a painting process with the steps S10 to S18.

In the first step S10, an aircraft component 10 is provided. The aircraft component 10 can, for example, be a component arranged on the outside of an aircraft. The aircraft component 10 can be painted for the first time or treated for repainting. The aircraft component 10 can undergo a pre-treatment (e.g. cleaning, grinding and the like).

In the second step S12, a first paint structure can be applied as a substrate 12 to the aircraft component. The paint structure can contain different layers, for example adhesion promoter, primer or other functional layers (e.g. corrosion and/or erosion protection). In addition, a further layer 14 can be applied to the substrate 12 to improve the adhesion of further layers. It can be applied in the usual way by rolling, brushing or spraying.

In the third step S14, a liquid film-forming masking agent 16 is printed. The printing is done by an ink jet print head. The masking agent 16 can be a spray film liquid, a functional printing ink, or a mold release agent.

The masking agent 16 forms a closed masking film 18 in that the solvent from the masking agent 16 evaporates. It is also possible that the masking means 16 forms the masking film 18 only through activation, for example through UV light or heat. The masking film 18 rests against the surface or only minimally adheres to the surface, but does not form a bond. This results in good detachability of the masking film 18 from the underlying layer.

In the fourth step S16, customary top coats can be applied as coating material 20 in a manner known per se. These can preferably be color-imparting, for example to produce a desired logo. It can additionally a top coat layer 22 (usually clear coat) can also be applied to the coating composition 20. The paint 20 and/or the top coat layer 22 can help to detach the masking film 18 in the further process.

In the fifth step S18, the masking film 18 is removed mechanically, for example peeled off, as a result of which the masked surface area 24 is uncovered.

2 and 3 FIG. 1 shows schematically a printing device 26 which can be used for the method described above. The printing device 26 comprises a robotic arm 28 at the end of which a print head 30 is attached. The print head 30 is designed as an inkjet print head 32 and, depending on the type of ink, can have an activation unit 34 for activating or curing the printed functional printing ink. The printing device 26 also has a reservoir 36 which contains the functional printing ink or the masking agent 16 .

How closer out 3 it can be seen that the print head 30 traces a predetermined masking path 38 on the aircraft component 10 in order to mask the surface area 24, for example in an elliptical shape. The targeted application masks the surface area 24 sharply, resulting in a clear contour after removal.

Further, the printing device 26 may include a masking film removing device 40 . The masking film removal device 40 can grasp the masking film 18 and mechanically remove it from the aircraft component 10 . Depending on the type of mechanical removal, the masking film removal device 40 may include a laser, knife, compressed air nozzle, gripper, suction cup, suction tube, water jet or high-pressure water jet device, brush, and/or rubbing or erasing device .

4 Figure 12 is a photograph of applicant's attempted peeling. The masking film 18 was applied to a white base coat layer 42 and then covered with a clear coat. The masking film 18 was then successfully peeled off manually from the base coat layer 42 between two predetermined separating lines 44 .

In order to improve the complex painting process of large three-dimensionally shaped components, preferably aircraft components, it is proposed to automate the masking step. This can be achieved by ink jet printing a masking agent onto the component forming a masking film. The masking film masks the desired surface area and can be removed after painting is complete. Spray foils, functional printing inks or mold release agents are preferably used as masking agents.

Reference list:

10

aircraft component

12

underground

14

another layer

16

masking agent

18

masking film

20

varnishing agent

22

topcoat layer

24

surface area

26

printing device

28

robotic arm

30

printhead

32

inkjet printhead

34

activation unit

36

reservoir

38

masking path

40

masking film removing device

42

base coat layer

44

parting line

Claims (9)

Painting method for painting a component, preferably an aircraft component (10), with the steps: 1.1 providing the component (10); 1.2 regional application of a film-forming masking agent (16) by printing the masking agent (16) by means of a print head (30) onto the component (10) in order to create at least one masked surface area (24); 1.3 allowing or forming a masking film (18) from the masking agent (16); 1.4 painting the component (10) with a painting agent (20); and 1.5 Removing the masking film (18) from the component (10) to expose the masked surface area (24). Method according to claim 1, wherein in step 1.1 the component (10) is or will be provided with a substrate (12). Method according to one of the preceding claims, wherein in step 1.1 a further layer (14) is applied to the component material or to the substrate (12). A method as claimed in any one of the preceding claims, wherein the masking agent (16) printed in step 1.2 is a liquid film-forming masking agent (16), preferably a spray foil liquid, a printing ink or a liquid mold release agent. The method according to any one of the preceding claims, wherein in step 1.3 the masking film (18) by evaporating solvent from the masking means (16) or by activating the masking means (16) by heating or by irradiation. A method according to any one of the preceding claims, wherein in step 1.5 the masking film (18) is removed by mechanical removal. Method according to one of the preceding claims, wherein in step 1.5 a topcoat layer (22) is applied to reduce the adhesion of the masking film (18) and then the masking film (18) is detached from the component by mechanical removal Printing device (26) for printing components, preferably aircraft components (10), the printing device having a print head (30) which can be moved relative to the component (10) and a reservoir (34) which is fluidly connected to the print head (30) and which holds the print head (30) supplied with material to be printed, the reservoir (34) containing a liquid masking agent (16), preferably a spray foil liquid, a printing ink or a liquid mold release agent. Use of a printing device (30) according to Claim 8 in carrying out a painting method according to one of Claims 1 to 7.

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