EP0993874B1 - Process for transfering a decoration to an object - Google Patents

Description

The invention relates to a method for transferring a color decoration to an object using a liquid on which the color decoration floats and in which the object is pressed in order to transfer the color decoration to the object.

From US-A-4,010,057 (corresponding to DE-A-25 34 640) such a method and a corresponding device are known.

US-A-4,348,246 describes a similar transfer printing technique in which the film with the decoration to be transferred is placed on a layer of granules which is so fine-grained that the decoration can be transferred to the curved surface of the object to be printed.

US-A-4,388,866 also describes a similar transfer printing in which the film with the decoration to be transferred is placed on a deformable layer of pins which are adaptable to the shape of the body to be printed.

US-A-4,436,571 discloses a transfer printing of the type mentioned in which the article to be printed is immersed in a certain way in the liquid with the decoration floating thereon, namely in a continuous movement obliquely downward in the direction of the flow and then obliquely above, also in the direction of the flow of the liquid.

US-A-4,229,239 describes for the aforementioned transfer printing technique a special embodiment in which the decor Prepared before transfer by means of a solvent, so that it dissolves easily from the support film.

US-A-4,407,881 (corresponding to DE-A-32 19 992) describes for the aforementioned transfer printing a particular embodiment of the support film, which has a hydrophilic, deformable layer which can swell by absorbing water, and a further layer, the is placed over the hydrophilic layer and which is different permeable to water, so that the hydrophilic layer expands more or less strongly.

US-A-4,231,829 describes a development of the aforementioned transfer printing technique to the effect that the decor on the liquid supporting PVA film or the water itself boric acid or a salt thereof is added to promote the transfer process.

Also US-A-4,269,650 describes the addition of a solvent to facilitate the release of the decoration from the supporting film.

In transfer printing, the colored decoration (also called printing pattern = printing pattern) on a film that supports the decor, applied to a water surface and there widened (stretched) and / or compressed (compressed). The prior art, for this expansion of the floating support film with décor, recognizes air blowers disposed over the film with décor to expand and / or compress the décor with the film by means of air flow, i. in certain directions, depending on the shape of the object to be printed, expand and optionally compress in other directions.

• EP 96 117 502.3, EP 96 117 501.5 und EP 96 118 791.1.

The following European patent applications are also presumed to be known and their content is expressly incorporated herein by reference.

• EP 96 117 502.3, EP 96 117 501.5 and EP 96 118 791.1.

In the dipping technique discussed above, a film of polyvinyl alcohol (PVA) is commonly used as the water-soluble carrier film.

The PVA film is relatively expensive and is largely lost in the process. The prior art also requires relatively thick (PVA) films to allow the color decoration to be printed in good quality and with the requisite stability. Another problem is that the PVA films are hygroscopic.

The invention aims to improve the above-described method for transferring a color decoration to an object in that relatively thin films for supporting the color decoration on the liquid surface can be used, further that the support film is faster in the liquid, such as. As water dissolves and the storage of the components used in the process is simplified.

• a) Aufbringen des Farbdekors auf einen ersten Träger mit "Release"-Eigenschaft,
• b) Übertragen des Farbdekors vom ersten Träger auf einen zweiten Träger,
• c) Anordnen des zweiten Trägers mit dem Farbdekor auf einer Flüssigkeit, und
• d) Eindrücken des Gegenstandes in das auf der Flüssigkeit schwimmende Farbdekor, um das Farbdekor auf den Gegenstand zu übertragen.

The invention achieves these goals with the following steps:

• a) applying the color decoration to a first carrier with "release" property,
• b) transferring the color decoration from the first carrier to a second carrier,
• c) arranging the second carrier with the color decoration on a liquid, and
• d) pushing the article into the color decoration floating on the liquid to transfer the color decoration to the article.

By using the first and second carriers, it is possible to optimize the carriers for their respective tasks. The first Carrier is chosen from a material that is easy to print on. Furthermore, the first carrier is chosen so that the color decoration applied to it can be transferred to a second carrier in a simple manner, the second carrier having properties that make it particularly suitable for floating on a liquid surface and thus required in the immersion technique described above Properties, such as in particular the ability to dissolve from the color decoration in the liquid, in particular by dissolution in the liquid itself. The term "dissolution in the liquid" is not to be understood in the narrower chemical sense, but physically so that the material of the carrier film in the liquid or even after the removal of the article from the liquid detaches from the color decoration.

In order to allow easy and complete transfer of the color decoration from the first carrier to the second carrier, the first carrier is chosen to have a so-called "release" characteristic.

Carriers with "release" properties are known as such (cf EP 0 573 676 A1). As a sheet carrier with "release" properties are in particular certain papers or plastic films that are designed or prepared on its surface that under certain conditions applied paint layers or paint layers in the manner of a "peeling off" (such as a decal) can be transferred to a substrate. For the present invention, plastic films, such as, in particular, polyester films, which have a suitable release layer in order to achieve the "release" (Abpell) property, are particularly suitable as carriers with "release" property.

For the second carrier, which floats on the liquid, in particular water, when the object to be decorated is pressed into the color decoration, in particular PVA is considered as a material, but in comparison with the prior art very thin PVA films can be used , It follows the further advantage that the film is faster in the liquid dissolves and also the hygroscopic properties of the film are less critical.

According to a preferred embodiment, it is provided that after the above step b) a paint layer is applied to the color decoration. In particular, it is provided that the lacquer layer consists of a lacquer which is suitable for priming the article to be decorated. A further preferred embodiment provides that the lacquer layer contains color.

Figur 1

schematisch das Ergebnis eines ersten Verfahrensschrittes, bei dem ein Farbdekor auf einen ersten Träger mit "Release"-Eigenschaft aufgetragen wird;

Figur 2

das Ergebnis eines weiteren Verfahrensschrittes, bei dem das Farbdekor vom ersten Träger auf einen zweiten Träger übertragen wird;

Figur 3

schematisch die Anordnung des zweiten Trägers mit Farbdekor auf einer Flüssigkeitsoberfläche und das Eintauchen des zu dekorierenden Gegenstandes; und

Figur 4

eine Variante des Verfahrens gemäß den Figuren 1 bis 3, bei der eine Lackschicht über dem Farbdekor aufgetragen wird.

Hereinafter, embodiments of the invention will be described with reference to the drawings. It shows:

FIG. 1

schematically the result of a first process step, in which a color decoration is applied to a first carrier with "release"property;

FIG. 2

the result of a further process step, in which the color decoration is transferred from the first carrier to a second carrier;

FIG. 3

schematically the arrangement of the second carrier with color decoration on a liquid surface and the immersion of the object to be decorated; and

FIG. 4

a variant of the method according to Figures 1 to 3, in which a lacquer layer is applied over the color decor.

First, a first carrier 10 is printed with a color decor 12. The first carrier 10 is in the illustrated embodiment of a polyester film that is well printable and has the explained "release" property. The color decor 12 is preferably made of diffusible dyes that can diffuse in paint and / or plastic, especially when heating the paint or the plastic.

Thereafter, according to a first embodiment, the color decoration 12 is transferred from the first carrier 10 to a second carrier 14. The transfer takes place by means of the "Release" property of the first carrier, i. H. the color decoration 12 peels in the manner of a decal from the first carrier 10 onto the second carrier 14.

The second carrier 14 is in the embodiment of polyvinyl alcohol (PVA).

Thereafter, the second carrier film 14 is placed with the overlying color decoration 12 on a liquid 18, which is arranged in a container 16. This so-called "dip tank technique" (ie immersion technology) is known as such in the prior art mentioned above and therefore does not need to be explained in more detail here for the person skilled in the art. Accordingly, the second carrier 14 floats on the surface 20 of the liquid 18 with the color decoration 12 lying thereon. An object 22 to be decorated is pressed in the direction of the arrow 24 into the color decoration 12 and thus also into the liquid 18, the static pressure of the liquid Color decorative layer against the object 22 presses, so that the color decoration adheres to the article 22. In this case, the second carrier 14 dissolves in the liquid 18 or is removed at the latest when moving out of the article 22 from the liquid from the article 22. The detachment and separation of the material of the second carrier 14 from the applied on the article 22 color decorative layer 12 is explained in the above-mentioned prior art.

Figure 4 illustrates a second embodiment, which differs from the above-described embodiment of Figures 1 to 3 characterized in that after the transfer of the color decoration 12 on the second carrier 14, ie in the state, Figure 2, a lacquer layer 26 on the color decoration 12 is applied (Figure 4). Thereafter, the second carrier 14 is then deposited with the overlying color decoration 12 and the paint layer 26 applied above according to the first embodiment on the surface 20 of the liquid 18 and the immersion process of the object 22 to be decorated is analogous to the above explained with reference to FIG 3 embodiment. Accordingly, then the lacquer layer 26 is at the bottom on the object 22 and the color decoration 12 on the lacquer layer 26th

The lacquer layer 26 serves as a base lacquer on the object 22. The lacquer layer preferably has a base color which dyes the object, eg. For example, when the article 22 is to be decorated in the manner of walnut or the like, a suitable brown is selected as the base color in the paint layer. Then the plastic that makes up the article 22 does not need to be dyed extra. Dyeing of the plastic material of article 22 typically alters its mechanical properties, e.g. the impact resistance can be reduced. Also, the production of colored plastic materials is much more complex than the production of undyed plastic materials. Therefore, in the second illustrated embodiment, the lacquer layer 26 as the base coat gives the article the appropriate color. In the illustrated embodiment, a opaque pigmented basecoat is preferably selected as the material for the lacquer layer 26, which has the same or similar chemical properties, such as in the color decor 12 optionally present binder.

An article 22 decorated in accordance with the exemplary embodiments described above can be provided with further layers via the described paint and varnish layers. Also, additional layers can be applied between the layers mentioned.

If finally a further lacquer layer is applied, it can preferably be cured with electron beam or UV radiation. Other curing techniques are possible (e.g., thermal).

It is also possible to effect a diffusion of the dye molecules of the diffusible disperse dye in the paint by deliberately heating the applied paint layers.

It can be provided that the heating of the upper lacquer layer is performed with a hot gas jet having at least in one direction a dimension (width) which is small compared to the dimension of the color decoration and the lacquer layers in this direction.

It is preferably provided that the hot gas jet is heated to a temperature at which it causes or at least promotes that the dye diffuses into the overlying paint layer. As a result, a very good aesthetic effect of the decorated product is achieved, in particular a certain depth effect of the color. The dye molecules diffuse different distances, depending on the molecular weight, in the overlying paint, which positively affects the visual impression of the decoration.

The adhesion of the layers to one another and also the mechanical properties of the applied paint and dye layers can be promoted according to a further preferred embodiment of the invention in that the gas jet has the shape of a knife when hitting the uppermost lacquer layer and is guided linearly over the lacquer layer. In particular, with this technique, a precisely targeted increase in temperature for a certain period of time can be achieved up to a certain depth of the layers, without the lowermost lacquer layer is increased to the same temperature as the uppermost lacquer layer on the substrate. In this way, the diffusion of the dye molecules can be controlled in a desired manner, namely in particular in the paint layer lying above the dye layer, for which therefore in particular a transparent lacquer or an at least substantially transparent or white lacquer is provided.

In the colored decoration and painting of products, the edge and edge areas of the product are often critical. According to a preferred embodiment of the invention, the quality of the painted decoration is particularly promoted in the edge area, characterized in that the line-shaped hot gas jet (Especially hot air jet) is guided so that it detects the affected edge or the edge of the substrate with the overlying, covering the edge color and lacquer layers, so z. B. acts equally on both surfaces in a right-angled edge.

Claims (7)

1. A method of transferring a coloured decoration onto an object, having at least the following steps:

   a) applying the coloured decoration (12) onto a first support (10) with release properties,

   b) transferring the coloured decoration (12) from the first support (10) onto a second support (14),

   c) arranging the second support (14) with the coloured decoration (12) on a liquid (18), and

   d) pressing the object (22) into the coloured decoration (12) floating on the liquid, in order to transfer the coloured decoration onto the object, wherein the liquid (18) and the material of the second support (14) are selected in such a way that the coloured decoration is released from the second support under the action of the liquid or the second support (14) dissolves in the liquid (18).
2. A method according to claim 1,
   characterised in that
   the second support (14) becomes detached from the coloured decoration (12) in the liquid.
3. A method according to either one of claims 1 or 2,
   characterised in that
   the second support (14) consists of a material which dissolves in the liquid (18) without impairing the coloured decoration (12).
4. A method according to any one of the preceding claims,
   characterised in that
   the second support (14) comprises polyvinyl alcohol (PVA) as a constituent or consists thereof.
5. A method according to any one of the preceding claims,
   characterised in that,
   after step b), a lacquer layer (26) is applied to the coloured decoration (12).
6. A method according to claim 5,
   characterised in that
   the lacquer layer (26) consists of a lacquer suitable for priming the object (22).
7. A method according to either one of claims 5 or 6,
   characterised in that
   the lacquer layer (26) contains colorant.

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