MODULAR COATING UNIT AND METHOD FOR COATING PLASTIC COMPONENTS

Abstract

A method for coating plastic components of a motor vehicle. A modular coating unit is provided having a first coating module for coating at least one workpiece composed of plastic. A second module for the preparation of the coating material may be provided in the coating unit. The completed coating material to be applied is mixed from a base material composed of non-volatile components from a first container, to which solvent or water from a second container and concentrated colour pigments and/or effect pigments from third containers may be admixed in the module for the preparation of the coating materials.

Claims

1. A modular coating unit, comprising: at least one module including a coating module for coating at least one workpiece composed of plastic, and a mixer to admix a coating material that includes a base material composed of non-volatile components from a first container, a solvent or water from a second container, and concentrated colour pigments and/or effect pigments from at least one third container.

2. The modular coating unit of claim 1, wherein the base material from the first container and the solvent or water from the second container are present in a quantitative volume fraction of at least 80% in the coating material to be applied.

3. The modular coating unit of claim 1, wherein the coating material to be applied comprises 10-20% base material.

4. The modular coating unit of claim 3, wherein the coating material to be applied comprises 60-70% solvent/water.

5. The modular coating unit of claim 4, wherein the coating material to be applied comprises 10-30% concentrated colour pigments and/or effect pigments.

6. The modular coating unit of claim 5, wherein the effect pigments comprises metal pigments.

7. The modular coating unit of claim 1, wherein the mixer is configured to access the first container, accesses the second container, and access the at least one third container.

8. The modular coating unit of claim 1, wherein the mixer is in fluidic communication with the coating module.

9. The modular coating unit of claim 1, wherein the mixer is integrated in the coating module.

10. A method for coating a plastic component of a motor vehicle, the method comprising: providing a modular coating unit that includes at least one module including a coating module for coating at least one workpiece composed of plastic, and a mixer to admix a coating material that includes a base material composed of non-volatile components from a first container, a solvent or water from a second container, and concentrated colour pigments and/or effect pigments from at least one third container; producing a completed coating material by mixing in situ, using the mixer, a base material, a solvent or water, and concentrated colour pigments and/or effect pigments.

11. The method of claim 10, further comprising transporting the completed coating material to the coating module.

12. The method of claim 10, wherein mixing in situ, using the mixer, is conducted in the coating module.

13. The method of claim 10, further comprising mixing the completed coating material in a spray mist of the coating module, and simultaneously supplying the completed coating material in a predetermined mixing ratio to at least one spraying head.

14. The method of claim 10, wherein producing the completed coating material comprises admixing paint residues from the at least one third container.

15. The method of claim 10, wherein producing the completed coating material comprises mixing the base material, the solvent or water, and the concentrated colour pigments and/or effect pigments in the coating unit.

16. The method of claim 15, further comprising supplying, in a predetermined mixing ratio, the base material, the solvent or water, and the concentrated colour pigments and/or effect pigments to at least one spraying head.

Description

DRAWINGS

[0028] Embodiments will be illustrated by way of example in the drawings and explained in the description below.

[0029] FIG. 1 illustrates a coating line, schematically, in the prior art.

[0030] FIG. 2 illustrates a schematic representation of a coating unit, in accordance with embodiments.

[0031] FIG. 3 illustrates a schematic representation of a coating unit, in accordance with embodiments.

[0032] FIG. 4 illustrates a schematic diagram of the method, in accordance with embodiments.

[0033] FIG. 5 illustrates an example of a distribution V of the colour pigments over the thickness d of the coating film, in accordance with embodiments.

DESCRIPTION

[0034] As illustrated in FIG. 2, a modular coating unit 1, provides for, instead of using the coating materials in the form of a completed mixture, a preparation module 2 for the preparation of the coating materials, and a coating module 3 that includes a coating apparatus 11 to spray a mist 10 to provide a coating on a workpiece 4. The workpiece 4 comprises, for example, a plastic component of a motor vehicle. The preparation module 2 includes a mixer 8 operatively or otherwise fluidically connected to a first container 7 for a base material, a second container 9 for solvent or water, and also additional containers 6, 6, 6, 6 . . . with concentrated colour pigments and/or effect pigments.

[0035] In accordance with embodiments, the coating material comprises volatile solvents and non-volatile constituents. The solvent, as the volatile constituent, evaporates during the drying process, while the non-volatile constituents adhere in the form of a smooth film on the coated article. The non-volatile components are binders, pigments, oils, resins, fillers and additives. The binder ensures effective and uniform suspension with pigments and solvent in the coating material, and is responsible for optimum drying and for the gloss after drying. The essential basis for a coating material is the binder and solvent. Pigments are not necessary constituents of a coating material.

[0036] For a motor vehicle, around 15 kg of paint is used, as wet weight, resulting in a dry weight of approximately 5 kg. The high proportion of solvent in completed coating materials is evident. By separating the constituents into non-volatile constituents and solvent/water and concentrated colour pigments and/or effect pigments, the handling, the transport and the mixing possibilities of the coating line are optimized.

[0037] In accordance with embodiments, the base material in the first container 7 comprises primarily of the non-volatile constituents, without concentrated colour pigments and/or effect pigments and a large percentage of solvent is useful for the further processing of the base material. Located in the second container 9 is the respective solvent; if a water-based coating mixture is being used, a container may also be considered as a water connection. In this case, the handling of the base material is even more efficient, since there is no longer any solvent that must be transported.

[0038] The containers 6, 6, 6, 6 . . . contain paints with a high colour pigment density or else metal particles of the kind required for metallic finishes. In the mixer 8, the components, the base material, solvent, or water and the concentrated colour pigments and/or effect pigments, are mixed to give the desired coating-material outcome, in the form of completed coating material.

[0039] An advantage here is a mixing ratio of approximately 80% base material plus solvent/water with 20% concentrated colour pigments and/or effect pigments. Of course it would be desirable to employ as much base material plus solvent as possible, as it is less expensive than the colour pigments. It must, however, always still be possible to admix sufficient colour and/or metal particles, in order to achieve the appropriate perceived colour for the entire colour palette which is to be offered. Optimum ranges are 10-20% base material, 60-70% solvent/water and 10-30% concentrated colour pigments and/or metal pigments.

[0040] The completed coating material premixed in the mixer 8 is supplied to the coating apparatus 11, and is applied to the workpiece 4.

[0041] As illustrated in FIG. 3, alternatively to an arrangement illustrated in FIG. 2, it is also possible for the mixing function as mixer 8 to be accommodated directly in the coating apparatus 11, near to or directly in the spraying head. In a continuation of this approach, the three components are mixed without a separate mixer directly in the spray mist 10, a possibility which exists as a result of appropriate design of the nozzles. The spray mist, accordingly, functions itself as mixer.

[0042] As illustrated in FIG. 5, the lines and methods described so far mix base material plus solvent/water and concentrated colour pigments and/or effect pigments virtually homogeneously over the thickness d of the coating film, as shown in the dashed line.

[0043] A further embodiment does not use uniform mixing of the three components in the coating film, but instead constructs the coating film from a mixture of base material plus solvent/water with at least one thin, concentrated colour and/or metal pigment film. This colour film may lie at the surface of the coating film or is integrated into the layers of the base material plus solvent/water.

[0044] For this purpose, the base material plus solvent/water is applied first of all and then a thin film of the concentrated colour and also, optionally, a sequence of basecoat material and colour is applied.

[0045] As illustrated in FIG. 4, a method includes in an initial block 41, providing a film of base material plus solvent/water. Block 42 includes admixing a component composed of concentrated colour and/or metal pigment film to the base material plus solvent/water. Block 43 involves applying the mixture. Accordingly, a uniformly coloured coating is provided.

[0046] Alternatively, the initial block 41 may include applying a film of base material plus solvent/water, followed by the application of a thin film of fully concentrated colour and/or metal pigments, a procedure which can be repeated as desired.

[0047] The result is either a completed coating material mixture, which is maintained homogeneous throughout the coating film, or which extends only to a thin film.

[0048] In accordance with embodiments, it is possible to admix paint residues, comprises colour pigments, to a colour mixture in current use in the completed coating material. Accordingly, for example, black colour pigments of one customer can be admixed at least partially to the black colour pigments of another customer, supplied by a different coatings manufacturer. It is therefore possible to recycle material which would otherwise have to be removed or thrown away.

[0049] The term coupled, or attached, or connected may be used herein to refer to any type of relationship, direct or indirect, between the components in question, and may apply to electrical, mechanical, fluid, optical, electromagnetic, electromechanical or other connections. In addition, the terms first, second, etc. are used herein only to facilitate discussion, and carry no particular temporal or chronological significance unless otherwise indicated.

[0050] This written description uses examples to disclose the invention, including the preferred embodiments, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of embodiments is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. Aspects from the various embodiments described, as well as other known equivalents for each such aspects, may be mixed and matched by one of ordinary skill in the art to construct additional embodiments and techniques in accordance with principles of this application

LIST OF REFERENCE SYMBOLS

[0051] 1 modular coating unit [0052] 2 module for the preparation of the coating materials [0053] 3 coating module [0054] 4 workpiece [0055] 5 container, coating materials [0056] 6 third container, concentrates [0057] 7 second container, base material [0058] 8 paint mixer [0059] 9 second container, solvent [0060] 10 coating mist [0061] 11 coating apparatus