EP2305483A1 - Method for producing printed products with a tactile overprint - Google Patents

Abstract

The method involves imprinting a print colorant (3) e.g. black print colorant, on a print substrate (2) in layers without displacement in multiple printing channels till a tactile, pyramid shaped elevation (5) of a logo (4) is formed. Predetermined printing data is converted into sectional-wise print data for production of contour (6) of the tactile logo for predetermined number of printing channels. The elevation of the logo per printing layer (7) increases around 0.03 mm. The print colorant is hardened by UV-light effect or using a LED, according to each printing channel.

Description

The present invention relates to a novel method for producing a printed product with an at least partially tactile imprint on a print carrier, as well as printed products produced by the novel method.

Tactile communication is used in science synonymously with haptic communication. Tactile communication is based on sense of touch as well as haptic perception with tickling, touch, movement, vibration, temperature, pressure and tension. Of particular importance is the tactile communication in visually impaired or blind persons.

To depict braille, the so-called Braille, on printing media, for example on information boards, it was previously relied on the use of engraving, embossing or etching for tactile design of the print carrier. In order to provide such print carrier with easily palpable increases, these are for example also constructed in relief from milled items.

Alternatively, for example, prefabricated letters or symbols are used for the production of generic information panels, which are inserted into mounting panels.

However, these known methods have the disadvantage that the production of such print carrier is complicated and the palpable elevations must have a certain minimum size. The presentation of a text or a graphic with surveys made in this way also requires a lot of space. A simple and cost-effective reproduction of these hand-crafted information panels as well as a stepless change or adaptation of the font sizes are not possible.

DE 10 2006 003 310 A1 is a method for producing a lenticular image can be seen, wherein the palpable elevations are formed by a plurality of respective lenticular layers which are printed or adhered to the print carrier. The lens bodies may also serve for use as Braille and are preferably made of a transparent material.

As a further prior art is for example from the DE 100 21 774 A1 a method for displaying braille is known in which a print image is first produced on a printing medium in a printing machine. On the still fresh print image is then applied a vaporizable granules, which adhere to the fresh, wet places. Excess non-stick granules are then removed from the print substrate again and in a subsequent further step, the expandable granules are inflated at temperatures between 60 ° C and 200 ° C. As an expandable granules, a mixture of resin and quartz is used, which may additionally contain auxiliaries such as stabilizers, binders, photopolymers and initiators.

A disadvantage of this production method is that the print quality significantly depends on the adhesion of the granules to the freshly printed areas of the printed image and that in any case an excess of expandable granules must be applied to the print carrier. The manufacturing process is very expensive due to the high consumption of expandable granules, which must also be disposed of. By the required heating of the granular-coated print carrier to bring the resin to melt, the operating costs for the production of the print carrier are additionally increased. Due to the high temperatures required for the melting of the resin, it is not possible to use any printable materials, which constitutes a further disadvantage of this production process.

Furthermore are from the DE 20 2004 015 355 U1 Ink known that are applied to any print carrier and then heated locally, for example by means of a marking laser. This heating triggers one or more chemical reactions in the ink which cause puffing or bursting of microcapsules trapped in the dye and thus foaming which increases the volume of the dye. For example, by the destruction of microcapsules catalytically active substances are released in the dye, which foam a chemical precursor such as polyurethane locally irreversible, hard micro bubbles of a few mm in diameter.

A disadvantage of such printing inks is that thus no exact, finely structured tactile contours can be achieved. Another disadvantage is that the local heating of the printing inks by means of a marking laser is very expensive and requires the operation of the laser specially trained professionals.

It is therefore the object of the present invention to provide a novel method for producing a printed product with an at least partially tactile imprint on a printing medium, which avoids the described disadvantages of the prior art.

This object is achieved in a manufacturing method according to the preamble of claim 1 with the features of the characterizing part of claim 1. The subclaims relate particularly / further advantageous embodiments of the invention.

It is a further object of the present invention to provide printed products produced by the novel process.

Advantageously, in a method according to the invention for producing a printed product with an at least partially tactile imprint on a print carrier, a printing ink is printed in layers without offset in a plurality of printing passes on the print carrier until a palpable elevation of the imprint is formed.

As a print carrier are preferably aluminum plates, aluminum composite materials (Dibond) and acrylic or plastic plates are used, which can be fastened in the interior and / or exterior, for example, buildings. All other printable sheet materials are in principle suitable as a print carrier.

Printing inks are to be understood as meaning all printing inks or mixtures thereof. Furthermore, the use of white, black and / or transparent printing inks is also included in the invention.

For example, sections with a tactile imprint as well as sections with a purely optically readable imprint can be arranged together on a print carrier in a particularly user-friendly manner.

For example, it may be necessary to provide a surface of the printed product with a tactile, characteristic structure. This structure may, for example, be a tactile cross stripe, longitudinal stripe or puncture.

In a method according to the invention, a print layer is expediently printed on the print carrier at each printing pass.

In turn, a print layer applied at one print pass may include, for example, four color layers. For example, black elements may be printed with either a black ink or a mixture of four individual dyes (CMYK, cyan, magenta, yellow, black). Surprisingly, it has been shown that color mixtures of several printing inks combine particularly well with the imprint.

In a method according to the invention, it is particularly expedient for a contour of the elevation of the imprint obtained in several printing passes to taper upwards from a lowermost printing layer printed on the printing substrate.

The elevations of the imprint can therefore be distinguished tactically particularly well. When imprinting dot-shaped Braille characters, it is possible that the printed dots can be produced particularly accurately in hemispherical form.

In an advantageous embodiment of the method according to the invention, the contour of the imprint tapers from the lowermost printing layer upwards after every 5 to 25, preferably after every 10 to 20 printing layers.

In particular, for blind or visually impaired people who can not read information in braille (Braille), it is necessary to represent information in plain text tactile particularly well distinguishable. Essentially pyramidal elevations of the imprint thereby facilitate the tactility of the information.

A variant of the invention provides a method in which the elevation of the imprint per printing layer increases by at least 0.01 mm, preferably by at least 0.03 mm.

In tactile label rules, the geometric dimensions are determined for tactile elevations of the tactile imprint. Advantageously, in the manufacturing method according to the invention, the contour or relief height of the palpable elevations as well as distances between adjacent elevations can be adapted very precisely to the respective requirements. The elevations of the imprint can be any height, for example, 0.6 mm, 1 mm or 2 mm high, designed. The contour or relief height of the elevations depends essentially on the number of pressure passes. In previous practice, elevations with relief heights of about 1.2 mm have proven to be very good tactile for tactile imprints.

In a further development of the process according to the invention, a photoresist which hardens under the action of light is used.

In the prior art a wide variety of printing dyes are known which cure under the action of light, for example under the action of ultraviolet light or infrared light, particularly rapidly. Such printing dyes are particularly suitable for use in the production of printed products by the method according to the invention.

A preferred embodiment of a method according to the invention provides that after each printing pass the printing dye is cured by the action of light, in particular by the action of UV light.

Depending on the type and composition of the printing dye, a wide variety of types of light sources can be used for rapid curing of the printing dye. For example, UV light emitters or infrared lamps can be used. The use of LED lamps that emit light in the respective wavelength range, is also conceivable.

Appropriately, in a method according to the invention after printing, the at least partially tactile imprint is sealed with a clearcoat.

The clearcoat used should be matched to the type of printing ink and combine with this particularly resistant to abrasion. It is also conceivable to apply several layers of clearcoat on the imprint. Furthermore, it is conceivable to use, for example, multicomponent coatings as a clearcoat.

In a further development of the method according to the invention, predetermined print data of the print are converted into layered print data for generating the contour of the tactile print for a predetermined number of print passes.

Depending on the requirement, a separate contour of the tactile imprint is calculated either for each individual print pass, or a contour is used in each case for several print passes. Another advantage of this method according to the invention is that all the print data are available as digital information. Thus, not only the predetermined printing data of a two-dimensional image can be converted into three-dimensional image information with the corresponding contours of the elevations of the image Tactile imprint be converted, but the image information can be reproduced as often as desired or font sizes can be easily adapted to each different requirements or sizes of the print carrier.

In a method according to the invention for printing the print carrier, a flatbed printer is particularly advantageously used.

In order to be able to print several printing layers without offset one above the other in multiple printing passes, the print carrier must remain immovably fixed on a printer and move a print head of the printer in both axial directions on the print carrier to apply the ink in layers exactly one above the other. This requirement is met particularly well by a flatbed printer or flatbed plotter.

In the context of the invention, it is also possible to use a printed product, which is produced according to a method according to the invention, wherein the printed product has one or more solid areas and / or color gradients and / or raster images and / or print effects.

Advantageously, with the method according to the invention, three-dimensional, tactile information containing printed products, such as information boards, can be produced, which can also be executed multi-colored depending on the requirements. Furthermore, it is easily possible to vary the inks of the print per print layer and thus to achieve color gradients.

With the method according to the invention can also be particularly effective printed products with raster images, i. with multicolored photos or pictures.

Especially with complex image information, which should be easily understandable and well palpable imaged on a printed product, other printing effects, such as hatched or dotted tactile imprints can be used. Thus, for example, on billboards that show a floor plan of a building, individual sections of the building with a specific, palpable structure tactile can be clearly identified. Blind or visually impaired persons can easily and safely orientate themselves with such inventive information panels, for example in public buildings, museums, theaters, hotels and restaurants, station areas of public transport or department stores.

The invention will now be explained in more detail by means of exemplary embodiments with reference to the drawings.

• Fig. 1 in einer Schrägansicht ein erfindungsgemäßes Druckerzeugnis mit einem taktilen Aufdruck auf einem Druckträger;
• Fig. 2 in einer Frontalansicht das in Fig. 1 dargestellte Druckerzeugnis;
• Fig. 3 in einer Schnittansicht den schichtweise gestalteten Aufbau des taktilen Aufdrucks eines erfindungsgemäßen Druckerzeugnisses;
• Fig. 4A bis 4D die Herstellung des in Fig. 1 gezeigten erfindungsgemäßen Druckerzeugnisses in mehreren Arbeitsschritten;
• Fig. 5A bis 5C die Herstellung eines weiteren erfindungsgemäßen Druckerzeugnisses in mehreren Arbeitsschritten.

Shown schematically in each case:

• Fig. 1 in an oblique view, an inventive printed product with a tactile imprint on a print carrier;
• Fig. 2 in a frontal view the in Fig. 1 illustrated printed matter;
• Fig. 3 in a sectional view of the layered structure of the tactile imprint of a printed product according to the invention;
• Figs. 4A to 4D the manufacture of in Fig. 1 shown printed product according to the invention in several steps;
• Figs. 5A to 5C the production of a further printed product according to the invention in several steps.

Fig. 1 shows a detail of a printed information panel as an example of a printed product according to the invention 1. A print carrier 2, which is made for example of an abrasion-resistant plastic material, is printed with a printing ink 3, which is curable under the action of UV light. The imprint 4 of the printing ink 3 takes place in layers without offset in several printing passes, so that palpable elevations 5 are formed. Advantageously, for example, lines in Braille with the required elevations 5 can be printed alternately with lines in optically readable writing only. In Fig. 1 All printed information are designed as palpable surveys 5. Thus, it is also possible for visually impaired persons who are unable to decipher the Braille, to feel the information.

The palpable elevations 5 of the optically readable font have a contour 6, which tapers in the shape of a pyramid from a lowermost print layer 7 printed directly onto the print substrate 2 and tapers upward. The palpable elevations 5 of the braille are printed as hemispherical contours 6. The number of print passes or the number of print layers 7 printed without offset one above the other thus determines the height of the elevations 5. The height of the elevations 5 of the tactile print 4 is thus easily adaptable to the respective requirements or standards.

With the manufacturing method according to the invention are precise, for example, hemispherical or pyramidal contours 6 of the tactile elevations 5 of the tactile imprint 4 achievable that can be particularly easily felt by the visually impaired or blind persons.

To attach the tactile imprint 4 particularly durable on the print carrier 2, the ink 3 is cured after each pass through UV light before a next print layer 7 is applied. Finally, the tactile imprint 4 is sealed with a clearcoat 8. This clearcoat 8 makes the imprint 4 particularly weather-resistant, protects the printed product 1 against contamination by the touch and facilitates its cleaning.

Due to the precise manufacturing process, it is also possible to display complex details with a tactile imprint 4 in a very small area on a printed product 1 according to the invention.

Fig. 2 shows in a frontal view the in Fig. 1 illustrated information panel, for example, represents a building floor plan with customary, additional information on room names, escape routes, stairwells or sanitary facilities. Both the building ground plan, as well as the additional information indicated by symbols or characters are shown in the printed product 1 shown here by means of tangible elevations 5 provided with contours 6. These elevations 5 were also formed by a plurality of printing layers 7 of a printing ink 3, which were printed without offset in several printing passes over each other.

Fig. 3 shows in a sectional view a detail of a printed product 1 according to the invention with an imprint 4 with a palpable elevation 5 on a print carrier 2. The ink 3 is printed without offset in numerous print passes or in numerous print layers 7 above each other until a palpable elevation 5 is formed. As shown here, the contour 6 of the imprint 4 tapers from a lowermost printing layer 7.1 printed on the printing substrate 2 up to an uppermost printing layer 7.45. For this purpose, a first contour 6.1 is selected and printed on each other in, for example, 15 printing passes or in 15 printing layers 7.1 to 7.15. In order to prevent crumbling or bleeding of the printing ink 3 during frequent printing, a printing ink 3 curing by means of UV light is used, the freshly applied printing layer 7 being cured by UV light after each printing operation.

For the next print layers 7.16 to 7.30, a second, somewhat tapered contour 6.2 is selected. For the further from the print carrier 2 pressure layers 7.31 to the top layer of pressure 7.45 a third, even further tapered contour 6.3 is selected, and such a pyramidal elevation 5 of the imprint 4 obtained. The layer thickness of a printing layer 7 is for example 0.03 mm in each case.

With this novel method thus different contours 6 of the palpable elevations 5 of a tactile imprint 4 can be achieved.

It is also conceivable to choose a separate contour 6 for each individual printing layer 7. Thus, for example, hemispherical elevations 5 can be printed on a print carrier 2. This application is not explicitly shown in the illustrations.

The Figs. 4A to 4D show a sequence of production steps to produce the in Fig. 1 respectively. Fig. 2 printed product 1. Fig. 4A shows a first intermediate product in which a first contour 6.1 in example 15 printed layers 7 without offset one above the other was printed on the print carrier 2, and already small elevations 5 are formed.

Fig. 4B shows the print image of a second contour 6.2, compared to the in Fig. 4A shown contour 6.1 is slightly tapered. This contour 6.2 will, as in Fig. 3 shown, printed in each case 15 printing layers 7 without offset on top of each other on the printed with the contour 6.1 print carrier 2, the elevations 5 of the imprint 4 are increased or further increased.

Fig. 4C shows the print image of a third contour 6.3, which is further narrowed in comparison to the contours 6.1 and 6.2 respectively. This third contour 6.3 is, for example, likewise printed in 15 printing layers 7 without offset one above the other onto the print carrier 2 provided with the contour 6.1 or 6.2. In this way, the elevations 5 are further increased and palpable for the blind or visually impaired.

Fig. 4D shows the print image of a fourth contour 6.4, which serves for example only the optical design and contains no tactile information. Contour 6.4 is printed, for example, only in a simple printing layer 7 on the print carrier 2, wherein the previously formed, palpable elevations 5 are excluded in the contour 6.4. This contour 6.4 contains, for example, solid surfaces 9 or may also include color gradients, raster images or other printing effects.

The Figs. 5A to 5C show a further embodiment of a printed product 1 according to the invention, in which fonts and symbols are shown. The optically readable fonts and symbols are executed here as elevations 5 with pyramidal contours 6. The optically readable characters are combined with punctuation marks in Braille, which are formed as elevations 5, each with a hemispherical contour 6. In order to form the palpable elevations 5, a first contour 6.1, as in FIG Fig. 5A shown, for example, printed in each case 20 printing layers 7 without offset on the print carrier 2, wherein between the individual printing passes the applied ink 3 is cured by UV light.

Subsequently, a relation to the contour 6.1 tapered contour 6.2, as in Fig. 5B shown again printed on the print carrier 2 in 20 print layers 7 without offset one above the other.

This process is then repeated several times, with an even more tapered contour 6.3 as in Fig. 5C shown in another 20 printed layers 7 without offset one above the other on the print carrier 2 is printed.

Solid areas 9, which contain no tactile information, are then subsequently printed, for example, in a single print layer 7. Printing effects, such as hatched or dotted areas, which should be palpable, must be considered accordingly in the contours 6.1, 6.2 and 6.3 respectively.

Furthermore, for the special protection of the printed product 1, to make the imprint 4 particularly smudge-proof and weather-resistant, one or more layers of clearcoat 8 can finally be applied.

List of item numbers:

1

Printed Media

2

print carrier

3

printing ink

4

imprint

5

survey

6

Contour of the imprint

6.1

1st contour

6.2

2nd contour

6.3

3. contour

7

print layer

7.1

Lowest pressure layer

7:45

Top pressure layer

8th

clearcoat

9

solid area

Claims (10)

Method for producing a printed product (1) having an at least partially tactile imprint (4) on a printing substrate (2), wherein a printing ink (3) is printed on the printing substrate (2) in layers without offset in a plurality of printing passes until a palpable elevation ( 5) of the imprint (4), characterized in that predetermined printing data of the imprint (4) are converted into layered printing data for generating the contour (6) of the tactile imprint (4) for a predetermined number of printing passes. A method according to claim 1, characterized in that each printing pass a respective printing layer (7) is printed on the print carrier (2). Method according to claim 1 or 2, characterized in that a contour (6) of the elevation (5) of the imprint (4) obtained in several printing passes tapers towards the top from a lowermost printing layer (7.1) printed on the printing medium (2). Method according to one of claims 1 to 3, characterized in that the contour (6) of the imprint (4) after every 5 to 25, preferably after every 10 to 20 printing layers (7) from the lowermost printing layer (7.1) upwards rejuvenated. Method according to one of claims 1 to 4, characterized in that the elevation (5) of the imprint (4) per printing layer (7) by at least 0.01 mm, preferably by at least 0.03 mm increases. Method according to one of claims 1 to 5, characterized in that a curing under the action of light printing ink (3) is used. A method according to claim 6, characterized in that after each printing pass the printing dye (3) is cured by exposure to light, in particular by the action of UV light. Method according to one of claims 1 to 7, characterized in that after printing the at least partially tactile imprint (4) is sealed with a clearcoat (8). Method according to one of claims 1 to 8, characterized in that for printing the print carrier (2) a flatbed printer is used. Printed product produced by a process according to one of claims 1 to 10.

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