Abrasive article

Abstract

The invention relates to an abrasive article comprising a substrate, on which an abrasive layer is arranged The abrasive article comprises one or more sustainable and / or renewable materials. The abrasive article is adaptive to contours of a working surface. The invention also relates to a manufacturing method for an abrasive article.

Description

[0001] Abrasive article

[0002] Technical field

[0003] This specification relates to an abrasive article, particularly for hand sanding applications. The specification also relates to a manufacturing method of such an abrasive article.

[0004] Background

[0005] Conventional hand abrasive articles often employ foams or sponges as substrate or core materials. However, most foams or sponges employ fossilbased raw materials. The availability of fossil-based raw materials may be very limited in the future. Thus, there is a need for more sustainable alternatives.

[0006] Summary

[0007] It is an object of the present invention to overcome the drawbacks present in conventional abrasive articles. Another object of the present invention is to provide an abrasive article that is sustainable and compatible with the concept of circular economy.

[0008] These objects are attained with the invention having the characteristics presented below in the independent claims. Some preferable embodiments are disclosed in the dependent claims.

[0009] The features recited in the claims and the embodiments in the description are mutually freely combinable unless otherwise explicitly stated.

[0010] A typical abrasive article according to the invention is an abrasive article comprising a substrate, on which an abrasive layer is arranged. The abrasive article comprises one or more sustainable and / or renewable materials. The abrasive article is adaptive to contours of a working surface.

[0011] A typical manufacturing method for an abrasive article according to the invention comprises arranging one or more sustainable and / or renewable materials as a substrate of the abrasive article, and arranging an abrasive layer on the substrate of the abrasive article.

[0012] Brief description of the drawings

[0013] Figure 1 presents abrasive articles according to the present invention;

[0014] Figure 2 presents cross-sections of abrasive articles according to embodiments of the present invention;

[0015] Figure 2 presents cross-sections of abrasive articles according embodiments of the present invention;

[0016] Figure 4 presents cross-sections of abrasive articles according to embodiments to the present invention;

[0017] Figure 5 presents an abrasive article that does not comprise a core in its non-collapsed and collapsed form;

[0018] Figure 6 presents layers partly coated with abrasive grains that may be folded to form a substrate on which an abrasive layer is arranged; and

[0019] Figure 7 presents a sheet folded in multiple layers to form a core, abrasive articles comprising such a core, and abrasive articles comprising a core comprising multiple stacked sheets.

[0020] Detailed description

[0021] The solution is described in the following in more detail with reference to some embodiments, which shall not be regarded as limiting. The exemplary embodiments presented in this text and their advantages relate by applicable parts to all aspects of the invention, both the abrasive article and the method, even though this is not always explicitly mentioned.

[0022] The following reference numbers are used in this specification:

[0023] 100, 200, 300, 400, 500, 700 Abrasive article

[0024] 201 , 301 , 401 , 701 Core

[0025] 102, 202, 302, 402, 502, 602, 702 Abrasive layer

[0026] 603, 703 Fastening system

[0027] 104, 204, 304, 404, 504, 604, 704 Substrate Sanding refers to surface treatment that aims at altering a surface. Sanding may cause a smoothening effect or a roughening effect on a working surface or at least a part of the working surface. Sanding may be used to generate or increase scratch patterns onto the working surface. On the other hand, sanding may be used to fade or decrease scratch patterns from the working surface. Sanding may be performed on a working surface of practically any shape. Flat surfaces, surfaces with positive curvature, and negative curvature may be treated by sanding. Sanding may also be performed on surfaces with portions of positive curvature, portions of negative curvature as well as flat portions. In case sanding precedes painting or coating, sanding may be performed to ensure that paint, varnish or any other coating is received by a smooth surface. Sanding is one of the most important steps in determining the end finish and quality of a product.

[0028] Sanding may be performed to various surface materials, such as wood, metal, putties, composites, plastics, minerals or different coatings such as primers, paints or varnishes. Sanding is performed by an article which comprises abrasive material for sanding. The article may be called an abrasive product, a sanding product, or an abrasive article. The ability of the abrasive article to follow the surface structure of the working surface, or in other words, the adaptivity of the abrasive article to contours of the working surface, is important for a high-quality finish for the working product.

[0029] Hand sanding refers to a sanding process performed by hand, utilizing only manual labour or work. Sanding may also be performed utilizing a power tool actuated by a power source. The abrasive article may be utilized in hand sanding applications or in power-actuated sanding, preferably in hand sanding applications.

[0030] Sanding may be performed with or without a lubricant, the most common lubricant being water. Lubricant-assisted, such as water-assisted sanding is commonly referred to as wet sanding, whereas sanding without a lubricant is referred to as dry sanding. The abrasive article may be utilized in dry sanding as well as in wet sanding processes. The abrasive article may comprise additives to increase its hydrophobicity. Therefore, the abrasive article may be more resistant to water and can be used in wet sanding processes for longer periods of time. Conventional hand sanding products often employ foams or sponges as substrate or core materials. However, most foams or sponges employ fossilbased raw materials. The availability of fossil-based raw materials may be very limited in the future. Thus, there is a need for more sustainable alternatives.

[0031] This specification aims to provide more sustainable solutions for sanding, particularly for hand sanding. Thus, a novel abrasive article and the production method thereof is provided.

[0032] The abrasive article disclosed herein comprises a substrate. An abrasive layer is arranged on the substrate. The shape of the substrate defines or affects several characteristics of the abrasive article, such as shape, malleability, bendability, and adaptivity to contours of the working surface. The shape of the substrate also defines or affects the feel of the abrasive article in the user’s hand.

[0033] The abrasive article disclosed herein is adaptive to contours of a working surface. Adaptivity to contours of the working surface should be understood as an ability to follow the structure of a working surface with the abrasive article, regardless of the shape of the working surface. Adaptivity to contours of the working surface may be provided by a flexible structure. Particularly, the flexibility is provided by the combination of properties of the core and / or substrate and the abrasive layer of the abrasive article. The flexible structure is defined as being able to bend or deform, or to be bent or deformed easily without breaking. For example, a sanding block having a wooden core or a core made of cork is not considered to be flexible enough to be adaptive to contours of a working surface. Adaptivity to contours of the working surface may also be provided by plasticity and / or elasticity of the abrasive article.

[0034] Adaptivity allows to treat both flat working surfaces as well as uneven or contoured working surfaces. The abrasive article can be bent or curved easily without breaking. Thus, sanding around an edge or corner, for example, may be achieved. The working surface, i.e., surface of a product on which the sanding is performed, may take any shape. For example, abrasive article may be used to treat a working surface having one or more portions with a positive curvature, such as an edge, a corner, a spherical or ellipsoidal structure, and / or the like. The abrasive article may also be used to treat a working surface having one or more holes, pits or hollows, and / or one or more portions with a negative curvature, such as a hyperbolic or saddle-like working surface. The abrasive article may further be used to treat working surfaces having one or more portions of positive curvature, one or more portions of zero curvature, i.e., flat portions, and / or one or more portions of negative curvature. Adaptivity of the abrasive article to any contours of the working surface facilitates good performance and a high-quality finish on all kinds of working surfaces.

[0035] The abrasive article comprises or consists of one or more sustainable and / or renewable materials, i.e., materials that are renewable, materials that are sustainable, or materials are both renewable and sustainable. Renewable materials are generally understood as materials which will replenish to replace the portion depleted by usage and consumption, either through natural reproduction or other recurring processes in a finite amount of time in a human time scale. Suitable renewable materials may comprise plantbased materials. In an embodiment, the one or more renewable materials comprise saccharide-based materials. Saccharide-based materials are materials that are based on oligomeric or polymeric chains of saccharide molecule units. Saccharide-based materials comprise oligosaccharides and polysaccharides, such as starch, cellulose, glycogen, galactogen, inulin, arabinoxylan, chitin, and pectin. In an embodiment, the renewable materials comprise protein-based materials, such as materials comprising or produced by algae or other unicellular organisms. Sustainable materials are generally understood as materials that are used to continue to meet human needs without undermining the integrity and stability of the natural system. Sustainable materials link closely with the concept of circular economy, which employs reuse, sharing, repair, refurbishment, remanufacturing and recycling to create a closed-loop system, minimizing the use of resource inputs and the creation of waste, pollution and carbon emissions. Suitable sustainable materials comprise any materials that may be reused or recycled according to the idea of circular economy. Examples of sustainable materials include recyclable and recycled materials, often also renewable materials, materials that originate from fungal spores, and sustainable polymers, such as poly(lactic acid) (PLA). In an embodiment, the one or more renewable and / or sustainable materials comprise fibrous materials. In an embodiment, the one or more renewable materials comprise starch-based material. In an embodiment, the starch-based material comprises starch-based adhesive.

[0036] In an embodiment, the saccharide-based material originates from hardwood, softwood, cotton, hemp, jute, sisal, crops, grasses, or any combination thereof. In an embodiment, the saccharide-based material comprises fibers or ligninlike materials.

[0037] In a preferred embodiment, the saccharide-based material comprises woodbased material, preferably paper or cardboard, such as corrugated board. In an embodiment, the one or more renewable and / or sustainable materials comprise recycled materials, such as recycled paper, cardboard or corrugated board. In an embodiment, the one or more renewable and / or sustainable materials comprise shredded paper that is treated to bond the paper shreds and / or fibers together. Preferably, the shredded paper is made of recycled paper. The shredded, bonded paper may exhibit foam-like properties. Preferably, the abrasive article is as light as possible while maintaining its structural integrity when used. An advantage of using paper or cardboard, such as corrugated board, is that the material is easy to manipulate to create a strong and flexible structure. Thus, a flexible abrasive article that can adapt to contours of the working surface may be produced in a simple, cost-effective and environmentally friendly manner. In course of this disclosure, the term flexible is understood as able to bend or deform, or to be bent or deformed easily without breaking.

[0038] In an embodiment, the one or more sustainable and / or renewable materials comprise foam, such as cellulose foam.

[0039] The substrate of the abrasive article typically comprises a sheet of material. The sheet of material may comprise any sustainable and / or renewable material processed into a sheet-like form. In an embodiment, the substrate of the abrasive article comprises or one or more sustainable and / or renewable materials. In an embodiment, the substrate comprises paper, plastic film, textile materials, non-woven materials, or any combination thereof. The one or more sheet may comprise, e.g., woven or non-woven fabric, paper or cardboard, such as corrugated board. In an embodiment, the substrate has a length L of 0.5-250 cm, a width W of 0.5-50 cm, and a height H of 0.5-50 cm to define a shape for the abrasive article. The length, width and height refer to a largest linear dimension in each individual axis direction. In a preferred embodiment, the substrate has a length L of 10-20 cm, a width W of 5-15 cm, and a height H of 1-5 cm. In an alternative preferred embodiment, the substrate has a length L of 100-250 cm, a width W of 10-30 cm and a height H of 0.5-5 cm. The abrasive article may be manufactured in several different shapes. In an embodiment, the abrasive article has a rectangular shape. In another embodiment, the abrasive article has a cylindrical shape. Base of the cylinder may have a parabolic or a semicircular shape, for example. In a yet another embodiment, the abrasive article has a spherical or ellipsoidal shape. In a still further embodiment, the abrasive article has an irregular shape. The shape of the abrasive article may be optimized for user comfort, e.g., a good grip or feel in the user’s hand.

[0040] In an embodiment, the substrate is folded to define the shape of the abrasive article. Typically, the substrate is folded such that it is self-supported. The substrate may comprise portions that are supported on top of each other to define the shape of the abrasive article.

[0041] Firmness of the abrasive article may vary according to a desired purpose of use. In an embodiment, the abrasive article has a firm structure, and the abrasive article may be used as a sanding block. In another embodiment, the abrasive article has a soft, sponge-like structure, and the abrasive article may be used as a sanding sponge. In a yet another embodiment, the abrasive article may have a medium firmness and the abrasive article may exhibit properties typical of both sanding blocks and sanding sponges. In course of this disclosure, the terms soft and softness refer to a property of the abrasive article related to good malleability, bendability and adaptivity to contours of the working surface. The terms firm and firmness, on the other hand, refer to a low malleability, bendability and a smaller adaptivity to contours of the working surface. The terms ‘soft’ and ‘firm’ should not be understood merely as measures of compressibility of the abrasive article.

[0042] In an embodiment, the abrasive article comprises a combination of portions of different firmness, e.g., at least one firm portion and at least one soft portion. The at least one firm portion and the at least one soft portion may be located, for example, on top of each other or adjacent to each other within the abrasive article.

[0043] In an embodiment, the abrasive article comprises a firm inner portion and a soft outer portion. In this embodiment, the abrasive article can benefit of both firmness of the inner portion for a good grip for the hand and softness of the outer portion for adaptivity to contours of the working surface. Thus, sanding around edges and corners may be easy. The abrasive article may also comprise a soft inner portion and a firm outer portion, a soft inner portion and a soft outer portion, or a firm inner portion and a firm outer portion.

[0044] In an embodiment, the abrasive article comprises a combination of portions of different firmness located adjacent to each other, e.g., on different sides of the abrasive article. In other words, the abrasive article may comprise a firm portion on a first side for aggressive sanding or planing, combined with a soft portion on a second side and optionally a medium-soft portion on a third side of the abrasive article for finishing. The soft portion and optionally the medium- soft portion may have a greater adaptivity to contours of the working surface compared to the firm portion. The abrasive article may benefit of added functionality compared to conventional abrasive articles or sanding blocks. The abrasive article has an advantage of combining portions with several different functionalities into the same product.

[0045] In an embodiment, the abrasive article comprises a core. The core may provide the abrasive article an adaptivity to contours of the working surface. The core may also function as a support for the substrate on which the abrasive layer is arranged. Thus, the substrate may be arranged as a layer on the surface of the core. The core may even act as the substrate on which the abrasive layer is arranged, i.e., the core may form the substrate on which the abrasive layer is arranged.

[0046] In an embodiment, the portions of different firmness, e.g., the at least one firm portion and the at least one soft portion may be arranged at the core of the abrasive article. In other words, the core may comprise a combination of portions of different firmness. In an embodiment, the core comprises a firm inner portion and a soft outer portion. The core may also comprise a soft inner portion and a firm outer portion, a soft inner portion and a soft outer portion, or a firm inner portion and a firm outer portion.

[0047] In an embodiment, the combination of portions of different firmness located adjacent to each other, e.g., on different sides of the abrasive article are arranged at the core. In other words, the core may comprise a firm portion on a first side for aggressive sanding or planing, combined with a soft portion on a second side and optionally a medium-soft portion on a third side of the core.

[0048] The core may have either a hollow structure or a dense structure. In an embodiment, the core has a hollow structure, wherein empty space makes up a majority of the core. In this embodiment, the core may comprise a network of materials, e.g., a network of sheet-like, fiber-like or foam-like materials, or any combination thereof.

[0049] In another embodiment, the core has a dense structure, wherein the majority of the core is filled with a material.

[0050] In an embodiment, the core comprises sustainable and / or renewable materials. The core may comprise a combination of multiple different materials. In an embodiment, the core comprises an inner portion and an outer portion. The inner portion and outer portion may comprise materials of different firmness or softness. In an embodiment, the inner portion comprises soft materials and the outer portion comprises firm materials. In another embodiment, the inner portion comprises firm materials and the outer portion comprises soft materials. In another embodiment, the inner portion comprises soft materials and the outer portion comprises soft materials. In another embodiment, the inner portion comprises firm materials and the outer portion comprises firm materials. In an embodiment, the core comprises laminates of saccharide-based and / or non-saccharide-based materials. In another embodiment, the core comprises a firm inner portion and a soft outer portion, wherein the firm inner portion and the soft outer portion may comprise different materials, e.g., the inner portion may comprise fiber-like materials, paper or cardboard, and the outer portion may comprise foam-like materials, such as cellulose foam. In an embodiment, the abrasive article may comprise other materials or additives generally understood compatible with and / or useful in sanding sponges or sanding blocks. In an embodiment, the abrasive article may comprise additives to increase its hydrophobicity, especially to improve the hydrophobicity of the core or the substrate. The hydrophobicity-improving additives may comprise, e.g., waxes or resins. The material of the core, e.g. saccharide-based material, such as cellulose fibers, may be modified to increase its hydrophobicity. The increased hydrophobicity of the abrasive article has an advantage of prolonged resistance to moist conditions or water in, e.g., wet sanding applications.

[0051] In an embodiment, the abrasive article or at least a part of the abrasive article is created using additive manufacturing technologies, such as 3D printing. In an embodiment, the core, the substrate, and / or the abrasive layer of the abrasive article is created using additive manufacturing technologies. In an embodiment, the abrasive grains of the abrasive article are created using additive manufacturing technologies. The abrasive grains may be created using additive manufacturing technologies either as a separate process or directly on top of the substrate.

[0052] In an embodiment, the core comprises one or more sheet of one or more sustainable and / or renewable materials arranged in one or more layers to form the shape for the abrasive article. The one or more sheet may be arranged in more than one layer, e.g., by folding or stacking. In an embodiment, the core comprises one sheet of one or more sustainable and / or renewable materials. In an embodiment, the core comprises one sheet of one or more sustainable and / or renewable materials arranged in more than one layer by folding the sheet on top of itself. In an embodiment, the core comprises more than one sheet of one or more sustainable and / or renewable materials arranged in more than one layer by stacking the sheets on top of each other. The one or more sheet may be any sustainable and / or renewable material processed into a sheet-like form. The one or more sheet may comprise, e.g., woven or nonwoven fabric, paper or cardboard, such as corrugated board.

[0053] Folding or stacking the one or more sheet enables to produce a light yet flexible abrasive article that is adaptive to contours of the working surface. Origami or conventional folding techniques may be used to fold the one or more sheet. The folding technique may be utilized to fine-tune the flexibility and adaptivity of the abrasive article to contours of the working surface. Choice of fold type and / or origami structure, as well as choice of material and thickness of the one or more sheet may have a great impact on the firmness of the core.

[0054] In an embodiment, folding and cutting techniques may be combined to create the core. Kirigami cutting and folding techniques may be used in shaping the core. In an embodiment, laser, knife or other cutting techniques may be used to produce cuts to the one or more sheet to increase flexibility and adaptivity to contours of the working surface. These cuts may be straight or patterned, e.g., in a fluctuating or wavy pattern. Patterning, dimensions, such as length and width, as well as penetration depth of the cuts in the sheet may be optimized for desired abrasive article characteristics. Some cuts may penetrate through the sheet and others may penetrate only partially through the sheet. By varying the patterning, lengths and the penetration depth of the cuts, flexibility and adaptivity of the abrasive article to contours of the working surface may be fine-tuned. Typically, an increased number and / or size of cuts in the sheet prior to folding results in a more flexible core, increasing the adaptivity of the abrasive article to contours of a working surface. On the contrary, using smaller and / or fewer cuts, a firm core may be produced, resulting in a slightly less flexible product. However, depending on the material choice, the abrasive article may exhibit some adaptivity to contours of a working surface.

[0055] In an embodiment, the core comprises or consists of one or more layers of the one or more sheet arranged to form a larger structure by folding or stacking. In an embodiment, the core is constructed by providing one or more sheet, followed by folding the one or more sheet on top of itself to form the core. In an embodiment, the core is constructed by providing more than one sheet, followed by stacking the sheets on top of each other to form the core. Edges, or the perimeter, of the core may be finished by cutting to a desired shape after the folding to provide a trim finish to the core. Finishing the core by cutting after folding to a desired shape defines the shape of the abrasive article provides a finished look for the core and simplifies further processing of the abrasive article, such as arranging the abrasive layer on top of the core. In an embodiment, the substrate, the core, or both may present dust attracting properties. The core, the abrasive layer, or both may comprise apertures, cuts or holes as dust attraction elements. The dust attraction elements in the core and in the abrasive layer may be optimized in terms of, e.g., position and size, for an improved dust attraction. In an embodiment, the abrasive article may be combined with a dust removing apparatus, e.g., a vacuum cleaner, for an efficient dust extraction or removal.

[0056] An abrasive layer is arranged on the substrate of the abrasive article. The abrasive layer may comprise abrasive grains. Abrasive grains may also be called abrasive particles. The abrasive grains may comprise conventional abrasive grains, ceramic abrasive grains, recycled abrasive grains, or any combination thereof. Typical materials used as abrasive grains are hard minerals, which may be synthetic or occur naturally. An exemplary list of minerals used as abrasive grains comprises cubic boron nitride, boron carbide, aluminium oxide, iron oxide, cerium oxide, silicon carbide, zirconia alumina, diamond, emery and corundum. The abrasive grains may comprise engineered grains shaped to certain shape and size. The abrasive layer may be prepared using thermally cured resins, radiation-cured resins, or a combination thereof. Strewing of abrasive grains onto the substrate may be carried out using electrostatic methods. Alternatively, the abrasive grains may be deposited using spray coating methods, slurry coating methods, dip coating methods, or a combination thereof.

[0057] In an embodiment, the substrate is covered by the abrasive layer on all sides. Alternatively, one or more sides of the substrate may be free of an abrasive layer for increased flexibility and adaptivity to contours of the working surface.

[0058] In an embodiment, the substrate is arranged as a layer on the surface of the core. The substrate may be folded on top of the core to receive the abrasive layer. Alternatively, the abrasive article does not comprise a core, and the substrate is folded to support itself to receive the abrasive layer. Abrasive grains may be deposited either before the substrate is folded or after the substrate is folded to receive the abrasive layer. The substrate may be coated with abrasive grains either completely or in certain portions only. In case the substrate is coated with abrasive grains in certain portions only, the portions may be selected in such a way that the grain-free portions receive grain-coated portions when folding the substrate to define the shape for the abrasive article. Thus, after folding, only the grain-coated portions are visible.

[0059] In an embodiment, the core forms the substrate on which the abrasive layer is arranged. In other words, the core, or more precisely, the surface of the core, acts as the substrate. The abrasive layer is arranged on the substrate as a coating deposited directly on top of the core. The coating may be deposited using spray coating methods, slurry coating methods, dip coating methods, or a combination thereof.

[0060] In an embodiment, the abrasive article may be collapseable, i.e., able to collapse on itself into a flat form. In other words, the abrasive article may be collapsed into the flat form. The abrasive article in its flat form has a height H’ substantially smaller than in the non-collapsed form. H’ for the abrasive article in the collapsed form may take values in the range of 0.05-2 cm, preferably 0.1-1 cm. The abrasive article may be collapsed into the flat form, e.g., by folding and / or compressing. The abrasive article may be transported in the flat form, bringing about a major decrease in transportation cost and carbon emissions. The abrasive article may then be assembled, i.e., reversed from the flat form into a non-collapsed form, by the end user.

[0061] In an embodiment, an abrasive article that does not comprise a core may be manufactured, transported and retailed directly in the flat form. The abrasive article may comprise pre-fold lines that guide the end user in reversing the abrasive article into the non-collapsed form. The abrasive article may also comprise an adhesive strip, preferably covered by a protective strip. The end user may revert the abrasive article into the non-collapsed form by folding along the pre-fold lines, removing the protective strip, thus revealing the adhesive strip, and assembling the abrasive article by pressing the adhesive strip against a designated receiving portion within the substrate of the abrasive article.

[0062] In an embodiment, an abrasive article comprising a core may be compressed into the flat form during the manufacturing process. Especially, an abrasive article comprising a core comprising foam may be compressed into the flat form during the manufacturing process. The abrasive article may be transported and retailed in the compressed flat form. Preferably, the abrasive article is retailed in a packaging that maintains the article in the flat form. The end user may assemble the abrasive article, e.g., by removing the packaging, whereupon the abrasive article reverts to the non-collapsed form through air intake into voids of the foam structure.

[0063] Different layers of the abrasive article may be fastened to each other by using a suitable fastening system. The fastening system may be used to fasten layers of the sheet to form the core, to fasten the substrate on the surface on the core, and / or to fasten portions of the substrate to support the substrate. Different layers of the abrasive article may be fastened using different fastening systems. The fastening system may comprise mechanical fastening, such as hook-and-loop fastener, or adhesive fasteners, such as adhesives, resins and / or sizes. Suitable adhesive fasteners may be of natural or synthetic origin. Suitable adhesive fasteners comprise solvent-based adhesives, emulsion adhesives, contact adhesives, hot-melt adhesives, multi-component adhesives, or any combination thereof, such as starch-based adhesive or stearate size. In a preferred embodiment, a bio-based adhesive, such as starch-based adhesive, is used.

[0064] In an embodiment, structure of the abrasive article may be a closed structure with all sides of the abrasive article comprising the substrate. In an alternative embodiment, the abrasive article may have an open structure, i.e., one or more sides being free of a substrate, leading to a more flexible structure and providing increased adaptivity to contours of the working surface. In a closed structure, one or more cuts may be arranged in the substrate to increase the flexibility and adaptivity. In an open structure, one or more cuts may be arranged in the substrate to increase flexibility and adaptivity in a predetermined direction. In a preferred embodiment, one or more holes or apertures are arranged in the substrate for dust collection.

[0065] Figures 1 a-1 c present abrasive articles according to the invention. The abrasive article 100 comprises a substrate 104 and an abrasive layer 102. The substrate 104 has a length L, a width W and a height H. The abrasive articles presented in Figure 1 have a closed structure, i.e., all sides of the abrasive article comprise the substrate. The abrasive article in Figure 1 b comprises the abrasive layer on all sides of the substrate, whereas the abrasive articles in Figures 1a and 1c have a portion of the substrate free of the abrasive layer. Figures 2a-2f present cross-sections of abrasive articles according to certain embodiments of the invention. The abrasive article 200 comprises a substrate 204, a core 201 , and an abrasive layer 202. The substrate 204 has a length L and a height H. The substrate 204 in Figures 2a-2f is arranged as a layer on the surface of the core 201 . The abrasive article 200 presented in Figure 2a has an abrasive layer 202 on one side of the substrate 204 in the Sx, Syplane. The abrasive articles 200 presented in Figures 2b-2c have an abrasive layer 202 on two sides of the substrate 204 in the Sx, Syplane, the abrasive articles 200 presented in Figures 2d-2e have an abrasive layer 202 on three sides of the substrate 204 in the Sx, Syplane, and the abrasive article 200 presented in Figure 2f has an abrasive layer 202 on all sides of the substrate 204 in the Sx, Syplane.

[0066] Figures 3a-3f present cross-sections of abrasive articles according to certain embodiments of the invention. The abrasive article 300 comprises a core 301 and an abrasive layer 302. The core forms the substrate 304 on which the abrasive layer 302 is arranged. The substrate 304 has a length L and a height H. The abrasive article 300 presented in Figure 3a has an abrasive layer 302 on one side of the substrate 304 in the Sx, Syplane. The abrasive articles 300 presented in Figures 3b-3c have an abrasive layer 302 on two sides of the substrate 304 in the Sx, Syplane, the abrasive articles 300 presented in Figures 3d-3e have an abrasive layer 302 on three sides of the substrate 304 in the Sx, Syplane, and the abrasive article 300 presented in Figure 3f has an abrasive layer 302 on all sides of the substrate 304 in the Sx, Syplane.

[0067] Figures 4a-4c present cross-sections of abrasive articles 400 according to certain embodiments of the invention. The abrasive articles 400 presented in Figures 4a-4c comprise a core 401 which forms the substrate 404 on which the abrasive layer 402 is arranged. In other words, the abrasive layer 402 is deposited directly on top of the core 401 . The abrasive article 400 presented in Figure 4a has a rectangular shape in the Sx, Syplane, the abrasive article 400 presented in Figure 4b has an ellipsoidal shape in the Sx, Syplane, and the abrasive article 400 presented in Figure 4c has an irregular shape in the Sx, Syplane. Figures 5a and 5b present an abrasive article 500 according to certain embodiments of the invention. The abrasive article 500 comprises a substrate 504 that is folded to support itself, and an abrasive layer 502. The abrasive article 500 does not comprise a core. The substrate 504 has a length L, a width W and a height H. The abrasive article 500 presented in Figures 5a and 5b has an open structure, i.e., at least one side of the abrasive article is free of substrate. Figure 5a presents the abrasive article 500 in its non-collapsed form and Figure 5b presents the abrasive article 500 in its collapsed form.

[0068] Figures 6a and 6b present substrate layers 604 coated with abrasive layers 602 according to the invention. The substrate layers are coated with abrasive grains in certain portions only. The portions not coated with abrasive grains are shown white. The substrate layers may be folded such that the non-grain coated portions receive and support the grain-coated portions, such that after folding, only the grain-coated portions are visible. Figures 6a and 6b may be considered as collapseable abrasive articles in their collapsed form. The end user may assemble the abrasive article. For example, Figure 6b shows a fastening system 603, e.g., an adhesive stripe. The end user may assemble the abrasive article by attaching the adhesive stripe to the opposite end of the substrate.

[0069] Figures 7a and 7b present a core 701 according to certain embodiments of the invention. The core 701 is formed of a sheet folded in several layers. The individual layers are fastened to each other using a fastening system 703. Figure 7c presents an abrasive article 700 comprising a core 701 formed of a sheet folded in several layers, a substrate 704 and an abrasive layer 702, wherein the substrate 704 is arranged as a layer on the surface of the core 701. The abrasive article 700 has a closed structure, i.e., all sides of the abrasive article 700 are covered by the substrate 704. All sides of the substrate 704 are covered by the abrasive layer 702. Figure 7d presents an abrasive article 700 comprising a core 701 formed of a sheet folded in several layers, a substrate 704 and an abrasive layer 702. The core 701 forms the substrate 704. The abrasive article 700 has a closed structure, i.e., all sides of the abrasive article 700 are covered by the substrate 704. All sides of the substrate 704 are covered by the abrasive layer 702. Figure 7e presents an abrasive article 700 comprising a core 701 formed of multiple stacked sheets, a substrate 704 and an abrasive layer 702, wherein the substrate 704 is arranged as a layer on the surface of the core 701 . The abrasive article 700 has a closed structure, i.e., all sides of the abrasive article 700 are covered by the substrate 704. All sides of the substrate 704 are covered by the abrasive layer 702. Figure 7f presents an abrasive article 700 comprising a core 701 formed of multiple stacked sheets. The core 701 forms the substrate 704. The abrasive article 700 has a closed structure, i.e., all sides of the abrasive article 700 are covered by the substrate 704. All sides of the substrate 704 are covered by the abrasive layer 702.

[0070] The abrasive article disclosed herein brings savings in costs. The core materials are inexpensive when compared to conventional fossil-based foams or sponges. Further, more cost-efficient transportation may be achieved. For example, paper or cardboard takes up less space and is easier to transport when compared to bulky foam. Less vehicles or smaller vehicles are needed for transportation of the raw materials. Procurement of conventional foams is difficult and requires long transports. The raw materials of the abrasive article disclosed herein can be made of materials from local partners, thereby leading to more efficient and shorter transports. Further, for at least some embodiments, less materials are used than in conventional sanding blocks. Use of renewable and in some cases recycled materials brings about reduced carbon emissions from manufacturing and transportation. The abrasive article disclosed herein may be partly or fully compostable and / or recyclable. Compostability and / or recyclability render the abrasive article to be compatible with the concept of circular economy. Some embodiments of the abrasive article further provide an advantage of advantage of combining several different functionalities into the same product.

Claims

Claims:1 . An abrasive article (100, 200, 300, 400, 500, 700) for sanding applications, wherein- the abrasive article (100, 200, 300, 400, 500, 700) comprises a substrate (104, 204, 304, 404, 504, 604, 704);- an abrasive layer (102, 202, 302, 402, 502, 602, 704) is arranged on the substrate (104, 204, 304, 404, 504, 604, 704);- the abrasive article (100, 200, 300, 400, 500, 700) comprises one or more renewable materials;- the abrasive article (100, 200, 300, 400, 500, 700) is adaptive to contours of a working surface.

2. The abrasive article (100, 200, 300, 400, 500, 700) of claim 1 , wherein the substrate (104, 204, 304, 404, 504, 604, 704) has a length L of 0.5-50 cm, a width W of 0.5-50 cm, and a height H of 0.5-50 cm, preferably a length L of 10-20 cm, a width W of 5-15 cm, and a height H of 1-5 cm to define a shape for the abrasive article.

3. The abrasive article (100, 200, 300, 400, 500, 700) of claim 1 or 2, wherein the one or more renewable materials comprise saccharide-based material.

4. The abrasive article (100, 200, 300, 400, 500, 700) of claim 3, wherein the saccharide-based material comprises wood-based material, preferably paper or cardboard, such as corrugated board.

5. The abrasive article (100, 200, 300, 400, 500, 700) of any of the preceding claims, wherein the abrasive article comprises a combination of portions of different firmness.

6. The abrasive article (100, 200, 300, 400, 500, 700) of any of the preceding claims, wherein the abrasive article may be collapsed into a flat form, e.g., by folding and / or compressing, and reversed into a non-collapsed form by an end user.

7. The abrasive article (100, 200, 300, 400, 500, 700) of any of the preceding claims, wherein the abrasive article comprises a core (201 , 301 , 401 , 701 ).

8. The abrasive article (100, 200, 300, 400, 500, 700) of claim 7, wherein the core (201 , 301 , 401 , 701 ) comprises one or more renewable materials.

9. The abrasive article (100, 200, 300, 400, 500, 700) of claim 7 or 8, wherein the core (201 , 301 , 401 , 701 ) comprises one or more sheet of one or more renewable materials arranged in one or more layers to form the shape for the abrasive article.

10. The abrasive article (100, 200, 300, 400, 500, 700) of claim 8, wherein the renewable materials comprise foam, such as cellulose foam.11 . The abrasive article (100, 200, 300, 400, 500, 700) of any of claims 7 to 10, wherein the substrate (104, 204, 304, 404, 504, 604, 704) is arranged as a layer on the surface of the core (201 , 301 , 401 , 701 ).

12. The abrasive article (100, 200, 300, 400, 500, 700) of any of claims 7 to 10, wherein the core (201 , 301 , 401 , 701 ) forms the substrate (104, 204, 304, 404, 504, 604, 704) on which the abrasive layer is arranged.

13. A manufacturing method for an abrasive article (100, 200, 300, 400, 500,700) according to any of the claims 1 -12, the method comprising- arranging one or more renewable materials as a substrate (104, 204, 304, 404, 504, 604, 704) of the abrasive article,- arranging an abrasive layer (102, 202, 302, 402, 502, 602, 702) on the substrate of the abrasive article.

14. The method of claim 13, wherein the method further comprises- arranging one or more renewable materials as a core (201 , 301 , 401 ,

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