Tool

Abstract

The present invention discloses an improved tool, which comprises a reinforced member; and a resin layer is coated on the reinforced member, wherein the weight of the resin layer per unit area of the reinforced member may be less than 90 g/m.sup.2. The weight of the resin layer may be less than 15% of the total weight of the improved tool. The present invention dramatically reduces the production costs while maintaining the application performance unchanged.

Claims

1. A fiber reinforced mesh for an abrasive tool, comprising: a fiber fabric layer; a resin layer coated on the fiber fabric layer; and wherein the resin layer comprises a weight per unit area of the fiber reinforced mesh of more than 3 g/m.sup.2 and less than 80 g/m.sup.2.

2. A fiber reinforced mesh for an abrasive tool, comprising: a fiber fabric layer; a resin layer coated on the fiber fabric layer; and wherein the resin layer comprises a weight of more than 1% and less than 15% of the total weight of the fiber reinforced mesh.

3. The fiber reinforced mesh of claim 1, wherein the weight of the resin layer per unit area of the fiber reinforced mesh is less than 65 g/m.sup.2.

4. The fiber reinforced mesh of claim 1, wherein the weight of the resin layer per unit area of the fiber reinforced mesh is less than 45 g/m.sup.2.

5. The fiber reinforced mesh of claim 1, wherein the resin layer comprises one of thermoset resins including phenolic resin, aniline-formaldehyde resin, melamine resin, epoxy resin or modified epoxy resin, furfural resin, phenol formaldehyde, furan resin, glyptal resin, polyester or modified polyester, and vulcanized rubber, or any combination thereof.

6. The fiber reinforced mesh of claim 1, wherein the material of the fiber fabric layer is fiberglass mesh, short fiberglass, or nylon yarn, or any combination thereof.

7. The fiber reinforced mesh of claim 2, wherein a weight of the resin layer is less than 10% of the total weight of the fiber reinforced mesh.

8. The fiber reinforced mesh of claim 2, wherein the weight of the resin material is 5%-14% of the total weight of the fiber reinforced mesh.

9. An abrasive tool, comprising: an abrasive substrate layer, a first fiber reinforced mesh and a second fiber reinforced mesh that is different from the first fiber reinforced mesh, wherein each is independently provided inside or on a surface of the abrasive substrate layer, wherein each of the first and second fiber reinforced meshes independently comprise: a fiber fabric layer; and a resin layer coated on the fiber fabric layer; wherein the resin layer of the first fiber reinforced mesh comprises a weight per unit area of more than 3 g/m.sup.2 and less than 80 g/m.sup.2; and wherein the resin layer of the second fiber reinforced mesh comprises a weight per unit area of not less than 80 g/m.sup.2.

10. The abrasive tool of claim 9, wherein the weight of the resin layer of the first fiber reinforced mesh is more than 1% and less than 25% of the total weight of the first fiber reinforced mesh, and the weight of the resin layer of the second fiber reinforced mesh is more than 25% of the total weight of the second fiber reinforced mesh.

11. The abrasive tool of claim 9, wherein the fiber reinforced meshes are all located inside the abrasive substrate layer of the abrasive tool rather than on an outer surface of the abrasive substrate layer.

12. The abrasive tool of claim 9, wherein the first fiber reinforced mesh and the second fiber reinforced mesh are provided on outer surfaces at two opposite sides of the abrasive substrate layer of the abrasive tool, respectively.

13. The abrasive tool of claim 9, wherein the first fiber reinforced mesh is overlaid on an outer surface of the abrasive substrate layer of the abrasive tool, the second fiber reinforced mesh is provided inside the abrasive tool, and a third fiber reinforced mesh is partially overlaid on the other outer surface of the abrasive substrate layer of the abrasive tool.

14. The abrasive tool of claim 9, wherein the abrasive tool comprises a thickness of 0.8 mm to 5 mm and an outer diameter of 50 mm to 400 mm.

15. The fiber reinforced mesh of claim 2, wherein the weight of the resin layer per unit area of the fiber reinforced mesh is more than 3 g/m.sup.2 and less than 80 g/m.sup.2.

16. The fiber reinforced mesh of claim 1, wherein the weight of the resin layer is more than 1% and less than 25% of the total weight of the fiber reinforced mesh.

17. The fiber reinforced mesh of claim 1, wherein the abrasive tool comprises a ratio of diameter-to-thickness (D:T) of 8 to 62.5.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a structural schematic view of a fiber reinforced mesh.

(2) FIG. 2 is a cross-sectional schematic view of an abrasive wheel of a first embodiment according to the present invention.

(3) FIG. 3 is a cross-sectional schematic view of an abrasive wheel of a second embodiment according to the present invention.

(4) FIG. 4 is a cross-sectional schematic view of an abrasive wheel of a third embodiment according to the present invention.

(5) FIG. 5 is a cross-sectional schematic view of an abrasive wheel of a fourth embodiment according to the present invention.

(6) FIG. 6 is a cross-sectional schematic view of an abrasive wheel of a fifth embodiment according to the present invention.

(7) FIGS. 7 and 8 show the effects of the resin content on the burst speed and the grinding ratio.

DETAILED DESCRIPTION OF THE INVENTION

(8) FIG. 1 shows a fiber reinforced mesh, wherein a layer of fiber fabric is firstly coated with a resin layer on each of the upper and lower surfaces through a dipping process and the like, then solidified by heating, and finally cut into a fiber reinforced mesh. The resin layer is produced by solidifying phenolic resin together with a solvent, a surfactant, and an aid and the like. After solidification by heating, the weight of the resin layer per m2 of the fiber reinforced mesh is more than 3 g and less than 90 g; for the convenience of large-scale production, the weight of the resin material per unit area of the fiber reinforced mesh is preferably between 5-90 g, and more preferably between 35-90 g.

(9) An example of the present invention is based on an ultra-thin abrasive wheel with a diameter of 105 mm, where two fiber reinforced mesh layers are each provided on an outer surface at either side of an abrasive substrate layer of the abrasive wheel. The cross-sectional structure of this example is similar to that shown in FIG. 3. The content of the phenolic resin coating on the glass reinforced mesh is gradually reduced from about 98 g/m2 as specified in the current production practice standard to about 3 g/m2. FIG. 7 shows the values of the burst speed and the grinding ratio for abrasive wheels comprising fiber reinforced meshes with different weights of resin per unit area, and the test results show that reduction of the resin content in the fiber reinforced mesh has slight effects on the burst speed and the grinding ratio; and when the resin content of the fiber reinforced mesh in the abrasive wheel is gradually reduced to 3 g/m2, the grinding ratio remains substantially unchanged, and the burst speed still conforms to the requirements of the grinding process.

(10) More examples and performance tests on abrasive wheels are provided hereinbelow.

Example 1

(11) Firstly, cutting wheels with a size of 180×3×22 (mm) were tested. The structure of the cutting wheel is as shown in FIG. 3. The cutting wheel comprises a grinding layer 10 and two fiber reinforced mesh layers 20-1 and 20-2 are respectively provided on the upper and lower surfaces on the grinding layer 10. According to the specifications as set forth in a national standard of the People's Republic of China GB/T2485-2008 Technical Conditions for Bonding Abrasive Tools, the burst performance of an abrasive wheel shall be tested in accordance with a rotation test method on abrasive wheels as provided in a national standard of the People's Republic of China GB/T2493-1995 and shall conform to the related requirements.

(12) Thus, the abrasive wheel of this embodiment was tested according to the national standard GB/T2493-1995, where the abrasive wheel was installed on a rotation testing machine (a POGGI rotation machine from Italy, type: PV22, maximum rotation speed: 22000 rpm) as specified in the standard. The weight of the resin layer per unit area of the single fiber reinforced meshes 20-1 and 20-2 is respectively set to be 3.2, 9.6, 16, 22.4, 28.8, 35.2, 41.9, 48, 56.9, 65.6, 70.4, 79.9, 86.8 and 98.6 (g/m2), and the cutting wheels were subject to the rotation test at 1.5 times their respective maximum operation speeds and maintained at the highest speed for 30 seconds. The results showed that all the tested cutting wheels passed the test.

(13) During the test, even if the resin content in a single fiber reinforced mesh is as low as about 3 g/m2, the cutting wheel did not burst and successfully passed the rotation test. Further, the inventor of the present invention measured the grinding ratios of these cutting wheels and compared them with those in the case of more than 90 g/m2. For details, refer to Table 1. This shows that the resin content in the fiber reinforced mesh does not affect the grinding ratio of the cutting wheel.

(14) TABLE-US-00001 TABLE 1 Resin weight per unit area of Rotation Grinding fiber reinforced mesh (g/m.sup.2) test ratio 3.2 Pass 0.63 9.6 Pass 0.64 16 Pass 0.66 22.4 Pass 0.67 28.8 Pass 0.62 35.2 Pass 0.64 41.9 Pass 0.64 48 Pass 0.65 56.9 Pass 0.65 65.6 Pass 0.66 70.4 Pass 0.62 79.9 Pass 0.63 86.8 Pass 0.64 98.6 Pass 0.65

Example 2

(15) Cutting wheels with the same size of 180×3×22 (mm) were tested. The cutting wheels in Example 2 are different from those in Example 1 and the cross-sectional structure of this group of cutting wheels is shown in FIG. 2. The grinding layer of the cutting wheel is divided into a first grinding layer 10-1 and a second grinding layer 10-2, and the cutting wheel comprises a fiber reinforced mesh 20 between the first grinding layer and the second grinding layer. The tests include a rotation test and a grinding ratio measurement test. The conditions of the rotation test are the same as those in Example 1, and according to the tests, all tested cutting wheels passed the test and changes in the resin weight per unit area of the reinforced mesh did not affect the grinding ratio of the cutting wheel.

(16) TABLE-US-00002 TABLE 2 Resin weight per unit area of Rotation Grinding fiber reinforced mesh (g/m.sup.2) test ratio 3.2 Pass 1.01 9.6 Pass 1.03 16 Pass 1.04 22.4 Pass 1.02 28.8 Pass 1.06 35.2 Pass 1.06 41.9 Pass 1.05 48 Pass 1.04 56.9 Pass 1.03 65.6 Pass 1.02 70.4 Pass 1.07 79.9 Pass 1.04 86.8 Pass 1.03 98.6 Pass 1.05

Example 3

(17) The inventor further tested angle grinding disks with a cross-sectional structure as shown in FIG. 4. The angle grinding disk has a size of 180×6×22 (mm), and comprises, along the direction as shown in FIG. 4 from top down, a first fiber reinforced mesh 20-1 overlaid on an upper surface of the grinding layer, a second fiber reinforced mesh 20-2 provided inside the grinding layer, and a third fiber reinforced mesh 20-3 partially overlaid on a lower surface of the grinding layer. The tests include a rotation test and a grinding ratio measurement test. The conditions of the rotation test are the same as those in Example 1. As shown in Table 3 hereinbelow, all the angle grinding disks passed the tests and changes in the resin weight per unit area of the fiber reinforced mesh did not affect the grinding ratio of the angle grinding disk.

(18) TABLE-US-00003 TABLE 3 Resin weight per unit area of Rotation Grinding fiber reinforced mesh (g/m.sup.2) test ratio 3.2 Pass 11.9 9.6 Pass 12.5 16 Pass 12.3 22.4 Pass 12.4 28.8 Pass 12.4 35.2 Pass 12.8 41.9 Pass 11.9 48 Pass 11.8 56.9 Pass 12.3 65.6 Pass 12.2 70.4 Pass 12.4 79.9 Pass 12.6 86.8 Pass 12.2 98.6 Pass 12.8

Example 4

(19) The inventor further tested cutting wheels with a size of 350×3×25. The structure of the cutting wheel is shown in FIG. 3. The grinding layer of the cutting wheel is divided into a first grinding layer 10-1 and a second grinding layer 10-2, and the cutting wheel comprises a fiber reinforced mesh 20 between the first grinding layer and the second grinding layer. The tests include a rotation test and a grinding ratio measurement test. The conditions of the rotation test are the same as those in Example 1, and according to the test, all tested cutting wheels passed the tests and changes in the resin weight per unit area of the reinforced mesh did not affect the grinding ratio of the cutting wheel.

(20) TABLE-US-00004 TABLE 4 Resin weight per unit area of Rotation Grinding fiber reinforced mesh (g/m.sup.2) test ratio 61.3 Pass 0.66 68.2 Pass 0.64 69.8 Pass 0.63 77.2 Pass 0.64 92.5 Pass 0.65

Example 5

(21) The inventor further tested cutting wheels with a size of 350×3×25. The structure of the cutting wheel is as shown in FIG. 2. The cutting wheel comprises a grinding layer 10, and two layers of fiber reinforced mesh 20-1 and 20-2 are each provided on the upper and lower surfaces of the grinding layer 10. The tests include a rotation test and a grinding ratio measurement test. The conditions of the rotation test are the same as those in Example 1. As shown by the test, all the cutting wheels passed the test and changes in the resin weight per unit area of the reinforced mesh did not affect the grinding ratio of the cutting wheel.

(22) TABLE-US-00005 TABLE 5 Resin weight per unit area of Rotation Grinding fiber reinforced mesh (g/m.sup.2) test ratio 61.3 Pass 0.82 68.2 Pass 0.81 69.8 Pass 0.84 77.2 Pass 0.86 92.5 Pass 0.85

(23) Based on the above three examples, it can be concluded that, when the resin content in the fiber reinforced mesh is reduced to be below 90 g/m2 which is traditionally considered as undesirable, both the burst speed and the cutting rate are not significantly influenced. That is to say, the resin content in the fiber reinforced mesh may be set to be below 90 g/m2 and above 3 g/m2. Nevertheless, considering the costs in conjunction with the workability, the weight of the resin material per m2 of the fiber reinforced mesh may be preferably set to be 5-90 g/m2, and more preferably 35-90 g/m2.

(24) Furthermore, the fiber reinforced mesh with the resin content reduced to be below 90 g/m2 may be incorporated into the grinding substrate layer of the abrasive wheel through various ways. In addition to the three different patterns as shown in Examples 1 to 3, the fiber reinforced mesh may further have the following structures.

(25) As shown in FIG. 5, an abrasive wheel 5 may comprise two layers of complete fiber reinforced mesh 20-1 and 20-2, wherein the first fiber reinforced mesh layer 20-1 is provided on one of the two outer surfaces of the substrate of the abrasive wheel, and the second fiber reinforced mesh layer 20-2 is axially provided inside the substrate of the abrasive wheel at an approximately middle position.

(26) Further, as shown in FIG. 6, an abrasive wheel 6 comprises two layers of complete fiber reinforced mesh 20-1 and 20-2 which are both provided inside the abrasive substrate of the abrasive wheel and divide the abrasive substrate into three layers.

(27) For the abrasive wheels provided with multi-layer fiber reinforced meshes as shown in FIGS. 4, 5 and 6, when prefabricated, the coated resin contents of all the fiber reinforced meshes are less than 90 g/m2, and the fiber reinforced meshes have the same resin weight per unit area.

(28) The overall inventive concept of the present invention is described through some specific embodiments, but the methods provided in the above related description or embodiments do not represent a sole option and various changes or combinations may be made to what is described in the specification by those skilled in the art. For example, in the abrasive wheel provided with more than two fiber reinforced meshes, the resin weights per unit area of the fiber reinforced meshes may be different: the resin content of one fiber reinforced mesh may be 35 g/m2 and that of the other may be 65 g/m2; or, the resin content of one fiber reinforced mesh is within the scope as set forth in the claims, and the other may use a traditional fiber reinforced mesh with a resin content of more than 90 g/m2.

(29) Again referring to FIG. 1, after solidification by heating, the resin layer accounts for equal to or more than 1% and less than 15% of the total weight of the fiber reinforced mesh, and for the convenience of large-scale production, the weight percentage of the resin layer can be preferably 11%, 12%, 13% and 14% relative to the fiber reinforced mesh.

(30) An example of the present invention is based on an ultra-thin abrasive wheel with a diameter of 105 mm, where two layers of fiber reinforced mesh are each provided on an outer surface at either side of an abrasive substrate layer of the abrasive wheel. The cross-sectional structure of this example is similar to that shown in FIG. 3. The content of the phenolic resin coating on the glass reinforced mesh is gradually reduced from 33% as specified in the current production practice standard to 1%. FIG. 8 shows the values of burst speed and grinding ratio for abrasive wheels comprising fiber reinforced meshes with different resin contents, and the test results show that the reduction of resin content in the fiber reinforced mesh has slight effects on the burst speed and the grinding ratio; and when the resin content of the fiber reinforced mesh in the abrasive wheel is gradually reduced to 1%, the grinding ratio remains unchanged, and the burst speed is slightly reduced but still conforms to the requirements of the grinding process.

(31) More examples and performance tests on abrasive wheels are provided hereinbelow.

Example 6

(32) Cutting wheels with a size of 180×3×22 (mm) were tested. The structure of the cutting wheel is as shown in FIG. 3, comprising a grinding layer 10 and two layers of fiber reinforced mesh 20-1 and 20-2 provided respectively on the upper and lower surfaces of the grinding layer 10.

(33) According to the specifications as set forth in a national standard of the People's Republic of China GB/T2485-2008 Technical Conditions for Bonding Abrasive Tools, the burst performance of an abrasive wheel shall be tested in accordance with a rotation test method of abrasive wheels as provided in a national standard of the People's Republic of China GB/T2493-1995 and shall conform to the related requirements.

(34) Thus, the abrasive wheel of this embodiment was tested according to the national standard GB/T2493-1995, where the abrasive wheel was installed on a rotation testing machine (a POGGI rotation machine from Italy, type: PV22, maximum rotation speed: 22000 rpm) as specified in the standard. The resin content in each of the fiber reinforced meshes 20-1 and 20-2 was set to be 1.00%, 3.00%, 5.00%, 7.00%, 9.00%, 11.00%, 13.10% and 15.00% respectively, and the cutting wheels were subject to the rotation test at 1.5 times their respective maximum operation speed and maintained at the highest speed for 30 seconds. The results show that all the tested cutting wheels pass the test.

(35) During the test, even if the resin content in a single fiber reinforced mesh was as low as 1.00%, the cutting wheel did not burst and successfully passed the rotation test. Further, the inventor measured grinding ratios of these cutting wheels and compared them with those when the resin content thereof was more than 15%. For details, refer to Table 6. As can be seen, the resin content in the fiber reinforced mesh does not affect the grinding ratio of the cutting wheel.

(36) TABLE-US-00006 TABLE 6 Resin Rotation Grinding content test ratio 1.00% Pass 0.63 3.00% Pass 0.64 5.00% Pass 0.66 7.00% Pass 0.67 9.00% Pass 0.62 11.00% Pass 0.64 13.10% Pass 0.64 15.00% Pass 0.65 17.79% Pass 0.65 20.53% Pass 0.66 22.01% Pass 0.62 25.00% Pass 0.63 27.14% Pass 0.64 30.82% Pass 0.65

Example 7

(37) Next, cutting wheels with the same size of 180×3×22 (mm) were tested. The cutting wheels in Example 7 are different from those in Example 6, and the cross-sectional structure of this group is shown in FIG. 2. The grinding layer of such a cutting wheel is divided into a first grinding layer 10-1 and a second grinding layer 10-2, and the cutting wheel comprises a fiber reinforced mesh 20 between the first grinding layer and the second grinding layer. The tests include a rotation test and a grinding ratio measurement test. The conditions of the rotation test are the same as those in Example 6, and according to the test, all tested cutting wheels passed the tests and the resin content in the reinforced mesh does not affect the grinding ratio of the cutting wheel.

(38) TABLE-US-00007 TABLE 7 Resin Rotation Grinding content test ratio 1.00% Pass 1.01 3.00% Pass 1.03 5.00% Pass 1.04 7.00% Pass 1.02 9.00% Pass 1.06 11.00% Pass 1.06 13.10% Pass 1.05 15.00% Pass 1.04 17.79% Pass 1.03 20.53% Pass 1.02 22.01% Pass 1.07 25.00% Pass 1.04 27.14% Pass 1.03 30.82% Pass 1.05

Example 8

(39) The inventor further tested angle grinding disks with a cross-sectional structure as shown in FIG. 4. The angle grinding disk has a size of 180×6×22 (mm), and comprises, along the direction as shown in FIG. 4 from top down, a first fiber reinforced mesh 20-1 overlaid on an upper surface of the grinding layer, a second fiber reinforced mesh 20-2 provided inside the grinding layer, and a third fiber reinforced mesh 20-3 partially overlaid on a lower surface of the grinding layer. The tests include a rotation test and a grinding ratio measurement test. The conditions of the rotation test are the same as those in Example 6. As shown in Table 8 below, all the angle grinding disks passed the test and the resin content in the fiber reinforced mesh did not affect the grinding ratio of the angle grinding disk.

(40) TABLE-US-00008 TABLE 8 Resin Rotation Grinding content test ratio 1.00% Pass 11.9 3.00% Pass 12.5 5.00% Pass 12.3 7.00% Pass 12.4 9.00% Pass 12.4 11.00% Pass 12.8 13.10% Pass 11.9 15.00% Pass 11.8 17.79% Pass 12.3 20.53% Pass 12.2 22.01% Pass 12.4 25.00% Pass 12.6 27.14% Pass 12.2 30.82% Pass 12.8

(41) Based on the above three examples, it can be concluded that, when the resin content in the fiber reinforced mesh is reduced to below 15% which is traditionally considered as undesirable, both the burst speed and the cutting rate are not significantly influenced. That is to say, the resin content in the fiber reinforced mesh may be set to below 15% and above 1%. Nevertheless, considering the costs in conjunction with the workability, the resin content in the fiber reinforced mesh may be preferably set to between 5% and 14%, and more preferably between 11% and 14%.

(42) Furthermore, the fiber reinforced mesh with the resin content reduced to below 15% may be incorporated into the grinding substrate layer of the abrasive wheel through various methods. In addition to the three different patterns as shown in Examples 6 to 8, the fiber reinforced mesh may further have the following structures.

(43) As shown in FIG. 5, an abrasive wheel 5 may comprise two layers of complete fiber reinforced mesh 20-1 and 20-2, wherein the first layer of fiber reinforced mesh 20-1 is provided on one of the two outer surfaces of a substrate of the abrasive wheel, and the second layer of fiber reinforced mesh 20-2 is axially provided inside the substrate of the abrasive wheel at an approximately central position.

(44) Further, as shown in FIG. 6, an abrasive wheel 6 comprises two layers of complete fiber reinforced mesh 20-1 and 20-2 which are both provided inside an abrasive substrate of the abrasive wheel and divide the abrasive substrate into three layers.

(45) For the abrasive wheels provided with multi-layer fiber reinforced meshes as shown in FIGS. 4, 5 and 6, when prefabricated, all the fiber reinforced meshes have the same resin content which is less than 15% of the total weight of the mesh.

(46) The overall inventive concept of the present invention is described through some specific embodiments, but the methods provided in the above related description or embodiments do not all represent a sole option and various changes or combinations may be made to what is described in the specification by those skilled in the art. For example, in the abrasive wheel provided with more than two fiber reinforced meshes, the resin contents thereof may be different: the resin content of one fiber reinforced mesh may be 14% and that of the other may be 10%; or, the resin content of one fiber reinforced mesh is within the scope as set forth in the claims, while that of the other may be more than 15% or traditionally more than 28%.

(47) Therefore, after reading the above content of the present invention, those skilled in the art may make various changes or combinations to the present invention and these equivalent changes or combinations shall also fall within the scope as defined by the appended claims of the present application.

(48) In addition, the present invention is especially applicable to thin abrasive wheels. Common thin abrasive wheels have an outer diameter of 50 mm to 400 mm, and a thickness of 0.8 mm to 5 mm. Generally, it is appropriate for these thin abrasive wheels to joint with work pieces at a tangential contact speed of 72 m/s to 120 m/s. These thin resin abrasive wheels may include cutting wheels and angle grinding disks.

(49) Moreover, the fiber reinforced mesh according to the present invention may be combined with various abrasive substrate materials to form abrasive wheels. For example, a combination of garnet and brown corundum may be used as the abrasive material, wherein garnet may account for 5% to 70% of the abrasive material by volume.

(50) Although the several specific embodiments of the present invention are described through the appended drawings and the description as mentioned above, the above description is only for the purpose of clearly describing the preferred embodiments of the present invention rather than limiting the scope of the present invention in any way. The scope of the present invention is to be defined by the appended claims.