DE102022127578A1 - Method and device for producing a printed concrete body - Google Patents

Abstract

A method for producing a printed concrete body (1), in particular a printed concrete block, a printed concrete slab or a printed concrete step, comprises at least the following steps:- printing at least one visible surface (2) of the concrete body (1); and- curing the concrete body (1) after printing.It is provided that 5% to 90% of the visible surface (2) of the concrete body (1) is printed in such a way that the visible surface (2) has a pattern through which the visible surface (2) of the concrete body (1) has a natural stone look, a wood look, a textile look, a tile look or a mosaic look.

Description

The invention relates to a method for producing a printed concrete body, in particular a printed concrete block, a printed concrete slab or a printed concrete step according to the preamble of claim 1.

The invention further relates to a device for producing a printed concrete body according to claim 17.

Furthermore, the invention relates to a printed concrete body.

Printing on concrete bodies, especially concrete blocks, has proven to be a suitable way to give the concrete body a colorful design. In particular, there is a need to design a visible surface of the concrete body in such a way that it is similar to natural stone or imitates the visible surface of natural stone. When printing on concrete blocks, however, a number of challenges must be taken into account, such as the difficulty of achieving good adhesion of the printing to the concrete.

The known methods for printing on concrete bodies are based primarily on the so-called dry printing process. Here, the concrete body is printed on after the concrete has hardened in order to apply a pattern to the visible surface or to add color to it.

It has been shown that printing on uncured, wet concrete can be particularly advantageous, as the printing compositions used for printing can result in patterns and structures due to the flow in the concrete that cannot be achieved using the dry printing process. However, the printing compositions used for this must be selected in such a way that they adhere well to the concrete body that is subsequently to be cured and are compatible with the conditions of curing the concrete body.

A generic procedure is known from the EN 10 2017 005 280 B4 known.

In the EN 10 2017 005 280 B4 A method for producing a printable concrete body is proposed, in which it is provided to pour concrete into a mold to form a concrete body. It is then provided to print a visible surface of the concrete body with a printing composition comprising a binder A and a dye B, wherein the binder A should contain at least one siloxane and one silane, and wherein the siloxane should be a condensed, pre-crosslinked silicone resin. After printing, the concrete body is provided to harden.

For further information on the state of the art, please refer to EN 10 2006 014 900 A1 referred to.

The EN 10 2006 014 900 A1 describes a wet printing process for concrete bodies. The concrete product described there has a print embedded in the concrete on a visible surface. The printing is carried out on the wet concrete, which has not yet set or has only partially set. In the EN 10 2006 014 900 A1 Neither the pressure composition nor the flow of the pressure composition on the wet concrete is discussed. EN 10 2006 014 900 A1 does not therefore disclose how deliquescent patterns can be achieved on and/or in the concrete. In addition, the document does not address the problem of the adhesion of the material to the hardened concrete and the properties that the printing composition must have so that the printing composition does not lose the desired structure during thermal hardening of the concrete body.

Based on the state of the art, it would be desirable to provide a method and a device for printing on concrete bodies, with which it is possible to give a visible surface of a concrete body a permanent aesthetic design in a simple, reliable and cost-effective manner. It would also be desirable if the method and the device could be integrated into the existing plant concepts, in particular into existing plants for the production of concrete bodies. The methods known from the state of the art, such as the EN 10 2017 005 280 B4 , usually involve the use of a so-called primer, which is applied to the visible surface of the concrete body and provides a white surface that can then be printed on. The white surface provided by the primer can be used to produce a good print image, and colors can be displayed particularly well, but there is the disadvantage that if the visible surface is damaged manually, the white primer underneath the print becomes clearly visible, which has a lasting impact on the appearance of the concrete body.

The present invention is based on the object of creating a method for producing a printed concrete body, with which a visible surface of the concrete body can be printed in a particularly advantageous manner in order to give the concrete To give the body an aesthetic appearance cost-effectively and permanently.

This object is achieved according to the invention by the features of claim 1.

The present invention is further based on the object of creating a device for producing a printed concrete body, with which a visible surface of the concrete body can be printed in a particularly advantageous manner in order to give the concrete body an aesthetic appearance in a cost-effective and permanent manner.

This object is achieved according to the invention by the features of claim 17.

The present invention is also based on the object of providing a printed concrete body which has an aesthetically pleasing and cost-effectively producible visible surface that is resistant to weather conditions.

This object is achieved according to the invention by claims 18 and 19.

• - Bedrucken mindestens einer Sichtfläche des Betonkörpers; und
• - Aushärten des Betonkörpers nach dem Bedrucken.

The method according to the invention for producing a printed concrete body, in particular a printed concrete block, a printed concrete slab or a printed concrete step, comprises at least the following steps:

• - Printing on at least one visible surface of the concrete body; and
• - Curing of the concrete body after printing.

According to the invention, it is provided that 5% to 90% of the visible surface of the concrete body is printed in such a way that the visible surface has a pattern through which the visible surface of the concrete body is given a natural stone look, a wood look, a textile look, a tile look or a mosaic look.

It has been shown that printing only 5% to 90% of the visible surface of the concrete body is particularly advantageous in order to give the visible surface of the concrete body a natural stone look, a wood look, a textile look, a tile look or a mosaic look. In contrast to the teaching of the prior art, which provides for printing the entire visible surface of the concrete body, it has been shown that by printing only part of the visible surface, an appearance can be achieved that is closer to that of natural stone, wood, textile, tile or mosaic than by printing the entire visible surface. By printing only part of the visible surface, the device used for printing, in particular a printer and in particular its nozzles, is also subjected to less strain. Furthermore, the consumption of ink or printing composition is reduced.

As a rule, in the case of a concrete body, for example a paving stone, only one side of the concrete body will form the visible surface when installed. In this case, it is sufficient if only one side of the concrete body, usually the top of the concrete body, which forms the visible surface, is printed. If the concrete body is designed as a concrete step, it can be provided that the concrete body has two visible surfaces, which preferably run at an angle of 90° to one another and which are a top and a side wall of the concrete body. In this case, both visible surfaces, i.e. the top and the side wall, of the concrete body can preferably be printed according to the invention. However, it is also possible in this case for only one visible surface, e.g. the top or the side wall of the concrete body, to be printed.

Even when the concrete body is designed as a wall or brick, it can be provided that the concrete body has more than just one visible surface, for example two visible surfaces, which are opposite side walls that preferably run parallel to one another. A concrete body designed as a brick can also have visible surfaces on the front (short) side walls and/or on the top. It can be provided that the concrete body is printed on two, three or even four sides/walls according to the invention. However, it can also be provided that only some of the visible surfaces are printed, for example if only one side of a free-standing wall is to have a natural stone look.

It is advantageous if 5% to 80%, preferably 10% to 80%, more preferably 20% to 70%, particularly preferably 30% to 70%, of the visible surface of the concrete body is printed.

The above values have proven to be particularly suitable for printing on the visible surface.

According to the invention, it can further be provided that the visible surface of the concrete body is printed with at least one, preferably several crack lines, in particular crack lines with a marble look, and/or structural lines and/or notches and/or speckles and/or spots and/or shading.

It has proven particularly suitable for creating a natural stone look, a wood look, a textile look, a tile look or a mosaic look if the visible surface is printed with crack lines, in particular crack lines with a marble look and/or structural lines, in particular in different lengths and with different gradients, and/or notches, in particular with different thicknesses and/or different color designs. The crack lines, structural lines, notches, speckles, spots and shading are preferably printed irregularly on the visible surface of the concrete body or distributed irregularly over the visible surface.

It may be sufficient if 10% to 20% of the visible surface is printed with crack lines and/or structural lines and/or notches and/or speckles and/or spots in order to achieve a natural stone look or a mosaic look, particularly in conjunction with a visible surface that is colored before printing. Please also refer to the following designs.

According to the invention, it can be provided that at least one region of the visible surface of the concrete body, preferably the entire visible surface of the concrete body, is colored before printing.

Surprisingly, it has been shown that by coloring at least one area of the visible surface of the concrete body, preferably the entire visible surface of the concrete body that is to be printed according to the invention, before printing, a particularly advantageous natural stone look, wood look, textile look, tile look or mosaic look can be achieved without full-surface printing being necessary. The coloring is preferably achieved by coloring the concrete that forms the visible surface. The coloring can preferably be done with a gray, light gray, beige, light blue, blue, green, black, white, brown, red or yellow color tone. The visible surface of the concrete body is preferably colored in such a way that it has a marble look and/or an irregular color gradient and/or an irregular structure and/or an irregular color intensity and/or shades and/or lighter and darker areas.

It can be provided that only the visible surface or several visible surfaces of the concrete body are colored accordingly, preferably to a depth orthogonal to the visible surface of 2 mm to 30 mm. It can be provided in particular that in a concrete body made of a core concrete and a facing concrete, only the facing concrete is colored. The facing concrete usually forms the top or the visible surface of the concrete body, for example a paving stone or a concrete slab.

According to the invention, it can further be provided that the visible surface of the concrete body is given a marbling appearance and/or a structuring and/or a multi-colored design by the concrete used to produce the concrete body before printing, and/or a color and/or additives, in particular fine-grained additives, are added to the concrete used to produce the concrete body.

It can be advantageous if, as already explained above, only the concrete forming the visible surface of the concrete body, for example a facing concrete, is designed in such a way that a marbling look and/or a structure and/or a multi-colored design is created. The facing concrete can alternatively or additionally also contain aggregates, in particular fine-grained aggregates made of granite or basalt, and/or a color can be mixed into the concrete.

• - Einfüllen eines eingefärbten Betons und/oder einer Mischung aus verschiedenfarbigem Beton in eine Verfüllform zur Ausformung des Betonkörpers, oder
• - Einfüllen eines Betons in eine Verfüllform zur Ausformung eines Grundkörpers des Betonkörpers und Einfüllen eines eingefärbten Betons und/oder einer Mischung aus verschiedenfarbigem Beton in die Verfüllform zur Ausformung der Sichtfläche des Betonkörpers, wobei der Beton, der den Grundkörper des Betonkörpers bildet, farblich von dem Beton und/oder der Mischung aus verschiedenfarbigem Beton, der bzw. die die Sichtfläche des Betonkörpers ausbilden, abweicht.

According to the invention, it can further be provided that the method comprises the following steps:

• - Pouring a coloured concrete and/or a mixture of different coloured concrete into a filling mould to form the concrete body, or
• - Pouring concrete into a filling mould to form a base body of the concrete body and pouring coloured concrete and/or a mixture of different coloured concrete into the filling mould to form the visible surface of the concrete body, wherein the concrete which forms the base body of the concrete body differs in colour from the concrete and/or the mixture of different coloured concrete which form the visible surface of the concrete body.

It has been shown that a suitable design of the visible surface or surfaces of the concrete body can be achieved by pouring a colored concrete and/or a mixture of different types of concrete into a filling mold for shaping the concrete body.

A particularly advantageous method to achieve a coloration of the concrete body is known from the EP 2 237 937 B1 The device and method disclosed therein can be used in a particularly advantageous manner to produce a multi-coloured Form concrete bodies, especially with a marbling look.

It can be provided that the entire concrete body is provided by pouring a colored concrete and/or a mixture of different types of concrete into a filling mold.

Alternatively, however, it can also be provided that a conventional, in particular an uncolored concrete, in particular a core concrete, is filled into a filling mold to form a base body of the concrete body and only the area of the concrete body that forms the visible surface of the concrete body is colored. Preferably, a facing concrete is used to produce the visible surface. The colored concrete and/or a mixture of different types of concrete, which forms the visible surface or the facing concrete, is preferably filled into the filling mold in which the core concrete is already located.

The concrete that forms the base of the concrete body differs in color from the concrete and/or the mixture of different types of concrete that form the visible surface of the concrete body, i.e. the facing concrete.

Typically, the concrete that forms the base of the concrete body, the so-called core concrete, is first poured into the filling mold and then the concrete that forms the visible surface, in particular the facing concrete, is filled in. It can be provided that after the core concrete has been poured in, vibration and/or compaction, for which a stamp can be used, takes place. To produce the concrete body, however, it can also be provided that the facing concrete is first poured into the filling mold and then the core concrete is filled in to form the base of the concrete body. It can also be provided that the backfill concrete, then the core concrete and then the or another facing concrete is poured into the filling mold, in particular to form two visible surfaces.

After both the facing concrete and the core concrete have been poured into the filling mold, regardless of the order, vibration and/or compaction takes place in the known manner.

A design of the concrete body in such a way that it has a base body made of uncolored concrete, in particular a core concrete, and only the concrete that forms the visible surface or surfaces of the concrete body, in particular a facing concrete, is colored and/or this is made from a mixture of different colored concrete, has proven to be particularly advantageous, since the uncolored concrete, in particular the core concrete, is available more cheaply. Despite the use of uncolored core concrete, impairments in the formation of the visible surface due to only the visible surface being provided by a colored concrete before printing are not to be expected.

It is advantageous if the colored concrete forming the visible surface or surfaces and/or the mixture of different colored concrete, in particular the facing concrete, has a thickness of at least 5 mm and preferably of at most 50 mm, particularly preferably at most 30 mm. It is particularly advantageous if at most 30%, particularly preferably at most 20%, in particular at most 15%, of the volume of the concrete body is formed from the colored concrete and/or the mixture of different colored concrete.

Within the scope of the invention, it can be provided that a fine-grained aggregate, for example made of granite or basalt, is added to the concrete in order to achieve a structuring or a colored appearance of the concrete.

According to the invention, it can further be provided that the printing of the concrete body is carried out in a green state of the concrete body in which the concrete body is dimensionally stable but not yet hardened.

It has proven to be particularly suitable if a concrete body is printed according to the invention in a green state.

A green-stable concrete body is a concrete body that is dimensionally stable but not yet hardened or completely set. In particular, this is understood to mean a concrete body that has not yet been placed in a setting room or a setting chamber/drying room to completely harden there.

A green-stable concrete body is understood to mean in particular a concrete body in which the main compaction process has been completed but which has not yet set.

A concrete body in the green state is also referred to as a “green” concrete blank in the state of the art. The green state of the concrete body means that the concrete body has already hardened to such an extent that it retains its shape when the concrete body leaves the production mold or the filling mold or the Concrete body would be removed from the mold.

The printing on the visible surface of the concrete body is therefore carried out in a state in which the visible surface of the concrete body is still damp or wet.

It has been shown that printing on the concrete body in a green state is particularly advantageous, as the ink or printing composition used for printing penetrates well or far into the concrete and flows. Although this can mean that exact structures cannot be printed with the same sharpness as is possible with a dry printing process, it has been shown to be advantageous for creating a natural stone look, a wood look, a textile look, a tile look or a mosaic look if the ink or printing composition runs slightly in a horizontal and/or vertical direction, i.e. in the plane of the visible surface (= horizontal) and orthogonal (= vertical) to it.

It has been shown that by printing on a concrete body in a green state, a print that is also resistant to weather conditions can be achieved, in particular because the print or the ink/the printing composition can penetrate comparatively deeply into the concrete of the concrete body.

According to the invention, it can further be provided that the concrete body is printed while the concrete body is still in a filling mold in which the concrete body is compacted, or the concrete body is printed after the concrete body has left a filling mold in which the concrete body is compacted.

It has proven to be particularly advantageous if the concrete body is printed after it has left a filling mold in which the concrete body is compacted. In this case, it is a green concrete body or a freshly manufactured and already molded concrete body. However, the concrete body has not yet set or is not yet in the setting area or the setting chamber. In this state, the concrete body can be printed in a particularly suitable way, both technically and economically.

Alternatively, it is also possible to print on the concrete body while it is still in a filling mold in which the concrete body is being compacted. The compaction of the concrete body has already taken place, so the concrete body is in a green state, but still in the production mold or the filling mold. It can be particularly suitable for special applications for the visible surface of the concrete body to be printed in this state of the concrete body.

One advantage is that printing can be particularly precise, since the position of the concrete body in the production mold or the filling mold is precisely specified.

However, it is advantageous if the visible surface is printed when the concrete body is already dimensionally stable, i.e. after the main compaction process has been completed but has not yet fully set. The concrete body is preferably no longer in the production mold or the filling mold in which it was compacted.

• - Aufbringen, vorzugsweise aufsprühen, wenigstens einer Beschichtung, vorzugsweise aus einer Acrylatdispersion, auf die bedruckte Sichtfläche des Betonkörpers vor dem Aushärten.

According to the invention, it can further be provided that the method comprises the following step:

• - Applying, preferably spraying, at least one coating, preferably made of an acrylate dispersion, to the printed visible surface of the concrete body before curing.

It has been found to be particularly advantageous if a coating is applied to the printed visible surface of the concrete body before the concrete body hardens, in particular the green-stable concrete body hardens. Spraying the coating has proven to be particularly advantageous. It has proven to be particularly advantageous to use an acrylate dispersion as a coating. Surprisingly, it has been shown that a particularly good bond between the printed ink or the printing composition and the concrete can be achieved if a coating, in particular an acrylate dispersion, is applied after printing but before hardening. The inventor has recognized that a cement paste that can form on the visible surface of the concrete body as a result of the compaction process when producing the concrete body is a disadvantage for printing and that this disadvantage can be overcome by applying a coating, in particular an acrylate dispersion, as a coating to the visible surface of the concrete body after printing.

• - Aufbringen, vorzugsweise aufsprühen, wenigstens einer Beschichtung, vorzugsweise einer UV-Beschichtung, insbesondere eines Lacks, auf die bedruckte und ausgehärtete Sichtfläche des Betonkörpers.

According to the invention, it can further be provided that the method comprises the following step:

• - Applying, preferably spraying, at least one coating, preferably a UV coating, in particular a varnish onto the printed and hardened visible surface of the concrete body.

It has proven particularly suitable if a coating is applied, preferably sprayed, to the printed and hardened visible surface of the concrete body, i.e. after the concrete body has hardened. It can also be provided that more than one coating is applied to the visible surface of the concrete body after hardening. The coating or one of the coatings can preferably be a so-called UV coating or a UV-curing coating, i.e. a coating that can be hardened by UV radiation. The coating can in particular be a varnish, in particular a UV varnish.

Within the scope of the invention, it has been found to be particularly suitable for protecting the printing if a first coating, preferably made of an acrylate dispersion, is applied after printing but before hardening and if after hardening of the visible surface, in particular when the concrete body has left a setting area or a setting chamber/drying room, at least one further coating, preferably a UV coating, in particular a varnish, particularly preferably a UV varnish, is applied. This makes it possible to create a particularly good and durable natural stone look, a wood look, a textile look, a tile look or a mosaic look and to maintain this even in harsh weather conditions, while also largely avoiding clouding.

It is advantageous if the printing is carried out with a printing composition consisting essentially of color-imparting inorganic pigments and a, preferably binder-free, solvent or a, preferably binder-free, solvent mixture.

Surprisingly, it has been shown that a printing composition consisting essentially of coloring inorganic pigments and a binder-free solvent or a binder-free solvent mixture is particularly suitable for printing the visible surface of the concrete body.

The coloring pigments can in particular be iron oxide pigments (red, yellow, black), cobalt oxide pigments (blue, green) and/or titanium oxide pigments (white).

In contrast to the teaching from the EN 10 2017 005 280 B4 , which explicitly recommends the use of a binder, whereby the binder should contain a siloxane and a silane, it has been found that particularly good printing results can be achieved without the use of a binder or by using a binder-free solvent or a binder-free solvent mixture, whereby the printing composition penetrates so deeply into the concrete composition in the horizontal and/or vertical direction that even if the visible surface is damaged, the applied pattern remains recognizable and the desired appearance is thus retained.

It has also been shown that particularly good printing on the visible surface of the concrete body can be achieved by using color-giving inorganic pigments.

The solvent or solvent mixture used with the inorganic pigments may optionally also contain a binder, but in this case it is at least provided that the solvent or solvent mixture is siloxane-free and/or silane-free and/or resin-free, i.e. that the solvent or solvent mixture does not contain siloxane and/or silane and/or resin.

According to the invention, it can also be provided that the printing is carried out with a printing composition consisting essentially of color-imparting inorganic pigments, polyacrylate as a binder and a solvent or a solvent mixture.

Tests have shown that good and durable printing can be achieved with a printing composition consisting essentially of color-imparting inorganic pigments, polyacrylate as a binder and a solvent or a solvent mixture. This means that it has been determined that if a binder is used, polyacrylate should be used as the binder in order to achieve suitable and high-quality printing.

It is an advantage if the coloring pigments are UV-resistant.

According to the invention, it can be provided that the solvent does not contain any water or is not an aqueous system.

The solvent may in particular be selected from a group consisting of alcohols or esters or petroleum spirits or aromatic solvents.

The solvent mixture preferably consists of water and alcohols, esters, petroleum spirits, aromatic solvents and mixtures thereof.

According to the invention, it has further been found to be advantageous if the printing composition consists of 10 wt.% to 90 wt.% of the solvent and the coloring pigments.

It has proven particularly suitable if the solvent makes up 50% by weight to 90% by weight, in particular 60% by weight to 80% by weight, of the printing composition, i.e. the coloring pigments particularly preferably make up 20% by weight to 40% by weight of the printing composition. In particular, it can be provided that the printing composition contains or consists of 70% by weight to 80% by weight of the solvent and correspondingly 20% by weight to 30% by weight of the coloring pigments, possibly apart from unavoidable residual impurities.

According to the invention, if the printing composition comprises a solvent mixture, it can be provided that the solvent mixture has a water content of 10% to 90% by weight. In particular, it can be provided that the printing composition consists of 20% to 40% by weight of the coloring pigments and 20% to 40% by weight of water, the water being a component of the solvent mixture, and the remaining components of the solvent mixture are then designed or selected accordingly, so that the solvent mixture makes up a total of 60% to 80% by weight of the printing composition.

It can be provided that the printing composition consists of 20 wt.% to 40 wt.% of the coloring pigments and 60 wt.% to 80 wt.% of the solvent mixture, wherein the solvent mixture consists of one third to two thirds wt.% water.

The inventors have recognized that the following three embodiments are particularly suitable for producing a printing composition.

Firstly (first embodiment), the printing composition can consist of a solvent with inorganic pigments, wherein the solvent does not contain water or is not an aqueous system and the solvent, preferably a hydrophilic solvent, has a proportion of 10 wt.% to 80 wt.%, preferably 60 wt.% to 90 wt.%, in the printing composition, and the proportion of the inorganic pigments is selected accordingly, preferably 20 wt.% to 40 wt.% of the printing composition.

Secondly (second embodiment), a printing composition is particularly suitable in which a solvent mixture and inorganic pigments are used. The solvent mixture preferably has a water content of 10% to 90% by weight. The proportion of inorganic pigments in the printing composition can preferably be 20% to 40% by weight, i.e. the solvent mixture preferably amounts to 60% to 80% by weight of the printing composition.

As a third printing composition (third embodiment), it has proven to be suitable if the printing composition contains inorganic pigments as well as polyacrylate as a binder and a solvent or a solvent mixture. The solvent or the solvent mixture can be constructed in such a way as was shown for the first or the second printing composition (first or second embodiment).

According to the invention, it is preferably provided that printing is carried out directly onto the concrete body, in particular directly onto a green-stable concrete body.

According to the invention, it can be provided in particular that no primer or adhesion promoter is applied to the visible surface before printing.

It has proven to be particularly advantageous if no primer is applied before printing. The prior art teaches that a primer or a primer/adhesion agent is applied before printing. The primer is white and enables the printing to be applied particularly well or sharply. However, the inventors have recognized that it is disadvantageous if a primer is applied to the visible surface of the concrete body, since if the visible surface or the printing is damaged, the white primer underneath becomes clearly visible, which permanently destroys the appearance of the visible surface. The fact that, within the scope of the invention, it is preferably provided not to use a primer, but rather to print directly onto the concrete body, in particular a green-stable concrete body, ensures that the printing composition penetrates deep into the concrete. If the visible surface is damaged, at least one Part of the print or the deeper part of the print is visible. In particular, in connection with the fact that it is preferably intended that the concrete itself is already colored or consists of a mixture of concrete colored in different colors, the desired overall visual impression is retained even if the visible surface is damaged.

According to the invention, it can be provided that the printing is carried out using an inkjet printing, screen printing, powder coating, laser printing, needle printing, electrostatic printing, liquid printing, digital printing and/or pad printing process.

It has proven to be particularly suitable if a digital printing process is chosen for printing and the print image is transferred directly from a file, a data stream or a computer to the printer. The use of an inkjet printing process has also proven to be particularly suitable, as an inkjet printing process can be carried out reliably even in the harsh environment of a stone production plant and is also inexpensive.

The method according to the invention can have further method steps in addition to the method steps already mentioned. Preferably, the concrete is compacted after being poured into the mold, in particular by means of vibration and/or by means of a stamp. Preferably, the concrete is compacted before printing. It is particularly preferred if a core concrete is poured in first, then preferably vibration and stamping take place and then the face concrete is poured in and again vibration and stamping or the main compaction takes place. As part of the method, preferably, the concrete body is removed from the filling mold before printing. Alternatively, printing can also take place in the mold.

It can be provided that the concrete body is subjected to a structure-imparting surface treatment after printing, preferably by brushing and/or embossing and/or grinding and/or shot blasting. The structure-imparting surface treatment can take place before or after the concrete body has hardened.

The method according to the invention makes it possible to print directly onto concrete blanks that come from the vibrating press. The printed concrete blanks can be produced using commercially available vibrating presses and preferably pass through the printing system or printer on the production base. The product arrangement according to the mold arrangement can remain untouched. The concrete blanks can then be transported, preferably on the production base, to a drying chamber or drying chamber system for curing. The hydration process binds the pigments deep into the concrete, in particular the visible surface or facing layer or the concrete matrix, and creates a resistant product during curing.

A preferred device for producing a printed concrete body is set out in claim 17.

The present invention also relates to a device for producing a printed concrete body, in particular a printed concrete block, a printed concrete slab or a printed concrete step, with a reservoir for receiving a printing composition for printing the concrete body and with a printer for printing at least one visible surface of the concrete body, wherein the printer is designed and configured to print a green-stable concrete body according to the method according to the invention.

Any suitable printer can be used as the printer, in particular an inkjet printer or a laser printer. A digital printing method is preferably selected as the printing method. It is preferably provided that the device according to the invention is integrated into a system for producing a concrete body, in particular in such a way that the device forms a station through which the concrete bodies pass after the main compaction pass, but before the setting area, in particular the setting chamber/drying chamber.

The invention also relates to a printed concrete body according to claim 18.

A particularly advantageous printed concrete body, in particular a printed concrete block, a printed concrete slab or a printed concrete step, is obtainable by the process according to the invention, in particular according to one of claims 1 to 16.

The invention further relates to a printed concrete body according to claim 19.

The present invention also relates to a printed concrete body, in particular a printed concrete block, a printed concrete slab or a printed concrete step, which has a printed concrete structure embedded in the concrete on at least one visible surface. dene printing, wherein only 5% to 90%, preferably 5% to 80%, more preferably 10% to 80%, particularly preferably 20% to 70%, in particular 30% to 70%, of the visible surface of the concrete body has a printing and the visible surface of the concrete body has a natural stone look, a wood look, a textile look, a tile look or a mosaic look due to the printing.

It has been shown that a concrete body whose visible surface is only 5% to 90% printed can be produced more cost-effectively than with the current state of the art. On the other hand, a particularly advantageous natural stone look, a wood look, a textile look, a tile look or a mosaic look can be achieved precisely by not printing the entire visible surface.

According to the invention, it can be provided that the printed visible surface of the concrete body has at least one coating covering the printing, preferably at least a lower coating made of an acrylate dispersion and an upper UV coating, in particular a varnish.

According to the invention, it can further be provided that printing is carried out directly on the concrete body and/or that no primer is applied to the visible surface below the printing.

According to the invention, it can further be provided that at least the visible surface of the concrete body is formed by a concrete colored before printing and/or a mixture of different colored concrete.

According to the invention, it can also be provided that the visible surface is printed with at least one, preferably several crack lines, in particular crack lines with a marble look, and/or structural lines and/or notches and/or speckles and/or spots and/or shading.

Furthermore, according to the invention it can be provided that the printing composition is a printing composition as described above, in particular a printing composition as defined in the claims, in particular in claims 11 to 16.

With regard to the advantages of the printed concrete body, reference is made analogously to the above statements on the method according to the invention.

Within the scope of the invention, it can be provided in particular that the printing consists exclusively of crack lines, structural lines, notches, speckles, shading and/or spots.

Features that have been described in connection with one of the objects of the invention, namely given by the method according to the invention, the device according to the invention and the concrete body printed according to the invention, can also be implemented advantageously for the other objects of the invention. Likewise, advantages that have been mentioned in connection with one of the objects of the invention can also be understood to relate to the other objects of the invention.

It should also be noted that terms such as "comprising", "having" or "with" do not exclude other features or steps. Furthermore, terms such as "a" or "the", which refer to a singular number of steps or features, do not exclude a plurality of features or steps - and vice versa.

It should be noted that terms such as “first” or “second” etc. are used primarily for reasons of distinguishability of respective device or process features and are not necessarily intended to indicate that features are mutually dependent or related to one another.

The invention is described in more detail below with reference to the drawing and an embodiment.

The figures each show preferred embodiments in which individual features of the present invention are shown in combination with one another. Features of one embodiment can also be implemented separately from the other features of the same embodiment.

In the figures, functionally identical elements are provided with the same reference symbols.

• 1 einen prinzipmäßigen Querschnitt durch eine Produktionsform mit einer beispielhaften Darstellung von fünf Verfüllformen, in denen jeweils ein Betonkörper ausgebildet ist bzw. ausgebildet wird, wobei der Betonkörper einen Vorsatzbeton und einen Kernbeton aufweist, und mit einer Darstellung von Stempeln, die von oben auf jeweils einen Betonkörper aufdrückbar sind, um diesen zu verdichten und gegebenenfalls zu strukturieren;
• 2 eine prinzipmäßige Darstellung eines Betonkörpers mit einer Sichtfläche, die durch eine Oberseite des Betonkörpers gebildet ist, wobei auf die Sichtfläche mittels des erfindungsgemäßen Verfahrens eine Bedruckung aufgebracht ist; und
• 3 eine prinzipmäßige Draufsicht auf eine Sichtfläche des Betonkörpers, die erfindungsgemäß bedruckt ist und die eine Natursteinoptik aufweist.

It shows:

• 1 a schematic cross-section through a production mold with an exemplary representation of five filling molds, in each of which a concrete body is or will be formed, wherein the concrete body has a facing concrete and a core concrete, and with a representation of stamps which can be pressed onto a concrete body from above in order to compact it and, if necessary, structure it;
• 2 a schematic representation of a concrete body with a visible surface, which is an upper side of the concrete body is formed, wherein a print is applied to the visible surface by means of the method according to the invention; and
• 3 a schematic plan view of a visible surface of the concrete body, which is printed according to the invention and which has a natural stone appearance.

The following exemplary embodiment serves to disclose an advantageous method for producing a printed concrete body 1 and to disclose an advantageous device for producing a printed concrete body 1. Furthermore, the exemplary embodiment serves to disclose an advantageous printed concrete body 1.

A printed concrete body 1 or a concrete body 1 produced according to the method or with the aid of the device is in principle in 2 shown.

The method according to the invention and the device according to the invention for producing a printed concrete body 1 are particularly suitable for producing a printed concrete block, in particular a paving stone, a printed concrete slab or a printed concrete step.

Accordingly, the concrete bodies 1 shown in the embodiment are preferably a concrete block, a concrete slab or a concrete step.

The method and device according to the invention provide that at least one visible surface 2 of the concrete body 1 is printed. A visible surface 2 of the concrete body 1 is to be understood in particular as a surface/side of the concrete body 1 that is visible or completely visible when the concrete body 1 is laid. Preferably, exactly one visible surface 2 of the concrete body 2 is printed using the method according to the invention.

In the exemplary embodiment, it is provided that 5% to 90%, preferably 10% to 80%, more preferably 20% to 70% and particularly preferably 30% to 70%, of the visible surface 2 of the concrete body 1 is printed in such a way that the visible surface 2 has a pattern through which the visible surface 2 of the concrete body 1 is given a natural stone look, a wood look, a textile look, a tile look or a mosaic look.

An example of printing the visible surface 2 in such a way that the visible surface 2 has a natural stone look is particularly in 3 shown.

In the exemplary embodiment, it is provided that the visible surface 2 is printed with at least one, preferably several, crack lines 3, in particular crack lines that simulate the cracks of a marble stone, and/or structural lines and/or notches 4 and/or speckles and/or spots and/or shading.

The printing with the crack lines 3 and/or the structural lines and/or the notches 4 and/or speckles and/or the spots is preferably carried out in such a way that, if necessary together with other printed images, such as shading, only the aforementioned percentage of the visible surface 2 of the concrete body 1 is printed.

After printing on the visible surface 2, the concrete body 1 is intended to harden. For hardening, the concrete body 1 can preferably be brought into a hardening area, in particular a drying chamber.

In the exemplary embodiment, it is provided that the visible surface 2 represents an upper side 1a of the concrete body 1. The concrete body 1 is preferably cuboid-shaped and further has a lower side 1b and side walls 1c running orthogonally thereto.

It should be noted that the visible surface 2 can also represent a bottom side 1b or one of the side walls 1c. Furthermore, it can be provided that several of the sides/walls 1a, 1b, 1c of the concrete body 1 are designed as visible surfaces 2 and printed using the method according to the invention.

In the exemplary embodiment, it is provided that at least one area of the visible surface 2 of the concrete body 1, in the exemplary embodiment the entire visible surface 2 of the concrete body 1, is colored before printing.

The natural color of a concrete used to produce the concrete body 1 is gray. In the exemplary embodiment, it is preferably provided that at least the concrete that forms the visible surface 2 of the concrete body 1 is colored before printing in such a way that the color of the concrete deviates from the natural color, possibly only by choosing a different shade of gray and/or by designing the concrete in such a way that a marbling effect is created and/or by adding fine-grained aggregates, for example made of granite or basalt, to the concrete. The concrete can also be given a structure and/or a multi-colored design.

In the embodiment, it can be provided that, in order to produce the concrete body 1, a colored concrete and/or a mixture of different colored concrete is filled into a filling mold 5 for forming the concrete body 1. A filling mold 5 for forming a concrete body 1 is in principle in the 1 shown. The 1 shows a production mold 6 for producing a layer of concrete bodies 1. In the exemplary embodiment, the production mold 6 has five filling molds 5 in order to form a corresponding number of concrete bodies 1. In the exemplary embodiment, it is provided that after the concrete has been poured into the filling mold 5, vibration and compaction take place, preferably using a stamp 7.

In the 1 a particularly advantageous method for producing the concrete body 1 is shown. It is provided that first a so-called core concrete is filled into the filling mold 5 to form a base body 8 of the concrete body 1. The core concrete used to produce the base body 8 is preferably not colored. After filling the core concrete, in the embodiment according to 1 a colored concrete and/or a mixture of different colored concrete is poured into the filling mold 5 to form the visible surface 2 of the concrete body 1. This is preferably a so-called facing concrete, which is generally less coarse than the core concrete. The concrete that forms the visible surface 2 of the concrete body 1 or the facing concrete differs in color from the core concrete in that the facing concrete is colored and/or is made from a mixture of different colored concrete.

The facing concrete or the concrete that forms the visible surface 2 is referred to in the embodiment as the facing layer 9. The base body 8 and the facing layer 9 together form the concrete body 1.

To produce a mixture of different coloured concrete, a colouring process is preferably used within the scope of the invention as described in EP 2 237 937 B1 described.

As in 1 and in 2 As shown in principle, it is preferably provided that the concrete body 1 is essentially formed from the base body 8 or the core concrete, preferably at least 80%, and the concrete which forms the visible surface 2, ie the facing layer 9 made of the facing concrete, makes up at most 20% of the volume of the concrete body 1.

To produce the concrete body 1, it is preferably provided that the core concrete is first filled into the filling mold 5. This is then preferably followed by vibration and/or intermediate compaction, preferably using the stamp 7. The facing concrete is then filled into the filling mold 5 to form the facing layer 9.

This is followed by vibration and compaction, preferably using the stamp 7. Vibration units are preferably used for vibration, which are placed underneath the production mold. After the face concrete has been poured in, the main compaction preferably takes place. It can be provided that a structure is introduced into the visible surface 2 of the concrete body 1 using the stamp 7. It can also be provided that a bevel is introduced all the way around the edge of the visible surface 2. The concrete body 1 is then removed from the filling mold 5 or demolded.

The order of filling the core concrete and the facing concrete can also be reversed, i.e. the facing concrete is filled into the filling form 5 first. Furthermore, facing concrete can be filled both before and after the core concrete.

The method according to the invention for printing the concrete body 1 can basically be carried out in any state of the concrete body 1, in particular also as a dry printing method. However, it has proven to be particularly advantageous if the printing of the concrete body 1 is carried out in a green state of the concrete body 1, in which the concrete body 1 is dimensionally stable but not yet hardened.

The concrete body 1 can be printed while the concrete body 1 is still in the filling mold 5 in which the concrete body 1 is compacted. However, it is advantageous if the concrete body 1 is printed after the concrete body has left the filling mold 5 in which the concrete body 1 is compacted.

In the exemplary embodiment, it can be provided, in a manner not shown, that a coating is applied after printing on the visible surface of the concrete body, but before hardening. The coating is preferably a coating made of an acrylate dispersion. The coating is preferably sprayed on. A rolling or curtain casting process can also be suitable for applying the coating.

In the exemplary embodiment (not shown), it can be provided that after hardening, ie a coating is applied, preferably sprayed on, to the printed and hardened visible surface 2 of the concrete body 1. This is preferably a coating that hardens with the aid of UV radiation or is self-hardening.

It can also be provided that more than one coating, for example two coatings, are applied to the printed and cured visible surface 2 of the concrete body 1, of which preferably one coating is a UV coating, preferably a UV varnish.

It has proven to be particularly suitable if, after printing but before curing, a coating of acrylate dispersion is applied to the visible surface 2 of the concrete body 1 and then, when the concrete body 1 has cured, at least one further coating, in particular a UV coating, is applied to the cured visible surface 2 of the concrete body 2.

In the exemplary embodiment, it is provided that the printing of the visible surface 2 of the concrete body 1, in particular a green-stable concrete body 1, is carried out with a printing composition 10, essentially consisting of color-imparting inorganic pigments and a preferably binder-free solvent (first embodiment) or a preferably binder-free solvent mixture (second embodiment). In 2 a reservoir 11 for receiving the printing composition 10 is shown only schematically. Furthermore, in 2 , also only schematically, a printer 12 is shown, in the embodiment preferably an inkjet printer, with which the printing of the visible surface 2 of the concrete body 1 takes place. In this case, printing preferably takes place directly on the visible surface 2 of the concrete body 1, ie directly on the concrete, in particular the facing layer 9.

In the exemplary embodiment (third embodiment), printing with a printing composition 10 can also be provided, which essentially consists of color-imparting inorganic pigments, polyacrylate as a binder and a solvent or a solvent mixture.

In the first embodiment of the printing composition 10, it is preferably provided that the solvent does not contain any siloxane, silane or resin, i.e. it is siloxane-free, silane-free and resin-free. The coloring pigments are preferably UV-resistant. Furthermore, in the first embodiment, it is provided that the solvent does not contain any water or is not an aqueous system. In the first variant, the printing composition 10 can preferably consist of 10% to 90% by weight of the solvent and a corresponding percentage by weight of the coloring pigments and of any unavoidable residual impurities.

In the second embodiment of the printing composition 10, it is preferably provided that the solvent mixture contains no siloxane, no silane and no resin, i.e. that the solvent mixture is siloxane-free, silane-free and resin-free. In the second embodiment of the printing composition 10, it is preferably provided that the coloring pigments are UV-resistant. Furthermore, in the second variant, it is provided that the solvent mixture has a water content of 10 wt.% to 90 wt. Within the scope of the printing composition 10, it can be provided that the coloring inorganic pigments make up 20 wt.% to 40 wt., i.e. the printing composition 10 consists of 20 wt.% to 40 wt.% of the coloring pigments and the solvent mixture has a corresponding weight percentage, so that the printing composition 10 is formed from these two components. Within the scope of the solvent mixture, the water content can be between 10% by weight and 90% by weight, preferably between 30% by weight and 60% by weight.

In the third embodiment of the printing composition 10, in which it is provided that polyacrylate is used as a binder in the printing composition 10, a solvent or a solvent mixture can be used, which can be selected in such a way as was described in the first embodiment and the second embodiment of the printing composition 10. In the third embodiment, it can be provided that the printing composition 10 consists of 20 wt.% to 40 wt.% of the color-imparting, inorganic pigments.

Within the scope of the method according to the invention, it is preferably provided that printing takes place directly on the visible surface 2 of the concrete body 1. Within the scope of the method according to the invention, it is particularly provided that no primer is applied to the visible surface 2 before printing, i.e. the visible surface 2 is primer-free.

In the embodiment (not shown) it can be provided that after printing, in particular after curing, the visible surface 2 is subjected to a structure-imparting surface treatment, preferably by brushing, Embossing, tapping or striking, in particular by shot blasting, as described in EP 1 893 391 B1 described.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• DE 102017005280 B4 [0007, 0008, 0011, 0065]
• DE 102006014900 A1 [0009, 0010]
• EP 2237937 B1 [0035, 0129]
• EP1893391B1 [0146]

Claims (24)

Method for producing a printed concrete body (1), in particular a printed concrete block, a printed concrete slab or a printed concrete step, comprising at least the following steps: - printing at least one visible surface (2) of the concrete body (1); and - hardening the concrete body (1) after printing, characterized in that 5% to 90% of the visible surface (2) of the concrete body (1) is printed such that the visible surface (2) has a pattern through which the visible surface (2) of the concrete body (1) is given a natural stone look, a wood look, a textile look, a tile look or a mosaic look. Procedure according to Claim 1 , characterized in that 5% to 80%, preferably 10% to 80%, particularly preferably 20% to 70%, in particular 30% to 70%, of the visible surface (2) of the concrete body (1) is printed. Procedure according to Claim 1 or 2 , characterized in that the visible surface (2) of the concrete body (1) is printed with at least one, preferably several crack lines (3), in particular crack lines (3) with a marble look, and/or structural lines and/or notches (4) and/or speckles and/or spots and/or shades. Procedure according to Claim 1 , 2 or 3 , characterized in that at least one region of the visible surface (2) of the concrete body (1), preferably the entire visible surface (2) of the concrete body (1), is colored before printing. Method according to one of the Claims 1 until 4 , characterized in that the visible surface (2) of the concrete body (1) is given a marbling appearance and/or a structuring and/or a multi-colored design by the concrete used to produce the concrete body (1) before printing and/or a color and/or additives, in particular fine-grained additives, are added to the concrete used to produce the concrete body (1). Method according to one of the Claims 1 until 5 , comprising the following step: - pouring a colored concrete and/or a mixture of different colored concrete into a filling mold (5) to form the concrete body (1), or - pouring a concrete into a filling mold (5) to form a base body (8) of the concrete body (1) and pouring a colored concrete and/or a mixture of different colored concrete into the filling mold (5) to form the visible surface (2) of the concrete body (1), wherein the concrete which forms the base body (8) of the concrete body (1) differs in color from the concrete and/or the mixture of different colored concrete which forms the visible surface (2) of the concrete body (1). Method according to one of the Claims 1 until 6 , characterized in that the printing of the concrete body (1) is carried out in a green state of the concrete body (1), in which the concrete body (1) is dimensionally stable but not yet hardened. Method according to one of the Claims 1 until 7 , characterized in that the concrete body (1) is printed while the concrete body (1) is still in a filling mold (5) in which the concrete body (1) is compacted, or the concrete body (1) is printed after the concrete body (1) has left a filling mold (5) in which the concrete body (1) is compacted. Method according to one of the Claims 1 until 8th , comprising the following step: - applying, preferably spraying, at least one coating, preferably made of an acrylate dispersion, to the printed visible surface (2) of the concrete body (1) before curing. Method according to one of the Claims 1 until 9 , comprising the following step: - applying, preferably spraying, at least one coating, preferably a UV coating, in particular a varnish, to the printed and cured visible surface (2) of the concrete body (1). Method according to one of the Claims 1 until 10 , characterized in that the printing is carried out with a printing composition (10), essentially consisting of color-imparting inorganic pigments and a, preferably binder-free, solvent or a, preferably binder-free, solvent mixture. Method according to one of the Claims 1 until 10 , characterized in that the printing is carried out with a printing composition (10), essentially consisting of color-imparting inorganic pigments, polyacrylate as a binder and a solvent or a solvent mixture. Procedure according to Claim 11 or 12 , characterized in that a) the solvent is siloxane-free and/or silane-free and/or resin-free, and/or b) the coloring pigments are UV-resistant, and/or c) the solvent has no water content or is not an aqueous system, and/or d) the printing composition (10) consists of 10 wt.% to 90 wt.% of the solvent and the coloring pigments. Procedure according to Claim 11 or 12 , characterized in that a) the solvent mixture is siloxane-free and/or silane-free and/or resin-free, and/or b) the coloring pigments are UV-resistant, and/or c) the solvent mixture has a water content of 10 wt. % to 90 wt. %. Method according to one of the Claims 1 until 14 , characterized in that printing is carried out directly on the concrete body (1) and/or no coating and/or no primer is applied to the visible surface (2) before printing. Method according to one of the Claims 1 until 15 , characterized in that the printing is carried out using an inkjet printing, screen printing, powder coating, laser printing, needle printing, electrostatic printing, liquid printing, digital printing and/or pad printing process. Device for producing a printed concrete body (1), in particular a printed concrete block, a printed concrete slab or a printed concrete step, with a reservoir (11) for receiving a printing composition (10) for printing the concrete body (1) and with a printer (12) for printing at least one visible surface (2) of the concrete body (1), wherein the printer (12) is designed and arranged to produce a green-stable concrete body (1) according to a method according to one of the Claims 1 until 16 to print. Printed concrete body (1), in particular printed concrete block, printed concrete slab or printed concrete step, obtainable by a process according to one of the Claims 1 until 16 . Printed concrete body (1), in particular printed concrete block, printed concrete slab or printed concrete step, which has a print integrated into the concrete on at least one visible surface (2), wherein only 5% to 90%, preferably 10% to 80%, more preferably 20% to 70%, particularly preferably 30% to 70% of the visible surface of the concrete body (1) has a print and the visible surface of the concrete body (1) has a natural stone look, a wood look, a textile look, a tile look or a mosaic look due to the print. Printed concrete body (1) after Claim 19 , characterized in that the printed visible surface (2) of the concrete body (1) has at least one coating covering the printing, preferably at least a lower coating made of an acrylate dispersion and an upper UV coating, in particular a UV varnish. Printed concrete body according to Claim 19 or 20 , characterized in that printing is carried out directly on the concrete body (1) and/or no primer is applied to the visible surface (2) below the printing. Printed concrete body according to one of the Claims 19 until 21 , characterized in that at least the visible surface (2) of the concrete body (1) is formed by a concrete colored before printing and/or a mixture of different colored concrete. Printed concrete body according to one of the Claims 19 until 22 , characterized in that the visible surface is printed with at least one, preferably several crack lines (3), in particular crack lines (3) with a marble look, and/or structural lines and/or notches (4) and/or speckles and/or spots and/or shades. Printed concrete body according to one of the Claims 19 until 23 , characterized in that the printing composition (10) in one of the Claims 11 until 16 is defined.

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