Abrasive Article and Method of Making such an Article

Abstract

A method for manufacturing an abrasive article (10), including: providing a sheet including a support layer (12) and members (20) of a quick release system, QRS (18, 19) applying a metal coating (36) onto the support layer and the QRS members; applying abrasive particles (38) onto at least part of the first surface of the support layer, so that the particles are thermally connected to the metal coating;

The support layer defines a plurality of openings (26) that extend from a first surface (14) of the layer, through the layer, to an opposite surface (16) of the layer, and which allow abrasion dust to pass through. The QRS members are fixed on or in the support layer and protrude from this opposite surface, and are configured to fix the article to a surface including complementary QRS members (19). The metal coating covers both the support layer and the QRS members, and forms thermally conductive paths from the abrasive particles on the first surface, via the openings, to the QRS members on the opposite surface.

Claims

1. A method for manufacturing an abrasive article, the method comprising: providing a base sheet that includes a support layer and fastening members of a quick release system, QRS; wherein the support layer defines a plurality of openings, the openings extending from a first surface of the support layer, through the support layer, to a second surface of the support layer opposite to the first surface, and being configured to allow abrasion dust to pass through the support layer; and wherein the fastening members are fixed on or in the support layer and protrude from the second surface thereof, and are configured to temporarily fix the abrasive article to a surface including complementary fastening members of the QRS; applying an electrically and thermally conductive coating onto the support layer and the fastening members; applying abrasive particles onto at least part of the first surface of the support layer, so that the abrasive particles are thermally connected to the coating; wherein the coating covers both the support layer and the fastening members, and forms thermally conductive paths from the abrasive particles on the first surface, via the openings, to the fastening members on the second surface of the support layer.

2. The method according to claim 1, wherein the fastening members are directly fixed onto or in the support layer before applying the coating, and wherein the method further comprises: applying the coating so as to cover and extend in a continuous manner across exposed outer surfaces of both the support layer and the fastening members.

3. The method according to claim 1, wherein the coating forms a matrix layer, and wherein the method further comprises: applying the coating onto the support layer and the fastening members and embedding the abrasive particles in a portion of the coating present at the first surface of the support layer, using electrolytic co-deposition.

4. The method according to claim 1, further comprising: before applying the coating, applying a metal primer coating directly onto the support layer and the fastening members, using electro-less plating, and; applying the coating onto the metal primer coating, using electroplating or electrolytic co-deposition.

5. The method according to claim 1, further comprising: providing the base sheet shaped as an elongated web that is stored on a roll or folded stack; continuously or intermittently unrolling or unfolding consecutive web portions of the base sheet from the roll or the folded stack; continuously or intermittently applying the coating onto both the support layer and the fastening members and applying abrasive particles onto the first surface of the support layer of respective consecutive web portions that have been unrolled or unfolded, thereby forming web portions of semi-finished abrasive sheet material; cutting a predetermined shape form at least one of the web portions of semi-finished abrasive sheet material, to form the abrasive article.

6. The method according to claim 1, forming the abrasive article as a pad, disc, sheet, or belt configured to carry out a grinding and/or polishing process.

7. An abrasive article for processing a surface, comprising: a base sheet that includes a support layer and fastening members of a quick release system, QRS; wherein the support layer defines a plurality of openings, the openings extending from a first surface of the support layer, through the support layer, to a second surface of the support layer opposite to the first surface, and being configured to allow abrasion dust to pass through the support layer; and wherein the fastening members are fixed on or in the support layer and protrude from the second surface thereof, and are configured to temporarily fix the abrasive article to a surface including complementary fastening members of the QRS; an electrically and thermally conductive coating covering both the support layer and the fastening members, and a deposit with abrasive particles covering at least part of the first surface of the support layer, and being thermally connected to the coating; wherein the coating forms thermally conductive paths from the abrasive particles on the first surface, via the openings, to the fastening members on the second surface of the support layer.

8. The abrasive article according to claim 7, wherein the support layer is an open mesh formed of multiple strands that mutually cross or intersect, and which define the openings in between.

9. The abrasive article according to claim 8, wherein the fastening members are integrated with the strands of the mesh so that the fastening members and strands engage along contact surfaces, and so that the coating covers and extends in a continuous manner across both the mesh and the fastening members, without extending directly in-between the fastening members and the strands along the contact surfaces.

10. The abrasive article according to claim 7, wherein the fastening members are formed by filaments having base portions that are mechanically fixed to or incorporated into the support layer, for instance embedded in or intertwined with strands of the mesh support layer according to claim 8 or 9.

11. The abrasive article according to claim 8, wherein the mesh is formed of woven, braided, or knitted strands.

12. The abrasive article according to claim 8, wherein the mesh is an extruded mesh, a punched mesh, or a slit-and-expanded material mesh.

13. The abrasive article according to claim 8, wherein the mesh is flexible.

14. The abrasive article according to claim 8, wherein the mesh is made of polyester fibres.

15. The abrasive article according to claim 7, wherein the openings in the support layer have an open area in a range of 20%-60% of the surface area of the abrasive article.

16. The abrasive article according to claim 7, wherein the openings in the mesh are provided in a regular pattern, the pattern having one or more of: two-dimensional periodicity; mirror symmetry; discrete rotational symmetry.

17. The abrasive article according to claim 7, being a rotationally symmetric pad, for instance a circular pad, and wherein the support layer and openings have discrete rotational symmetry.

18. The abrasive article according to claim 7, wherein the coating is a metal coating consisting essentially of nickel or nickel-based alloy.

19. The abrasive article according to claim 7, wherein the abrasive particles consist essentially of diamond or cubic boron nitride.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0052] Embodiments will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts. In the drawings, like numerals designate like elements. Multiple instances of an element may each include separate letters appended to the reference number. For example, two instances of a particular element 22 may be labelled as “22a” and “22b”. The reference number may be used without an appended letter (e.g. “22”) to generally refer to an unspecified instance or to all instances of that element, while the reference number will include an appended letter (e.g. “22a”) to refer to a specific instance of the element.

[0053] FIG. 1 schematically shows a perspective view of an abrasive article according to an embodiment;

[0054] FIGS. 2a-b show a top view and a cross-sectional side view of the article from FIG. 1;

[0055] FIG. 3 schematically illustrates system and process embodiments for manufacturing an abrasive article, and

[0056] FIGS. 4a-c illustrate steps in a process for manufacturing an abrasive article, according to an embodiment.

[0057] The figures are meant for illustrative purposes only, and do not serve as restriction of the scope or the protection as laid down by the claims.

DESCRIPTION OF EMBODIMENTS

[0058] The following is a description of certain embodiments of the invention, given by way of example only and with reference to the figures.

[0059] FIG. 1 schematically shows a perspective view of the abrasive article 10, of which a part has been schematically cut out to show part of the article 10 in cross-section. The article 10 may be used to grind surfaces made of glass, metal, stone, ceramics, or composites.

[0060] The article 10 comprises a support layer 12 formed as a wire mesh, which defines an upper surface 14 and a lower surface 16 on opposite sides. The upper surface 14 carries a deposit with abrasive particles 38, and is adapted to face a surface of an object that is to be processed (e.g. grinded, polished, etc.).

[0061] The article 10 is configured to be attached to a disc-shaped base pad 42 of an abrading tool 40, by means of a hook-and-loop fastening system 18, 19. Such a base pad 42 may be rotatable about a nominal rotation axis A, relative to the remainder of the abrading tool 40 (not shown). On the lower surface 16 of the mesh 12, the article 10 is provided with first QRS-layer 18 formed by a dense distribution of fastening members 20 that protrude downwards from the lower surface 16. In this example, the fastening members 20 are loops configured to engage and interlock with hooks on the complementary QRS-layer 19 with hooks on the base pad 42. In attached state ready for operation, the disc-shaped article 10 is centred with respect to the nominal axis A.

[0062] FIG. 2a shows a top view of a portion of the abrasive article 10 from FIG. 1 in more detail. The wire mesh 12 is coated with multiple layers 34, 36. The article and layers are shown in a partially stripped manner, only for illustrative purposes.

[0063] The wire mesh 12 is flexible, and formed by warp yarns 22 and weft yarns 24 that are woven together, so that the warp yarns 22 and weft yarns 24 cross each other in an alternatingly overlaying manner. In this example, the yarns 22 and 24 are made of polyester fibres that have initially been coated with a phenol formaldehyde resin (not shown). The yarns 22 and 24 each have a diameter of approximately 250 μm. It should be understood that different thread diameters may be used, depending on the desired mechanical characteristics of the resulting article.

[0064] As shown in FIG. 2a, the weaving pattern creates through openings 26 in the mesh 12, which are enclosed between adjacent pairs of mesh strands 22, 24. The surface area of each of the openings 26 is approximately 0.5 mm.sup.2. The open area (percentage) of the openings 26 relative to the total area of the bare mesh 12 is approximately 40%.

[0065] In this example, the fastening members 20 are also made of polyester filaments that are coated with a phenol formaldehyde resin. The resin-coated filaments have a diameter of approximately 60 μm, and are intertwined in the weaving pattern of the wire mesh 12 to form loops. The length of a loop is on average approximately 5.5 mm.

[0066] The wire mesh 12 and intertwined fastening members 20 are covered with a metal primer coating 34, with a metal main coating 36 that covers and fully envelops the primer coating 34, and with deposits of abrasive particles 38 that are embedded in the main coating 36 present on the upper surface 14 of the article 10. The main coating 36 fixes (immobilizes) the warp yarns 22, weft yarns 24, and fastening members 20 with respect to each other.

[0067] FIG. 2b shows a cross-sectional side view of a portion of the abrasive article 10, which illustrates that the deposits with abrasive particles 38 are mainly positioned on the top surface 14 of the wire mesh 12. By contrast, the metal coating 36 is distributed in a continuous manner across the outer surfaces of the mesh 12 and the fastening members 20.

[0068] In this embodiment, the primer coating 34 has a thickness of approximately 0.2 μm and the main coating 36 has a thickness of approximately 100 μm. The main coating 36 and primer coating 34 are both made of nickel. It should be understood that a large variety of other metals, metal alloys, or metal-resembling materials with high thermal and electrical conductivities may be applied, and that the preferred thickness of the metal coating 36 relates to the desired thermal conductivity of the selected material. Preferably, a bulk thermal conductivity of coating 36 is at least 40 Watts per meter Kelvin.

[0069] The deposits with abrasive particles 38 are embedded in the main coating 36 on the upper surface 14 of the wire mesh 12. In this example, the matrix coating 36 is made of nickel, and the abrasive particles 38 are diamond particles with a median particle diameter of 40 μm. Nevertheless, it will be understood that in other embodiments, other matrix materials with high melting temperature and high heat conductivity, and abrasive particles of a different material and/or grit size may be used, dependent on the application purpose of the article.

[0070] The application of the coatings 34, 36 on the mesh 12 changes the openings 26 into openings 27 of reduced size. As a result, the surface area of each of the reduced openings 27 is approximately 0.3 mm.sup.2, and the open area of the reduced openings 27 relative to the total area of the abrasive article 10 is approximately 30%. The size and amount of openings 27 are still sufficiently large to allow dust particles to pass through the article 10. Such dust particles may for instance originate from the processed surface of the object, or from wear of the article 10 itself. Besides removing dust, the openings 27 also allow ventilation through the abrasive article 10.

[0071] The coatings 34, 36 provide thermally conducting paths from the upper surface 14 of the article 10, through the openings 27, and to the fastening members 20 on the lower surface 16. During use of the article 10, heat produced by friction between the upper surface 14 with abrasive particles 38 and the surface of the treated object, can be conducted along these paths, through the wire mesh 12, and towards the fastening members 20. The abrading tool 40 may be equipped with a cooling device in the base 42, which extends along surface with QRS-layer 19 and allows heat accumulated in the QRS-layer 18 to be removed by conductive heat transfer.

[0072] Alternatively or in addition, heat accumulated in the layers 34, 36 may be absorbed and dissipated by convective heat transfer, for instance by air that is circulated through the openings 27 to absorb part of the heat in the coating 36, and to convey this heat away from the article 10. For this purpose, the abrading tool 40 may be equipped with an air suction system having suction apertures provided in the base 42 (FIG. 1, not indicated), to promote flow of air through the openings 26.

[0073] FIG. 3 illustrates a method and a system 50 for manufacturing an abrasive article 10 according to embodiments. An elongated web of mesh precursor material is stored on supply roll 52, and continuously or intermittently unrolled into consecutive web portions 53 that are fed via guide rolls 56 towards a first bath 60 with an electro-less plating liquid 62. The resulting web portions with primer coating are continuously or intermittently moved by electrostatic roll 58 towards and into second bath 64, which is filled with a second liquid 66 with in which nickel ions and abrasive particles 38 are present. An electric field is applied between the coated web portion 53 and the source region of abrasive particles in the basin 64, so that the nickel ions are deposited as coating 36 onto both the support layer 12 and the fastening members 20 while the abrasive particles 38 are simultaneously embedded in the resulting coating 36 onto the first surface of the support layer of respective consecutive web portions 53. The resulting web portions 55 of semi-finished abrasive sheet material are moved out of the second bath 64, and are stored on a collector roll 54. These web portions 55 of subsequently be cut into separate abrasive articles 10.

[0074] FIGS. 4a-4c further illustrate method steps for manufacturing the abrasive article 10. FIG. 4a shows an initial step, in which a base sheet with a mesh 12 and loop-shaped fastening members 20 is provided. Only three warp yarns 22 of the mesh 12 and a fastening loop 20 are shown in cross-section, whereas weft yarns 24 are omitted. The fastening members 20 are attached with base portions 28 wrapped around the mesh, so that the base portions 28 and strands 22 (and/or 24) engage along contact surfaces 30. The loop portions of members 20 protrude on a lower side 16 of the mesh 12.

[0075] FIG. 4b illustrates that a metal primer coating 34 is applied onto the exposed outer surface regions 32 of the mesh 12 and fastening members 20, so that the mesh 12 and members 20 become essentially entirely embedded inside the primer coating 34. These exposed surface regions 32 do not coincide with contact surfaces 30, meaning that the primer coating 34 is not applied onto the surface regions 30 directly in between the mesh 12 and fastening members 20.

[0076] FIG. 4c illustrates that a metal coating 36, is applied to the exposed surface of the primer coating 34, so that the mesh 12 and fastening members 20 with primer coating 24 become essentially entirely embedded inside coating 36. FIG. 4c also illustrates that deposits with diamond grains 38 are embedded in portions of the metal coating 36 that are present on the upper surface side of the mesh 12. The resulting coating 36 fixes the members 20 and strands 22 (24) to each other, and simultaneously forms a metal matrix material for fixing in place the diamond grains 38 embedded therein.

[0077] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. It will be apparent to the person skilled in the art that alternative and equivalent embodiments of the invention can be conceived and reduced to practice. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

[0078] Those skilled in the art and informed by the teachings herein will realize that the invention is applicable to any wire mesh or netting with integrated hook or loop surface that is or can be made thermally conductive. The wire mesh may also for instance be an extruded mesh, a slit-and-expanded material mesh, a knitted mesh, or a welded wire mesh. It will be clear to a person skilled in the art how to entangle or differently integrate the fastening members of the hook and loop system into the wire mesh. The selection for hooks or loops on the abrasive article will be determined by the type of fastening members provided on the base pad of the abrading tool.

[0079] This size and shape of various conceivable abrasive articles according to the present invention, may be adjusted to fit the dimensions of base pads or mounting members of various abrading tools. Exemplary alternatives are disc-shaped abrasive articles with a diameter in the order of 1 cm to several tens of cm. Other alternatives are closed-loop cylindrical sheets having a width comparable to their diameter, or elongated closed-loop belts having a length significantly larger than their width. Yet other embodiments include square or rectangular abrasive sheets with widths in a range of 10 mm to 60 cm and lengths in a range of 10 mm to 10 m. Abrasive pads with alternative shapes, like (rounded) triangle shapes, trapezoid shapes, or pentagonal shapes, are also conceivable.

[0080] In the above described embodiment, the abrasive particles 38 were densely but randomly distributed along an upper side of the article 10. In alternative embodiments, particles may be distributed in a non-uniform manner to form a plurality of localized deposits, these deposits being shaped into predetermined patterns on the upper surface of the article, for instance to optimize functionality of the abrasive article or to make the abrasive article aesthetically more attractive.

[0081] In the above embodiment, the mesh yarns and fastening members were formed of resin-coated polyester fibres. In alternative embodiments, the mesh may be formed of other types of (continuous) fibre material, provided the resulting filaments/twines/yarns are flexible, and have a high resistance to heat (melting/burning/thermal decomposition temperature of at least 160° C.) and a high ultimate tensile strength (of at least 100 MPa) along their length direction.

[0082] Also, the shape of openings in the wire mesh should not be considered limited to square openings. In alternative embodiments, the wire meshes may have openings with a regular cellular shape such as squares, honeycombs, triangles, or other polygons, or even a combination of different shapes.

LIST OF REFERENCE SYMBOLS

[0083] 10 abrasive article [0084] 12 support layer (e.g. wire mesh) [0085] 14 first surface [0086] 16 second surface [0087] 18 QRS layer [0088] 19 QRS layer with complementary members [0089] 20 fastening member [0090] 22 warp yarn [0091] 24 weft yarn [0092] 26 through opening [0093] 27 reduced opening [0094] 28 base portion [0095] 30 contact surface [0096] 32 (initially) exposed surface [0097] 34 primer coating [0098] 36 deposit coating [0099] 38 abrasive particles [0100] 40 abrading tool [0101] 42 rotator base [0102] 50 manufacturing system [0103] 52 supply roll [0104] 53 web portion (of base sheet) [0105] 54 collector roll [0106] 55 web portion (of abrasive sheet) [0107] 56 guide roll [0108] 58 electrostatic roll [0109] 60 first bath [0110] 62 first liquid [0111] 64 second bath [0112] 66 second liquid [0113] X longitudinal direction [0114] Y transverse direction [0115] Z normal direction [0116] A rotation axis