WO2022175579A1

WO2022175579A1 - Composite structure and use thereof in construction

Info

Publication number: WO2022175579A1
Application number: PCT/ES2022/070082
Authority: WO
Inventors: José Ramón ALBIOL IBÁÑEZ; Miguel SÁNCHEZ LÓPEZ
Original assignee: Universitat Politècnica De València
Priority date: 2021-02-19
Filing date: 2022-02-18
Publication date: 2022-08-25
Also published as: ES2826674B2; ES2826674A1

Abstract

The present invention relates to a composite structure comprising a frame formed by a platform that has reinforcement elements joined thereto on at least one of the main faces thereof, such that the free ends of the reinforcement elements reach or project beyond the upper visible face of the composite structure, the lower visible face thereof or both, giving rise to pattern images visible on the upper or lower visible face or both, the reinforcement elements being bonded by at least one filling material that occupies all the space delimited by the external faces of the structure, except the space occupied by the frame. The structure is characterised in that the platform does not reach either of the two visible faces of the structure, and in that at least 5%, preferably 10%, of the total number of reinforcement elements have different-sized cross-sections. The invention also relates to the use of the structure in construction, in the advertising industry or the furniture industry.

Description

COMPOSITE STRUCTURE AND ITS USE IN CONSTRUCTION TECHNICAL SECTOR

The present invention is related to materials for the construction, advertising or furniture industry.

STATE OF THE ART In the construction industry, including the furniture industry, there are currently many needs that are not met in the most appropriate and economical way.

In particular, in the manufacture of composite structures in which images are to be displayed on the visible faces of the structure, and more particularly, in the manufacture of large-format structures, there are many drawbacks with current materials and methods. These drawbacks are concentrated in a special way in aspects such as the resistance of the structures and economic aspects.

Current concretes are complex to manufacture, with very limited and rigid geometries. Its expensive elaboration, implies excessively high sales prices and within the reach of a few. The use of materials such as fiber optics in the case of translucent concrete makes the product especially expensive. The way it is made does not allow large formats and small thicknesses, which means that the weight of the structures is high. The structural resistance is scarce, requiring auxiliary elements for its use in panels.

Document US2018071949A1 discloses a composite material, which can be printed by 3D printing and formed by reinforcing fibers of polypropylene, carbon fiber, optical fiber, metal, PET, PP, PE or basalt, and a matrix based on cementitious material. Once the fibers have been printed, the prototype is filled with the cementitious material. It discloses a lost formwork system (technical type of Ferrocement) that uses a robotic arm to make a kind of shotcrete. According to this document, the reinforcing elements described can be meshes or tubes, but the structure does not have an internal platform located inside the piece on which they are placed. filaments, which are also capable of forming certain images or patterns, visible on the external faces of the piece and therefore the obtaining of pattern images on the visible face or faces of the structure is not mentioned or described.

Document CH713396A1 describes a translucent object comprising a hardenable moldable material and a plurality of optical fibers embedded in the molded material. The optical fibers are arranged in a three-dimensional structural framework formed by a mesh, where the fibers pass through the mesh in such a way that the ends of said fibers protrude laterally from the mesh of the frame and at different points of the object, all of this such that the molded material surrounds the structural framework and the plurality of fibers. In this way, light passes from one point on the surface of the object to another point on the surface, and can enter the object at one point and leave the object at another point.

The three-dimensional structural framework may have any shape, eg, cubic, pyramidal, cylindrical, or other three-dimensional shape, depending on the design specifications of the object. The external shape of the fabricated structure is substantially determined by the three-dimensional shape of the structural frame, which acts as a kind of exoskeleton, or external metallic reinforcement. The structure itself can form a design object, such as a lamp, decorative element, or piece of furniture, or it can be used as a component in the design of larger structures, such as large-format furniture and even buildings. The structural frame described in CH713396 does not correspond in any case to the internal platform of the composite structure object of the present invention. In addition, the internal platform in the present invention is located inside the piece or composite structure with composition, shape and filling characteristics that prevent large format and thin structures from breaking. Another difference of the present invention that confers an advantage is that the reinforcing elements arranged on the internal platform can give rise to any type of desired image or pattern, in addition to the fact that they can have variable thicknesses of reinforcing elements. Document US2020005757A1 refers to a soundproofing structure for selectively absorbing low-frequency sound, comprising one or more soundproofing cells that are formed by a frame, a hole passing through the frame and a vibrating film fixed to the frame, such that the film covers an opening surface of a portion of the hole. The cells have a plurality of projecting portions arranged on the film and fixed to the frame, and a rear member fixed to the frame, said member covering the other opening surface of the aforementioned hole portion. The cell frame can be made of ceramic, glass, polyamide, for example. However, this document, in addition to pursuing a different objective, is far from the object of the present invention because it does not disclose a structure with an internal platform of a particular material located in a specific area of the structure on which reinforcing elements are arranged. Document FR3060043A1 discloses a multiplatform translucent composite material, manufactured by 3D printing and that includes elements that give it a phosphorescent property, in order to provide visibility to a construction in dark conditions. The composite material is also made up of a matrix based on cementitious material arranged between said elements. However, the material grafts described in this document are not equivalent to the reinforcing elements of the present invention, neither in structure nor in composition. Therefore, it does not disclose reinforcing elements on a platform, which give rise to pattern images on the visible faces of the structure, bonded by a filler material.

US20100281802 discloses a building block that comprises a platform housed inside it that has translucent elements on it and, optionally, also reinforcement elements. However, the translucent elements are all the same with respect to their cross section, unlike the present invention, in which, on the one hand, there are no reinforcement elements differentiated from the translucent elements, and on the other hand, said reinforcement elements they have at least in a portion of them, different transversal section. With this, an enormous flexibility is achieved in the constructive possibilities. Document KR20150144503A refers to a multiplatform composite material, manufactured with 3D printers, from reinforcing materials and a matrix of cementitious material, which is poured into the gaps left by the reinforcing materials. It does not mention an internal platform housed in the structure that provides it with rigidity, and on which the reinforcing elements are arranged.

The present invention solves the problems of the state of the art on obtaining large format and thin composite structures, and has the following advantages:

- allows to build a multi-platform lightweight resistant structural system, with composite materials.

- Allows ease in the elaboration and automation of production.

- allows finishes with any type of geometry and ease of reproduction. - allows production of large formats and minimum thicknesses at low cost.

- facilitates transport and installation, reducing costs and carbon footprint.

- it is very economical, even in the case of using fiber optics for the reinforcing elements. The present invention makes it possible to make all kinds of formats and especially large formats and even "oversize", without structural problems.

The composite structures are obtained by the union and strategic arrangement of the reinforcing elements and the filling arranged between them, conferring, for any aesthetic design of the composite structures, an internal structural rigidity suitable for large formats and small thicknesses.

The way of using the filler and the reinforcing elements together and the geometry of the deposition of the reinforcing elements, is what provides the advantages of the invention.

DESCRIPTION OF THE INVENTION

The present invention refers to a composite structure formed by: - a frame composed of:

- a platform that has attached to it, and on at least one of its main faces, reinforcing elements, such that the free ends of the reinforcing elements reach or exceed the upper visible face, or the lower visible face, or both , of the composite structure, giving rise to pattern images, visible on one or both of the top and bottom views, and the reinforcing elements are bonded by

- at least one filling material that occupies the entire space delimited by the external faces of the structure, except for the space occupied by the frame, characterized in that the platform does not reach any of the two visible faces of the structure, and that at least 5%, preferably 10% of the reinforcing elements with respect to the total number of reinforcing elements, have cross sections of different sizes.

According to a particular embodiment, the composite structure of the invention has reinforcing elements only on one of the main faces of the internal platform.

All the alternatives described below in this report relative to the case in which the reinforcing elements are arranged on both main faces apply equivalently to the case in which the reinforcing elements are arranged on only one of these two main faces of the internal platform.

In the event that the composite structures have reinforcing elements only on one of the main faces of the platform, if they include lighting devices, they will also only be in the same area of the frame that has the reinforcing elements.

Reinforcing elements of different thicknesses or different sections give rise to technical advantages: the first advantage refers to structural behavior, providing greater fixation of the reinforcing elements to the fill, providing the assembly with greater stability against bending and torsion at As the format of the composite structure. In addition, greater clarity and definition is achieved in the images obtained, giving an improved three-dimensional appearance in the same plane.

That "the platform does not reach any of the two visible faces of the structure", means that the platform is located at a minimum distance from the visible faces of the structure, of at least 1% of the length of the structure composed in one direction perpendicular to any of the seen faces - direction of the Z axis - at any point on the surface of the platform. That is, with respect to the Z axis direction, the platform is located inside the composite structure.

The platform can reach an external surface of the perimeter faces of the composite structure, but in no case does it reach the visible faces or upper and lower visible faces of the structure.

The platform preferably has two dimensions of a length at least 50% greater than the length of the third dimension.

"Viewed faces" refer in this specification to the upper and lower external faces of the structure, which are the visible faces, on which pattern images are obtained.

“Perimeter faces” are all external faces of the composite structure other than the top and bottom faces.

"Filling" and "filling material" are used interchangeably herein.

The visible faces, or visible faces of the composite structure, may be formed by portions or fragments at different levels, that is, they may not have their entire surface in the same plane.

The visible faces of the composite structure can also be curved.

They may also have, according to further embodiments, contour lines. That the composite structure has contour lines means that the surface of one or both visible faces can be divided into at least two portions that are in different planes, that is, that reach different heights on the vertical axis or Z axis. In other words, having contour lines means that the thickness of the structure along the X and Y axes is variable.

The reinforcing elements may be flush with one or both of the visible faces, or beyond the upper and/or lower visible faces, with the reinforcing elements equidistant from the visible faces, or beyond the upper and/or lower visible faces, with the reinforcing elements not equidistant from the faces.

According to particular embodiments, the filler material shapes the composite structure, forming its external faces, and the free external faces of the reinforcing elements are in this case flush with one or both of the visible faces. According to other alternatives, the filler material forms the external faces of the composite structure, and the free external faces of the reinforcing elements protrude from the visible faces formed by the filler material. When the free ends of the reinforcing elements protrude from the visible faces of the structure, they can end up giving rise to a flat surface, or they can give rise to surfaces with different levels, warped or with contour lines.

In addition, the reinforcing elements can be of different lengths on one side and the other of the platform, if they are present on both sides. The exposed faces of the composite structure may be warped or may have level surfaces. In addition, both things can happen in a structure: that is, one or both of the visible faces may have a warped surface and simultaneously the reinforcing elements may be protruding from one or both of the visible faces, and the reinforcing elements may be of the same or different length.

According to particular embodiments, the platform is located at a minimum distance of at least 1%, it can be for example 3%, or 5%, 30%, 60% or even up to 90%, of the total length of the platform. composite structure in a direction perpendicular to one of the top and bottom views, ie the height of the composite structure. According to particular embodiments, the platform can be arranged parallel to one or both of the visible faces of the structure or it can be arranged at an angle with one or both of the visible faces. According to a particular embodiment, the internal platform is flat

According to a further particular embodiment, the internal platform is not flat.

“Main face” of the platform refers to the upper face or the lower face in case the platform is flat or warped; or it refers to the upper face or the lower face with the largest surface, respectively, in the event that the platform is formed by portions of several levels.

The inner platform may have main faces that are not parallel to each other. It can also be warped, or even contoured. That the platform has contour lines means that it can be divided into at least two portions that are in different planes, that is, that they reach different heights on the vertical axis or Z axis. That it has contour lines means that the thickness of the internal platform along the X and Y axes is variable. This may be due to the structural calculation that is necessary depending on the efforts that the composite structure as a whole must withstand when it is a large-format structure.

The internal deck may be solid or it may be partially hollow, with perforations passing through it, eg of the mesh, or grid type. The internal platform may have holes that give it the shape of a lattice. Preferably, the platform comprises recesses. It can have between 1 and 99% of its hollow volume, preferably between 10% and 90% and more preferably between 30 and 50%. The gaps give the platform a mesh-like structure. The holes can have a section of diverse geometry. For example, it can be gaps that give the deck a grid shape, a line pattern, or a honeycomb pattern. They can be hollow with a cross section in the form of a spiral, concentric, gyroid, zig-zag, with a cross section in the form of a regular polygon such as a parallelogram, pentagon, triangle, combinations thereof. For example, the holes can have a frustopyramidal, cubic, prismatic, octagonal, etc. shape. These meshes or types of grid can give rise to fill patterns with the shapes mentioned in the previous paragraph, corresponding to each mesh: for example, in the form of a grid, lines, triangles, cubic (filling of inclined cubes), tetrahedral , concentric, gyroid, honeycomb or zigzag, so that the fill pattern can be seen on the visible faces of the structure.

In the case of a partially hollow platform that includes perforations, the reinforcing elements are arranged on the edges that make up the holes in the platform, and according to the image that is intended to be obtained on one or both of the visible faces of the structure.

In the case of a solid platform, its surface does not reach the perimeter faces of the structure, but in this case, the perimeter faces form a wall that forms a frame made up of filler material. Said wall rises in this case on the four perimeter faces of the composite structure.

The platform may or may not be centered with respect to the vertical direction of the part, that is, with respect to the length of the composite structure in the Z-axis direction. Preferably, the platform is centered, and therefore both equidistant from the upper view face and from the lower view face of the composite structure.

The platform can have a thickness on the Z axis of the composite structure between 1 and 99%, for example between 10 and 95% of the total thickness of the composite structure, preferably between 40 and 60% of the total height of the composite structure. For example, when the thickness of the platform is 80% of the total height of the composite structure, and in the case that the internal platform is centered with respect to the Z axis (that is, with respect to the vertical direction of the composite structure ), this means that the platform will be at a distance from any of the visible faces of the composite structure of 10% of the length of the structure along the Z axis.

The platform can be arranged at any height of the composite structure, but it will not reach any of the two visible faces of the same. According to particular embodiments, the platform is flat and parallel to the XY plane of the composite structure.

According to particular embodiments, the platform can extend in the XY plane until it has a maximum surface area of 99% of the section of the composite structure in the XY plane, in the event that the platform is solid. The platform has a length in the X axis direction of at least 80% of the length of the composite structure in that direction, and preferably at least 90% of the length of the composite structure in the X axis direction. X, and has a length of at least 80% of the length of the composite structure in the Y-axis direction, and preferably at least 90% of the length of the composite structure in the Y-axis direction.

The perimeter planes of the composite structure may be composed of filler material with a minimum thickness of 3 mm, when the internal platform does not reach the perimeter faces of the structure.

When the deck has perforations through it, and is therefore partially hollow, it can extend in the XY plane to the perimeter edges of the composite structure.

The reinforcement elements, by virtue of their arrangement on the platform, their thickness, their length and/or their composition, can give rise to visible pattern images on one or both of the top and bottom views of the composite structure,

The reinforcing elements can be arranged at any angle with respect to the platform. The reinforcing elements may or may not be parallel to each other. Preferably, the reinforcing elements are arranged parallel to each other to improve light transmission when necessary. More preferably they are parallel to each other and perpendicular to the platform. This arrangement favors light transmission if necessary.

Also its position on the main face or faces of the platform can be any, and therefore, it is not conditioned to a certain grid resolution. (type and/or size of the holes in the case of a mesh-type platform). The reinforcing elements may be arranged on one or both sides of the platform in a regular order, such as a geometric pattern, or in an unordered manner.

In the composite structure of the invention, the reinforcing elements may have a different cross-sectional shape. The reinforcement elements can be in the form of a filament (pillar type) or surface (wall type). Filament-type and wall-type reinforcing elements may be present in the same composite structure. In the event that a structure has only filament-type elements, these have at least 5%, preferably 10%, of different thicknesses. And similarly, in the event that it only has wall-type reinforcement elements, these will have a different cross-section in at least 5%, preferably 10% of them.

When in the composite structure the reinforcing elements are filaments, there may be filaments of different cross-sections in combination. For example, there may be filaments with different shapes in the structure, such that they may have a polygonal section of any type, such as triangular, square, rectangular, circular, star-shaped, among others.

The platform may also have reinforcing elements distributed over 100% of the surface of one or both main faces, or said faces may be partially free of reinforcing elements.

The composition of the framework (platform and reinforcement elements) of the composite structure can be made of various materials. The reinforcement elements and the platform are of the same material as each other.

The frame, and therefore the platform and reinforcement elements, can be translucent, transparent, photoluminescent or opaque. The frame can be made of a material selected, for example, among: polylactic acid (PLA), acrylonitrile-butadiene-styrene (ABS), flexible thermoplastic elastomer (Flexible TPE), carbon fiber, polyethylene terephthalate (PET), polyethylene glycol (PETG), PETT, high impact polystyrene (HIPS), polyvinyl butyral, fiber optics, nylon, polycarbonate, carbon fiber, polypropylene, fiberglass, metal such as aluminum, photopolymerizable resins such as epoxy resins.

The material that makes up the frame can be a luminescent material. The frame may further comprise one or more lighting devices, such as LED devices. The lighting devices (for example, LEDs) can be arranged both on the edges of the frame and in internal areas.

For example, the frame can have lighting devices arranged in a strip of devices (such as LED diodes) that is located attached to one or more sides of the platform that supports the reinforcing elements so that they light up and can be seen. in dark ambient conditions (at night or in a closed room).

Optionally, an electronic board with a printed circuit and lighting, for example, with LED-type lighting devices, can be included within the frame itself before the matrix is poured.

In the case of having lighting devices, the frame has at least one cable for connection to the electrical network.

According to particular embodiments, a strip of lighting devices can be controlled thanks to a cable arranged on one of the sides of the platform (preferably one of the 4 perimeter faces) and which is connected to a power supply external to the structure, which can be available, for example, on a wall.

According to additional particular embodiments, the platform can incorporate a battery that allows the lighting to be maintained in the established conditions for the duration of its charge. In order to increase the duration between charges, a microcontroller chip and, optionally, some sensor can be included in the assembly, which allows the lighting of the lighting devices to be conditioned to the desired lighting level, for example, in a room, so that only is activated when it is dark and it is possible that said lighting, for example, of the LED type, will be seen. The structure of the invention can have permanent or intermittent lighting. According to additional particular embodiments, the lighting obtained is not constant but in the form of flashes to reduce consumption and increase battery life, in the specific case that the electricity comes from a battery.

The battery charge can be obtained through an external power supply or by replacing it if so decided. In any case, access to some of the non-visible faces, that is, the perimeter faces, is necessary in these alternatives of the structure of the invention to connect the power supply or to change the battery. In the case of the feeder, the way to access the perimeter faces can be, for example, by means of a cable that protrudes from one of said perimeter faces.

In the case of exchanging the battery, it will be housed in a box, for example, made of polymeric composition, inside the composite structure flush with one of the perimeter faces, as a register box.

According to additional particular embodiments, it is also possible to completely eliminate the need for the use of cables by incorporating wireless charging technology into the frame, which only requires the placement of a charging coil on one of the four perimeter faces of the structure, to allow permanent recharging of the battery. In this case, the battery and lighting devices, such as LEDs, are located inside the frame, as well as a circuit that protects the battery from possible overloads.

In general, battery-based lighting systems, compared to those that only use power from the electrical network, have the advantage that they will work for hours or days after a power outage, while the latter will turn off as soon as possible. power outage occurs.

In order to be able to incorporate and survive the pouring of the material that is going to fill the structure, the lighting devices, the battery and the electronic board, or any element on which the lighting devices are arranged, are covered - in these cases - with a protective coating. .

In order to achieve the best lighting performance and when the lighting obtained through the use of a strip of lighting devices on the platform proves insufficient, an alternative comprises arranging lighting in each of the reinforcing elements. In this case, a printed circuit is arranged under each and every one of the reinforcing elements (see figure 6).

The platform, and therefore the frame, is what prevents the piece from breaking, which is why large-format composite structures can be manufactured, for example, for facades. A large format composite structure can be, for example, a 5 meter long composite structure with a thickness of 5 cm. For smaller format structures, such as 2x3 m, the thickness can be 10 mm.

The usual in large formats are, for example, composite structures from 100x50x3 cm to structures of 500x200 x 5 cm, but it can be any.

The pattern images visible on one or both of the top and bottom views of the composite structure can be of any type, for example, patterns resulting simply from the geometry of the openings in a mesh-type platform, or they can be legends, numbers , objects, landscapes, reproductions of portraits, works of art, etc.

The padding of the areas above and below the internal platform can be of the same material or of different material.

According to particular embodiments, the filling material of the composite structure is a single material, and the same, above and below the internal platform.

According to particular embodiments, the filler material of the part of the composite structure above and below the internal platform is different from the material of the frame.

According to particular embodiments, the material of the padding of the part of the composite structure above and below the internal platform is the same as the material of the frame. In this case, the reinforcement elements have artificial lighting, so that the image can be seen on the visible faces of the structure. The backfill material must be a very fluid self-compacting material.

The filling material can be any material commonly used in construction, which is fluid enough to be poured into a mould.

According to particular embodiments, the filler of the composite structure is a polymeric matrix that can be:

- a resin matrix,

- a ceramic matrix - a cementitious matrix, such as a mortar, micro-concrete, or polymer concrete or micro-mortar

- a geopolymer.

The matrix may comprise materials based on polyester resins such as polyethylene terephthalate, polyethylene naphthalate, vinyl ester resins, acrylics such as polymethylmethacrylate or, epoxy, phenolic, urethane, cement, geopolymers and mixed.

A micro-mortar is a mortar with very small aggregates, usually less than 1 mm. A micro-concrete is a concrete with very small aggregates, usually less than 1 mm.

The composition of the filling of the composite structure is independent of its manufacturing method, which can be molding or 3D printing.

The external shape of the composite structure can be any geometric shape. According to a particular embodiment, it has the shape of a polyhedron, such as a parallelepiped, for example a cube. The rectangular parallelepiped shape is particularly suitable, among other uses, for countertops, tiles, flat pieces, boards, cladding.

The thicknesses of the composite structure are variable at the request of the design, in the case of boards or cladding pieces it will be between 4 - 50 mm approximately. The perimeter planes of the structure are perpendicular in the case of orthohedral shapes, but in other cases they can have different degrees of inclination, depending on the geometric shapes that are to be given to the composite structure.

The composite structures resulting from the union and strategic arrangement of the reinforcing elements and their filling, confer, for any aesthetic design of the composite structures, an internal structural rigidity suitable for large formats and small thicknesses.

The present invention also relates to a method for manufacturing the composite structure defined above, comprising:

- a first stage that comprises obtaining a design of the internal platform and the reinforcing elements, that is, of the frame, according to the image that is desired to appear on at least one of the two visible faces of the composite structure

- a second stage comprising obtaining the frame, or a matrix of said frame, by 3D printing,

- a third step comprising placing the frame inside a mold and filling the hollow space between the mold and the frame with filler material, obtaining the composite structure in its intended shape and size.

Frame "matrix" refers to a frame negative. From a negative obtained by 3D printing, a mold (a frame positive) can be obtained to obtain all the desired frame units with the help of said mold, by a molding technique, such as injection molding. These are particular embodiments of the process of the invention.

After the third stage, the structure obtained is hardened or cured. The structure can be allowed to cure at room temperature or can be actively cured if desired, for example, in an oven or autoclave. The structure preferably hardens at room temperature. Finally, the method optionally comprises polishing the obtained composite structure.

The image that is desired to appear on each of the two visible faces of the composite structure facing each other may be the same or different. According to particular embodiments, the first stage comprises performing a triangulation, for example, a "Delaunay triangulation" using a computer tool, obtaining a design of the internal platform and the reinforcement elements. The computer tool can be conventional, with the only requirement that it has the ability to perform triangulations, such as any computer program that contains the option to perform the "Delaunay triangulation".

In the second stage, a printer converts an image obtained in the first stage into reinforcement elements that grow in the upward direction of the Z axis. The second stage comprises 3D printing the frame, or a negative of the frame.

Various printing technologies can be used, for example:

The most widely used are FDM (thermoplastic filament melt deposition), stereolithography (SLA) that uses a photopolymerizable liquid resin, and selective laser sintering (SLS) that works by joining particles of powdered material to form the piece through the heat action of a laser.

Preferably, it is desirable that the printed pieces have certain optical properties, and therefore, the SLA technology is the one that gives rise to the most transparent pieces, followed by the FDM technology that allows the creation of translucent objects, and finally the SLS technology. .

According to particular embodiments, the second stage comprises obtaining a matrix by means of 3D printing, which will be a negative of the internal platform and the elements of reinforcement - that is, the frame - and obtain by molding the positive of the internal platform and the reinforcement elements.

In the case of carrying out the manufacture of the structure by molding, the reinforcing elements are arranged in any position relative to each other, and preferably parallel to each other. According to particular embodiments, in this case a matrix is previously generated by means of 3D printing, which is a negative, and then a metal mold is generated - for example, aluminum- Next, a polymer is injected by pressure, - for example, translucent - inside the mold.

In the event that the platform is in the form of a lattice, the composite structure is manufactured by 3D printing the frame and subsequently filling a mold in which the frame will have been placed.

In the event that the matrix is a ceramic, the second stage of the procedure comprises printing the shell and the third stage comprises filling the mold where the shell has been placed with the ceramic powder, then carrying out a pressing, carrying out a drying, submitting to the oven (sintering) and carrying out - optionally - the desired finishes, such as applying a varnish, etc.

The printer management programs allow to generate fills with a % of meshing, they go from 100% which would be the fill without totally solid holes (solid platform) to, for example, a 10% fill that would be with 90% of holes. (mesh platform) in that area of the composite structure.

Regarding the image to be displayed on one or both of the visible faces (upper and lower XY planes of the piece), it is the result of the multiple 3D printed reinforcement elements that originate in the internal platform and reach up to, at least, the seen faces.

The images on the visible faces of the structure can be made with lines (as is usual in a drawing) or with points (pointillism), so that they are seen in the structure as lines or as points, or as combinations of lines and points.

A filament obtained by 3D printing is a superposition of layers of a molten material where the height (Z) predominates over the plane (X,Y). In the event that the images look like dots, the reinforcing elements resemble vertical threads that grow in the direction of the Z axis when obtained by 3D printing.

In the case where the images are seen as lines, the reinforcing elements are adjacent, stacked together, and the superimposition of layers of a material results, growing in the Z-axis direction, in a surface, similar to a wall (a filament would be a pillar and the simile would be a continuous superposition of pillars resulting in a wall) that rises during printing.

Once the frame manufacturing process is finished, the prototype is filled with filler material.

In the event that the reinforcing elements are transparent or translucent filaments, these can also be found commercially available and are placed in the feeder spool of the 3D printer.

According to particular embodiments, 24 hours after the completion of the third stage, the visible faces are optionally polished to achieve the desired finish depending on the printing material or fibers that have been used to give it a good finish.

In the case of using Programmable Viscoelastic Materials (PVM) or materials that allow the passage of light for the frame, it is advisable to apply alcohol to their surface to improve the lighting effect. The alcohol can be, for example, ethyl or isopropyl alcohol with a concentration greater than 70°C.

Optionally, a transparent finishing varnish or resin can be applied to the finishing surfaces, to the perimeter surfaces and/or to the visible faces, after pouring the matrix, as a protection (in the external XY planes), to improve its appearance. scratch hardness and durability against chemical products. Optionally, an electronic board with lighting, for example, with LED-type devices, can be incorporated within the frame itself before the matrix is poured.

There are several ways to place lighting devices, such as LEDs, in the structure:

- they can be in an internal area within the platform: to achieve this arrangement, the platform is printed in two parts with their corresponding reinforcement elements, the light devices are placed on their electronic board in the desired place and then the two parts are joined of the frame, once printed separately, for example, with resin, so that the frame will have the lighting devices inside it (a section can be seen in figure 6),

- The lighting devices can be placed on one, several, or all sides of the frame (figure 5), and in particular, of the platform.

Optionally, there can be a projecting plane of the composite structure, made of opaque or transparent material, in the XY plane, which allows illumination of the motif or image from the side with a light source. In this case, said projecting plane can have lighting devices, such as LEDs.

The present invention also has as its object the use of the material in construction, advertisements, or in the furniture industry.

According to particular embodiments, the material can be used in:

- manufacture of kitchen countertops.

- tesserae for coatings in bathrooms, kitchens.

- realization of cladding and panels as cladding, inside buildings or on their facades or as false facades.

- interior or exterior floors,

- low ceilings.

According to particular embodiments, the use of a composite structure according to the invention, which only has reinforcing elements on one of the main faces of the platform, and that has luminous devices, comprises carrying out, in the order in which they are numbered, the following operations:

1.- apply on a base surface, a layer of a base material,

2.- arrange a mesh with luminous devices, such that the arrangement of said devices reproduces the desired pattern or the shape of the desired drawing so that it is visible on the main view face of the composite structure,

3. - arrange the composite structures on the mesh with light devices from step 2,

4 optionally, and preferably, add a final coating layer.

Alternatively, the previous stage 2 and 3 can be carried out simultaneously in the event that the lighting devices and the composite structures are already previously joined. In stage 3 above, the composite structures can be:

- Arrange the composite structures that are in one of the following forms: a.- joined together with an adhesive mesh b.- or individually. c.- or the composite structures, and the mesh of luminous devices, are united in the same piece.

Brief description of the figures

In the figures equal numbers represent the same elements. Figure 1 shows a diagram of a particular embodiment of a parallelepiped-shaped composite structure of the invention where dimensions X and Y predominate over Z. The following faces can be seen in it:

- Two visible faces (1) and a lower face coinciding with the baseXY plane (3) perpendicular to the perimeter planes.

- Perimeter planes (2) perpendicular to the visible faces, in the case of orthohedral forms

Figure 2 shows a particular embodiment of a composite structure, in the form of a parallelepiped, in which it is observed that the reinforcing elements - filaments in this particular embodiment - are of different thicknesses. On the left side of the structure, the sections of the same are observed, in which (4) represents an area with a filling that extends up to 90% of the X axis of the composite structure, that is, in this example, the The frame does not reach the perimeter edge in the X axis and the YZ perimeter plane forms a wall-like frame. (8) represents the section of the structure in the YZ plane. Similarly, the perimeter plane XZ also forms a wall-like frame.

In the YZ plane, the section of the internal platform (zone 6) can be seen, which in this case is in the form of a lattice, on which the reinforcing filaments are arranged, in this case above and below the platform. The platform is approximately centered with respect to the length of the structure in the vertical direction. Zones 5 and 7 correspond to the part of the structure composed above the platform and below the platform, respectively, and the reinforcement elements are located there.

Figure 3 ^a shows a diagram of a particular embodiment of a structure according to the invention. Inside you can see the framework with the lattice-shaped platform and the reinforcing elements on the platform perpendicular to it. In this case, the platform does not extend in the XY plane to the perimeter planes (9) row of reinforcement elements on the internal platform ( ^10a ) filament-type reinforcement element, upper and lower of the platform in the form of a lattice (10b) platform diagonal connectors

The flat faces formed by the elements (10 ^to ) correspond to the Delaunay triangulation of the two-dimensional coordinates of the filaments. The connecting ribs (10b) or connectors serve to create triangles in a third dimension to reinforce the structure forming a truss.

Figure 3b shows a diagram of a particular embodiment of a structure according to the invention. Inside you can see the frame with the flat platform, in the form of a mesh, and the reinforcing elements on the platform perpendicular to it. In this case the platform does not extend in the XY plane to the perimeter planes. The element indicated as (10) is the internal platform

Figure 4 shows an example of a structure in which the reinforcing elements (9) are of the same length with respect to each other in the area (5) below the internal platform and are of different length with respect to each other in the area ( 11) above the internal platform, giving rise to a surface with contour lines. It is observed that the reinforcing reinforcement elements above the platform exceed the upper visible face of the structure. In this example, the inner platform is mesh-shaped, so it is partially hollow, and it is also not centered on the Z axis. Zones 5 and 7 are not equal in length on the Z axis.

(11) area of the structure formed by the parts of the reinforcing elements that go beyond the visible face.

Figure 5 shows an example of an appropriate frame for a structure according to an additional particular embodiment of the invention, comprising a row of LED devices on a perimeter edge of the platform. According to other alternatives, it could have analogous longitudinal plates in the rest of the perimeter edges of the platform.

Figure 6 shows an appropriate frame for a structure according to an additional particular embodiment of the invention, which includes lighting devices inside it. Specifically, LED devices (13) and a plate electronics with a printed circuit (12). Furthermore, in this figure it can be seen that each individual filament (9) can be illuminated.

Figure 7 shows an appropriate framework for a structure according to an additional particular embodiment of the invention, in which it can be seen that the reinforcing elements in this case are not distributed in a regular manner and have different thicknesses.

The image observed in this figure has been obtained using the Delaunay triangulation

In Figure 8, an additional particular embodiment of a finished composite structure prototype is observed, in which the image of a woman's face is observed.

Figure 9 shows a specific embodiment of a finished prototype, with light projection, on the left, (any light source) and natural (on the right). This prototype has been made by manual modeling, another way of doing it is by 3D printing.

Figure 10 shows a specific embodiment of a composite structure, in which the platform has a warped shape.

Figure 11 shows an example of a composite structure with a lattice-shaped platform, where the reinforcing elements are a combination of strands and walls; and it can be seen that the ends of the reinforcing elements give rise to the image of a face.

Figure 12 shows an appropriate framework for a structure according to the invention, in which the reinforcing elements are present only on one of the main faces of the internal platform.

Throughout the description and claims the word "comprise" and its variants are not intended to exclude other technical characteristics, additives, components or steps. For those skilled in the art, other objects, advantages and characteristics of the invention will be will be apparent in part from the description and in part from the practice of the invention. The following examples are provided by way of illustration, and are not intended to be limiting of the present invention.

EXAMPLES

Example 1

According to a particular embodiment (shown in Figure 3), the composite structure of the invention has a parallelepiped shape with the X and Y dimensions of the Cartesian axes predominating with respect to the dimension on the Z axis. According to this embodiment, the composite structure It's formed by:

- an internal, partially hollow, mesh or lattice-shaped platform housed inside the composite structure, parallel to the XY plane, not reaching the perimeter edges (i.e. the length of the platform on the X axis and the Y axis is equal to the length of the structure in these two dimensions), and centered with respect to the Z axis, that is, equidistant from the upper and lower seen faces of the composite structure; on the platform that is housed inside the composite structure are arranged:

- reinforcing elements perpendicular to the platform, and on both its upper and lower faces, said reinforcement elements reaching the upper visible face and the lower visible face, respectively, of the structure, that is, they are flush with the seen faces. The reinforcing elements are all the same length, are placed parallel to each other and are bound by a filler material.

The frame dimension in the Z-axis direction is 100% of the total length, in that direction, of the composite structure.

The arrangement of the reinforcing elements in this case gives rise to a visible pattern image on both the top and bottom views of the composite structure, and which in this case is a grid pattern.

Example 2 According to a particular embodiment (shown in figure 12), the composite structure of the invention has reinforcing elements only on one of the main faces of the internal platform. In the particular case shown in figure 12, the reinforcing elements are of the filament type, and are parallel to each other, and perpendicular to the internal platform. Optionally, in this particular embodiment, the frame can include light devices inside it, as shown in figure 12. For example, they can be LED devices (13) and an electronic board with a printed circuit (12). Furthermore, each individual filament (9) may be illuminated.

To obtain a surface covered with composite structures according to the embodiment of the type shown in figure 12, the following operations can be carried out in the order in which they are numbered: 1.- apply to a base surface, a layer of a base material, such as cement, adhesive, plaster or chemical bonding material or mechanical anchor (depending on whether it is for a surface that will be exposed to the outside or inside a building).

2.- arrange a mesh with luminous devices - for example, LEDs - (such that the arrangement of said devices reproduces the desired pattern or the shape of the desired drawing so that it is visible on the main view face of the composite structure, or random shapes or ruled, that is, any type of geometric figure (random) or a figure with a specific pattern (regulated) can be inserted.

3. - arrange the composite structures directly on the mesh with luminous devices 4 optionally, and it is a preferred alternative, a final coating layer can be added, "in situ"

The optional final coating layer can be made of various materials, such as micro-concrete, concrete, mortar, stoneware, polymeric concrete/mortar/paste or plaster. These base surfaces that can be covered with composite structures according to the invention, for example of the type shown in Figure 12, can be, for example, floors, walls, ceilings. The composite parts or structures of the type shown in figure 12 can be previously prefabricated, so said stage 3 comprises:

- arrange these prefabricated pieces so that they are in one of the following forms: a.- joined together with an adhesive mesh to stick -if desired- on the lighting devices, such as LEDS, in the case of structures made up of large formats, b.- or individually (in the case of small formats). c.- Or, the composite structures, and the mesh of lighting devices, such as LEDs, can be joined in the same piece.

This mesh, which may be joining the composite structures together, is made of a material that may be soluble in water, such that once placed on the base surface, the mesh will dissolve with water.

In the event that the composite structures are joined together, the joints between the composite structures may be of the type: tongue-and-groove, puzzle, mosaic, trencadis, bone to bone, dovetail, or other forms of union, one of the forms being of preferred union, for being the simplest, that are to "head". This mesh that joins the composite structures in these cases can be soluble in water.

Claims

1. A composite structure comprising:

- a framework made up of: - a platform that has attached to it, and on at least one of its main faces, reinforcing elements, such that the free ends of the reinforcing elements reach or exceed the top view face, or the lower view face, or both, of the composite structure, giving rise to pattern images, visible on one or both upper and lower view faces, and the reinforcing elements are bonded by

- at least one filling material that occupies the entire space delimited by the external faces of the structure, except for the space occupied by the frame, characterized in that the platform does not reach any of the two visible faces of the structure, and that at least 5%, preferably 10%, of the reinforcing elements with respect to the total number of reinforcing elements, have cross sections of different sizes.

2. A composite structure according to claim 1, in which the reinforcing elements are found only on one of the main faces of the internal platform.

3. A composite structure according to claim 1, wherein the reinforcing elements are in a position selected from:

- flush with one or both visible faces, - exceeding the upper and/or lower visible faces, with the filaments equidistant from the visible faces,

- surpassing the upper and/or lower visible faces, the filaments being not equidistant from the visible faces.

4. A composite structure according to claim 1, wherein the internal platform is arranged in a position selected from:

- parallel to one or both visible faces of the composite structure and

- forming an angle with one or both visible faces.

5. A composite structure according to claim 1 or 2, wherein the internal platform is selected from a flat platform and a warped platform.

6. A composite structure according to claim 1 or 2, in which the internal platform is divided into at least two portions that are in various planes on the vertical axis or Z axis.

7. A composite structure according to claim 1 or 2, wherein the internal platform has contour lines.

8. A composite structure according to claim 1 or 2, wherein the internal deck is selected from a solid deck and a partially hollow deck.

9. A composite structure according to claim 7, in which the internal platform is partially hollow, with perforations passing through it, and has a hollow volume percentage of between 1% and 99% of its total volume, preferably between 10 % and 90% and more preferably between 30 and 50%.

10. A composite structure according to claim 1 or 2, wherein the internal platform is disposed in a position selected from centered with respect to the vertical direction of the composite structure in the Z-axis direction and not centered along the Z-axis .

11. A composite structure according to claim 1 or 2, wherein the internal platform has a thickness or height on the Z axis of the composite structure comprised between 1 and 99%, preferably between 40 and 80% of the total height of the composite structure.

12. A composite structure according to any one of the preceding claims, in which the platform extends in the XY plane to have a surface selected from:

- a surface identical to the section of the composite structure in the XY plane.

- and a surface smaller than the section of the structure in said plane.

13. A composite structure according to claim 1 or 2, wherein the frame has a length of at least 70% of the length of the composite structure in the X-axis direction, and at least 70% of the length of the composite structure in the Y-axis direction, preferably at least 90% of the length of the composite structure in the X-axis direction, and at least 90% of the length of the composite structure in the Y-axis direction Y.

14. A composite structure according to any one of the preceding claims, in which the reinforcing elements are arranged in a position selected from:

- parallel to each other

- not parallel to each other.

15. A composite structure according to any one of the preceding claims, in which the reinforcing elements are arranged in a position relative to the platform selected from:

- perpendicular and

- forming an angle other than 90° with the platform.

16. A composite structure according to any one of the preceding claims, in which the reinforcing elements are arranged on one or both main faces of the platform, so that they do not follow a regular order.

17. A composite structure according to any one of the preceding claims, in which the reinforcing elements have a proportion of at least 5% of them, preferably at least 10% of them, with respect to the total of the elements of reinforcement, a cross section with a different shape.

18. A composite structure according to any one of the preceding claims, wherein the framework is of a material selected from translucent, transparent, photoluminescent and opaque.

19. A composite structure according to any one of the preceding claims, in which the frame is made of a material selected from polylactic acid (PLA), acrylonitrile-butadiene-styrene (ABS), flexible thermoplastic elastomer (Flexible TPE), carbon fiber , polyethylene terephthalate (PET), polyethylene glycol terephthalate (PETG), PETT, high impact polystyrene (HIPS), fiber optics, nylon, polycarbonate, polyvinyl butyral (PVB), carbon fiber, polypropylene, fiberglass, light-curing resins and metal.

20. A composite structure according to any one of the preceding claims, in which the framework is of a luminescent material.

21. A composite structure according to any one of the preceding claims, wherein the frame further comprises one or more lighting devices, preferably LEDs, and a printed circuit board.

22. A composite structure according to any one of the preceding claims, having dimensions between 5 meters and 10 m and a thickness between 4 and 50 mm.

23. A composite structure according to any one of the preceding claims, wherein the padding of the part of the composite structure below the internal platform and above the internal platform is of a material selected from: the same material and different material.

24. A composite structure according to any one of the preceding claims, wherein the filler of the composite structure is of a material selected from:

- a resin matrix, - a cementitious matrix

- a ceramic matrix and

- a geopolymer.

25. A composite structure according to any one of the preceding claims, wherein the padding of the composite structure and the frame are of the same or different material.

26. A composite structure according to any one of the preceding claims, in which the perimeter planes are arranged in a manner selected from: - perpendicular to each other

- and with a degree of inclination between them.

27. A method for manufacturing the composite structure defined in any one of the preceding claims, comprising: - a first stage comprising obtaining a design of the internal platform and the reinforcing elements, that is, of the frame, according to the image that it is desired to appear on at least one of the two visible faces of the composite structure

- a second stage that comprises obtaining the frame, or a matrix of said frame, by 3D printing, - a third stage that comprises arranging the frame inside a mold and filling the hollow space between the mold and the frame with filling material up to the Obtaining the composite structure in its intended shape and size.

28. A method according to claim 27, wherein the second stage comprises obtaining a matrix by 3D printing, which will be a negative of the frame, and obtaining the positive of the frame by molding.

29. A method according to claim 27, wherein the second step of the method comprises printing the framework and in the third step a ceramic matrix is used, and comprises filling the mold where the framework has been placed with ceramic powder, then carrying pressing, drying and subjecting the structure to sintering treatment in a furnace.

30. A method of claim 27, further comprising polishing the obtained composite structure.

31. A method according to any one of claims 27 to 30, further comprising applying a clear finishing varnish or resin to the finishing surfaces.

32. A method according to any one of claims 27 to 31, further comprising including one or more lighting devices, arranged at: - the perimeter edges of the frame and/or

- inside the platform and/or

- in each of the reinforcing elements.

33. A method according to any one of claims 27 to 32, further comprising having a projecting plane of the composite structure, in the XY plane, of opaque, translucent or transparent material, preferably transparent.

34. Use of the composite structure defined in any one of claims 1 to 26 in construction, in the advertising industry or in the furniture industry, preferably in

- manufacture of kitchen countertops,

- tesserae for coatings in bathrooms, kitchens, - realization of cladding and panels as cladding, inside buildings or on their facades or as false facades,

- interior or exterior flooring,

- low ceilings.

35. Use of the composite structure defined in claim 2, comprising carrying out, in the order in which they are numbered, the following operations:

1.- apply on a base surface, a layer of a base material,

2. - Arrange a mesh with luminous devices, such that the arrangement of said devices reproduces the desired pattern or the shape of the desired drawing so that it is visible on the main view face of the composite structure,

3. - arrange the composite structures on the mesh of luminous devices,

4 optionally add a final coating layer.

36. Use of the composite structure according to claim 35, wherein step 3 comprises: