EP0799111B1 - Recyclable zones on abrasive wheels - Google Patents

Description

The invention relates to grinding wheels Abrasive grain and an inorganic or organic binder for this in an outer peripheral zone and thus in Contact non-grinding zone in contact to accommodate Fasteners, in particular clamping flanges, a process for the production of the grinding wheels and a method for recycling the used grinding wheels.

In the production of ceramic or phenolic resin-bound According to the state of the art, grinding wheels these holistically from the known corundums or, for example Manufacture silicon carbide. Are also known. finer or harder non-grinding zones in phenolic resin-bonded or ceramic-bonded grinding wheels. This non-grinding zones, however, consist of the abrasive grain itself and selected binders and are usually created in one operation with the outer wear layer. The In the case of phenolic resin-bonded grinding discs, the inner zones are said to Increase strength or only allow the necessary Fracture speeds of the grinding wheels reached can be.

DE 42 44 476 A1 relates to a master blade for circular saw blades and / or cut-off wheels, consisting of a circular, at least partially embedded with one Fiber reinforced plastic material existing disc body. The fibers are in several superimposed, cohesively connected, flat, circular and Disc body arranged in concentric fiber layers. In a First type of fiber layer, the fibers are in a - related on the disc body - at least approximately radially in the direction rectilinear and in one across the circumference even distribution arranged. In a second type of Fiber layer, the fibers have at least approximately circular, substantially concentric with the disc body Course, using the two types of fiber layers one depending on the size of the disc body selected distribution are arranged in the disc body.

In the outer peripheral area of the disc body is on everyone a single or multi-part retaining ring on both sides attached. These two retaining rings are in parallel Planes, and the outer periphery of the disc body is regionally arranged between these retaining rings. The functional The cutting disc therefore always consists of three parts; the inner reinforced plastic master sheet, which on the circumference attached holding device made of steel and the cutting segments. Connection mechanisms are, for example, welding, Soldering and clamping. With the cutting discs described here it is necessary that the outer cutting active segments are wider in the axial direction than the master sheet described and the holding device.

A circumferential grinding wheel is known from DE-C-27 40 891, which consists of an inner hub part and an outer, one The grinding ring consists of a wheel part carrying a grinding wheel, with hub and rim over preloaded - and thus the Performing the function of "spokes" - wires, fibers or threads are interconnected. The "spokes" are in Plastic embedded. In addition to the "spokes" is said in the plastic is a common fabric mat Fiber reinforcement must be embedded. With this state of the art So there is a division into four, with a fiber-reinforced, circular plastic disc in the center of one Hub, which is preferably made of steel or metal, is provided with an outer ring, which is also made of steel or other metals is shaped and to hold the cutting active Serves segments.

DE 43 11 529 A1 describes a grinding wheel described in particular a cutting wheel, the one ring-cylindrical inner support body made of metal and a this surrounding slip ring, which with each other are connected. The slip ring is on both sides in the direction the common axis over the support body. The slip ring can be sanded completely. The supporting body is reusable or at least recyclable.

DE 28 25 576 B2 describes a method for lining the Bore of a large grinding wheel described. In practice the procedure has only been introduced to a very limited extent since it is very complex and also the grinding wheels through the described procedure from the borehole with only forces that are very difficult to control. It must worked here with granulate and in parallel with high temperatures become. The problem of melting leaves no Wall thickness of the linings above 20 mm. This publication clearly refers to a lining of the Hole and not on an inner zone of a grinding wheel. At Grinding wheels with such a bore liner the problem arises during disposal a three - material system consisting of a residual grinding wheel, coolant and Plastic lining.

US-A-2,475,517 describes a grinding wheel, in particular a cutting disc comprising abrasive grain made of thermoplastic bound material and a non-grinding zone with at least one hole, the non-grinding zone from a reinforcing material containing organic Plastic material is made.

In addition, special grinding wheels, namely So-called grinding cups and screw-on grinding wheels Soils or fine layers in use, some of which are made of Plastic. However, these are generally used for recording of threaded pieces.

The solutions common in the prior art have in common that the non-grinding zone or clamping zone from one high-quality material, namely the abrasive grain, that for multiple reuse or recycling in the Is usually hardly suitable. With ceramic-bonded abrasives is a reprocessing by mechanical crushing of the remaining grinding wheels. You get here only grain quality mixtures. As a so-called regenerate this material in parts, especially resin-bound, inferior grinding wheel qualities added. Phenolic resin bound Residual discs are treated thermally and the regenerations obtained with great effort, especially in the coarse grain area (8-36), also mixed in proportions. This burning of phenolic resin compounds is in industrialized countries hardly feasible in terms of environmental protection. Due to the necessary porosity of the grinding wheels and the use of cooling lubricants during the Grinding diffuses more or less large amount of these cooling lubricants in the non-grinding active Zones of grinding wheels, making them practical cannot be recycled. In addition, the Formation of the non-grinding zones of grinding wheels with a considerable cost factor due to the high quality Provided abrasive grain.

The non-grinding zones of grinding wheels can fastening and safety reasons never complete can be used for grinding. Accordingly remains according to the state of the art solutions regularly a waste product from high quality feedstocks that for reuse is limited and at a very high cost suitable is.

The object of the present invention is therefore in Manufacture of inexpensive grinding wheels through provision of reusable and recyclable non-grinding zones to hold fasteners, especially flanges.

The above-mentioned object is achieved according to the invention by grinding wheels with an outside diameter of 200 to 1600 mm and 10 to 600 mm wide, including abrasive grain Aluminum oxide, zirconium dioxide, silicon carbide, boron carbide, Garnet, emery and flint or a mixture of these and inorganic ceramic binder for this in one outer grinding zone (1) and one in contact with it non-grinding zone (2) with at least one hole for Inclusion of clamping flanges, the non-grinding active Zone (2) from a structure-sealed, filler and optionally Organic plastic material containing reinforcing agents consists.

1 shows an example of a grinding wheel according to the invention shown with an inner bore and clamping flanges.

The grinding wheel is over the non-grinding active zone 2 held on the shaft by the clamping flanges. The size the non-grinding zone 2 corresponds essentially to the External dimensions of the clamping flanges. Radially from the inside out a transition zone follows the non-grinding zone 2 3, which essentially consists of abrasive grain, that however within this area 3 by the organic Plastic material is impregnated to make a firm connection between the non-grinding zone 2 and the grinding zone To create 1. The outer grinding zone 1 is thus complete for processing the object to be ground Available. If the grinding wheel to the desired minimum is ground off, which is made of grinding and safety technology This grinding wheel can meet requirements can be recycled with the aid of the present invention. For this purpose, the non-grinding zone 2 is removed from the adherent Abrasive grain freed and an outer grinding zone 1 in itself manufactured in a known manner. Then the non-grinding active Zone 2 centered within the outer grinding zone 1 and the remaining space between the non-grinding active Zone 2 and the outer grinding zone 1 with a plastic material filled out and possibly a temperature treatment subject, you get a new grinding wheel, the non-grinding active zone 2 of a recycling is fed.

The grinding wheel shown in Figure 1 has a transition zone 3 between the outer grinding zone 1 and not active grinding zone 2, which consists essentially of the abrasive grain and the plastic material of the non-grinding zone (2) exists. Such a transition zone 3 is in principle not absolutely necessary in the sense of the present invention. However, if the fracture speeds are high Grinding wheel is desired is a very firm connection the outer grinding zone 1 with the non-grinding zone 2 required. This requires that the plastic material more or less deep in the grinding zone 1 penetrates to an extraordinarily good connection of not Form active grinding zone 2 with grinding zone 1. Here however, it should be noted that transition zone 3 is a necessary one Depth does not exceed, otherwise the grinding wheel, due to contamination by the plastic material cannot be used optimally.

With the help of the present invention is an optimal use of raw materials possible, with certain grinding wheels a more than 60% saving in high quality Corundum or silicon carbide results. Due to the higher Volume throughput per firing batch of the outer zone will continue Energy saved. Another potential for energy and Cost savings result from casting or molding processes with cold or warm curing plastics as well as from the possibility the refitting of the non-abrasive interior or Tension zones. In addition, there is an improvement in the peripheral circumferential speeds possible, resulting in greater security results from the use of special reinforcements is capable of further increase.

High clamping forces, even with non-ideal surface pressure of the clamping flanges, are possible with the aid of the present invention, in particular in the production of soft grinding wheels, for example hardness A (extremely soft) to J (medium), with a modulus of elasticity according to Grindo Sonic from 10 to 39 kN / mm ² (depending on the grain size) or highly porous grinding media with a pore volume of more than 50%, which can be held with the aid of the present invention with secure clamping forces. Mounting devices for grinding wheels usually consist of two flanges with ring-shaped wings, between which the grinding wheel is held non-positively. Flanges according to DIN 6375 are mainly used in industry. They have a mounting flange and a counter flange, between which the grinding wheel can be clamped and balanced outside the machine.

The clamping force required to clamp a grinding wheel On the one hand, it must be so large that the pane is under maximum operating load not to slide between the Flanges coming; on the other hand, the clamping force only be chosen so large that it certainly won't damage to the grinding wheel and thus a risk of breakage can come.

• Infolge Schrägstellung der Tragflächen durch Verbiegung der Flansche durch die Einspannkraft kommt es zu keiner ebenen Flächenpressung auf den Schleifscheiben.
• Eine ungleichförmige Belastung der aufgespannten Schleifscheibe entsteht durch Unebenheiten der Schleifscheibe.
• Eine Kontrolle mittels Momentenschlüssel kann nicht zur Ermittlung von Einspannkräften führen, weil die Reibbeiwerte von Schraubenkopf und Gewindeflanke starken Streuungen unterlegen sind.

However, the application of a defined clamping force and thus the generation of a certain disc load by this force cannot be achieved for the following reasons:

• Due to the inclination of the wings by bending the flanges due to the clamping force, there is no flat surface pressure on the grinding wheels.
• An uneven load on the clamped grinding wheel arises from unevenness of the grinding wheel.
• A check using a torque wrench cannot lead to the determination of clamping forces because the friction coefficients of the screw head and thread flank are subject to strong scatter.

Furthermore, there is no generally valid definition of surface pressure of the flanges possible because of the qualities and thus the strength of the grinding wheel is manufacturer-specific are and are therefore not defined uniformly can.

The present invention now enables an uncomplicated one Construction of grinding wheel clamping devices and drives, so that a central shaft can often be dispensed with and the screw connection in the non-grinding zone 2 is possible.

Usually by pouring a new one, or pouring on sufficient strength in an existing interior or tension zone achieved for later use up to at least 63 m / s become. Special preparations such as sandblasting the joint surfaces or additional roughening included, activation of the plastic surfaces by loosening and the grinding wheel surfaces by impregnation and / or surface coating possible here. According to the invention are also mechanical Anchoring of the parts to be joined. Depending on the area of application and volume of the grinding wheels can be the non-grinding zone of the Grinding wheels, as well as the outer area of the transition zone 3 defined geometries that have an intimate connection enable. A dovetail-shaped training can Abrasive discs from 20 mm width can be used usually immediately when the blanks are pressed, i.e. without later mechanical processing can be attached, for example for grinding discs, cylindrical grinding discs and centerless discs. Grooves 4,5, both perpendicular 4 and in certain angular position 5, if necessary, both in the Grinding wheels, as well as in the non-grinding active to be cast Zone 2 are cut using a diamond saw as in Fig.2a and 2b shown. In addition, it is possible to Grinding wheels, in particular non-grinding zone 2, to be equipped with channels running radially from the inside out, which allow coolants or cooling lubricants, due to the centrifugal force of the rotating grinding wheel directly into the working area of the grinding wheels transport, instead of with high pressure against the air cushion to spray the rotating disc.

An essential prerequisite for realizing the present Invention is the structural integrity of the not grinding active zone 2 forming plastic material. The Structural density, i.e. the ratio of pore volume to Grain and binder volume is not in the prior art clearly defined. Numbers indicate with increasing number towards a more open structure. To achieve grinding wheels with pore volume that can no longer be increased by pressing and casting technology pore formers are used in addition to hollow spherical grains, which evaporate when the grinding wheels burn or burn. This material of the non-grinding zone 2 must be designed in such a way that contamination with the Coolants or coolants are practically avoided, otherwise recycling is not an option. Minor soiling of the surface can, however, be avoided further, for example mechanically or by cleaning, be removed.

With the help of the present invention it is possible to use grinding wheels with the abrasive grain known per se in the prior art produce, so that in a preferred embodiment of the present invention, the abrasive grain of the outer grinding zone 1 made of aluminum oxide, zirconium dioxide, silicon carbide, Boron carbide, garnet, emery, flint stone, cubic boron nitride and diamond or a mixture of these. Especially in this sense, aluminum oxide (corundum) and Silicon carbide.

The binder of the outer grinding zone 1 corresponds to that in Inorganic or organic known in the art Binders. A distinction is usually made between ceramic, phenolic (or other resins) rubber, and / or magnesite-bonded grinding wheel, so that the physical Properties of the manufacturers are completely different. This Accordingly, it particularly affects the strength data the clearly defined clamping forces.

The proportion of binder is particularly preferably the outer one Grinding zone 1 1 to 50 wt .-% and is selected in particular from ceramic binders, in particular mullite, kyanite, Nepheline, syenite, clay, kaolin and fries or a mixture the same and from binders containing phenolic resin.

The structural density, filler and possibly reinforcing agent not containing organic plastic material Active grinding zone 2 preferably consists of thermoplastic or thermosetting plastic materials, in particular from single or multi-component casting resins such as Polyester resins or epoxy resins. Choosing the appropriate Materials is essentially due to the breaking strength, the structural tightness and the storage stability without major Loss of strength determines which is crucial for the Prevention of contamination from coolants or coolants is. Accordingly, the non-grinding active Zone 2 has the lowest possible porosity at least Have surface. With a total service life of up to 3 Months, up to 12 cycles are possible.

Break-proof plastic materials as they are in the sense of the present Invention for the non-grinding zone 2 required are usually associated with high costs. Accordingly, it is in the sense of the present invention desirable, a high proportion, for example 5 to 200 Parts by weight, in particular 10 to 50 parts by weight, inorganic or organic fillers, especially sand, quartz sand, Wollastonite or abrasive grain residues, based on 100 parts by weight Add plastic material. The abrasive grain remains preferably obtained from abrasive residues. In the same Of course, it is also possible to waste plastic as filler material or as the plastic material itself if the required quality requirements are met can be. So it is possible, for example, organically coated quartz flours such as wollastonite with doping of 1 to 100%, in particular 10 to 50% in general for increasing strength of plastic parts. As organic Coating agents can be silanes, for example are used, which are commercially available in a variety are. The selection is made according to the type of plastic material and of hardening. Activation is also possible in this context the transition zone 3 by an additional organic Coating.

The temperature of the hardening of the plastic materials can also an influence on the strength of the non-grinding zone Have 2. A hardening of cold hardening plastic materials at room temperature is preferred according to the invention, since this is the Stress relief favors. Possible tensions when curing are degraded in the viscous state, provided that the curing at room temperature. The hardening shrinkage is in the liquid phase.

To increase safety and improve the peripheral speed of fracture it is in the same way in the sense of the present Invention possible that the plastic material of non-abrasive zone 2 contains reinforcing agents. According to the invention, these include, in particular, reinforcements, in particular glass and / or wire mesh or the plastic material to understand added, strengthening fibers.

The size of the non-grinding zone 2 of the invention Grinding wheels should be at least the outside diameter of the Fasteners, especially the clamping flanges. This ensures that within the bracing area of the non-grinding zone 2 a load distribution occurs as evenly as possible. However, the non-grinding active zone 2 is usually used slightly larger than the outside diameter of the fasteners be made, or as large as the Permits the use of the outer grinding zone 1. With With the help of the present invention, grinding wheels are on the Basis of ceramic or resin-bonded abrasive grains on a scale of 200 to 1600 mm outside diameter, 10 to 600 mm width and all common holes, for example 32 to 550 mm, in particular 51 to 305 mm, excellently producible.

With the help of the present invention practically all known grinding wheels of the prior art become. Accordingly, the term includes grinding wheels in the sense of the present invention in particular one-sided or recessed on both sides and / or on one side and / or on both sides tapered grinding wheels, cylindrical cup wheels, cylindrical Double cups, tapered cups, grinding plates, glued or screwed grinding wheels with Carrying disks, glued or screwed grinding cylinders.

In a further embodiment of the present invention is the process for the preparation of the invention Grinding wheels characterized in that one a) the outer grinding zone 1 in a manner known per se manufactures and b) the area of non-grinding zone 2 with a structural seals, filler and optionally reinforcing agent filled plastic material and if necessary subjected to a temperature treatment.

Is particularly preferred in the sense of the present invention it, the area of the non-grinding zone 2 with the Pour plastic material and if necessary by Harden exposure to elevated temperature.

Alternatively, it is possible to use the non-grinding zone pour out in multiple layers, for example two layers. This makes it possible to use different physical resins or chemical properties, especially in layers or combine in a ring shape, for example the durability of non-grinding zone 2 continues to increase improve. Especially for the exposed outside surface thus resins are used, if necessary at room temperature poured and hardened, very good physical Possess properties.

The viscosity of the plastic material to be filled in that may contain filler, should be set that at least part of the plastic material penetrates into the outer grinding zone 1 and thus a transition zone 3 trains that an intimate connection between the non-grinding zone 2 and the outer grinding zone 1 for Provides.

After using the grinding wheel, the remains of the outer grinding zone 1 and possibly the remains of the transition zone 3 from the outer surface of the non-abrasive Zone 2, for example mechanically, removed. In another Operation is a newer outer peripheral zone 1 in itself known manner and a new, custom-made or used inner zone 2 within the outer grinding zone 1 centered and the remaining space 2 'between the non-grinding zone 2 and the outer grinding zone 1 with a plastic material 2 'that meets the above requirements to the plastic material of the non-abrasive Zone 2 corresponds, filled, as in Fig. 3 and 4, in particular Embodiment is shown and optionally a temperature treatment subject.

The space 2 'to be filled is preferably designed such that as shown in Figures 3 and 4, since the undercut a particularly good interlocking of the materials causes. It is an alternative to the method described here here, too, the filling in layers as described above possible.

In Figure 5, a grinding wheel with a not active grinding zone 2 shown next to the teeth 3 and 4 is designed such that the height the inner zone 2, 2 'somewhat above the level of the grinding active Zone 1 and the transition zone 3 protrude and therefore in each Level of recycling processed and new by the Plastic material can be poured out. This area is in particular 0.5 to 3 mm, preferably 0.5 to 1.5 mm. In addition to the two-sided projection shown in FIG. 5 the level of the inner non-grinding zone 2 above that Level of active grinding zone 1 and transition zone 1 of course also a one-sided projection with the reachable by the same means.

The following exemplary embodiment illustrates the method for the production of the grinding wheel, the grinding wheel thus obtained themselves and their recycling.

Example:

A grinding wheel according to the invention was produced initially in the manufacture of the ceramic bonded outer zone in a manner known per se. With the user became the greatest possible Degree of wear of the grinding wheel set so determine the raw bore of the outer zone.

A grinding wheel with the dimensions 350 x 12 x 150 mm in EK quality made of high-grade corundum, grain size = 50% grain 80 and 50% grain 90, hardness = J (modulus of elasticity 39 kN / mm ² ) structure 9 (highly porous through 1.2% based on the grain fraction, addition of a conventional pore former), density of the grinding wheel = 1.95 g / cm ³ , ceramic bond (14% based on the grain).

The non-grinding zone 2 was cut to a diameter of 255 mm, the transition zone 3 including the non-grinding active Zone 2 set to an area of 270 mm.

The dimensions of the blank were 353 x 15 x 253 mm with a recess of 260 x 2.5 mm compared to 353 x 15 x 147 mm usual manufacturing.

A volume comparison of the previous volume of 1213 cm ³ corresponds to a volume of 706.9 cm ³ corresponding to 58.3% by volume of the previous grinding wheel in a production according to the invention.

The blank of 353 x 15 x 253 mm was planned on both sides 13 mm to achieve flat side surfaces. Then followed machining the bore to a dimension of 255 +/- 0.5 mm. For this purpose, the grinding wheel was placed on a CNC lathe on the outside clamped in the three-jaw chuck and the hole with 2 roughing chips drilled to size.

The present blank now had the dimensions of 353 x 13 x 255 mm with a recess of 260 x 1.5 mm.

The purpose of this recess was to run the cast resin to prevent the casting process.

It had to be about 0.5 to 1.5 mm over due to the hardening shrinkage Slice level to be poured. The recess edge jammed the Casting compound and prevented unwanted running on the Side surface of the disc.

After the mechanical preparatory work, the lining of the Interior zone.

For this purpose, a metallic core was first used, too Plastics or the like, with a correspondingly smooth surface (Roughness <0.3 µm) on a flat surface made of suitable Material, for example plastic or metal centered, placed at right angles. The surface of the core and the The plate was coated with a release agent. Corresponding complete plastic parts are also possible, for example silicone, polyethylene or polypropylene molded parts.

To achieve a finished bore of 150 mm -0. + 0.25 mm (H11) a core dimension of 150.2 mm was chosen.

A metal adhesive from the company was available as casting resin - WEVO-Chemie with the resin types WEVO® metal adhesive A with a Mallison viscosity of 5.5 s and WEVO® Hardener B263 with a Mallison viscosity of 1.5 s.

A suitable choice of hardener types allowed different ones Pot times and thus a control of the large Achieve batches of reaction heat.

W10 quartz powder and classified were used as fillers Abrasive residues from mechanical processing used in the grain size range 100 to 280.

700 g of metal adhesive A, 600 g quartz flour Millisil®W10 and classified abrasive corundum with a low content of SIC, bulk density 1.35 to 1.62 kg / dm ³ , grain size 150/180 100g, grain size 180/220 150g and grain size 220/240 350g were mixed together.

Then 315 g of hardener B263 were added, thereby the viscosity was reduced.

The pourable mass was poured 0.6 to 0.8 mm above the level and after 24 hours the blank is demolded, the one after another Could be machined for 48 hours.

Attempts to determine the breaking strength showed that Discs with no internal non-grinding zone with dimensions 350 x 12 x 150 from the same production and quality at 109 to 112 m / s, the panes according to the invention after complete hardening broke at 120 to 125 m / s at a predetermined breaking circumferential speed from 70 m / s for use up to 40 m / s working speed.

The casting compound was with the viscosity of 65 set in this way s penetrated 3 to 4 mm deep into the panes according to Mallison.

Claims (13)

1. An abrasive disk having an external diameter of from 200 to 1600 mm and of from 10 to 600 mm in width containing an abrasive grain of aluminium oxide, zirconium dioxide, silicon carbide, boron carbide, garnet, emery, and flintstone or a mixture thereof and an inorganic ceramic or organic binder for said abrasive grain within an outer abrasive zone (1) and a non-abrasive zone (2) contacting said abrasive zone having at least one bore for the mounting of fixing flanges, wherein the non-abrasive zone (2) consists of an organic plastic material having a close spacing and containing a filler and optionally a reinforcing material.
2. The abrasive disk according to claim 1, characterized in that the outer abrasive zone (1) and the non-abrasive zone (2) are contacted by a transition zone (3) comprising an abrasive grain, a binder and a plastic material.
3. The abrasive disk according to claim 1, characterized in that the binder portion of the outer abrasive zone (1) is of from 1 to 50 % by weight and the ceramic binder is selected from mullite, kyanite, nepheline, syenite, clay, kaoline, or frits and a mixture thereof.
4. The abrasive disk according to claim 1, characterized in that the binder portion of the outer abrasive zone (1) is of from 1 to 50 % by weight and selected especially from phenolic resin containing binders.
5. The abrasive disk according to claims 1 or 2, characterized in that the plastic material of the non-abrasive zone (2) and/or the transition zone (3) is selected from thermoplastic or thermosetting plastic materials, in particular one- or multicomponent casting resins such as polyester resins or epoxy resins.
6. The abrasive disk according to claim 5, characterized in that the plastic material of the non-abrasive zone (2) contains of from 5 to 200 parts by weight, in particular of from 10 to 50 parts by weight of inorganic or organic fillers, in particular sand, quartz sand, or abrasive grain residues, based on 100 parts by weight of plastic material.
7. The abrasive disk according to claim 5, characterized in that the plastic material of the non-abrasive zone (2) contains reinforcements, in particular glass fabrics and/or metal fabrics or strength-improving fibres as reinforcing material and/or channels running radially from inside to outside in order to provide the working area with coolants and/or lubricant coolant.
8. The abrasive disk according to any one of claims 1 to 7, characterized in that the size of the non-abrasive zone (2) corresponds at least to the external diameter of the fixing flanges.
9. The abrasive disk according to any one of claims 1 to 8, containing abrasive disks recessed on one or both sides and/or tapered on one or both sides, cylindrical cup wheels, cylindrical double cup wheels, conical cup wheels, dish wheels, adhesively bonded or bolted cup wheels.
10. The abrasive disk according to any one of claims 1 to 9, characterized in that the non-abrasive inner zone (2) has geometries (4) and (5) for an interlocking with the transition zone (3) or the outer abrasive zone (1).
11. A process for manufacturing abrasive disks according to any one of claims 1 to 10, characterized in that

    a) the outer abrasive zone (1) is manufactured and

    b) the area of the non-abrasive zone (2) is filled with a plastic material having a close spacing and optionally containing a reinforcing material and optionally subjected to a thermal treatment.
12. The process according to claim 11, characterized in that the area of the non-abrasive zone (2) is filled with the plastic material and, optionally, cured by subjecting it to an elevated temperature.
13. A process for recycling abrasive disks according to any one of claims 1 to 10, characterized in that the outer abrasive zone (1) and the optionally present transition zone (3) are removed completely from the surface of the non-abrasive zone (2), a new outer abrasive zone (1) is produced in a manner known per se, the used non-abrasive zone (2) is centred within the outer abrasive zone (1) and the remaining gap between the non-abrasive zone (2) and the outer abrasive zone (1) is filled with a plastic material having a close spacing and optionally containing a reinforcing material and, optionally, subjected to a thermal treatment.

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