Printable composition for additive or subtractive manufacturing, method of production therof and respective uses

Abstract

This description relates to a printable composition for additive or subtractive manufacturing, and to the method of production and respective uses thereof. The present description discloses a printable composition for additive manufacturing comprising at least 30% (m / m) stone powder; at least 10% (m / m) of at least one polymer resin; and at least one functional agent selected from a list consisting of colloidal silica, fibres, silanes, titanates, binders, thickeners, superplasticisers or combinations thereof; wherein the particle size of the stone powder is less than 1 mm.

Description

DESCRIPTION PRINTABLE COMPOSITION FOR ADDITIVE OR SUBTRACTIVE MANUFACTURING, ITS METHOD OF OBTAINING AND RESPECTIVE USES TECHNICAL DOMAIN

[0001] This disclosure relates to a printable composition for additive (3D printing) or subtractive manufacturing, its method of production, and respective uses. The composition includes stone powder, a polymeric resin, and at least one functional agent, and is suitable for creating articles with complex shapes and high mechanical strength.

[0002] The printable composition for additive or subtractive manufacturing of the present disclosure can be used to manufacture complex articles with a high natural stone content, such as reinforcement of facade and flooring products, ornamental stone reinforcement structures, decorative pieces or furniture. BACKGROUND

[0003] Geological resources are essential for modern society, as they constitute the raw material for a large number of economic activities, including a reasonable number of processing industries.

[0004] The responsible exploitation of geological resources constitutes an important means of development and is increasingly considered a lever for improving the performance of economies through circular economy ecosystems, thus encompassing economic, social, and environmental aspects in an integrated manner.

[0005] Preventing waste production and encouraging its reuse and recycling with a view to extending its life cycle and developing circular economy strategies must increasingly be a priority for the sector, taking into account that the waste generated in this sector is one of the largest sources of waste in the European Union (EU), which is characterized mainly by material removed from the surface to allow exploration, rock and mineral waste generated during the activity and what remains after the end of exploration.

[0006] Among the waste generated in the ornamental rock sector, particularly in the processing of stone, the most notable are stone dust, sludge from treatment plants, industrial wastewater, landfill and stone waste / chips, which are destined for civil construction or as filling material in the landscape restoration of quarries, as it is seen as a less noble material.

[0007] In the case of stone remains, resulting from cutting the final products and stone dust, resulting from various dust-producing activities in extraction and processing, these residues have an inert inorganic nature, possessing the same composition / characteristics as the final products, presenting a different final destination.

[0008] Stone dust occurs during the various processes of ornamental rock extraction and processing. In the ornamental rock extraction sector, this dust can be generated during drilling, blasting, loading, transporting, and unloading. In the processing sector, stone dust is generated primarily during sawing, polishing, cutting, and finishing processes to customize the final product. During the sawing and cutting processes, the generation of this waste would be expected; however, the high use of water in stone cutting has prevented its formation. This dust is an inert residue, considering that, as it constitutes a fine fraction of the marketable product, it has the same composition. However, its most common destination today is still landfill.

[0009] Document EP1415792B1 describes three-dimensional printing methods and compositions for three-dimensional printing. The method described in this document involves constructing cross-sections of a three-dimensional article and assembling the individual cross-sectional areas in layers to form a final article. Individual cross-sectional areas are constructed using an inkjet print head to deliver a fluid to a particulate material.

[0010] EP1272334B1 describes a system and method for printing three-dimensional materials that produce appearance models and a small number of functional parts in an office environment. The method may include constructing cross-sections of a three-dimensional article and assembling the individual cross-sections in layers to form a final article. Individual cross-sections may be constructed by using an inkjet print head to apply an aqueous solvent or binder to a mixture of adhesive particles, causing the particles in the mixture to adhere to each other and to the previous cross-sections. The binder may include at least one non-aqueous organic monomeric compound, an ionizable anionic polymer, a cationic polymer, a polymer, an aqueous colloid, or an inorganic solute.

[0011] EP1174471A1 describes a soft, high-hardness composite material consisting of an organic / inorganic composite material with at least 60% by weight of inorganic components, including an aggregate component, and having a Vickers surface hardness of at least 400 and a radius of curvature, at which the material is bendable without breaking, of at least R25 mm based on a plate body 3 to 15 mm thick, the high-hardness organic / inorganic composite material being soft and bendable.

[0012] These facts are described in order to illustrate the technical problem solved by the achievements of this document. GENERAL DESCRIPTION

[0013] This disclosure relates to a printable composition for additive or subtractive manufacturing, its method of production, and respective uses. The composition of this disclosure can be used in a variety of industrial applications, including civil construction and the creation of detailed architectural models. The improved mechanical strength and remarkable printing accuracy allow for use in environments that require high durability and precision.

[0014] One objective of this dissemination is to provide a technical solution for the reuse and valorization of sludge resulting from stone processing, such as limestone. As previously mentioned, this sludge is currently wasted or sent to landfill, so it is extremely important to reintroduce it to the market, thus ensuring an important contribution to the circular economy and reducing potential damage to ecosystems.

[0015] The printable composition for additive manufacturing is particularly useful in obtaining items such as structures such as ornamental stone reinforcement, decorative pieces or furniture.

[0016] In one embodiment, the sludge resulting from stone processing can be treated by different chemical and physical processes to obtain a powder, which may still be hydrated or dehydrated, hereinafter referred to as stone powder.

[0017] The particle size / particle size of stone dust can be measured in several ways, and therefore, in this publication, the particle size / particle size measurement was considered to be based on the determination of particle size distribution by laser diffraction. This type of measurement is based on the fact that the angular distribution of light scattered by a particle, i.e., its scattering pattern, depends on the particle size. When scattering originates from a cloud or collection of particles, the scattering intensity for any size class is related to the number of particles and their optical properties present in that size class. Within certain limits, the scattering pattern of a collection of particles is identical to the sum of the individual scattering patterns of all the particles.Theoretical dispersion patterns of unit volumes of particles in selected size classes are used to solve the inverse problem, yielding a volumetric particle size distribution. To determine the particle size distribution of the various stone processing sludge samples, dispersion measurements were performed using a Mastersizer 2000 instrument coupled to a Hydro 2000S wet dispersion unit manufactured by Malvern. To this end, the samples were dispersed in deionized water and subjected to ninety seconds of ultrasound.

[0018] Throughout this description, and in order to present the values ​​related to the particle size distribution of powder particles, the median diameter (D50) will be used. Throughout this disclosure, the median diameter (D50) is considered to be the particle size corresponding to a 50% cumulative percentage. For example, for a powder sample with a D50 of 5 pm, this means that 50% of the particles are larger than 5 pm and 50% are smaller than 5 pm.

[0019] The solution described here involves the development of new printable composites of stone powder and polymeric binders and / or hydraulic binders and other additives. The solution must allow the use of various manufacturing methods, including additive manufacturing processes, and the composite must have the ideal rheological properties for the process and the mechanical and durability characteristics required in the construction sector. Depending on of the composite's constituents, the material can be used for different applications, with the reinforcement of facade and flooring products being one of the most important;

[0020] One aspect of the present disclosure relates to a printable composition for additive manufacturing or 3D printing comprising at least 30% (w / w) stone powder; at least 10% (w / w) of at least one polymeric resin, and at least one functional agent selected from a list consisting of colloidal silica, fibers (e.g., polymeric fibers, carbon fibers, or combinations thereof), silanes, titanates, binder, superplasticizers, thickeners, or combinations thereof; wherein the particle size of the stone powder is less than 1 mm.

[0021] The composition of this disclosure integrates stone powder, at least one polymeric resin, and functional agents in a printable composition for additive manufacturing. This innovative combination surprisingly overcomes the limitations of current technologies by providing a solution that enables the 3D printing of articles with high mechanical strength. The specific selection of materials and the precision in the particle size of the stone powder, combined with the production method, result in a unique composition that offers significant improvements in the durability and versatility of the final products, expanding the scope and applications of 3D printing in sectors such as construction, decoration, and the manufacture of functional parts.

[0022] The viscosity and rheological capabilities of the composition of this disclosure are improved, enabling rapid printing of complex shapes with a high stone content. With the composition of this disclosure, structures with complex geometries, such as honeycomb, grids, zigzags, cubic infill, gyroids, and others, can be created.

[0023] To achieve better results, the use of different resins improves the rheological and mechanical properties of the composites obtained. As seen in Figure 3, water-based polyurethane resin (Ra) performs worse than fiber-reinforced water-based polyurethane resin (Rb) in flexural stress tests, with maximum values ​​of 2 MPa vs. 8 MPa, even with the use of additives that increase mechanical strength.

[0024] In one embodiment for best results, the viscosity of the composition of the present disclosure is above 200 Pa.s.a. at 20°C, preferably between 200-1000 Pa.s.a. at 20°C.

[0025] Layer viscosity measurement can be performed in several ways; in this presentation, viscosity measurement was performed on a TA Instruments TA HR10 at 20 °C.

[0026] In one embodiment for best results, the polymeric resin used in the printable composition is a water-based polymeric resin, or epoxy, or mixtures thereof.

[0027] In one embodiment for best results, the polymeric resin used in the printable composition is selected from a list consisting of polyurethane, polypropylene, polyester, epoxy, or combinations thereof; preferably polyurethane.

[0028] In one embodiment for best results, the printable composition comprises at least 20% (w / w) polymeric resin.

[0029] In an embodiment for best results, the printable composition comprises from 20 to 55% (w / w) polymeric resin, preferably from 35 to 50% (w / w) polymeric resin, more preferably from 40 to 45% (w / w) polymeric resin.

[0030] In an embodiment for best results, the printable composition comprises from 30 to 70% (w / w) stone powder, preferably from 40 to 55% (w / w) stone powder, more preferably from 40 to 50% (w / w) stone powder.

[0031] In an embodiment for best results, the stone powder used in the printable composition is selected from a list consisting of: limestone, granite, basalt, marble or their combinations.

[0032] In one embodiment for best results, the thickener of the printable composition is selected from a list consisting of: cellulosic organics, synthetics of the associative or non-associative type, inorganics or combinations thereof.

[0033] In one embodiment for best results, the superplasticizer of the printable composition is selected from a list consisting of: modified lignin sulfonates, sulfonated synthetic polymers, polyacrylate polymers or combinations thereof.

[0034] In an embodiment for best results, the stone powder used in the printable composition has a particle size of less than 0.5 mm, preferably less than 90 pm.

[0035] In an embodiment for best results, the stone powder used in the printable composition has a median diameter (D50) between 3 and 90 pm.

[0036] In an embodiment for best results, the stone powder used in the printable composition has a particle size with a median diameter (D50) between 3 and 88 pm, preferably between 4 and 86 pm, more preferably between 5 and 85 pm.

[0037] In an embodiment for best results, the printable composition comprises from 1 to 20% (w / w) functional agent, preferably from 3 to 10% (w / w) functional agent, more preferably from 5 to 8% (w / w) functional agent.

[0038] In one embodiment, for best results, the functional agent used in the printable composition is selected from a list consisting of colloidal silica, fibers, silanes, or combinations thereof. Preferably, colloidal silica and / or fibers.

[0039] In an embodiment for best results, the printable composition further comprises an additive; preferably a colorant, a surfactant, an anti-corrosive agent, an anti-foaming agent, a flame retardant, or other functional agent.

[0040] In an embodiment for best results, the printable composition further comprises at least one fiber, preferably wherein the fiber is selected from a list consisting of: polypropylene, polyester, polyamide, carbon, natural or regenerated base, or combinations thereof; even more preferably wherein the largest dimension of the fiber is less than 20 mm; preferably between 5 mm and 10 mm.

[0041] This application also describes an article comprising the printable composition for additive manufacturing described above, preferably a reinforcement structure for ornamental stones, decorative pieces or furniture.

[0042] In one embodiment, the article further comprises a coating.

[0043] A method for obtaining a printable composition for additive manufacturing comprising the steps of treating sludge resulting from stone processing and formulating stone powder with a polymeric resin and at least one functional agent is also disclosed.

[0044] A method for obtaining a printable composition for additive manufacturing comprising the homogeneous mixture: of at least 30% (w / w) of stone powder with at least 10% (w / w) of a polymeric resin and at least one functional is also disclosed.

[0045] In one embodiment, stone powder is added in the form of slurries resulting from stone processing.

[0046] In one embodiment, the treatment of sludge resulting from stone processing comprises drying and / or crushing and / or screening.

[0047] In one embodiment, the curing of the manufactured article is carried out at room temperature.

[0048] The use of the printable composition according to any of the preceding claims in additive manufacturing applications that require high mechanical strength and dimensional accuracy, preferably in civil construction, is also described. BRIEF DESCRIPTION OF THE FIGURES

[0049] For easier understanding, the figures are attached, which represent preferred embodiments that are not intended to limit the scope of this description.

[0050] Figure 1 - Photographic illustration of two distinct, non-printed, state-of-the-art examples of low-density solutions for reinforcing limestone tiles. One solution uses low-density mortars, while the other features an aluminum honeycomb layer; the second also features overlapping fiberglass layers.

[0051] Figure 2 - Schematic representation of the steps for reinforcing ornamental stone using the formulation developed and manufactured using additive manufacturing techniques.

[0052] Figure 3 - Graphical representation of the results of different formulations when subjected to a 3-point bending test. The formulations are made from different resins - water-based polyurethane resin (Ra) and fiber-reinforced water-based polyurethane resin - and present disparate data regarding bending stress, with the highest value being 8 MPa, while in the cases with less interesting results, this value is 2 MPa.

[0053] Figure 4 - Representation of an embodiment of a composite via 3D printing. DETAILED DESCRIPTION

[0054] This description concerns a printable composition for additive or subtractive manufacturing, its method of obtaining and respective uses.

[0055] In one embodiment, the printable composition for additive manufacturing or 3D printing comprises at least 30% (w / w) stone powder; a polymeric resin and at least one functional agent selected from a list consisting of colloidal silica, fibers, silanes, titanates, binder, superplasticizers, thickeners, or combinations thereof; wherein the particle size of the stone powder is less than 1 mm.

[0056] In one embodiment, the printable composition for additive manufacturing or 3D printing comprises at least 30% (w / w) stone powder; at least 10% (w / w) of at least one polymeric resin and at least one functional agent selected from a list consisting of colloidal silica, fibers, silanes, titanates, binder, superplasticizers, thickeners, or combinations thereof; wherein the particle size of the stone powder is less than 1 mm.

[0057] In one embodiment, the polymeric resin used in the printable composition is a water-based polymeric resin, or epoxy, or mixtures thereof.

[0058] In one embodiment, the polymeric resin used in the printable composition is selected from a list consisting of polyurethane, polypropylene, polyester, epoxy, or combinations thereof; preferably polyurethane.

[0059] In one embodiment, the printable composition comprises at least 20% (w / w) polymeric resin.

[0060] In one embodiment, the printable composition comprises from 20 to 55% (w / w) polymeric resin, preferably from 35 to 50% (w / w) polymeric resin, more preferably from 40 to 45% (w / w) polymeric resin.

[0061] In one embodiment, the printable composition comprises from 30 to 70% (w / w) stone powder, preferably from 40 to 55% (w / w) stone powder, more preferably from 40 to 50% (w / w) stone powder.

[0062] In one embodiment, the stone powder used in the printable composition is selected from a list consisting of: limestone, granite, basalt, marble, or combinations thereof.

[0063] In an embodiment for best results, the thickener of the printable composition is selected from a list consisting of: cellulosic organics, synthetics of the associative or non-associative type, inorganics or combinations thereof.

[0064] In one embodiment for best results, the superplasticizer of the printable composition is selected from a list consisting of: modified lignin sulfonates, sulfonated synthetic polymers, polyacrylate polymers or combinations thereof.

[0065] In one embodiment, the stone powder used in the printable composition has a particle size of less than 0.5 mm, preferably less than 90 pm.

[0066] In one embodiment, the stone powder of the printable composition has a median diameter (D50) between 3 and 90 pm.

[0067] In one embodiment, the stone powder used in the printable composition has a particle size with a median diameter (D50) between 3 and 88 pm, preferably between 4 and 86 pm, more preferably between 5 and 85 pm.

[0068] In one embodiment, the printable composition comprises from 1 to 20% (w / w) functional agent, preferably from 3 to 10% (w / w) functional agent, more preferably from 5 to 8% (w / w) functional agent, for best results.

[0069] In one embodiment, the printable composition comprises the addition of at least one fiber for higher mechanical strength.

[0070] In one embodiment, the fiber used in the printable composition is selected from a list consisting of: polypropylene, polyester, polyamide, carbon, natural or regenerated based, or combinations thereof.

[0071] In one embodiment, the printable composition further comprises an additive; preferably a colorant, a surfactant, an anti-corrosive agent, an anti-foam, a flame retardant, or other functional agent.

[0072] This disclosure also describes an article comprising the printable composition for additive manufacturing also described in this same disclosure. Examples of ways to manufacture articles include reinforcing facade and flooring products, preferably reinforcing structures for ornamental stones, decorative pieces, or furniture.

[0073] In one embodiment, the polymeric resin used in the printable composition is an aqueous-based polymeric resin or epoxy; preferably the polymeric resin is selected from a list consisting of polyurethane, polypropylene, polyester, epoxy, or combinations thereof.

[0074] In one embodiment, the printable composition further comprises at least one fiber, preferably wherein the fiber is selected from a list consisting of: polypropylene, polyester, polyamide, carbon, natural or regenerated based, or combinations thereof; even more preferably wherein the largest dimension of the fiber is less than 20 mm.

[0075] In one embodiment, the article is obtained by additive manufacturing methods, via 3D printing, with the composition of the present disclosure it is possible to obtain quite complex parts with a composite with a high content of natural stone and stone reinforcement such as in a network (fig 2, fig 4 for example).

[0076] In one embodiment, the article is obtained by subtractive manufacturing methods after mold deposition, without the use of pressure.

[0077] In one embodiment, the article comprises a coating, whether for purely aesthetic or functional reasons.

[0078] The present application further describes a method for obtaining a printable composition for additive manufacturing comprising the steps of treating the sludge resulting from stone processing and formulating the stone powder with a polymeric resin and at least one functional agent.

[0079] Further disclosed is a method for obtaining a printable composition for additive manufacturing comprising the homogeneous mixture: of at least 30% (w / w) of stone powder with at least 10% (w / w) of a polymeric resin and at least one functional agent, such as colloidal silica.

[0080] In one embodiment, the stone powder is added in the form of slurries resulting from stone processing.

[0081] In one embodiment, the treatment of sludge resulting from stone processing used in the method comprises drying and / or grinding and / or screening. In one embodiment, and in order to obtain better results, the stone powder is dehydrated.

[0082] In one embodiment, the article is cured at room temperature, i.e., at a temperature of approximately 25°C and 50-60% humidity, and after approximately 14 days, the curing is practically complete, and after 28 days it will be stabilized.

[0083] The connection between the stone and the printed structure is made using an adhesion-promoting resin that is applied by brush to the surface to be glued.

[0084] The use of the printable composition according to any of the preceding claims in additive manufacturing applications that require high mechanical strength and dimensional accuracy, preferably in civil construction, is also described.

[0085] Table 1 - Characterization of composition and mechanical properties

[0086] The term "comprises" or "comprising" when used in this document is intended to indicate the presence of the features, elements, integers, steps and components mentioned, but does not preclude the presence or addition of one or more other features, elements, integers, steps and components, or groups thereof.

[0087] The present invention is, of course, in no way restricted to the embodiments described in this document and a person with average knowledge of the area will be able to foresee many possibilities for modifying it and replacing technical characteristics with equivalent ones, depending on the requirements of each situation, as defined in the attached claims.

[0088] The following claims define additional embodiments of the present description.

Claims

CLAIMS 1. Printable composition for additive or subtractive manufacturing comprising at least 30% (w / w) of stone powder; at least 10% (w / w) of at least one polymeric resin; at least one functional agent selected from a list consisting of colloidal silica, fibers, silanes, titanates, binder, thickeners, superplasticizers or combinations thereof; in which the particle size of the stone powder is less than 1 mm.

2. Printable composition according to any one of the preceding claims, wherein the polymeric resin is an aqueous-based polymeric resin, or epoxy, or mixtures thereof.

3. Printable composition according to any one of the preceding claims, wherein the polymeric resin is selected from a list consisting of polyurethane, polypropylene, polyester, epoxy, or combinations thereof; preferably polyurethane.

4. Printable composition according to any one of the preceding claims, comprising at least 20% (w / w) of polymeric resin.

5. Printable composition according to any one of the preceding claims, comprising from 20 to 55% (w / w) of polymeric resin, preferably from 35 to 50% (w / w) of polymeric resin, more preferably from 40 to 45% (w / w) of polymeric resin.

6. Printable composition according to any one of the preceding claims, comprising from 30 to 70% (w / w) of stone powder, preferably from 40 to 55% (w / w) of stone powder, more preferably from 40 to 50% (w / w) of stone powder.

7. Printable composition according to any one of the preceding claims, wherein the stone powder is selected from a list consisting of: limestone, granite, basalt, marble or combinations thereof.

8. Printable composition according to any one of the preceding claims, wherein the thickener is selected from a list consisting of: cellulosic organics, synthetics of the associative or non-associative type, inorganics or combinations thereof.

9. The printable composition of any one of the preceding claims, wherein the superplasticizer is selected from a list consisting of: modified lignin sulfonates, sulfonated synthetic polymers, polyacrylate polymers, or combinations thereof.

10. Printable composition according to the previous claim, in which the stone powder has a particle size of less than 0.5 mm, preferably less than 90 pm.

11. Printable composition according to any one of the preceding claims, wherein the stone powder has a median diameter (D50) between 3 and 90 pm.

12. Printable composition according to any one of the preceding claims, wherein the stone powder has a particle size with a median diameter (D50) between 3 and 88 pm, preferably between 4 and 86 pm, more preferably between 5 and 85 pm.

13. Printable composition according to any one of the preceding claims, comprising from 1 to 20% (w / w) of functional agent, preferably from 5 to 10% (w / w) of functional agent, more preferably from 5 to 8% (w / w) of functional agent.

14. The printable composition of any one of the preceding claims, wherein the functional agent is selected from a list consisting of colloidal silica; fibers, such as carbon / polymeric fibers; silanes; or combinations thereof.

15. A printable composition according to any one of the preceding claims further comprising an additive; preferably a colorant, a surfactant, an anti-corrosive agent, an anti-foam, a flame retardant or other functional agent.

16. Printable composition according to any one of the preceding claims, further comprising at least one fiber, preferably wherein the fiber is selected from a list consisting of: polypropylene, polyester, polyamide, carbon, natural or regenerated base, or combinations thereof; even more preferably wherein the largest dimension of the fiber is less than 20 mm.

17. Printable composition according to any one of the preceding claims, comprising a viscosity above 200 Pa.s.a. at 20°C, preferably between 200-1000 Pa.s.a. at 20°C.

18. Article comprising the printable composition for additive manufacturing described in any of the preceding claims, preferably a reinforcement structure for ornamental stones, decorative pieces or furniture.

19. Article according to the preceding claim, comprising a coating.

20. Method for obtaining a printable composition for additive manufacturing described in any one of claims 1 to 17, comprising the homogeneous mixture: of at least 30% (w / w) of stone powder with at least 10% (w / w) of at least one polymeric resin and at least one functional agent.

21. Method according to the preceding claim, in which the stone powder is added in the form of sludge resulting from stone processing.

22. The method of claim 20, wherein the treatment of the sludge resulting from stone processing comprises drying and / or crushing and / or sieving.

23. Use of the printable composition according to any one of claims 1 to 17 in additive and / or subtractive manufacturing applications that require high mechanical strength, preferably in civil construction.

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