EP3167957A1 - Modular coating unit and method for coating plastic components - Google Patents

Abstract

A paint system comprising a provision (1) of the paints, at least one painting device (3) for painting a workpiece (4) is proposed, the paint applied by the painting device (3) consisting of a base material (B) consisting of a container (7), the color pigments and / or effect pigments from containers (6, 6 ', ...) are immiscible.

Description

The invention relates to a modular coating unit for painting plastic components, according to the preamble of claim 1. Furthermore, the invention relates to a method for painting plastic components.

State of the art

In addition to the shape and the technical equipment, an impeccable finish is an important aspect when buying a vehicle. The paintwork should be immaculate and must do a lot from the corrosion protection of the body to the protection against mechanical and harmful weather conditions. When it comes to painting a series of different technologies are used, which in their interaction make only a car painting perfect and cause the body is optimally protected, looks shiny and long-term to the value of the vehicle.

As a rule, a car series paint today consists of four layers, which are applied in several operations with different methods. First, the degreased and cleaned body is provided by means of an electrochemical painting system into each cavity with a closed paint film. This cathodic dip coating, KTL for short, is the basis for comprehensive corrosion protection. Here, the cathodic, ie negatively charged body is driven through an aqueous, conductive dip paint, in which the positively charged paint particles adhere to the body and form a closed and uniform coating.

Then follows the order of the so-called filler, who has to fulfill several tasks. In addition to the protection against stone chipping it resembles minor bumps on the surface, she fills up, so to speak. He also ensures that the subsequent topcoat can adhere better.
Only now gets the body with the so-called base coat their color. In the automotive plants, painting robots spray the complete body in the respective current colors. These today water-based paint systems may contain effect pigments or - as in the case of a metallic paint - aluminum platelets. Launching is the spraying of a colorless clearcoat. The clear coat has the function of protecting the coloring coating against external influences such as UV radiation, organic or chemical soiling or other damage.
With these four steps, the bodywork is complete. Only then are exterior and interior accessories such as exterior mirrors or bumpers mounted. They are usually made of plastic and are painted separately. Despite the different substrates and production conditions, the colors must match those of the body.

In paint shops for plastic components for the automotive industry, premixed mixed paints are used by paint suppliers, whereby the paints are mixed according to the specifications of the paint shop and the specification of the raw material manufacturer and the end customer at the manufacturer. The vote in new series starts is carried out directly to Farbmustervorgaben and Lackieranlagenanforderungen and is therefore very complicated and costly, since only relatively small batch production be carried out and a large range of colors must be prepared and stored.

This results in a batch production of small and / or very small amounts to very large storage of different small containers with different paints. The paints are available as finished mixtures and there is no possibility of adjustment after receipt of approved color pattern and no opportunities for repair at the slightest deviations in color. For the supplier The plastic parts that are to be delivered painted, there is thus the problem that he stock all the colors of all customers and in case of problems always approach the paint supplier.
From the DE102008053178A1 a method of coating is known in which primary colors in the spray or on the painted surface are to be mixed to the final result. However, this color preparations are used, which are already premixed ready. The color mixture of the primary colors is not easy and is not used in practice so.

It is therefore an object of the invention to obtain a cost-effective coating of plastic components with more flexible adjustment and intervention options in the field of paint processing, as well as the color of Lackiermaterialien.

The invention pursues the idea of self-responsible mixing and packaging of different components in situ in the paint shop to a finished paint mixture and their use.

The object is achieved with a modular coating unit with at least one module as Lackiermodul for painting at least one workpiece made of plastic, and a mixer, wherein at least one module for the preparation of the paints for painting in the painting is present, the applied finish from a Base material is mixed from non-volatile components from a first container, in the module for the preparation of the coatings, solvent or water from a second container and concentrated color pigments and / or effect pigments from third containers are admixed.

It is advantageous that the finished paint is based on base material, which can be made very low and transportable has a small volume and the other properties, for example, the final color are added only and be coordinated only on site by the painter himself. Also simplified by the late mixing of the solvent or water, the handling of the material and, especially when using water, the transport volume reduced overall.

Advantageously, the finished paint of base material from the first container (8) and solvent or water (L) from the second container (9) in a volume fraction of at least 80%. Thus, a very cheap base material can be used by the paint manufacturer, which on different shades or properties of the finished coating can be the same and the final final vote is then achieved by an admixture of solvent or water and concentrated color pigments and / or effect pigments in the coating unit.
This results in several advantages, which are mainly in a cost optimization, but also in processing benefits, as this intervention options of the processor to the paint shop itself be extended.

It is advantageous if the mixer accesses the first container for base material, second container with solvent or water and the respective third container for concentrated color pigments and / or effect pigments (P).

Advantageously, the mixer communicates with the painting device, wherein it is also possible for the mixer to be integrated in the painting device.

The process according to the invention for the coating of plastic components with a modular coating unit provides that the finished finish used is mixed in situ in the coating unit from a base material, solvent or water and concentrated color pigments and / or effect pigments.

It is advantageous that the finished paint is mixed in a mixer in the module for the preparation of the paints and transported as a finish to the coating unit.

Alternatively, it is also possible that the paint is mixed in a mixer in the coating unit.
Even without an upstream mixer, it is advantageous if the finished paint is mixed in the spray of Lackiereinheit by the components are fed simultaneously in the correct mixing ratio to at least one spray head. The spray mist should be considered as a mixer.

The method has the further advantage that the paint is not premixed, but the components are applied successively in the correct application time.
Depending on the coating system concept, the application of the different components can take place without real mixing. In this case, a kind of pre-painting with the first robots or painting elements of the favorable base coat takes place and the final color tone adjustment takes place at the end by the application of the concentrate.

Dark colors and multi-layer paints and metallic applications can be produced more cheaply. In the case of metallic paints, for example, a pre-painting can be carried out without the aluminum or metal flakes and the cost-intensive component of the metallic paints is applied only as a small, thin layer on the basecoat.
The paints are purely evaporation-curing paints, ie one-component systems, not two-component systems with chemical reaction hardening.

Description of the invention

• Fig. 1 zeigt eine Lackieranlage schematisch im Stand der Technik.
• Fig. 2 und Fig. 3 zeigen jeweils eine schematische Darstellung einer beispielhaften Ausführungsform der Lackiereinheit
• Fig. 4 zeigt einen schematischen Verfahrensablauf.
• Fig. 5 zeigt die Verteilung der Farbpigmente in der Lackschicht exemplarisch.

The invention will now be described by way of example with reference to the accompanying drawings.

• Fig. 1 shows a painting system schematically in the prior art.
• Fig. 2 and Fig. 3 each show a schematic representation of an exemplary embodiment of the painting
• Fig. 4 shows a schematic process flow.
• Fig. 5 shows the distribution of the color pigments in the lacquer layer by way of example.

In FIG. 1 a conventional painting plant is shown, as used for example for the painting of exterior components in the automotive industry. It is initially irrelevant whether metal components or plastic components are painted. The paint shop has a Lackiermodul and consists mainly of a painting device 11, which can spray paint mist 10 with a robot or a permanently attached device on a workpiece 4. The painting device 11 is a spray gun on a robot arm or a spray head of a Lackierbrücke. Of course, a module is only an example. It can be used in parallel or successively a plurality of Lackiermodulen.

The paint sprayed by the spray gun or the painting bridge is covered by a container for paints 5. These containers contain ready-to-use lacquers, which are delivered ready-mixed by the paint manufacturer.
The painting device can be connected to all containers for the paint 5 to be used. If, for example, bumpers are painted, the respective colors from the respective containers are used and exchanged for a respective group or individual workpieces.

The paints are finished mixed provided by the manufacturer. This results in large volumes of stockpiled finished paints, since each customer calls for his own red, his own black and so on.

In FIG. 2 is a first variant of the solution according to the invention to see. Instead of using the lacquers as a finished mixture, a mixer 8 is used in a module for the preparation of lacquers 2. This mixer 8 is connected to a container 7 for a base material B and to a container 9 for solvent or water and also has connections to containers 6, 6 ', 6 ", 6"' with concentrated color pigments and / or effect pigments ,

A paint consists of volatile solvents and non-volatile components. The solvent as the volatile component vaporizes during the drying process, the non-volatile components adhere as a smooth film on the painted object. The non-volatile components are binders, pigments, oils, resins, fillers and additives. The binder provides a good, uniform suspension with pigments and solvent in the paint, is responsible for an optimal drying process and the gloss after drying. The essential basis of a paint is the binder and solvent. Pigments are not necessary components of a paint.

For a vehicle, around 15 kg of wet weight is used, resulting in approximately 5 kg of dry weight. One recognizes the high proportion of solvent in finished paints. The separation of the constituents into non-volatile constituents and solvent / water and concentrated color pigments and / or effect pigments optimizes the handling, transport and mixing possibilities of the paint shop.
The base material in the first container 7 consists mainly of the non-volatile constituents without concentrated color pigments and / or effect pigments, wherein a small percentage of solvent is useful for the further processing of the base material.
In the third container 9 is the respective solvent, we used a water-based paint mixture, the container 3 is also used as a water connection consider. In this case, the handling of the base material is even more efficient, since no solvent needs to be transported.

The second container 6 ... contain colors with a high color pigment density or metal particles, as they are needed for metallic finishes. In the mixer 8, the components, the base material, solvent or water and the concentrated color pigments and / or effect pigments are mixed to obtain the desired paint result as a finished finish.

A mixing ratio of approximately 80% base material + solvent / water with 20% concentrated color pigments and / or effect pigments is advantageous. Of course, one would like to use a lot of base material + solvent that is less expensive than the color pigments. However, it must still be possible to mix sufficient color and / or metal particles to achieve the appropriate color impression for the entire color palette to be offered.

Optimal is a range of 10-20% base material, 60-70% solvent / water, 10-30% concentrated color and / or metal pigments.

The pre-mixed in the mixer 8 finished paint is supplied to the painting device 11 and applied to the workpiece 4.

As an alternative to such an arrangement, it is also possible to accommodate the mixing function as a mixer 8 directly in the painting device 11, close or directly in the spray head, which is in FIG. 3 is shown.

In a continuation of this approach, the three components without a separate mixer are mixed directly in the spray 10, which is possible by suitable design of the nozzles. Thus, the spray itself acts as a mixer.

The systems and methods described so far mix base material + solvent / water and concentrated color pigments and / or effect pigments almost homogeneously over the thickness d of the lacquer layer, as in the dashed line of FIG FIG. 5 shown. FIG. 5 shows the distribution V of the color pigments over the thickness d of the lacquer layer.

Another embodiment does not use a uniform mixture of the three components in the lacquer layer but builds up the lacquer layer from a mixture of base material + solvent / water with at least one thin concentrated color and / or metal pigment layer. This color layer can be on the surface of the lacquer layer or is integrated in the layers of the base material + solvent / water.

For this purpose, first the base material + solvent / water is applied and then applied a thin layer of the concentrated color and optionally again a series of basecoat and paint.

In FIG. 4 a process schematic is shown. In a first step 41, a layer of base material + solvent / water is provided for the painting device. The component of concentrated color and / or metal pigment layer is mixed in a further step 42 to the base material + solvent / water and in step 43, the mixture is applied. For a uniformly colored coating is possible.

Alternatively, the first step is to apply a layer of base material + solvent / water followed by application of a thin layer of concentrated color and / or metal pigments, which may be repeated as desired.

The result is either a finished paint mixture that is homogeneously maintained throughout the paint layer, or extends only to a thin layer S.

With the method according to the invention is an admixture of color residues, consisting of color pigments to a currently used color mixture in the finished paint possible. Thus, e.g. black color pigments of one customer, to the black color pigments of another customer, supplied by another paint manufacturer at least partially immiscible.

This material can be recycled, which would otherwise be disposed of.

LIST OF REFERENCE NUMBERS

1

Modular painting unit

2

Module for the preparation of paints

3

coating module

4

workpiece

5

Container paints

6

third container concentrates

7

second container base material

8th

color mixer

9

second container solvent

10

spraying paint

11

painter

41-43

steps

d

thickness

V

distribution

S

layer

B

base material

L

Solvent / water

P

concentrated color and / or metal pigments

Claims (13)

Modular painting unit (1) with at least one module as a painting module (3) for painting at least one workpiece (4) made of plastic, and a mixer (8), characterized in that at least one module (2) for the preparation of one-component paints for the paint finish in the painting unit (1) is present, wherein the applied finish is mixed from a base material (B) of non-volatile components from a first container (7), in the module (2) for the preparation of the paint solvent or water (L ) from a second container (9) and concentrated color pigments and / or effect pigments (P) from third containers (6, 6 ', 6 "...) are immiscible. Modular painting unit (1) according to claim 1, characterized in that the applied finished paint in a mixer (8) of base material (B) with solvent or water (L) from a second container (9) and concentrated color pigments and / or effect pigments (P ) from third containers (6, 6 ', 6 "...) is mixed. Modular coating unit according to claim 1 or 2, characterized in that the base material B from the first container (8) and solvent or water (L) from the second container (9) is present in a volume fraction of at least 80% in the applied finish. Modular coating unit according to claim 1 or 2, characterized in that 10-20% of base material, 60-70% solvent / water, 10-30% of concentrated color and / or metal pigments is present in the applied finish. Modular coating unit according to any one of the preceding claims, characterized in that the mixer (8) acts on the first container for base material (7), on second containers with solvent or water and the respective third ones Container (6) for concentrated color pigments and / or effect pigments (P) accesses. Modular painting unit according to one of the preceding claims, characterized in that the mixer (8) is in communication with the painting device (11). Modular coating unit according to one of the preceding claims, characterized in that the mixer (8) is implemented integrated in the painting device (11). Process for the coating of plastic components with a modular coating unit according to the preceding claims, characterized in that the used finish of a base material, solvent or water and concentrated color pigments and / or effect pigments (P) is mixed in situ in the coating unit. A method according to claim 8, characterized in that the paint is mixed in a mixer (8) in the module (2) for the preparation of the paints and transported as a finish to the painting unit (11). A method according to claim 8, characterized in that the paint is mixed in a mixer (8) in the coating unit (11). A method according to claim 8, characterized in that the finished paint in the spray (10) of the coating unit (11) is mixed by the components are supplied simultaneously in the correct mixing ratio to at least one spray head. A method according to claim 8, characterized in that for the production of the finished paint paint residues from individual third containers are admixed in small proportions for recycling. A method according to claim 8, characterized in that the finished paint with the painting unit (11) is mixed by the components are staggered in time in the correct mixing ratio supplied to at least one spray head.

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