KR20160028456A - Abrasive article and adapter therefore - Google Patents

Abstract

Accordingly, abrasive articles and adapters are disclosed. The abrasive article includes abrasive coating on the surface of the backing and backing and forming a working surface, having a center point and a peripheral edge. A plurality of holes extending through the backing and the abrasive coating are provided, through which the particulate material can be extracted. The working surface is divided into at least a first inner zone and a second outer zone, the second zone being concentric with the first zone and the center point. Each zone has at least one hole, and the sizes of the holes and the total number of them in each of the first and second zones form the hole density for that respective zone. The hole density in the first zone is less than the hole density in the second zone. The adapter has a mounting surface for an abrasive article configured in a similar manner.

Description

ABRASIVE ARTICLE AND ADAPTER THEREFORE < RTI ID = 0.0 >

The present invention relates to an abrasive article, in particular a abrasive coating having a center point and a periphery and on the surface of a backing and backing,

An abrasive article comprising a plurality of holes through backing and abrasive coating; And also to provide an adapter for an abrasive article which also provides holes through which the particulate material can be extracted through.

Many sanding and polishing processes are performed in a dry environment, i. E. In an environment where the workpiece is processed without the use of any lubricant. One situation in which this occurs is for example the rectification of paint or lacquer surfaces on automotive parts during the repair process, or the sanding of primers and fillers used in such processes , Sanding of the painted workpiece. This generates fine particulate matter, often referred to as "dust" (such as paint shavings), which not only needs to be removed from the workpiece, but can also pose hazards to workers using abrasives, Because dust can enter the atmosphere around the workpiece and pose a potential hazard to health. One way of dealing with this is by extracting dust from around the workpiece (e.g., using a workbench with dust extraction capability, such as a downdraft workbench) (Using a sanding tool that has an abrasive) to remove dust through the abrasive. These latter options are particularly popular due to his convenience.

The coated abrasive typically includes a backing such as paper or cloth on which a backing is coated with a polishing coating formed of a resin with an abrasive grit dispersed therein. To attach the abrasive article to a tool such as an orbital sander, a layer of adhesive material such as hook and loop material, or brushed nylon material is provided on the surface of the backing opposite the abrasive coating. This allows the abrasive article to be mounted on a back up pad, which is then attached to the tool. To facilitate dust extraction, holes are typically disposed in the abrasive article through the backing, abrasive coating, and adherent layer, which are in communication with the holes provided in the back-up pad, Lt; / RTI > Some designs of abrasive articles are typically aligned with holes provided in a backup pad, such as a 15-hole 255P polishing disc, available from 3M United Kingdom PLC, RG12 8HT Bracknell, Lord, Lt; RTI ID = 0.0 > holes. ≪ / RTI > Some designs of abrasive materials used for dust extraction may require alignment with corresponding holes in backup pads, such as 334U and 734U (Purple) polishing disks, also available from 3M United Kingdom, Different structures are used, including many small holes that may not be.

The previous approach to maximizing the amount of dust to be extracted included as many holes as possible in the abrasive article, depending on maximizing the surface area of the holes relative to the surface area of the abrasive. An example of this is the abrasive article discussed in EP 781 629, wherein a perforated section including substantially uniformly distributed pores over at least a portion of the surface of the abrasive article, together with the hook and loop attachment material, It has been shown that it provides improved dust extraction compared to articles. Similarly, WO2012 / 034785 discusses the use of many small holes for improved dust extraction, but rather than suggesting a uniform distribution of holes over the surface of an abrasive article, Fibonacci sequence ), Or the use of a golden number is discussed, showing that a non-uniform arrangement also provides beneficial dust extraction results.

However, the use of an increased number of holes in the abrasive article obviously increases the amount of dust extraction, regardless of the distribution of extraction holes in the back-up pads or their alignment with them, but the use of too many holes is related to the structural integrity of the abrasive article This can lead to problems. Particularly when many small holes are included toward the edge of the disc, the abrasive tends to be destroyed in use due to the force generated by the rotation of the backup pad. It is also the point at which too much of the total surface area of the abrasive article is applied to the holes and the cutting or overall life of the abrasive article drops beyond the actual usable or economical amount. The complex pattern of many holes can also be expensive to produce, given the wear and tear of the tool and the cost of converting the web of abrasive material into a disk and sheet with precise hole patterns. However, the use of smaller larger holes is still ideal for many applications, but does not provide equivalent dust extraction, and thus there was a compromise between the number of holes and cutting to improve both dust extraction and cutting in previous products . Thus, it is desirable to balance both cost and performance to ensure that the dust extraction behavior of the product does not deteriorate while maintaining a cost-competitive manufacturing approach.

An abrasive article having a center point and a periphery, the abrasive article comprising: a polishing coating on the surface of the backing and backing and forming a work surface; And a plurality of apertures extending through the backing and abrasive coating and allowing the particulate material to pass through and being extracted, the article being divided into at least a first inner zone and a second outer zone, And each zone has at least one hole, the sizes of the hole (s) in each of the first zone and the second zone, and the total number of them, And the hole density of the first zone is less than the hole density of the second zone.

By considering both the relative amount of the surface area of the abrasive and the surface area of the holes and the position of the holes on the abrasive article in relation to how such holes will move on the tool in use, the ability of the abrasive article to extract dust is greatly improved .

Preferably, in each zone, the ratio between the distance of each hole from the center point multiplied by the total surface area of the abrasive coating in its respective zone and the total surface area of at least one hole in the respective zone, And a size and position within the respective zones such that they are substantially constant with respect to the second zone.

Preferably, the holes in each zone are uniformly distributed around the center point.

Preferably, the article is in the form of a disk.

The abrasive article may further include a third zone positioned between the first zone and the second zone and free of holes. Alternatively, the abrasive article may further include a third zone located between the first zone and the second zone and including at least one aperture.

If the abrasive article is a disk situation, preferably the holes are located along the radii of the disk. At least one additional hole may be provided on the outside of the at least two zones. The at least one additional hole may be a center hole located at the center point. Alternatively, at least one additional hole may be located away from the center point. Preferably, at least two holes in each zone form an overall asymmetric pattern across the abrasive article.

The holes preferably have a diameter in the range of 1.0 mm to 25.0 mm. Preferably, the abrasive article comprises 7 to 100 holes. More preferably, the abrasive article comprises 7 to 30 holes.

Even more preferably, the particulate is dust, and the abrasive article is configured for use with a dust extraction equipment.

In another aspect, the present invention also provides an abrasive article adapter having a center point and a periphery, the adapter comprising: a body having a mounting surface configured to attach an abrasive article; And a plurality of apertures extending through the body and allowing the particulate material to pass through and be extracted,

The mounting surface is divided into at least a first inner zone and a second outer zone, the second zone being located outside of the first zone and concentric with the first zone and the center point, each zone having at least one hole, The sizes of the holes and their total number in each of the first and second zones form the hole density for such respective zones, wherein the hole density of the first zone is less than the hole density of the second zone, Adapter.

By considering both the relative amount of the surface area of the mounting surface and the surface area of the holes and the location of the holes on the abrasive article in relation to how such holes will move on the tool in use, the dust extraction capability of the adapter can be greatly improved compared to existing devices . This can be done with or without optimization of the relevant abrasive article.

Preferably, in each zone, the ratio between the distance of each hole from the center point multiplied by the total surface area of the mounting surface in its zone and the total surface area of at least one hole in the respective zone, And a size and position within the respective zones such that they are substantially constant with respect to the second zone.

Preferably, at least two holes are provided in each zone, and the holes in each zone are uniformly distributed around the center point.

Preferably, the adapter is in the form of a circular backup pad.

The adapter may further include a third zone located between the first zone and the second zone and free of holes. Alternatively, the adapter may further include a third zone located between the first zone and the second zone and including at least one hole.

If the adapter is a circular backup pad, the holes are located along the radius of the circular backup pad.

At least one additional hole may be provided on the outside of the at least two zones. The at least one additional hole may be a center hole located at the center point. Alternatively, at least one additional aperture is located away from the center point. At least two holes in each zone may form an overall asymmetric pattern across the adapter.

Preferably, the holes have a diameter in the range of 1.0 mm to 25.0 mm. Preferably, the adapter comprises 7 to 100 holes, more preferably 7 to 30 holes.

Preferably, the particulate is dust and the adapter is configured for use with a dust extraction equipment.

The present invention will now be described by way of example only and with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic cross-sectional view illustrating the construction of an abrasive article suitable for use with any of the embodiments of the present invention.
2 is a schematic view of an abrasive article according to a first embodiment of the present invention.
3 is a schematic view of an abrasive article according to a second embodiment of the present invention.
4 is a schematic view of a 15-hole abrasive and a 78-hole abrasive used in comparative experiments with the first and second embodiments of the present invention.
5 is a schematic cross-sectional view of an adapter for an abrasive article according to a third embodiment of the present invention.
6 is a schematic plan view of an abrasive article adapter according to a third embodiment of the present invention.

The present invention not only requires a uniform level of dust extraction across the surface of the abrasive article for good performance but also provides a situation where it is ideally used in a tool that provides the orbit and / Take an understanding approach to consider. For example, a random orbital or dual action (DA) sander, such as the 3M Random Orbital Sander family available from 3M as above, not only rotates the abrasive article but also moves it in an elliptical orbital pattern Thereby providing translational motion components in the rotational motion of the abrasive article. For abrasive articles such as discs rotating during use, the relative linear velocity near the center of the polishing disc is significantly smaller than the linear velocity at the outer edge of the disc, depending on the rotational velocity of the polishing disc.

Without wishing to be bound by theory, as the larger area of abrasive material passes over the surface of the workpiece, an increased speed at the edge of the abrasive article results in increased cutting on the surface of the workpiece, Are more likely to produce more invasive cutting. This allows dust particles, consisting of paint debris or filler, to be removed from the surface of the workpiece due to an increased amount of particulate material, typically an application, which reduces clogging of the surface of the workpiece and the release of particulate material into the ambient atmosphere Timely removal is required.

The present invention solves this by dividing the working surface of the abrasive article formed by the abrasive coating into at least a first inner zone and a second outer zone, wherein the second zone is concentric with the first zone and the center point. Each zone has at least one hole, and the sizes of the holes and the total number of them in each of the first and second zones form the hole density for that respective zone. The hole density in the first zone is less than the hole density in the second zone. Hole density is thus a measure of the surface area of the abrasive article used exclusively for the holes and is its relationship only to the surface area of the abrasive article which is the abrasive coating, i. In each zone, the ratio of the distance between each hole from the center point of each hole multiplied by the total surface area of the abrasive coating in its zone to the total surface area of at least one hole in the respective zone, In the region of its size, such that it is substantially constant with respect to the surface of the substrate. One way of doing this is to provide at least one hole in each zone and ensure that these holes are evenly distributed around the center point.

This relationship can be eliminated for each zone so that the increased extraction capability is provided in the area of the abrasive article where a greater amount of particulate material is produced so that the constant K remains substantially constant for each zone Effectively determining the amount of particulate material. Overall, this extends beyond the ability to extract both conventional perforated abrasive articles (smaller larger holes) and the more modern so-called "multi-holes" (many smaller perforations) abrasive articles, Improve your ability. This is due to the abrasive article according to the invention having variable hole density, i. E. The number and size of the holes in each zone are different for each zone depending on the relative position of the respective zones.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic cross-sectional view illustrating the construction of an abrasive article suitable for use with any of the embodiments of the present invention. The abrasive article 1 comprises a backing 2 having a first surface 3 and a second surface 4 and a polishing coating 5 on the first surface 3 of the backing 2. The abrasive coating 5 comprises a resin layer 6 in which abrasive particles 7 are dispersed, forming a working surface 8 intended to be used for sanding a workpiece (not shown). An adhesive layer 9, in this example a hook and loop attachment layer, is provided on the second surface of the backing 2. [ This allows the polishing disk to be mounted on a backup pad of a tool (not shown), wherein the tool is provided with dust extraction capabilities. A plurality of holes 10 extending through the backing 2 and the abrasive coating 5 are provided. The plurality of holes 10 also extend through the adhesive layer 9. This enables fluid communication between the work surface 8 and the tool so that dust generated at the work surface 8 by the abrasive article 1 can be extracted from the workpiece through the holes 10 by the tool.

Although the first embodiment of the present invention uses an abrasive disk intended for dust extraction as an example, the same approach may be used for polishing articles of different shapes, or other types of abrasive articles used for particulate extraction, such as wet or wet It should be understood that the invention can be used with dry abrasive articles as well as surfaces. Thus, the use of a polishing disc should not appear to limit the present invention, nor should the use of circular holes. 2 is a schematic view of an abrasive article according to a first embodiment of the present invention. This has the structure shown in Fig. 1 and includes five (first to fifth) zones centered on the center point 12 and concentric with each other, namely A (center 0 - 14 mm radius), B (14 - 28 mm (28 - 42 mm radii), D (42 - 56 mm) and E (56 - 70 mm). The polishing disk had a diameter of 150 mm. A total of 59 holes uniformly distributed around the center point 12 are contained within the disc. The location and size of the holes were determined as follows.

Such a circular polishing disk is intended for use in an orbital sander in which the orbital sander causes the disk to rotate at an angular velocity? Leading to a linear velocity v (where v =? R) and to move the disk in orbit O. Therefore, a uniform arrangement of the holes 10 across the surface of the polishing disk 11 does not allow optimal dust extraction because it will affect the cutting and therefore the rotational speed of the polishing disk 11 and the tool Lt; Desc / Clms Page number 2 > produced by both the orbits produced by the two orbits. The non-uniform distribution will also suffer from the same problem, and thus the adjustment of the hole positions due to the effects of disk rotation and orbits needs to be made. The amount of dust to be extracted will be proportional to the amount of open area, i.e. the surface area of the holes 10 provided over the polishing disk 11. [ In order to determine the surface area of the required holes, the following equation is used:

[Equation 1]

Here, K is a constant, O is an orbit, v is the above linear velocity at the considered point, A _hole is the surface area of the polishing disk 11 occupied by the holes, and A _polishing is the surface area of the remaining polishing disk 11 ). In order to determine the theoretical value of K, an ideal amount of hole area is selected for the polishing disk 11. The hole area was selected to be 10% of the total surface area of the polishing disk 11, and using an orbit of 2.5 mm and a rotational speed of 4000 rpm, the equation (1) was solved to obtain K Respectively. This yielded a value of K of 199. The holes 10 were then selected according to manufacturing constraints to try to reach this theoretical value of K using equation 1 for each zone.

The holes 10 were sized and positioned as follows (all dimensions in mm) as shown in Table 1 below. Holes are located at the edges of each zone, where for each of Zone B, Zone C and Zone D, half of the number of holes in each zone is located on the inner edge of the zone and half is located on the outer edge of the zone And one third of the holes in Zone E were placed on the boundary between Zone D and Zone E. As discussed above, the orbit O used in the calculation was 2.5 mm and the rotational speed o was 4000 rpm. Calculated hole diameters are shown in parentheses in Table 1, and actual hole diameters are also shown:

[Table 1]

Total number of holes: 59

The ratio of the surface area of the polishing disk 11 occupied by the holes to the surface area of the remaining polishing disk 11 was 0.098 (9.8%). The holes 10 were arranged in the respective zones so as to be uniformly distributed around the center point 12 of the polishing disk 11. [ It can be seen that, despite the relaxation of the equation for the required surface area, the manufacturing constraints on hole size and location actually lead to a difference in K values for some zones (hole diameter according to equation (1) In the parentheses, and the actual pore diameter is also shown). A test of the polishing disk 11 was performed to determine whether this had adversely affected performance.

Comparative tests between a polishing disk 11 according to the first embodiment of the present invention and a polishing disk with a diameter of 150 mm and 15 holes and a polishing disk with a diameter of 150 mm and 78 holes were carried out. All three polishing discs were made from 255P abrasive material available from P300 grade as above. The 15-hole disk had a ratio of the surface area of the polishing disk to the surface area of the remaining polishing disk occupied by the holes of 0.062 (6.2%), and that of the 78-hole disk was 0.05 (5%). Each disk included the remaining holes uniformly distributed over the surface of the polishing disk, along with the center hole, as illustrated in Fig.

All tests were performed on a Fanuc Robotics robot using a 150 mm National Detroit Air Powered Sander available from National Detroit, Rockford, North Rock, IL, USA, 61103, USA. . A 600 x 600 mm primer panel was painted with a Standox VOC System filler available from Standox of Wedgewood, Stafford, Hertfordshire, UK, SG1 4QN to a thickness of approximately 100 [mu] m, Weighed, and the weight recorded. Before sanding, the surface of the primer panel was cleaned with a clean tack cloth, and then the sticky cloth was discarded. To begin the test, the robot sanded the surface of the primer panel for 15 seconds in an alternating north-south and east-west direction at an intermediate pressure (5.5 lbs / 2.5 kg). The primer panel was then weighed again and the weight recorded. This was repeated for an additional 45 second period and a 180 second period, after which the panel was weighed after each sanding session. After a 45 second period, the panel was wiped with a second sticky cloth having a known initial weight, and then the second sticky cloth was weighed and placed in an airtight bag. Subsequently, the second sticky cloth was weighed to determine the amount of dust remaining on the panel. By measuring the weight of the primer panel, the total amount of removed material in grams provides the amount of cut, and by measuring the weight of the sticky cloth, the additional weight of dust in grams represents the efficiency of the dust extraction process.

Six individual polishing discs were tested, with all polishing discs at grade P500. Both the 15-hole and the 78-hole polishing discs were unable to align the holes in the 59-hole polishing disc according to the first embodiment of the present invention, while their holes were aligned with the holes in the backup pad. The test results are shown in Table 2 below:

[Table 2]

The 59-hole disk exhibited improvement in both dust extraction and cutting, with less dust remaining on both the 15-hole and 78-hole polishing discs on the surface of the panel after the test. Despite having fewer aligned holes and a smaller total surface area of the abrasive article used exclusively for the holes that enable dust extraction than the 78-hole disk, the 59-hole abrasive article of the present invention And provides better performance.

3 is a schematic view of an abrasive article according to a second embodiment of the present invention. This shows a polishing disk 13 having a central point 14 and being divided into four zones A, B, C, and D, similar to the first embodiment described above. The polishing disk had a diameter of 150 mm. Twenty-one holes 15 were provided using the same methodology above in each zone, as shown in Table 3 below. Initially, Equation 1 was solved to provide the desired surface area of 0.066 (6.6%, same as a conventional 15-hole polishing disk) and a theoretical value of K of 316. The orbit O was 2.5 mm, the velocity ω was 4000 rpm, and all dimensions are in mm units. Using 21 holes in the four zones, the ratio of the surface area of the polishing disk 13 occupied by the holes 15 to the surface area of the remaining polishing disk 13 was 0.068 (6.8%). The pore diameters according to Equation (1) are shown in parentheses in Table 3, and the actual pore diameters are also shown:

[Table 3]

Total number of holes: 21

All tests were carried out in a Fanakrobotics robot using an Elite orbital sander with a theoretical free rotation speed of 12000 rpm and 4000 rpm and a 2.5 mm orbital under loading, available from 3M as above. Backup pads with 51 holes were used. A wood panel (pine) approximately 200 x 400 mm in dimensions was weighed and weighed. Which was then placed on a painted metal panel approximately 600 x 600 mm in size for sanding. Before sanding, the surface of the wood panel and the painted panel on which the wood panel was placed was wiped with a sticky cloth, and the sticky cloth was then discarded. To begin the test, the robot sanded the surface of the wood panel for 2 minutes in an alternating north-south and east-west direction at an intermediate pressure (5.5 lbs / 2.5 kg). The wood panel was then weighed again and the weight recorded. This was repeated for an additional short period and a one minute period. After a total of 5 minutes of sanding, the wood panel was wiped with a second primary lint-free cloth of known initial weight, the painted metal panel was also cleaned with the same lint-free cloth, and then the lint-cloth was placed in an airtight bag for subsequent weighing. The sticky cloth was weighed to determine the amount of dust remaining on the panels. By measuring the weight of the wood panel, the total amount of removed material in grams provides the amount of cut, and the measurement of the weight of the sticky cloth provides the additional weight of the dust in grams remaining in the working area, Efficiency.

This was used to compare the 15-hole disk with the polishing disk 13 according to the second embodiment of the present invention. However, the back-up pad used was a 51-hole back-up pad on which the holes in both the 15-hole polishing disc and the 21-hole polishing disc according to the present invention could be aligned. Again, the ratio of the surface area of the grinding disk to the surface area of the remaining grinding disk occupied by the holes was 0.066 (6.6%) for the 15-hole disk. Both polishing discs were formed from 236 U polishing material available from P320 grade as described above. Five discs of each type were tested. The results of the comparative tests are shown in Table 4 below:

[Table 4]

Again, the polishing disc 13 according to the present invention removed more dust during use than a 15-hole polishing disc. 4 is a schematic view of a 15-hole abrasive 16 and a 78-hole abrasive 17 used in a comparative experiment with the first and second embodiments of the present invention. This illustrates that the present invention provides similar or improved performance when compared to conventional hole patterns and porous abrasive discs, as the ratio between the surface area of the abrasive coating within the zone and the surface area of the holes is optimized for hole size and distribution.

The level of accuracy of the constant K will also be influenced by the method used to form the holes in the abrasive article. For example, with respect to absolute size (minimum radius) or engineering tolerance, there may be some degree of variability in K if there is a limit on the achievable hole size. Thus, if equation (1) is best met by a hole size that is not feasible, a more reasonable hole size may be used. Methods for creating holes in an abrasive article include mechanical punching and cutting using a laser. In addition, it may be desirable to adjust the size of the holes in the abrasive article to form a complete system with the back-up pads. For example, it is convenient to create a 7 mm hole in the abrasive article, but if a backup pad is provided with an alignable 5 mm hole, the entire dust extraction is affected by the 5 mm hole. This will also affect the level of accuracy of the constant K. For example, if Equation 1 predicts an ideal hole size of 4.89 mm as in the second embodiment described above, the use of backup pads with 5 mm holes Has a significant impact on K because it can be effectively assigned to calculations. This provides a K value that is closer to the value predicted by equation (1).

In the example described above, the circular abrasive article is intended for use in situations where dust extraction is required. However, other shapes of abrasive article, such as a sheet having a central point and a peripheral portion, such as a rectangular sheet, may also be formed, because the above equation is based on the distance d from the center, It can be rewritten.

&Quot; (2) "

In the same manner as described with respect to the circular polishing discs of the first and second embodiments of the present invention, the article in this situation is divided into at least two zones that are concentric with each other and with the center point. Each zone has at least one hole, preferably two holes, uniformly distributed around the central point. Each hole has a size and position such that the ratio between the distance of the zone from the center point multiplied by the surface area of the abrasive coating in the zone and the surface area of the holes in the zone is approximately constant for each zone. Thus, in the example above, the abrasive article is a polishing disk, so that the holes are located along the radii of the disk. The trajectory can be a linear translation in the case of a tool used with a polishing sheet, the constant O representing the amplitude of the translational motion. In situations where the abrasive article is used with tools that do not provide trajectory or other translational motion, the constant O may be omitted.

Also, the holes used need not necessarily be circular, but need to be shaped, for example, triangular, square, rectangular, or other polygonal or curved shape to suit their intended use. In the above examples, 21 and 59 holes were used. However, Equations (1) and (2) can be used to position any number of holes as needed. Preferably, it may be from 7 to 100 holes, more preferably from 7 to 30 holes. The sizes of the holes used in the above examples are within the range of 3.5 mm to 10 mm in diameter, but preferably may be 1.0 mm to 25.0 mm in diameter if desired.

The use of hook and loop layers as attachment layers is particularly suitable because it allows both air (thus allowing extraction by vacuum) and dust (of typical particulate size found in sanding) to be deposited with little or no Because it is permeable to pass through without clogging. Other materials that provide similar advantages include brushed nylon. In the above examples, the abrasive coating comprises a resin material in which abrasive particles are dispersed. However, the abrasive coating may comprise other materials, such as grinding aids, other layers, such as a supersize layer, or may be formed from abrasive materials or slurries. Other layers, such as tie-coats or other reinforcing or reinforcing layers, may be provided between the backing and the abrasive coating. If desired, microreplication techniques may be used to form the abrasive coating, or the coating may include an adhesive and various abrasive grains or particles. Suitable backing materials include paper and textiles (both treated and untreated), foams, and other materials commonly used in the manufacture of coated abrasive grains.

In the above examples, the particulates are dust, and the abrasive article is configured for use with the dust extraction equipment. Such equipment may include a vacuum extraction means or a self-generated vacuum extraction means, or may simply rely on a centripetal force to move dust and air away from the surface of the workpiece through the holes. However, other types of particulate extraction can be performed. This is one such situation in which the abrasive is used in a wet or damp state or with a polishing agent and the movement of the tool causes the cutting swarf, paint or other particulate debris to move through the holes in the liquid carrier, .

It may be desirable to include additional zones within the abrasive article. For example, the abrasive article may include a third zone positioned between the first zone and the second zone and free of holes. Alternatively, the abrasive article may include a third zone located between the first zone and the second zone and including at least one hole.

In the above embodiments, the holes 10 and 15 are uniformly distributed around the center point 12. However, this need not be the case. The holes may be distributed in any manner, whether or not forming a regular array or pattern, since the dust extraction performance of the abrasive article is optimized so long as Equations 1 and 2 above are met.

In the above embodiments, at least one additional hole may be provided outside of at least two zones. This may be, for example, a center hole located at the center point. Often, this is required to be aligned with the standard backup pads or other tool attachment means, for example the holes provided on the block for the polishing sheet. Alternatively or additionally, at least one additional hole may be located elsewhere on the abrasive article, e.g., away from the center point. At least two holes in each zone may form an overall asymmetric pattern across the surface of the abrasive article. This may be desirable from an aesthetic point of view, or for ease of manufacture. Alternatively, at least two holes in each zone may form an overall symmetric pattern across the surface of the abrasive article. For example, the arrangement of the holes shown in both the first and second embodiments of the present invention has arms that are approximately helical or distributed in a helical arrangement, which should not be seen as limiting, Will be within the scope of the appended claims any arrangement of holes within each zone satisfying Equations (1) and (2) above.

In the above examples, equations (1) and (2) are applied to abrasive articles, such as abrasive discs and sheets. However, these equations can also be applied to accessories used with such abrasive articles as follows. Although the appendices themselves do not generate dust or other particulate matter in the workpiece, they drive the behavior of the abrasive article, so similar considerations apply. 5 is a schematic cross-sectional view of an adapter for an abrasive article according to a third embodiment of the present invention. This is used to mount an abrasive article, e.g. a polishing disk, on a tool, e.g., a sander. In this example, the adapter is a circular backup pad, but it may alternatively or additionally include an interface pad (disposed between the abrasive article and the backup pad to provide a cushioning effect in use) or other adapter, . The backup pad 18 includes a body 19, a mounting surface 20 configured to attach a polishing article, e.g., a polishing disk 11, 13 as shown in FIGS. 2 and 3, and a tool (not shown) (Not shown). The mounting surface 20 includes a hook material provided on the polishing discs 11 and 13 and a hook material 22 suitable for engaging the loop or bristled nylon layer 9 so that during use the polishing discs 11 and 13 To be firmly attached to the back-up pad 18. The backup pad 18 is provided with a plurality of apertures 23 extending through the mounting surface 20 and through at least a portion of the body 19 and allowing the particulate material to pass through and be extracted. This allows fluid communication between the dust extraction means (not shown) and the surface of the workpiece (also not shown) during use. Thus, dust or other particulate matter generated at the surface of the workpiece during use is removed through the holes 23 in the backup pad.

6 is a schematic plan view of an abrasive article adapter according to a third embodiment of the present invention. The backup pad 18 has a periphery 24 and a center point 25 and is divided into a series of zones A, B, C, D, as well as the abrasive articles described above. Each zone includes at least two apertures uniformly distributed about the center point 15. [ The plurality of holes 23 are arranged as follows. (1) and (2) may be modified to be applied to the backup pad 18 since the backup pad 18 will undergo the same rotation and / or translation or orbital motion as the abrasive article. For circular backup pads:

&Quot; (3) "

Here, K is a constant, O is an orbit, v is the linear velocity as above, A is the surface area of _{the hole} of the backup pad 18 are occupied by holes, A is the surface area of _attachment of the rest of the backup pad. In this situation, the holes are located along the radius of the circular backup pad. For non-circular backup pads, for example sheet holders:

&Quot; (4) "

Here, K is a constant and, O is orbit, d is the surface area of the center point 25, the distance of the holes, the back pad 18 occupy their hole A _hole from, A _attached is the surface area of the rest of the backup pad.

Thus, as in the first and second embodiments discussed above, the mounting surface is divided into at least a first inner zone and a second outer zone, wherein the second zone is concentric with the first zone and the center point. Wherein each zone has at least one hole wherein the sizes of the holes and their total number in each of the first and second zones form a hole density for each such zone and the hole density of the first zone is Is smaller than the hole density in the second zone.

For a circular backup pad, in each zone, each hole has a ratio between the distance of each hole from the center point multiplied by the total surface area of the mounting surface in its respective zone and the total surface area of at least two holes in the respective zone Lt; RTI ID = 0.0 > 1 < / RTI > and the second zones. As described above, K is calculated for the specific hole area required. This ensures that the holes 23 in the polishing discs 11 and 13 or other abrasive articles are completely aligned with the holes 23 in the back-up pads, 11, 13), or on both of the other abrasive articles. Alternatively, the holes 23 may be positioned so that there is no alignment or only partial alignment, or the holes 23 in the back-up pads 18 may be located in the polishing disc 11, 13 or other abrasive article The diameter may be larger or smaller than the holes 10 and 15. Additionally or alternatively, if equations (3) and (4) are also applied to the interface pads, the holes in the interface can be used for both the holes 23 in the backup pad and in any abrasive article mounted on the interface pad Can be similarly adjusted so as not to be aligned or aligned as desired.

In the above example, at least two holes are provided in each zone, and the holes in each zone are evenly distributed around the center point, but only one hole is needed. However, the holes may be distributed in a non-uniform or irregular pattern, similar to the abrasive article described above. For example, holes may be distributed throughout the adapter in an overall asymmetric pattern. This may be true whether the adapter is used with or without an abrasive article according to embodiments of the present invention, or whether the abrasive article has a uniform or non-uniform distribution of holes. The adapter may include a third zone located between the first zone and the second zone and having no holes. Alternatively, the adapter may further include a third zone located between the first zone and the second zone and including at least one hole. This allows for additional freedom in the design of the adapter and overall optimization of the adapter / abrasive article combination. To facilitate this, at least one additional hole may be provided outside of at least two zones. This one additional hole may be a center hole located at the center point, or may be located away from the center point. Preferably, the holes have a diameter in the range of 1.0 mm to 25.0 mm. Preferably, the adapter comprises 7 to 100 holes, more preferably 7 to 30 holes. Preferably, the particulate is dust and the adapter is configured for use with a dust extraction equipment.

Claims (30)

An abrasive article having a center point and a peripheral edge,
An abrasive coating on the surface of the backing and backing and forming a work surface; And
A plurality of apertures extending through the backing and the abrasive coating and allowing the particulate material to pass through and be extracted,
The working surface is divided into at least a first inner zone and a second outer zone, the second zone being concentric with the first zone and the center point,
Each zone having at least one hole and the sizes of the holes and the total number of them in each of the first zone and the second zone form the hole density for that respective zone,
Wherein the hole density of the first zone is less than the hole density of the second zone. 2. The method of claim 1, wherein, in each zone, each of the holes has a ratio between the distance of each hole from a center point multiplied by the total surface area of the polishing coating in its respective zone and the total surface area of at least one hole in the respective zone Having a size and location within their respective zones that are substantially constant with respect to the first zone and the second zone. The abrasive article of claim 1, wherein at least two holes are provided in each zone, and the holes in each zone are uniformly distributed around the center point. The abrasive article of claim 1, in the form of a disk. The abrasive article of claim 1, further comprising a third zone positioned between the first zone and the second zone and free of holes. The abrasive article of claim 1, further comprising a third zone positioned between the first zone and the second zone and including at least one aperture. 5. The abrasive article of claim 4, wherein the holes are located along the radii of the disk. The abrasive article of claim 1, wherein at least one additional hole is provided outside of at least two zones. 9. The abrasive article of claim 8, wherein the at least one additional aperture is a central aperture located at a central point. 9. The abrasive article of claim 8, wherein at least one additional aperture is located away from a center point. The abrasive article of claim 1, wherein at least two holes in each zone form an overall asymmetric pattern across the abrasive article. 12. An abrasive article according to any one of claims 1 to 11, wherein the holes have a diameter in the range of 1.0 mm to 25.0 mm. The abrasive article of claim 1, comprising 7 to 100 holes. The abrasive article of claim 1, comprising 7 to 30 holes. The abrasive article of claim 1, wherein the particulate is dust, and the abrasive article is configured for use with a dust extraction device. An abrasive article adapter having a center point and a peripheral edge,
A body having a mounting surface configured to attach an abrasive article; And
A plurality of holes extending through the body and allowing the particulate material to pass through and be extracted,
The mounting surface is divided into at least a first inner zone and a second outer zone, the second zone being concentric with the first zone and the center point,
Each zone having at least one hole and the sizes of the holes and the total number of them in each of the first zone and the second zone form the hole density for that respective zone,
Wherein the hole density of the first zone is less than the hole density of the second zone. 17. A method according to claim 16, wherein in each zone, each hole has a ratio between the distance of each hole from a center point multiplied by the total surface area of the mounting surface in the respective zone and the total surface area of at least one hole in the respective zone Having a size and location within their respective zones that are substantially constant with respect to the first zone and the second zone. 17. The adapter of claim 16, wherein at least two holes are provided in each zone, wherein the holes in each zone are uniformly distributed about the center point. 17. The adapter of claim 16, in the form of a circular backup pad. 17. The adapter of claim 16, further comprising a third zone positioned between the first zone and the second zone and free of holes. 17. The adapter of claim 16, further comprising a third zone located between the first zone and the second zone and including at least one hole. 20. The adapter as claimed in claim 19, wherein the holes are located along the radius of the circular backup pad. 17. The adapter of claim 16, wherein at least one additional aperture is provided on the exterior of the at least two zones. 24. The adapter of claim 23, wherein the at least one additional hole is a center hole located at a center point. 24. The adapter for an abrasive article of claim 23, wherein at least one additional aperture is located away from a center point. 17. The adapter of claim 16, wherein at least two of the holes in each zone form an overall asymmetric pattern across the adapter. 27. The adapter for an abrasive article according to any one of claims 16 to 26, wherein the holes have a diameter in the range of 1.0 mm to 25.0 mm. 17. The adapter of claim 16, comprising 7 to 100 holes. 17. The adapter of claim 16, comprising 7 to 30 holes. 17. The adapter of claim 16, wherein the particulate is dust and the adapter is configured for use with a dust extraction equipment.

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