Abrasives

Abstract

The invention relates to an abrasive, in particular flexible abrasive (11), preferably hand abrasive (11), for grinding a workpiece with a grinding element (13), with a, in particular flexible, carrier element (15) for arranging the grinding element (13) on the carrier element (15), with a binder element (17) for holding the grinding element (13) on the carrier element (15) and with a foam element, in particular arranged on a side of the carrier element facing away from the grinding element. It is proposed that the abrasive has a perforation, in particular designed as a foam recess.

Description

[0001] The invention relates to an abrasive according to the preamble of claim 1. State of the art

[0002] Abrasives with a foam element arranged on a carrier element are known. Disclosure of the invention

[0003] The invention is based on the object of improving an abrasive with simple constructive measures.

[0004] The object is achieved with an abrasive, in particular a flexible abrasive, preferably a hand abrasive, for grinding a workpiece with a grinding element, with a, in particular flexible, carrier element for arranging the grinding element on the carrier element, with a binder element for holding the grinding element on the carrier element and with a foam element, in particular arranged on a side of the carrier element facing away from the grinding element.

[0005] It is proposed that the abrasive has a perforation formed in particular as a foam recess.

[0006] The perforation can be arranged along a perforation line. The perforation line can be straight and / or curved. The abrasive can have a plurality of perforations or be formed from them. The perforation can extend through the entire foam element. The perforation can extend from one end to another end of the foam element facing away from the end.

[0007] The carrier element can be made of a nonwoven fabric and / or a paper material. It is understood that the carrier element can also be made of other materials deemed appropriate by a person skilled in the art, such as a plastic, in particular a plastic film.

[0008] The abrasive can be provided for the grinding or abrasive processing of a workpiece, in which material of the workpiece is mechanically removed from the surface of the workpiece in the form of chips. The abrasive can preferably be a composite abrasive. The abrasive can particularly advantageously be designed to be flexible, whereby the abrasive can be folded and unfolded particularly easily, in particular reversibly. In particular, this can be done while avoiding tearing of the abrasive. The abrasive can, in particular when using a nonwoven fabric, be designed to be flexible or elastic in such a way that the abrasive can be stretched by more than 5%, in particular more than 10%, preferably more than 15%, preferably more than 20%, without the abrasive tearing.

[0009] This allows a stable sanding corner to be provided when folded or bent along the perforation of the abrasive, which can better reach and sand angled areas to be sanded.

[0010] This can also improve the static friction or slip resistance against the hand of an operator of the abrasive. The foam element can provide a flexible element that allows for better control of the abrasive. At the same time, the pressure load can be distributed over a larger area, thus preventing pressure sores on the hand of an operator.

[0011] In addition, the perforation makes it easier to fold the abrasive along the perforation. This allows the abrasive to be optimally adapted to the surface to be sanded.

[0012] The abrasive can have a longitudinal extent or - in the case of a disc - a diameter of up to 500 mm, in particular up to 400 mm, preferably up to 300 mm, more preferably up to 200 mm, particularly preferably up to 170 mm, such as 150 mm or even less. The abrasive can have a thickness of up to 5 mm, in particular up to 3 mm, preferably up to 2 mm, preferably up to 1 mm, particularly preferably up to 0.5 mm, such as 0.4 mm or even less. The abrasive can be present in various forms, for example as a grinding disc or as an abrasive belt, as a sheet, roll, strip or even as an abrasive article web (e.g. in production). The abrasive can be manufactured for use with grinding machines such as eccentric sanders or by hand sanding. The abrasive can be flexible in order to compensate for local unevenness and provide an optimal sanding pattern.The abrasive means may have a plurality of abrasive elements on one side, in particular a grinding side, of the carrier element. The abrasive elements may protrude from the carrier element and / or delimit the abrasive means.

[0013] The grinding element can be provided for grinding a workpiece. The grinding element can have a deforming and / or abrasive effect on the workpiece to be machined. The grinding element can be designed as an abrasive body. The grinding element can be known to a person skilled in the art, among other things, as abrasive grain. The grinding element can contact a workpiece to be machined in a processing state, in particular directly, and in a processing state can lead to abrasive material removal from the workpiece to be machined. The grinding element can be designed as a broken and / or shaped grinding element. The grinding element is not limited to a specific material, but can be made, for example, of corundum (in various variants, in particular white corundum, semi-precious corundum, blue corundum, zirconium corundum, ceramic corundum and / or brown corundum), silicon carbide, cubic boron nitride, diamond or mixtures thereof.The grinding element can be designed as a mesh grinding element.

[0014] The carrier element can be formed from a nonwoven fabric. The nonwoven fabric can be formed from fibers (of limited length), continuous fibers (filaments), or (cut) yarns. The fibers can be combined to form a nonwoven fabric, a fiber layer, or a fiber web and bonded together in a suitable manner. The carrier element can be nonwoven. The carrier element can comprise a plurality of fibers. The fibers can be mechanically, chemically, and / or thermally bonded using a suitable process. The fibers can be bonded to form a (fiber) composite. The fibers of the carrier element can be bonded to one another. The fibers can be bonded in a material-to-material manner, in particular adhesively and / or cohesively. The fibers can be formed from a thermoplastic material. The fibers, in particular fibers of the same raw material, can be bonded or bonded to one another without the use of a binder.The fibers can be bonded together by, particularly temporary, heat and / or pressure. The fibers can be bonded by heated embossing calenders or ultrasonic bonding systems. This allows adjacent fibers to be thermally bonded together at their contact points. The carrier element can be designed as a spunbonded nonwoven.

[0015] The carrier element can be made from a paper material. The paper material can essentially be made from fibers, particularly of plant origin. Conventional fibers such as cellulose, wood pulp, and recycled paper can be used, as can other fibers deemed appropriate by a person skilled in the art. Different paper materials can be considered, adapted to the intended use, and can be designed in particular with regard to toughness, tear resistance, flexibility, and various other properties. The desired properties can be achieved, in particular, by adding fillers and / or additives to the (paper) fibers. To improve durability or resistance, the carrier element can be impregnated, for example.

[0016] The carrier element can be made of a plastic, in particular a plastic film.

[0017] The carrier element can be designed as a carrier layer and impart specific properties to the abrasive with regard to adhesion, elongation, tear and tensile strength, flexibility and stability. The abrasive elements can be applied to and fixed on the carrier layer. The abrasive elements can be arranged and / or bonded to the carrier element by means of a binder element known per se. For example, in the case of a coated abrasive, abrasive elements can be held directly or indirectly to the carrier element due to the binder element. The binder element can be used to pre-fix the abrasive elements in the desired position and distribution on the carrier element. Suitable binder elements for attaching abrasive elements to the carrier element are well known to those skilled in the art.

[0018] The carrier element can be made of a material with a specific weight in a range of at least 35 to a maximum of 400 g / m 2 , in particular at least 50 to a maximum of 150 g / m 2 , preferably at least 50 to a maximum of 75 g / m 2 The carrier element may be made of a material with a specific weight in a range of at least 7 g / m 2 up to a maximum of 225 g / m 2 be educated.

[0019] The carrier element can be designed to be flexible such that the carrier element is essentially elastically deformable by more than 15%, in particular more than 20%, preferably more than 30%, preferably more than 35%. The carrier element and / or the fibers of the carrier element can have a tensile strength of at least 70 N, in particular at least 80, preferably at least 100 N. The carrier element can have a thickness of less than 0.4 mm, in particular less than 0.3 mm. This makes it possible to provide a carrier element that is temperature-stable with respect to deformation and shrinkage. This allows the carrier element to be bonded to a TPU binder element while avoiding deformation. Polyethylene terephthalate (PET) can be considered as the carrier element instead of polypropylene (PP) or polyethylene (ÜPE).

[0020] The binder element can be provided for holding the abrasive element to the carrier element. The binder element can be designed as a film element, in particular an adhesive film element, which is arranged on the side of the carrier element facing away from a grinding side. The binder element can be fully bonded to the carrier element. The binder element can be formed from a base binder element and / or a cover binder element. The binder element can be provided for covering the carrier element and / or the abrasive element. The base binder element and / or the cover binder element can be arranged as layers on the carrier element.

[0021] The binder element can form a substance or mixture of substances, in particular one arranged in a planar manner, which is arranged in the normal direction of a main extension surface of a carrier element of the abrasive, in particular directly, between a surface of the carrier element of the abrasive and the abrasive element(s). The binder element can be provided for a material-to-material connection of the abrasive element(s) and the carrier element of the abrasive and / or can be arranged between the abrasive element and the carrier element. Synthetic resins, such as phenolic resin, epoxy resin, urea resin, melamine resin, polyester resin, or the like, are particularly suitable as the binder element. The base binder element and the top binder element can also contain other conventional active ingredients and / or fillers. The binder element is preferably formed from a synthetic resin, in particular a TPU, preferably a phenolic resin.Alternatively, the binder element may contain or consist of a PU dispersion, an acrylate or an epoxy.

[0022] The binder element can be flexible and stable enough to allow folding and grinding. The extensibility of the binder element, measured according to DIN 53504-S2, can be more than 200%, in particular more than 400%, preferably more than 600%. The binder element can have a melting temperature of more than 100°C, in particular more than 120°C, preferably more than 140°C. To enable stable use of the abrasive, an operating temperature of the abrasive of more than 160°C, in particular more than 180°C, preferably more than 200°C, can also be enabled. The binder element can have a specific gravity in a range from at least 80 to at most 300 g / m^2, in particular from at least 90 to at most 180 g / m^2, preferably from at least 120 to at most 170 g / m^2. The abrasive can have a tear resistance with a tear force measured according to BS EN ISO 1798-2008 of more than 35 N.

[0023] The foam element can be formed from a foam. The foam element can be artificially produced. The foam element can have a cellular structure. The cellular structure can consist of a large number of individual hollow or usually air-filled cells. The foam element can have a low volume weight and a low density. The foam element can be formed from a plastic, in particular a foamed plastic. A variety of plastics are suitable as a foam element. The foam element can have a high compressibility and can therefore significantly reduce its volume when a force acts on the foam element. The compressibility can be adjusted using suitable means and manufacturing processes.Closed-cell foam elements are particularly suitable, as the cell walls between the individual cells are completely closed, such as in cellular rubber. Open-cell foam elements are particularly suitable, as the cell walls are not completely closed, such as in sponge rubber. Mixed-cell foam elements are particularly suitable, as the cell walls are occasionally open and occasionally closed, such as in sponge rubber. Foam elements can be designed as integral foams, whose outer skin is closed and whose inner core is cellular with a density decreasing towards the inside. Physical, chemical and / or mechanical foaming are conventionally used to produce the foam element.The perforations can extend along an entire extent, in particular from one end to the other end, of the abrasive or the foam element. The perforation can extend along a perforation line. The perforations can be formed from a plurality of recesses. The recesses can extend through the entire foam element, in particular through a thickness of the foam element. The recesses can extend from a side of the foam element facing away from the carrier element to a side of the foam element facing the carrier element. The recess, in particular substantially every recess, can be surrounded by the foam element, in particular completely. The recess, in particular every recess, can be delimited by the carrier element on a side of the foam element facing the carrier element.The recess, in particular each recess, can be open on a side of the foam element facing away from the support element. The perforation can be introduced into the foam element by means of a punching process, a laser process, a piercing process (e.g., a needle roller), or the like. The recess can be designed as a perforation recess. The recess can be formed as a foam recess.

[0024] It may be expedient for the foam element to be formed in one piece. It may be expedient for the foam element to delimit or form a perforation delimited by the foam element. The perforation may extend through the entire foam element or the entire thickness of the foam element. The perforation may be formed by deforming, in particular elastically, in particular stretching, the foam element. The perforation may be provided by a prestressed foam element. The perforation, in particular each perforation, may be formed such that the foam element is stretched transversely, in particular perpendicularly, to the perforation line in order to widen the perforation.

[0025] The foam element can be connected to the carrier element in a stretched state. In a tensioned state, the foam element can be stretched or tensioned such that the foam element forms a perforation or foam recess. The stretched state of the foam element can be achieved by pulling the foam element apart at two opposite sides or ends using a stretching force or a tensioning force in order to create the perforations or the foam recesses. The foam element can have a structure designed such that the foam element provides a grinding-direction-dependent static friction with an operator's hand.

[0026] It may be appropriate for the perforation to be essentially elliptical.

[0027] It may be expedient for the abrasive to have a group of perforations or foam recesses arranged substantially along a perforation line. It may be expedient for the abrasive to have a further group of perforations or foam recesses arranged substantially along a further perforation line. It may be expedient for the perforation lines to be arranged substantially parallel to one another. The perforations or foam recesses of the further perforation line adjacent to the perforation line can be arranged offset from one another when viewed along the perforation line.

[0028] The perforations can be arranged in a row. The perforations can be arranged tangentially to the perforation line. The perforations can be aligned along the perforation line. The perforations can have a maximum extent that extends along a longitudinal axis. The longitudinal axis can be arranged tangentially and / or parallel to the perforation line or a perforation line section of the perforation line. The perforations can be arranged opposite one another in a type of half bond or a type of third bond. It is understood that a person skilled in the art would also consider other arrangement patterns. The perforation line can be straight and / or curved.

[0029] It may be expedient for adjacent perforations, particularly viewed along the perforation line, to have uniform or different spacings. It may be expedient for the perforations to be of different lengths. The perforations may each have longitudinal extensions which are of different sizes compared to one another. It may be expedient for two adjacent perforations to have a web delimiting the two perforations, wherein the web has a length which is shorter than a length of the perforation, in particular of each perforation. In particular, the perforation is slit-shaped. In particular, the perforation has a width which is much smaller than its length.In particular, two adjacent perforations have a distance of at least 0.5 mm, in particular at least 0.8 mm, preferably at least 0.9 mm, preferably at least 1 mm, particularly preferably at least 1.1 mm, more preferably at least 1.2 mm, further preferably at least 1.4 mm, and / or at most 2.5 mm, in particular at most 2.2 mm, preferably at most 1.8 mm, preferably at most 1.5 mm, more preferably at most 1.2 mm, such as 1 mm, from one another. In particular, the perforation, in particular each perforation, has a longitudinal extent of at least 1 mm, in particular at least 1.2 mm, preferably at least 1.5 mm, preferably at least 1.8 mm, particularly preferably at least 2 mm, further preferably at least 2.2 mm, further preferably at least 2.5 mm, and / or at most 4 mm, in particular at most 3.5 mm, preferably at most 3 mm, preferably at most 2.5 mm, further preferably at most 2.2 mm, such as 2 mm.In particular, the perforations are arranged along and / or tangentially to the perforation line. In particular, the extent of the perforation, in particular each perforation, relative to a distance to an adjacent perforation, in particular each adjacent perforation, is configured in a ratio of approximately at least 1 to at most 3, in particular 1.5 to at most 2.5, preferably 2.8 to at most 2.2, such as 2. This makes it possible to provide an abrasive with particularly advantageous folding properties.

[0030] With a high ratio, the abrasive can be bent more easily, allowing a smaller bending radius to be achieved. With a low ratio, a larger bending radius can be achieved. With a smaller distance between adjacent recesses, the grinding surface becomes correspondingly smaller, since grinding occurs with the abrasive folded between the recesses. However, with a small distance between adjacent recesses, the stability of the abrasive in a folded state is reduced.

[0031] It may be appropriate for the perforation or foam recess to be limited by the carrier element.

[0032] It may be expedient for the foam element to be connected to the carrier element over its entire surface, in particular by means of a material bond. The foam element can be connected to the carrier element by means of an adhesive element. The adhesive element can be designed as an adhesive layer. The adhesive element can be arranged on the carrier element, in particular over its entire surface. The adhesive element can delimit the perforation. The adhesive element can be arranged between the carrier element and the foam element. The foam element can be connected to the carrier element by means of an adhesive process. A possible adhesive process is lamination, such as flame lamination, hot melt lamination, or wet lamination. It is understood that other adhesive processes that appear appropriate to a person skilled in the art can also be considered.

[0033] It may be expedient for the foam element to form a perforation surface which delimits or surrounds the perforation in one plane by 360°. The foam element can delimit the perforation in one plane by 360°. The foam element can be formed continuously from one piece. The perforation can have two corners. The two corners can be arranged on opposite sides. The corners can define a maximum extent or a longitudinal extent of the perforation. The corners can be formed as acute corners. The corners can have an angle of less than 90°, in particular less than 60°. The longitudinal extent can be at least two times greater than the transverse extent, in particular three times greater.

[0034] It may be expedient for the foam element to have a foam surface facing away from the carrier element, which is larger than a perforation surface delimited by the foam surface.

[0035] In a relaxed state of the foam element, the perforation can have a length that is greater than a length in a stretched state. In a relaxed state of the foam element, the perforation can have a width that is smaller than a width in a stretched state. A distance between two adjacent perforations in a relaxed state can approximately correspond to the distance in a stretched state.

[0036] In a further aspect of the invention, a method for producing an abrasive is proposed.

[0037] In one step, a grinding element is provided for grinding a workpiece.

[0038] In a further step, a support element, in particular a flexible one, is provided for arranging the grinding element on the support element. In a further step, a foam element is provided for arrangement, in particular on a side of the support element facing away from the grinding element.

[0039] In a further step, a perforation is provided, in particular extending through the entire foam element.

[0040] In a further step, the foam element is deformed to create foam recesses by means of the perforation. The deformation can be achieved by applying a force perpendicular to the perforation extension or perforation line.

[0041] It may be expedient to heat the foam element, particularly briefly, in one step, in particular by means of an air stream, preferably a hot air stream, above a glass transition temperature of the foam element. The foam element can then be cooled. This allows a change in shape of the foam element to be maintained.

[0042] The subclaims specify further expedient developments of the abrasives according to the invention.

[0043] It may be advantageous for the perforation to be arranged along a perforation line, with the perforation line running straight and / or curved. This allows for optimized grinding in hard-to-reach areas. For example, a curved perforation line can provide a larger grinding edge.

[0044] It may be expedient for the carrier element to have a first carrier side and a second carrier side facing away from the first carrier side, wherein the binder element and / or the abrasive means is arranged on the first carrier side, wherein an / the adhesive element is arranged on the second carrier side. Short description of the drawings

[0045] Further advantages will become apparent from the following description of the drawings. The drawings illustrate exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will conveniently consider the features individually and combine them into useful further combinations. Here: Fig. 1 a view of an abrasive during manual grinding, Fig. 2 a section through an exemplary abrasive, Fig. 3 a view of the abrasive, Fig. 4 an enlarged view of the abrasive, Fig. 5 a view of a foam element in a relaxed state, Fig. 6 a view of the foam element in a stretched state and Fig. 7 exemplary process steps for the production of the abrasive.

[0046] In the following figures, identical components are provided with the same reference numerals.

[0047] The present abrasive 11 is for manual or hand-working of a workpiece, as in Fig. 1. The abrasive 11 is touched by an operator's hand and guided along a surface 9 of the workpiece 7. A compressive force can be exerted on the abrasive 11 in the direction of the workpiece 7 in order to increase friction or a grinding effect. The abrasive 11 is used for the grinding or abrasive processing of a workpiece, during which material of the workpiece is mechanically removed from the surface of the workpiece in the form of chips. In the present case, the abrasive 11 is a composite abrasive. The abrasive 11 can be present in various finished forms. In the present case, the abrasive 11 is designed as a rectangular part, for example of a grinding roller.

[0048] Fig. 2 shows a flexible abrasive 11 for grinding a workpiece with a grinding element 13, with a flexible carrier element 15 for arranging the grinding element 13 on the carrier element 15 and with a binder element 17 for holding the grinding element 13 on the carrier element 15.

[0049] In the present case, the abrasive means 11 has a plurality of grinding elements 13 on one grinding side, wherein the grinding elements 13 protrude from the carrier element 15 and delimit the latter. The grinding elements 13 are provided for grinding a workpiece and are designed as broken and / or shaped grinding elements 13. The grinding elements 13 can be scattered openly or closed on the carrier element 15 in order to set a scattering density adapted to the desired application. The grinding elements 13 protrude from the carrier element 15 and delimit the abrasive means 11. The grinding element 13 is designed as an abrasive body or abrasive grain and is intended to directly contact a workpiece to be machined in a processing state. The grinding element 13 is preferably a mixed grain with a ceramic content of approximately 40 to 80%. The grinding element 13 can be made of semi-precious corundum / blue burnt for a grain size of approximately P100 to approximatelyP400 and white corundum for a grain size of approximately P500 to P1500. For a grain size in the range of 40 to P600, a paper carrier element 15 can be considered. For a grain size in the range of P800 to P1500, a plastic film carrier element 15 can be considered. The types of scattering that can be considered are electrostatic scattering for a grain size in the range of 40 to P180, electrostatic (open scattering) for grain sizes in the range of P220 to P600, and special processes for a grain size in the range of P800 to P1500.

[0050] The carrier element 15 serves as a carrier layer onto which the grinding elements 13 are applied and fixed by means of the binder element 17. The grinding elements 13 are arranged and bonded to the carrier element 15 by means of a known binder element 17. Various carrier elements 15 adapted to the intended use can be considered as the carrier element 15.

[0051] The binder element 17 is provided for holding the grinding elements 13 on the carrier element 15 and is fully bonded to the carrier element 15. The binder element 17 is provided for covering the carrier element 15 and / or the grinding element 13 and is arranged as a layer on the carrier element 15. The binder element 17 is provided for a materially bonded connection of the grinding element(s) 13 and the carrier element 15 of the abrasive 11. The binder element 17 is preferably formed from a (solid) synthetic resin, in particular a TPU, preferably a phenolic resin. The binder element 17 can be covered or coated with a special coating formed from a stearate (not shown). The abrasive 11 has a foam element 41 arranged on a side of the carrier element 15 facing away from the grinding element 13 ( Fig. 2 to 4). In the present case, the abrasive 11 has a cover binder element 19 for coating the abrasive elements 13 and the binder element 17.

[0052] The foam element 41 is formed from a foam which has a cellular structure made up of a large number of individual hollow or usually air-filled cells. The foam element 41 is formed from a foamed plastic. A wide variety of plastics are suitable as the foam element 41. The foam element 41 can have a high compressibility and thus significantly reduce its volume through a force acting on the foam element 41. The compressibility can be adjusted using suitable means and manufacturing methods. Closed-cell foam elements 41, whose cell walls are completely closed between the individual cells, such as in the case of cellular rubber, are particularly suitable as the foam elements 41. Open-cell foam elements 41, whose cell walls are not completely closed, such as in the case of sponge rubber, are particularly suitable as the foam elements 41.Foam elements 41 are particularly suitable for mixed-cell foam elements 41, whose cell walls are partially open and partially closed, such as in sponge rubber. Foam elements 41 can be designed as integral foams, whose outer skin is closed and whose inner core is cellular with a density decreasing toward the inside. Physical, chemical, and / or mechanical foaming processes are conventionally considered for the production of the foam element 41.

[0053] For optimal operability of the abrasive 11, the abrasive 11 has a plurality of perforations 51, each of which is formed from a plurality of foam recesses 51 ( Fig. 5). The perforations 51 are arranged along rectilinear and parallel perforation lines 55, 57. The perforations 51 extend through the entire foam element 41. The perforations 51 extend from an end of the foam element 41 facing away from the support element 15 to an end of the foam element 41 facing the support element 15.

[0054] The perforations 51 extend along an entire extent, in particular from one end to the other end, of the foam element 41. The perforations 51 extend along a perforation line 55, 57. The perforations 51 are formed from a plurality of recesses which extend through the entire foam element 41 or a thickness 65 of the foam element 41 ( Fig. 2). The recesses extend from a side of the foam element 41 facing away from the support element 15 to a side of the foam element 41 facing the support element 15. The recesses can be completely surrounded by the foam element 41. Each recess is delimited by the support element 15 on a side of the foam element 41 facing the support element 15 and is open on a side of the foam element 41 facing away from the support element 15 ( Fig. 3, Fig. 4). The perforations 51 can be introduced into the foam element 41 by means of a punching process, a laser process, a piercing process (e.g., needle roller), or the like.

[0055] The foam element 41 is formed in one piece from a continuous foam element 41 and delimits the foam recess 51. The foam recess 51 extends through the entire foam element 41 or the entire thickness 65 ( Fig. 2) of the foam element 41. The foam recess 51 is formed by elastically deforming or stretching the foam element 41. The foam recess 51 can be provided by a prestressed foam element 41. The prestressed foam element 41 can remain prestressed by being connected to the carrier element 15 or can be equalized in the prestressed state or designed to reduce the prestress by a process. The foam recesses 51 are formed from the perforations 51. The foam recesses 51 can be formed such that the foam elements 41 are stretched transversely, in particular perpendicularly, to the perforation line 55 in order to widen the perforations 51.

[0056] The foam elements 41 are connected to the support element 15 in a stretched state. In the stretched state, the foam element 41 can be stretched or tensioned such that the foam element 41 widens a foam recess 51. The stretched state of the foam element 41 can be achieved by pulling the foam element 41 apart at two opposite sides or ends by means of a stretching force or a tensioning force in order to create the foam recesses 51.

[0057] The foam element 41 has a group 71 of foam recesses 51 and a further group 73 of foam recesses 51, which are arranged substantially along a perforation line 55 and a further perforation line 55. The perforation lines 55 are arranged substantially parallel to one another. The foam recesses 51 of the adjacent perforation lines 55 are offset from one another when viewed along the perforation line 55. The foam recesses 51 are arranged in a row and tangential to the perforation line 55 and are aligned along the perforation line 55. The foam recesses 51 have a maximum extent which extends along a longitudinal axis, which in turn is arranged parallel to the perforation line 55 or a perforation line section of the perforation line 55.The foam recesses 51 are arranged opposite each other in a kind of half-array, whereby a foam recess 51 begins or ends halfway up the height of an adjacent foam recess 51 of an adjacent group 71, 73. The perforation lines 55 run straight.

[0058] The foam recesses 51 are evenly spaced from each other along the perforation line 55 and are of somewhat uniform length.

[0059] The foam recess 51 is slit-shaped in a relaxed state ( Fig. 5). The foam recess 51 has a much smaller width B in a relaxed state than in the stretched state ( Fig. 5). The length L relative to the width B is in a ratio of more than a factor of 2, in particular more than a factor of 4, preferably more than a factor of 6, preferably more than a factor of 8, further preferably more than a factor of 10. The foam recess 51 is essentially elliptical in a stretched state, in particular a stressed state ( Fig. 6). The foam recess 51 has, in a stretched state, a width B which is smaller than the longitudinal extent ( Fig. 6). The length L relative to the width B is in a ratio of less than a factor of 5, in particular less than a factor of 4, preferably less than a factor of 3, more preferably less than a factor of 2. Two foam recesses 51 adjacent to one another, viewed along the perforation line 55, have a distance AS of at least 0.5 mm, in particular at least 0.8 mm, preferably at least 0.9 mm, preferably at least 1 mm, particularly preferably at least 1.1 mm, more preferably at least 1.2 mm, further preferably at least 1.4 mm, and / or at most 2.5 mm, in particular at most 2.2 mm, preferably at most 1.8 mm, preferably at most 1.5 mm, more preferably at most 1.2 mm, such as 1 mm.The foam recesses 51 have an extension of at least 1 mm, in particular at least 1.2 mm, preferably at least 1.5 mm, preferably at least 1.8 mm, particularly preferably at least 2 mm, more preferably at least 2.2 mm, further preferably at least 2.5 mm, and / or at most 4 mm, in particular at most 3.5 mm, preferably at most 3 mm, preferably at most 2.5 mm, more preferably at most 2.2 mm, such as 2 mm.

[0060] The foam recesses 51 are limited by the support element 15.

[0061] The foam element 41 is integrally bonded to the carrier element 15 over its entire surface. The foam element 41 is bonded to the carrier element 15 by means of an adhesive element. The adhesive element (not shown) is designed as an adhesive layer and is arranged over its entire surface on the carrier element 15. The adhesive element delimits the foam recess 51. The adhesive element is arranged between the carrier element 15 and the foam element 41. The foam element 41 is bonded to the carrier element 15 by means of an adhesive process.

[0062] The foam element 41 delimits the foam recess 51 in a plane by 360°. The foam element 41 forms a recess surface 81, which delimits or surrounds the foam recess 51 in a plane by 360°. The foam element 41 is formed in a continuous, one-piece manner. The foam recess 51 has two corners 53a, 53b, which are arranged on opposite sides and delimit a maximum extent of the foam recess 51. The corners 53a, 53b are designed as pointed corners and have an apex angle SW of less than 60°. The longitudinal extent must be at least two times larger than the transverse extent, in particular three times larger.

[0063] The foam surface 83 of the foam element 41 facing away from the support element 15 is larger than a recess surface 81 of the foam recesses 51 delimited by the foam surface 83.

[0064] In a relaxed state of the foam element 41, the foam recess 51 has a length which is greater than a length in a stretched state. In a relaxed state of the foam element 41, the foam recess 51 has a width B which is smaller than a width B in a stretched state. A distance AS between two adjacent foam recesses 51 in a relaxed state corresponds approximately to the distance AS in a stretched state ( Fig. 5, Fig. 6).

[0065] In a manufacturing method for producing the abrasive 11, a grinding element 13 for grinding a workpiece is provided in a step 101 ( Fig. 7).

[0066] In a further step 103, a, in particular flexible, carrier element 15 is provided for arranging the grinding element 13 on the carrier element 15.

[0067] In a further step 105, a foam element 41 is provided for arrangement, in particular on a side of the carrier element 15 facing away from the grinding element 13.

[0068] In a further step 107, a perforation 51 is provided, in particular extending through the entire foam element 41.

[0069] In a further step 109, the shape change of the foam element 41 is provided to create foam recesses 51 by means of the perforation 51. The shape change can be effected by means of a force acting in a direction perpendicular to the perforation extension or the perforation line 55.

[0070] In a further step 111, the foam element 41 is heated, in particular briefly, by means of a hot air stream above a glass transition temperature of the foam element 41. In a subsequent step 113, the foam element 41 is cooled in order to maintain the change in shape of the foam element 41 in the stretched state. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited non-patent literature

[0000] BS EN ISO 1798-2008

[0022]

Claims

[1] Abrasive, in particular flexible abrasive (11), preferably hand-held abrasive (11), for grinding a workpiece with a grinding element (13), with a, in particular flexible, carrier element (15) for arranging the grinding element (13) on the carrier element (15), with a binder element (17) for holding the grinding element (13) on the carrier element (15) and with a foam element (41), in particular arranged on a side of the carrier element (15) facing away from the grinding element (13), characterized by a perforation (51), in particular designed as a foam recess (51). [2] Abrasive according to claim 1, characterized by that the foam element (41) is formed in one piece and forms a perforation (51) delimited by the foam element (41). [3] Abrasive according to one of the preceding claims, characterized by that the perforation (51) is essentially elliptical in shape. [4] Abrasive according to one of the preceding claims, characterized by a group of perforations (51) arranged substantially along a perforation line (55), and by a further group of perforations (51) arranged substantially along a further perforation line (57), wherein the perforation lines (55, 57) are arranged substantially parallel to one another, wherein the perforations (51) of the adjacent perforation line (55) are arranged offset from one another when viewed along the perforation lines (55, 57). [5] Abrasive according to one of the preceding claims, characterized by that the perforation (51) is limited by the carrier element (15). [6] Abrasive according to one of the preceding claims, characterized by that the foam element (41) is connected over its entire surface to the carrier element (15), in particular by a material bond. [7] Abrasive according to one of the preceding claims, characterized by that the foam element (41) forms a perforation surface which delimits the perforation (51) in a plane by 360°. [8] Abrasive according to one of the preceding claims, characterized by that the foam element (41) has a foam surface facing away from the carrier element (15) which is larger than a perforation surface delimited by the foam surface. [9] Method for producing an abrasive, in particular according to one of the preceding claims, comprising the following steps - providing a grinding element (13) for grinding a workpiece, - providing a, in particular flexible, carrier element (15) for arranging the grinding element (13) on the carrier element (15), - Providing a foam element (41) for an arrangement, in particular on a side of the carrier element (15s, - providing a perforation (51), in particular extending through the entire foam element (41), - Changing the shape of the foam element (41) to create a foam recess (51) by means of the perforation (51). The change in shape can be effected by applying a force in a direction perpendicular to the perforation (51) or the perforation line (55). [10] Method according to claim 9, characterized by heating, in particular briefly, the foam element (41), in particular by means of an air stream, preferably a hot air stream, above a glass transition temperature of the foam element (41). The foam element (41) can then be cooled.

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