DK180350B1 - GRINDING ELEMENT FOR USE IN ROTARY GRINDING OR GRINDING TOOLS - Google Patents

Abstract

A grinding element (1) for use in rotary grinding or polishing tools for use in grinding or polishing surfaces is described, and of the type comprising an elongate profile rail (2) as well as a grinding canvas (4) and support brushes (5). The sanding cloth (4) and the support brushes (5) are mounted in or on the profile rail (2), so that the sanding cloth (4) is supported by its support side (15) by the support brushes (15). The sanding canvas outside the profile rail (2) has a sanding canvas height (9) in a height direction (7) and a canvas length (12) in a longitudinal direction (3). The support brushes (5) and the sanding canvas (4) have different heights, the support brush height (11) and the sanding canvas height (9), respectively, from the profile rail (2), so that the sanding canvas (4) is terminated by an outer free edge area (19) extending beyond the top of the support brushes (5) and a short distance down along the outer free end portions (10) of the support brushes (5). The outer free edge area (19), when used, constitutes an effective area (17) of the active side (16) of the abrasive cloth (4). The abrasive cloth (4) is coated only with abrasive material (18) in the effective area (17). The abrasive material consists of particles (22) of, for example, diamonds (21) or similar materials. The abrasive canvas (4) is cut from an outer free canvas edge (8) against the profile rail in a direction parallel to the height direction (7) to form slats (6). The particles are placed in side rows (26) so that the particles (22) of the abrasive material in a row (26) are placed with the particles offset relative to the particles (22) in side rows (26). The particles in the rows (26) are arranged at a distance from each other (29), so that an overlap of the abrasive particles occurs in the longitudinal direction (3) of the abrasive canvas.

Description

DK 180350 B1 1 GRINDING ELEMENT FOR USE IN ROTARY GRINDING ELECTRIC

FIELD OF THE INVENTION The present invention relates to an abrasive element as described in the preamble of claim 1 of the present patent application. Background of the Invention In the present description of the invention, which is for use in grinding or polishing tools, the terms "grinding" and "polishing" are arbitrarily interchangeable. For example, a sanding canvas also means a sanding canvas and so on. Grinding elements for use in grinding or polishing machines built, for example, as drum grinders or grinding wheels are known. These will typically consist of sanding canvas and support brushes in IS combination. The sanding cloth and the support brushes are typically mounted in an elongate supporting profile rail, where the sanding canvas and the support brushes protrude from the profile rail. Alternatively, the support brushes may be mounted in an elongate supporting profile rail, and the abrasive cloth may be arranged outside the profile rail or be arranged directly on the brushes. The profile rail is typically intended to hold the grinding element in an undercut groove on a tool on grinding or polishing machines. The abrasive cloth is terminated in a free outer edge area extending beyond the top of the bristles and along the upper end portions of the support brushes, which in use constitutes the active abrasive area of the abrasive cloth. However, this abrasive area forms only a part of the entire abrasive canvas, which is mounted in the profile rail. Furthermore, known abrasive elements are limited in their effect in that the flexibility, flexibility, perpendicular to the longitudinal direction is determined by the flexibility, the flexibility, of the sandpaper, and that the flexibility, the flexibility, is an important parameter in treating surfaces by grinding or sanding various items surfaces.

Finally, it is well known that sandpaper in the form of sandpaper is relatively inexpensive and has a limited life. However, this is not a problem as the grinding elements can be replaced quickly and easily without significant time consumption.

However, grinding canvases are also known where the material price is significant, just as machines are also known where it is important that there is a long service life for the grinding elements in the machines.

However, there is a desire to be able to reduce costs, including providing grinding elements where it is possible to reduce material consumption. This is especially pronounced when it comes to expensive sanding canvases.

US 4,969,299 discloses a rotary grinding tool with grinding elements which contains flaps consisting of canvas with glued-on grinding grain. There is no instruction in this writing on the use of support brushes. An area of the canvas for supporting the flaps is kept free of abrasive grains.

Furthermore, WO 2011/110176 discloses an abrasive element of the type described in the preamble of claim 1 in the present patent application. This sanding element has for years functioned satisfactorily in many contexts, as there is experience with reduced material consumption of expensive sanding materials and a long service life. However, disadvantages have been experienced in the form of grinding grooves in surfaces treated with tools in which the grinding elements are used.

Although abrasive materials are used which are fine-grained, problems have been experienced in several tasks when finishing the treated surface. The treated surface will typically be post-treated with some form of coating or paint.

Thus, problems have been experienced with a coating adhering to the treated surface. To remedy this, experiments have been made with various primers and binders as a basis for surface varnishing or surface coating. The use of several layers for finishing is undesirable both for reasons of cost and for reasons of weight.

DK 180350 B1 3 Similarly, problems have been experienced with the gloss of the surface. For more products, this will cause problems in the form of unwanted glare and reflection. Even when finishing with a coating, this can cause a problem in the finished surfaces. This is because treated surfaces due to abrasive grooves have a non-uniform surface with areas from which glare and reflection occur. This problem has been particularly experienced in connection with fiber surfaces in public spaces, such as wind turbine blades, crash helmets and photovoltaic systems. To remedy this, experiments have been made with special varnishes. However, there is a desire to keep the weight down, especially on products such as wind turbine blades and crash helmets, thereby reducing the use of paints and coatings as much as possible.

Thus, several experiments have been made with different types of finishing, including the use of binders and special varnishes. The use of binders, primers, special varnishes - possibly 1 more layer - is a cost increase and also entails a weight increase, which is undesirable for several products.

There is therefore a desire to be able to improve the sanding / sanding in order to be able to achieve a surface where it is possible to achieve a better basis in the form of the treated surface, so that the need for finishing can be minimized and so that there is no problem with glare and adhesion.

Object of the invention It is the object of the present invention to be able to use sanding elements of the known type, where there is a reduced material consumption of expensive sanding materials, and which has a long service life, but where a uniform sanding of the surface is also achieved, so that problems with adhesion and glare can be minimized.

Description of the invention This object is achieved by the present invention by an abrasive element of the type mentioned in the introduction, which is characterized in that the particles 1 of the abrasive material are arranged in a row with the particles offset relative to the particles in parallel rows, and that the particles in the rows are spaced apart so that there is an overlap of the abrasive particles in the longitudinal direction of the abrasive cloth.

DK 180350 B1 4 The commercially available abrasive canvases are manufactured by machine with the particles of the abrasive material placed in rows, which are juxtaposed. The rows of particles are positioned so that particles in every other row are offset from each other when viewed in a direction transverse to the extent of the rows. Using these commercially available abrasive canvases, it has hitherto been a common custom that the cutting to form lamellae in the abrasive element has taken place in an orientation parallel to the rows in a space between adjacent rows. This has made it possible to establish a clean cut without interfering with the particles of the abrasive material, which typically consists of diameter or similar hard materials that act as a superabrasive material.

With such a cut, the slats of the grinding element are provided with rows of particles which are oriented parallel to the height direction. This has caused sanding grooves with areas where a surface is sanded in areas off the rows and little or no sanding in areas between these rows. In other words, in the longitudinal direction of the abrasive canvas, areas will appear where there are no abrasive particles that can be used to form the surface to be machined.

This problem is avoided with the present invention, as there is an overlap of the abrasive particles in the longitudinal direction of the abrasive cloth. In this way, particles will be provided in the longitudinal direction of the abrasive canvas. The particles are suitably arranged in rows. As the particles of the abrasive material are arranged in rows, it will be possible to use commonly commercially available abrasive canvases. By changing the orientation of the rows so that they are not parallel to the height direction of the abrasive canvas, it is possible to establish an overlap of the abrasive particles in the longitudinal direction of the abrasive canvas.

Despite the fact that for many years it has been possible to “reverse” the orientation of the rows in the commercially available sanding canvases, the desire to make cuts in parallel with the rows has so far been a skilled solution to the formation of the slats.

With the invention it is thus possible in a surprisingly simple way to establish an abrasive canvas, where the location of the particles of the abrasive material enables a sanding of the entire surface covered by the abrasive canvas. As a result, no specific sanding grooves occur with areas where no sanding has taken place.

These areas of the surface where no sanding occurs are undesirable as they occur with a smooth surface. This smooth surface can partly give poor adhesion, but can also give rise to reflection and glare from the top of the surface. With a sanding cement according to the present invention, a surface which is more rough without smooth areas which gives glare will be established. This greater roughness in the surface will also form a larger area, which allows a larger surface for adhesion of coating or varnish on the surface. This increases the adhesion.

As the surface appears rubbed without smooth areas, the reflection will be much more diffuse. It is thus possible to control the surface and only determine the possibility of glare and gloss with the coating or varnish used. This varnish can be applied in a thinner layer than traditional due to the larger surface where there is adhesion and due to less need for more layers to reduce glare from the sanded and coated surface.

Especially with wind turbine blades, it is desirable to be able to control the glare from the turbine blade. A similar challenge applies in photovoltaic systems, where it is undesirable to have glare from the often very large surfaces of such a photovoltaic system.

In crash helmets, a corresponding reduction in glare is also desirable for traffic safety reasons.

With the specific positioning of the particles continued in relation to particles 1 juxtaposed rows compared with the angle of rows in relation to the extent of the slats, an improved grinding / polishing is thus obtained in a simple manner, with which a surface can be obtained which forms a better basis. , where the need for finishing is minimized, while problems with glare are avoided and that an adhesion can be optimized.

DK 180350 B1 6 The abrasive material consists of particles placed in the effective area of the abrasive cloth. This area therefore has a particularly effective sanding ability, which increases the service life compared to traditional sanding canvases. In a preferred embodiment, the abrasive material is particles of diamonds. The abrasive material may comprise material units whose unit size is between 0.1 micrometers and 1000 micrometers. By this is meant that the abrasive material may be in the nature of a powder in the sense that the unit size is at the smallest end of the range and that the abrasive material may be particulate in the sense that the unit size is at the larger end of the range. The said range is typical of the grinding and polishing tasks typical of the invention. It is immediately up to the person skilled in the art for special, and here typically finer grinding and polishing tasks, to go outside the range and, for example, use grinding materials with unit size in the nano range. The units of the abrasive material can be variable in shape and structure. Thus, the units may be angular or round, or the units of the abrasive material may be a combination thereof. The units may also be crystalline or non-crystalline. The characteristic of the abrasive material in the form of particles is in an alternative embodiment produced by the fact that it is the abrasive canvas itself which has local projections, which gives rise to a really effective contact with the surface to be sanded.

The area between the local projections gives rise to channels which can direct sanding dust away from the surface being sanded. In addition, these projections and channels provide increased heat conduction.

The sanding canvas is cut from the outer free edge area to form slats. The abrasive canvas is typically cut perpendicular to the profile rail from the outer free canvas edge. In one embodiment, the sanding canvas can be cut from the outer free canvas edge to the profile rail to form long slats. The sanding canvas may alternatively be cut from the outer free canvas edge to a position between the effective area and the profile rail to form short slats. The grinding canvas can be cut to form slats of the same slat length or to form slats of varying slat lengths. According to a further embodiment, the grinding element according to the invention is characterized in that the juxtaposed rows are located with their orientation at an angle different from 0 ° with respect to the height direction.

When sanding canvases are used, where the particles are placed in rows, with very little orientation of the rows in relation to the height direction of the sanding canvas, an overlap of the particles in the longitudinal direction of the sanding canvas can be established.

Depending on the distance between the adjacent rows, the angle can be varied from an angle of 1 ° to 179 °.

It is preferred to place the sanding canvas with the orientation of the adjacent rows at an angle of 90 ° to the height direction of the sanding canvas.

According to a further embodiment, the grinding element according to the invention is characterized in that the adjacent rows are located with their orientation in the longitudinal direction.

Thus, when the rows are positioned with their longitudinal orientation, they will be oriented below 90 ° relative to the vertical direction. This is a particularly simple design.

As the particles are placed in rows, it will be possible in a relatively simple manner to vary the particle size and shape and the mutual distance between the particles in the rows and thereby ensure the overlap in the longitudinal direction of the abrasive canvas.

According to a further embodiment, the grinding element according to the invention is characterized in that the particles have an extent in the orientation of the row which is greater than the mutual distance between the particles in the adjacent rows.

By using particles which have a greater extent in the longitudinal direction of the row than the distance between subsequent particles in a juxtaposed row, one will at

DK 180350 B1 g particularly simple way to achieve an overlap in the longitudinal direction of the sanding canvas. This is a particular advantage when using a sanding canvas, where the rows are oriented in the longitudinal direction of the sanding canvas.

According to a further embodiment, the abrasive element according to the invention is characterized in that the abrasive material is a super-abrasive material which consists of the particles as well as powder of, for example, diamonds or similar materials.

By the abrasive material being a super-abrasive material is essentially meant that the units of the abrasive material have a certain strength, such as a crystal strength or breaking strength, and that this strength is around the strength of diamonds. As an example of an alternative embodiment, the superabrasive material is Boron Nitride with a cubic unit shape (cBN), which material has a hardness near diamonds and at the same time a thermal conductivity comparable to traditional abrasive materials. In a further alternative embodiment, the superabrasive material is coated with a coating, which coating may be a metal coating, and which metal coating may, for example, be based on nickel, copper or similar coating materials. According to a further embodiment, the sanding element according to the invention is characterized in that the effective area constitutes between 4 and 4 and typically about 1/3 of the sanding canvas height of the sanding canvas.

In this way, a typical effective area is obtained for typical compositions of abrasive canvases and abrasive materials, which has the desired abrasive effect and a material-saving effect in relation to abrasive canvases, which also have abrasive material in ineffective areas of the abrasive canvas.

According to an alternative embodiment, the sanding element is characterized in that the active area has a sanding profile in the height direction of the sanding canvas. By this is meant, for example, an abrasive profile with varying abrasive material or, for example, abrasive profile with on / off abrasive material.

DK 180350 B1 9 According to an alternative embodiment, the abrasive element is characterized in that from the active area of abrasive material to the end of the outer free edge area there is a smaller area of the abrasive cloth which is not coated with abrasive material, which advice makes up between 0 and 1/8 of the sanding canvas height.

According to a further embodiment, the sanding element according to the invention is characterized in that the sanding canvas height of the sanding canvas is between 20 mm and 80 mm and typically around 40 mm.

In this way, a suitable abrasive effect is obtained with the grinding element by practical applications of the grinding element in tools and machines that can be manually operated by a person, and in tools and machines that are used in a typical production of elements in industry.

It is immediately up to a person skilled in the art to extend the height of the sanding canvas for use in sanding elements for use in larger or special sanding or polishing tasks.

It is also immediately apparent to a person skilled in the art to reduce the height of the sanding canvas for use in sanding elements for use in smaller or special sanding or polishing tasks.

According to a further embodiment, the abrasive element according to the invention is characterized in that the abrasive material is adhered to the abrasive canvas in the operative area with a binder which binds said particles to the abrasive canvas. If powder is also used, such powder will also be bonded to the abrasive cloth with the binder.

With this, it is achieved with a sanding element that the effective area is directly embedded in the sanding canvas, and the sanding canvas can be easily replaced in the profile rail in the event of wear.

The sanding canvas can then be recycled, as a new sanding material can be applied in the active area.

In one embodiment, the binder is a resin based binder. In alternative embodiments, other binders such as lacquer, glue or the like can be used.

The binder may additionally be a polymide or a phenolate. According to a further embodiment, the sanding element according to the invention is characterized in that sanding material is provided on a second canvas, which second canvas is mounted in the operative area of the sanding canvas. By this is meant that the abrasive material is applied to a separate substrate, the second canvas, and that the second substrate and the effective area of the abrasive canvas are produced for assembly. The mounting shape can be with a gluing, a weld, a velcro lock or a rail arrangement. According to a further embodiment, the grinding element according to the invention is characterized in that the flexibility of the grinding canvas in an area between the active area and the profile rail is greater than the flexibility of the grinding canvas in the active area. By flexibility is meant flexibility and essentially in the direction perpendicular to the longitudinal direction of the profile rail. The flexibility in the effective area of the abrasive fabric is essentially related to the abrasive material layer in the effective area of the abrasive fabric. The flexibility of the abrasive cloth in an area between the effective area and the profile rail is essentially related to the flexibility of the support layer of the abrasive canvas, which lies between the active area and the profile rail. According to an alternative embodiment of the sanding canvas, the inner area is produced with at least one area with increased flexibility. Which area in one embodiment is provided by the sanding canvas in a narrow area being thinner than the rest of the area.

This further achieves that the effective area can act against the surface, almost parallel to the surface, the effective area coming between the surface and the tips of the support brushes.

According to a further embodiment, the abrasive element according to the invention is characterized in that the abrasive cloth is made of a plastic material such as Polyethylene (PE), Polypropylene (PP), or Polyvinyl chloride (PVC), that the abrasive cloth is made of a rubber material, or that the abrasive cloth is made of a biomaterial. 3 With this, the sanding canvas can be used in the sanding element for a longer period and thus with an increased service life than for traditional canvases.

Drawing description The invention will now be explained in more detail with reference to the accompanying figures, in which Figs.

Fig. 1 shows a known sanding element from a side where the support brushes and the passive side of the sanding canvas are seen, 13 Figs. 2 shows it in FIG.

In the sanding element shown from a side where the active side of the sanding canvas is seen, Figs. 3 shows an isometric view of the device shown in FIG. 1 with the support brushes and the active side of the sanding canvas, FIG. 4 shows an isometric view of the device shown in FIG. 1, which is preferably a cross-section perpendicular to the longitudinal direction of the grinding element in use against a surface, where the support brushes press the effective area of the grinding canvas against the surface, FIG. 5 shows a view corresponding to the section in FIG. Fig. 2 of an abrasive cloth for an abrasive element according to the present invention; Fig. 6 shows a principle sketch with an enlarged design of the 1 Fig. 5, FIG. Fig. 7 illustrates a principle sketch of a surface machined with an abrasive element according to prior art, and 8 is a view similar to FIG. 7, wherein a surface is machined with an abrasive element according to the present invention.

Detailed description of the invention Figures 1 - 4 show the basic design of an abrasive element 1 according to prior art from WO 2011/110176. This construction is common to the design of an abrasive element 1 according to the present invention. The difference is seen in the way the abrasive particles are placed on the abrasive canvas. Thus, the explanation of the grinding element 1 according to the invention will be given with reference to the explanation of the known grinding element. The new features of the invention will be explained in more detail with reference to Figures 5 - 8.

Figure 1 shows a grinding element I fixed in a profile rail 2, which is intended for use 1 in a grinding or polishing tool or machine. The profile rail 2 is elongated, and thus the grinding element 1 has a natural longitudinal direction 3.

A sanding canvas 4 and support brushes 5 are mounted in the profile rail 2. The sanding canvas 4 is made with slats 6.

In the specific embodiment, the profile rail 2 limits the possibility of the sanding cloth 4 and the support brushes 5 being pulled out of the profile rail. From the mounting area 2 of the profile rail 2 and in a height direction 7, the grinding canvas 4 and the support brushes S radiate or rise substantially in the same height direction 7 within a narrow angle.

Opposite the profile rail 2, the sanding canvas 4 ends in a canvas edge 8, and the distance from the canvas edge 8 to the profile strip 2 defines a canvas height 9.

Opposite the profile rail 2, the support brushes 5 terminate in a support brush end 10, and the distance from the support brush end 10 to the profile strip 2 defines a support brush height 11. longitudinal direction 3.

In the embodiment shown, the sanding canvas 4 is made with a plurality of slats 6, which in the specific embodiment have approximately the same slat length 14. However, there is nothing to prevent the slat length 14 from varying.

DK 180350 B1 13 In the embodiment shown, the brush length 13 is longer than the canvas length 12, and there is a majority of bristles per. lamella length 14. In the embodiment shown, the canvas height 9 is greater than the support brush height 11. 3 The passive side 15 of the sanding canvas 4 is as shown facing the support brushes 5. Figure 2 shows the same sanding element 1 as in figure 1 from another side, where especially the sanding canvas 4 active page 16 appears.

The active side 16 of the abrasive cloth 4 has an active area 17 (marked as ---) coated with an abrasive material 18. The active area 17 is an area at an outer free edge area 19 (marked as…) of the abrasive canvas 4 from the abrasive canvas edge 8 against the profile rail 2. It is immaterial whether the outer free edge area 19 has a height which is greater than the height of the effective area 17. The essential thing is that the two mentioned areas 17, 19 have a certain overlap. In the embodiment shown, and illustrated in the section of the figure, the abrasive material 18 is provided as a super-abrasive material 20, which consists of diamonds 21 in the form of particles

22. A powder 23 is also illustrated here, which can optionally be used together with the particles 22. The abrasive material 18 is here provided on a second canvas 24, which in turn is mounted in the effective area 17 of the abrasive canvas 4. In the specific embodiment, the second canvas 24 is glued to the sanding canvas 4. In the embodiment shown, the sanding material 18 on the second canvas 24 is cut corresponding to the slats 6. It is seen here that the particles 22 are placed in rows 26. It is quite common with commercially available sanding canvases of this type that the particles are placed in side rows on a canvas. The particles 22 in every other row 26 are located next to each other seen in the longitudinal direction 3. The particles 22 in the intermediate rows 26 are located offset from spaces. Thus, the rows 26 of particles 22 are oriented parallel to the height direction 7. It is also seen that the cut-off is established parallel to the height direction 7 in spaces 30 between the rows 26. In these spaces 30 there is no overlap of the particles 22, so that the spaces 30 in the abrasive canvas longitudinal direction 3 occurs without abrasive material.

This gives rise to grinding marks, as areas on the surface 25 (see Figs. 3 and 4). which is sanded with the sanding element 1 will not be coated by the particles 22. Figure 3 shows an isometric view of the sanding element 1 with the support brushes 5 and the active side 16 of the sanding canvas 4. The support brush end 10 rests or acts on a surface 25, which surface 25 likewise cooperates with the passive side 15 of the sanding canvas 4 here. The sanding canvas 4 essentially has an inner flexibility and an outer flexibility, the outer flexibility being connected to the active area 17 of the sanding canvas 4, and the inner flexibility to the area between the active area 17 and the profile rail 13 2. Figure 4 shows an isometric view of the grinding element 1, which is preferably a cross section perpendicular to the longitudinal direction 3 of the grinding element 1 in use or acting with the active side 16 of the grinding canvas 4 facing the surface 25, where the support brushes 5 press the passive side 15 of the sanding canvas 4, so that the effective area 17 of the sanding canvas 4 acts or works on the surface 25. Figure 5 illustrates e a section of an abrasive canvas 4 for an abrasive element 9 according to the present invention.

The device shown in FIG. 5 corresponds to the section in fig. 2 and thus illustrates the abrasive canvas 16 on which a second canvas 24 is placed, where the abrasive material 18 is provided.

The abrasive material 18 is provided in the form of particles 22 which are arranged on rows 26. The rows 26 are arranged parallel to the longitudinal direction 3 of the abrasive cloth and thus perpendicular to the height direction 7 of the abrasive cloth. The abrasive rows have an orientation 28 which is arranged at an angle 27 in with respect to the direction of elevation 7. The particles 22 have an extent 30 in the orientation 28 of the row which is greater than a mutual distance 29 between the particles 22 in the adjacent rows 26. Furthermore,

The particles are arranged offset relative to each other in the rows 26. In this way, an overlap of abrasive particles is obtained over the entire longitudinal direction 3 of the abrasive canvas, so that any area of a surface 25 to be machined will be coated with particles 22 from one or more second row 26. 3 In fig. 6, there is an enlarged section showing the abrasive particles 22 placed in rows 26. Likewise, it is more clearly shown that the extent 30 of the particles is greater than the distance 29 between particles 22.

In FIG. 6, the particles are shown with a substantially circular shape. However, the particles 22 may alternatively have a different shape.

FIG. 7 illustrates a surface 25 ground with a conventional grinding element of the type illustrated in FIG. It can be seen here that the surface 25 is provided with sanding grooves or depressions 32. These are formed in areas next to each row 26 of particles 22, which in the known design have an orientation in the height direction 7 of the sanding canvas.

Between the recesses 32 there are areas with a planar surface 31. This planar surface 31 is an untreated planar surface which appears without rubed. It may have a smoothness which makes it difficult to obtain an adhesion of lacquer or other coating to the flat surface 31 of the surface 25. These flat surfaces 31 will also give rise to undesired reflection and reflection from incident light, as diffusion does not occur from the flat surfaces 31.

FIG. 8 illustrates a surface 25 machined with an abrasive member according to the present invention. It can be seen here that the entire upper side of the surface 25 is machined by grinding elements, so that a number of adjacent grinding grooves or depressions appear.

32. Between the adjacent grinding grooves or depressions 32, peaks 33 are provided which are approximately pointed.

With this sanding, a roughness is obtained over the entire surface of the surface 25, which increases the possibility of adhesion of varnish or other coating. Furthermore, the rough surface will have a diffuse reflection of incident light. Thus, glare and reflection will be largely avoided with a surface 25, as illustrated in FIG. 8.

Experiments have been made with grinding elements of the known type, which are illustrated in fig. 1, and grinding elements of the new type illustrated in FIG. 5. Gelcoat and carbon experiments have been performed here.

At a grain size of 200, gelcoat has shown that an abrasive element according to the invention gives a roughness parameter - RA of 2.7, and with the known system an RA of 2.5. Similarly, at carbon and grain size of 200, an RA of 2.8 with an abrasive element according to the invention and an RA of 2.4 with the known abrasive element have been measured.

Furthermore, tests with a grain size of 120 have shown an RA value of 4.4 and 3.6, respectively, for the abrasive element according to the invention in relation to the old one on a gelcoat. Similarly, at a grain size of 120 in a carbon, an RA of 3.4 and 2.9, respectively, has been measured for an abrasive element according to the invention in relation to the old one.

In other words, there is evidence of improved roughness with both grain size 120 and 200. For grain size 120, there is thus a 22% increase in the roughness value. For customers, this will mean a significant improvement not only in adhesion and reduced reflection, but also in the speed of grinding and the service life of the grinding elements.

Claims (10)

DK 180350 B1 17 PATENTKR AV I. Grinding element (1) for use in rotary grinding or polishing tools for use in grinding or polishing surfaces and of a type comprising an elongate profile rail (2) and a grinding cloth (4) and support brushes (5), and wherein the sanding canvas (4) and the support brushes (5) are mounted in or on the profile rail (2), so that the sanding canvas (4) is supported by its passive side (15) by the support brushes (15), the sanding canvas outside the profile rail (2) having a sanding canvas height (9) in a bending direction (7) and a canvas length (12) in a longitudinal direction (3), where the support brushes (5) and the sanding canvas (4) have different heights, support brush height (11) and the sanding canvas height (9), respectively, from the profile rail ( 2) so that the abrasive cloth (4) is terminated by an outer free edge area (19) extending beyond the top of the support brushes (5) and a short distance down along the outer free end portions (10) of the support brushes (5), which outer free edge area (19) in use constitutes an effective area (17) of the active side (16) of the abrasive cloth (4), which abrasive cloth (4) is only IS coated with abrasive material (18) in the active area (17), which abrasive material consists of particles (22) of, for example, diamonds (21) or similar materials, which abrasive canvas (4) is cut from an outer free canvas edge (8) against the profile rail in the direction parallel to the height direction (7) to form slats (6), and which particles are placed in adjacent rows (26), characterized in that the particles (22) of the abrasive material in a row (26) are placed with the particles offset relative to the particles (22) in adjacent rows (26), and that the particles in the rows (26) are arranged at a mutual distance (29) , so that there is an overlap of the abrasive particles in the longitudinal direction of the abrasive cloth (3). Abrasive element (1) according to claim 1, characterized in that the adjacent rows (26) are located with their orientation (28) at an angle (27) different from 0 ° relative to the height direction (7) . Abrasive element (1) according to any one of claims 1 to 2, characterized in that the juxtaposed rows (26) are located with their orientation (28) in the longitudinal direction (3). Abrasive element (1) according to any one of the preceding claims, characterized in that the particles (22) have an extension (30) in the orientation of the row (28) which is greater than the distance between them (29). ) between the particles (22) in the adjacent rows (26) 3 Abrasive element (1) according to any one of the preceding claims, characterized in that the abrasive material (18) is a super-abrasive material (20) which consists of the particles (22) and powder (23) of, for example, diamonds (21) or equivalent materials. Abrasive element (1) according to any one of the preceding claims, characterized in that the effective area (17) constitutes between 4 and 2 and typically about 1/3 of the abrasive canvas height (9) of the abrasive canvas (4). Abrasive element (1) according to any one of the preceding claims, characterized in that the abrasive canvas height (9) of the abrasive canvas (4) is between 20 mm and 80 mm and typically about 40 mm. Abrasive element (1) according to any one of the preceding claims, characterized in that the abrasive material (18) is adhered to the abrasive canvas (4) in the operative area (17) with a binder which binds said particles (22) to the sanding cloth (4). Abrasive element (1) according to any one of claims 1 to 7, characterized in that the abrasive material (18) is provided on a second canvas (24), which second canvas (24) is mounted in the operative area (17) of the abrasive cloth (4). Abrasive element (1) according to any one of the preceding claims, characterized in that a flexibility of the abrasive canvas (4) in an area between the active area and the profile rail is greater than the flexibility of the abrasive canvas (4) in the effective area. advise.