EP0011867A1 - Process for reproducing oil paintings or the like - Google Patents

Abstract

A process for the reproduction of oil painting and the like, having a relief surface, using a relief mold taken from the original and a thermoplastic foil, imprinted with a color picture corresponding to the original, the foil being molded while being heated and which includes placing the foil upon the relief mold in a fitting alignment and heating the foil essentially homogeneously to its liquefying temperature across its entire surface.

Description

The invention relates to a method for the reproduction of oil paintings and the like with a relief surface using a relief mold removed from the original and a thermoplastic film printed with the original color image, which is deformed under heating.

For the reproduction of oil paintings, for example, copying is the first option. However, good copies require a great deal of expertise and a great deal of time, so that they are expensive and cannot meet the increasing demand with home decor in their quantity. In contrast, the high fidelity in color and open results Solution developed multicolor art print inexpensive replicas, but there is the disadvantage that the relief-like spatial form of the original is missing, which is also an expression of the artist in an oil painting or a similar work of art and is recognized as such even by a layperson.

To solve this problem, DE-PS 494 894, FR-PS 15 21 466, DE-AS 20 19 699 and DE-OS 2 352 966 specified methods in which a true-to-original multi-color print on the image side a transparent layer of gelatin or plastic is applied, which is given the relief design of the original surface by means of a shape removed from the original before or after application. Although this emulates the relief-like surface design of the transparent layer, it does not give the same impression as the original, since it is not formed by the color as in the original, so that the effect of the surface formed by the transparent layer is extremely strong from the viewing angle dependent on lighting and the like.

nach der Wiedererhärten die Oberflachenform des Originals. Das gemäß der FR-PS 15 48 337 entspricht diesem bekannten Verfahren mit der Ausnahme, daß die bedruckte Folie durch Bestrahlung mit Infrarotlicht anstelle der Kontakterwärmung mittels einer Polystyrolfolie erwärmt wird und die Formung allein durch _Un-terdruck unterhalb der Reliefform erfolgt. Gegenüber den bei den vorangehend genannten Verfahren erzielten durchsichtigen Reliefoberflächenschichten stellt die sich ergebende farbige Reliefoberfläche der Folie eine Verbesserung dar. Da jedoch bei beiden Verfahren zur Formung der Folie beträchtliche Druckkräfte an derselben wirken, die bei dem ersteren bekannten Verfahren beispielsweise mit 7 kg/cm angegeben sind, muß die Folie zwangsläufig eine bestimmte Dicke haben. Dies führt wiederum dazu, daß feine Reliefgestaltungen nicht mit ausreichender Originalgetreue reproduzierbar sind. Bei manchen Originalen mag dies zwar nicht von großer Bedeutung sein, jedoch ergibt sich beispielsweise bei der feinen Maltechnik des Manierismus vornehmlich der Münchner Schule eine merkliche Abweichung vom Original.These shortcomings are eliminated in the method according to the preamble of claim 1, which are described in FR-PS 14 93 516 and FR-PS 15 48 337. According to FR-PS 14 93 516, the relief shape with ventilation through holes will be given away. The printed film, over which a thick polystyrene film is attached, is then placed over the relief shape with a registration. The thick polystyrene film is heated to the softening temperature of the printing film. Then, by means of negative pressure below the relief mold and / or positive pressure above the polystyrene film, the latter is pressed together with the printing film into the depressions in the relief form. This gives the

after re-hardening the surface shape of the original. The according to the FR-PS 15 48 337 corresponding to this known method with the exception that the printed film in place by irradiation with infrared light the contact heating is heated by means of a polystyrene film and carried out the forming solely by _U n-terdruck below the relief mold. The resulting colored relief surface of the film is an improvement over the transparent relief surface layers obtained in the above-mentioned processes. However, since both processes for forming the film have considerable compressive forces acting on it, which in the former known process are given as 7 kg / cm, for example are, the film must have a certain thickness. This in turn means that fine relief designs cannot be reproduced with sufficient original fidelity. For some originals this may not be of great importance, but for example the Munich School's fine painting technique of mannerism results in a noticeable deviation from the original.

The invention has for its object to provide a method according to the preamble of claim 1, which produces inexpensive reproductions with the highest original fidelity.

This object is achieved with the measures mentioned in the characterizing part of claim 1.

Due to the homogeneous heating of the printed film to the flow temperature over its thickness or thickness, the film is melted into the depressions of the relief forms Da during this melting process is deformed essentially by its own weight and therefore no strong forces have to be exerted on it, especially in the flowing state, the film can be very thin, so that even barely perceptible surface shapes are faithfully reproduced. Another advantage of the use of a very thin film that is thus made possible is that, due to the very low heat capacity, the inks used for printing are exposed to heating for a much shorter time, so that the risk of color falsification is reduced. This also results in a faster work cycle, since the times for heating and cooling are shorter. Another advantage of the method according to the invention is that the relief shape used can be produced extremely simply. Only in very special cases could it be necessary to make microscopic openings for the release of air pockets under the melting film.

A particular advantage results from the fact that a support layer is applied to the back of the film when the film is formed. The support layer is preferably heated in the same way as the film over its thickness essentially homogeneously to the flow temperature of its flowable component, so that it flows together with the film to the relief form and thus forms a solid background as soon as the film through Relief form given structure. A fabric embedded in polyvinyl chloride is preferably used as the supporting film, canvas being used as the carrier material for the reproduction of the reproduction as true to the original as possible, which is impregnated with the polyvinyl chloride. In this case, the film and the polyvinyl chloride layer are heated essentially homogeneously. on the other hand, the film flows into the contours of the relief shape, which is supported by the flow of the polyvinyl chloride.

Since air inclusions could form when the film sinks to the relief shape quite suddenly due to the heating, it is advantageous to apply the heat from the center of the film to the edges.

The heating methods for the film or for the film in addition to the support layer applied are in particular the following: heating by means of a high-frequency field, heating by means of infrared radiation and heating by means of contact heating with an elastic support element. Compared to the upper or lower pressures used according to the previous techniques, this does not result in any change insofar as the formation corresponding to the relief shape is not impaired by the generation of the flow state in the film or in the film together with the support layer, since ultimately both Foil as well as the possibly attached support layer is not directly exposed to pressure and thus can take on the shape of the relief shape "unaffected".

The essentially homogeneous heating of the film and also of the film together with the support layer can be carried out by heating by high-frequency energy in a dielectric manner in a high-frequency field, by heating with infrared rays suitably chosen with regard to the wavelength, or by contact heating by means of a pad sufficiently high thermal conductivity, there is a sudden heating of the film or the film in addition to the support layer.

Although the originals in question, and thus the relief shapes they remove from the surface, are usually rough enough to allow air under the melting film to escape laterally, it is advantageous to start the heating from the center and proceed to the edge.

As an advantageous embodiment of the method, the relief shape used is galvanized at least on its shaping surface. So that the dimensional accuracy is ensured even at a high eproduktionsstückzahl _R. Furthermore, the surface metallization on the incoming, melting film results in good and rapid heat dissipation, so that the film quickly assumes the correct final shape and is also easily detachable from the relief shape due to the quenching. Depending on the particular surface shape, the relief shape can optionally be made porous and / or provided with holes, even in the case of galvanic metallization.

In order to avoid excessive exposure to heat on the colors used for printing on the film, the film is preferably placed with the printed side down on the relief mold. This quickly cools the layer of paint from the relief shape when it reaches it. For this purpose, the relief shape can also advantageously be additionally cooled.

• Die Fig. 1 zeigt ein Ausführungsbeispiel für das Verfahren zur Formung allein der Folie.
• _Fig. 2 zeigt ein Ausführungsbeispiel für das Verfahren bei gleichzeitiger Formung der Folie sowie Überlagerung der Folie mit einem Stützmaterial.

The invention is explained below using exemplary embodiments with reference to the drawing.

• Fig. 1 shows an embodiment for the method for forming the film alone.
• _F ig. 2 shows an exemplary embodiment of the method with simultaneous shaping of the film and overlaying the film with a support material.

According to FIG. 1, a thermoplastic film 2 printed with the color image corresponding to the original is placed with the image side 3 down over a relief mold 1 which reproduces the surface design of an original oil painting or the like as a negative form. The relief shape is produced by known methods. for example, a negative hard casting can be made from the original oil painting using polyester resin. In this process, however, small damage can occur, so that the artist must give his consent and, if necessary, restore the original. Therefore, if the oil painting is a valuable original from an old master, this casting process cannot be used. In such a case, therefore, an extremely careful copy must be used, which is necessarily expensive, but the costs of which are spread over a large number of copies of the reproduction, so that they are not significant. Another way out in such a case is to scan the original by means of a laser beam and transfer it photochemically to a gelatin matrix or the like. This is then implemented by pouring into a hard die or into a hard casting. A metal layer 4 is applied galvanically to the molding surface of the polyester hard die produced in this way.

A particularly advantageous production of the relief mold 1 results from the fact that the original is cast in a so-called "cold" process with silicone rubber. This method does not damage the original, so that very valuable originals can be molded without hesitation. The silicone rubber casting is used as a relief mold 1 after appropriate support by a rigid plate and optionally coating by means of the metal layer 4.

The printing of the film 2 on the image side 3 takes place, for example, according to the offset method, whereby a color recording of the painting with extremely precise color values without light reflections is processed into exactly true offset films in four colors. Of course, you have to pay attention to extremely precise dimensional accuracy. Both in the production of these offset films and in the production of the relief shape, it is possible from the outset to provide registration marks outside the image field, which then facilitate the alignment of the printed film 2 with respect to the relief shape 1.

To perform the process, the metallization layer 4 on the one hand and a ten above the Imprinted ⁼ film 2 disposed electrode 5 are connected to a high frequency generator. 6 By briefly switching on the high-frequency generator 6, the film is dielectrically heated to its flow temperature and deforms into the negatively formed shaping surface of the relief mold 1 in less than 1 second. The metallization layer 4 serves on the one hand as an electrode and on the other hand as a heat dissipation layer which solidifies the image side 3 of the film in a very short time and thus ensures the rapid and precise shaping of the film 2. If the normal roughness of the original painting and thus the shaping surface of the relief mold 1 should not be sufficient to ensure the removal of the air enclosed in the depressions below the film, microscopic air channels can be formed in the relief plate 1, which are indicated, for example, at 7. Furthermore, the relief shape 1 can also be made with its metal lization layer 4 are formed microscopically porous, so that the air can evade the entire surface of the film 2. Depending on the circumstances, the electrode 5 can be designed in such a way that a uniform, homogeneous heating of the film 2 is ensured over its entire strength and its entire dimensions. By suitable shaping of the electrode 5, however, a somewhat higher or somewhat earlier heating can take place in the middle of the surface of the film, which can be done, for example, by dividing the electrode 5 and correspondingly stepped activation of the resulting partial electrodes.

The printed film 2 deformed by the process results in an extremely exact replica of the original with the finest structures, so that even the almost smooth-looking surface shapes can be reproduced faithfully in the painting technique, for example of the 19th century. The process is also extremely economical, since quick heating and rapid cooling can be achieved by choosing a thin film. The metallization layer galvanically applied to the relief form 1 practically does not change the accuracy achieved in the impression, which can be concluded, for example, that such galvanization is also used in record matrices. The metallization. Rungsschicht 4 results in a longer life of the relief form 1 without any signs of wear and also contributes to a faster cooling of the melted printed film. The rapid cooling of the image side 3 of the film 2 is of particular importance here, since the risk of color falsification of the printing inks used is thus reduced as a result of the heating. In comparison with the known methods, with simpler production of a mold, the method thus results in higher accuracy with faster and cheaper production of the reproductions.

A modification is shown in Fig. 2. In this method, a support layer 8 is placed on the film 2 and, together with the film 2, is subjected to the dielectric high-frequency heating by means of the electrode 5 and the metallization 4, which in this case serves as the counter electrode, of the relief shape. For this purpose, the electrode 5 can be placed on the support layer 8, as a result of which a particularly concentrated high-frequency heating takes place towards the relief shape 1 or its coating 4. As soon as the film 2 and, if possible simultaneously, a flowable component of the support layer 8, which can consist, for example, of PVC-impregnated canvas, are brought to the flow temperature, the film 2 first drops and then the flowable component of the support layer 8 into the respective shapes of the relief shape 1, wherein a fabric of the support layer 8 remains essentially in its original shape. The "inflow" of the film 2, possibly under the weight of the material of the support layer 8, into the corresponding depressions of the relief mold 1 is primarily due to gravity, which, however, is caused by the contact pressure of the electrode 5 on the original layering of the film 2 and the support layer 8 can be increased. However, the electrode 5 can also be fixed completely independently of the layering of the film 2 and the supporting layer 8, so that even if the two layers lie on top of them, they detach from the electrode 5 and assume the desired shape after they have been heated to the flow temperature.

Claims (14)

1. A process for the reproduction of oil paintings and the like with a relief surface using a relief mold removed from the original and a thermoplastic film printed with the original color image and deformed under heating, characterized in that the film is placed on the relief mold with a registration and is heated essentially homogeneously to its flow temperature via its strength. 2. The method according to claim 1, characterized in that a support layer is placed over the film, which is simultaneously heated with the film. 3. The method according to claim 2, characterized in that at the same time with the film, the support layer on its thickness is heated substantially homogeneously to the flow temperature of its flowable component. 4. The method according to any one of claims 2 or 3, characterized in that the support layer is a fabric layer embedded in polyvinyl chloride. 5. The method according to claim 4, characterized in that the fabric is canvas which is impregnated with the polyvinyl chloride. 6. The method according to any one of claims 2 to 5, characterized in that the supporting layer is pressed by its own weight and / or additional pressure by means of a support or a pressing device against the film. 7. The method according to any one of the preceding claims, characterized in that the film or the film with the support layer is progressively heated from the center of the relief shape to the outside. 8. The method according to any one of the preceding claims, characterized in that the film or the film with the support layer is dielectrically heated by means of an electrical high-frequency field. 9. The method according to any one of claims 1 to 7, characterized in that the film or the film with the support layer is heated by infrared rays. 10. The method according to any one of claims 1 to 7, characterized in that the film or the film with the support layer is heated by contact heating by means of a preheated elastic pad high heat capacity. 11. The method according to any one of the preceding claims, characterized in that the relief shape is galvanized at least on the side facing the film. 12. The method according to any one of the preceding claims, characterized in that the relief shape is porous on a microscopic scale or is provided with holes on a microscopic scale. 13. The method according to any one of the preceding claims, characterized in that the relief mold is cooled. 14. The method according to any one of the preceding claims, characterized in that the relief form is designed as a negative form and the film is placed with the printing side on the relief form.

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