CN105324213B

CN105324213B - Coated abrasive article based on sunflower pattern

Info

Publication number: CN105324213B
Application number: CN201480035212.1A
Authority: CN
Inventors: A·赛思
Original assignee: Saint Gobain Abrasifs SA; Saint Gobain Abrasives Inc
Current assignee: Saint Gobain Abrasifs SA; Saint Gobain Abrasives Inc
Priority date: 2013-06-28
Filing date: 2014-06-27
Publication date: 2020-03-24
Anticipated expiration: 2034-06-27
Also published as: EP3013528A4; JP6805292B2; KR101832124B1; JP2019166634A; EP3013528A1; US20150004889A1; KR20160021250A; CA2915506C; JP6588895B2; BR112015031335A2; TWI589404B; CA2915506A1; AU2014302200B2; CN105324213A; JP2016523726A; AU2014302200A1; WO2014210470A1; TW201500148A

Abstract

The present invention relates to an abrasive article having a plurality of abrasive regions arranged in a non-uniformly distributed pattern, wherein the pattern is a helix or phyllotactic, such as a helical lattice, and particularly those patterns described by the Vogel model, such as a sunflower pattern.

Description

Coated abrasive article based on sunflower pattern

Technical Field

The present disclosure relates generally to abrasives, and more particularly to coated abrasive articles having sunflower-based pattern abrasive sections that may be discrete, continuous, semi-continuous, and combinations thereof.

Background

Abrasive articles, such as coated abrasive articles, are used in various industries to abrade a workpiece by hand or by a machine process, such as by lapping, or polishing. Machining with abrasive articles spans a wide industry and consumer range from the optics industry, automotive paint repair industry, and metal fabrication industry to the construction and wood industry. Consumers also typically accomplish machining in domestic applications, for example, by hand or the use of common tools such as orbital polishers (both random and fixed axes) and belt vibratory sanders. In each of these examples, abrasives are used to remove surface materials and affect the surface characteristics (e.g., flatness, surface roughness, gloss) of the abraded surface. In addition, various types of automated processing systems have been developed to abrasively process articles having various compositions and configurations.

Surface characteristics include, among others, shine, texture, gloss, surface roughness, and uniformity. In particular, surface characteristics such as roughness and gloss are measured to determine quality. For example, when coating or painting a surface, certain drawbacks or surface defects may occur during the application or curing process. These surface defects or surface imperfections may include pockmarks, "orange peel" texture, "fish eyes" or encapsulated bubbles and dust defects. Typically, these defects in the painted surface are removed by first sanding with a coarse grit abrasive, followed by sanding with a tapered grit abrasive, and even buffing with a rough or foam pad until the desired smoothness is achieved. Thus, the properties of the abrasive article used generally affect surface quality.

In addition to surface characteristics, the industry is also sensitive to the costs associated with abrasive handling. Factors that affect operating costs include: the speed at which the surface can be prepared, and the cost of the materials used to prepare the surface. Generally, the industry seeks cost-effective materials with high material removal rates.

However, abrasives that exhibit high removal rates often exhibit poor performance in achieving desired surface characteristics. As a result, abrasives that produce desirable surface characteristics often have low material removal rates. For this reason, the preparation of surfaces is often a multi-step process using various grades of abrasive sheets. Typically, surface imperfections (e.g., scratches) introduced by one step are repaired (e.g., removed) in one or more subsequent steps using a tapered grain abrasive. Thus, abrasives that introduce scratches and surface imperfections result in an overall increase in increased time, effort, and material expenditures in subsequent processing steps, as well as overall processing costs.

An additional factor affecting the rate of material removal and surface quality is that the abrasive is "loaded" with "swarf," i.e., material abraded from the surface of the workpiece, which tends to accumulate on the surface of and between abrasive articles. Loading is undesirable because loading generally reduces the effectiveness of the abrasive product and can also adversely affect surface properties by increasing the likelihood of scratch defects.

While various efforts have been made to reduce the accumulation of abrasive dust, such as the introduction of a stroking fluid onto the surface of a workpiece to flush away the abrasive dust, and the application of a vacuum system to carry away the abrasive dust as it is generated, there continues to be a need for improved, cost-effective abrasive articles, processes, and systems that promote effective abrading and improved surface characteristics.

Drawings

The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings.

Fig. 1 is an embodiment of a coated abrasive disc without any porosity and with a controlled uneven distribution of abrasive areas (also called dots) according to the present invention.

Fig. 2 is an illustration of an embodiment of a coated abrasive having abrasive regions in the form of a plurality of spiral arms passing through points conforming to the Vogel model.

Fig. 3 is an illustration of an embodiment of a coated abrasive disk without any apertures and having abrasive areas corresponding to a phyllotactic spiral pattern with clockwise and counterclockwise diagonal lines, specifically a type of spiral lattice, according to the present invention.

Fig. 4 is another illustration of an embodiment of a coated abrasive disk without any apertures according to the present invention having abrasive regions in the form of a phyllotactic spiral pattern of clockwise and counterclockwise diagonal lines.

FIG. 5 is an illustration of another embodiment of a coated abrasive disk according to the present invention having abrasive areas corresponding to a phyllotactic spiral pattern having clockwise and counterclockwise diagonal lines, in particular a type of spiral lattice, in conjunction with circular abrasive areas where the diagonal lines intersect.

FIG. 6 is an illustration of a Vogel model for placement of abrasive regions according to the present invention.

FIG. 7 is another illustration of a Vogel model showing a numerical array of placement of abrasive regions in accordance with the present invention.

Fig. 8A-8C are illustrations of phyllotactic spiral patterns for abrasive region placement on a coated abrasive according to the present invention, the patterns conforming to the Vogel model and having different angles of divergence.

Fig. 9 is an illustration of another embodiment of a coated abrasive disk according to the present invention having circular abrasive areas of various sizes corresponding to abrasive areas having a phyllotactic spiral pattern of clockwise and counterclockwise diagonal lines, in particular a type of spiral lattice, in conjunction with the intersection of the diagonal lines.

FIG. 10 is an illustration of another embodiment of a coated abrasive disk according to the present disclosure having abrasive areas corresponding to a phyllotactic spiral pattern with branched diagonal lines in conjunction with circular abrasive areas of various sizes at the branches of the diagonal lines.

FIG. 11 is an illustration of another embodiment of a coated abrasive disk according to the present disclosure having abrasive areas corresponding to a phyllotactic spiral pattern with branching clockwise diagonal lines in conjunction with circular abrasive areas of various sizes at the diagonal branches.

FIG. 12 is an illustration of another embodiment of a coated abrasive disk according to the present invention having abrasive areas corresponding to a phyllotactic spiral pattern having branching clockwise and counterclockwise diagonal lines in conjunction with circular abrasive areas of various sizes at the branches of the diagonal lines.

FIG. 13 is an illustration of another embodiment of a coated abrasive disk according to the present disclosure having abrasive areas corresponding to a phyllotactic spiral pattern with branched diagonal lines in conjunction with circular abrasive areas of various sizes at the branches of the diagonal lines.

FIG. 14 is an illustration of another embodiment of a coated abrasive disk according to the present disclosure having abrasive areas corresponding to a phyllotactic spiral pattern with branched diagonal lines in conjunction with circular abrasive areas of various sizes at the branches of the diagonal lines.

FIG. 15 is a graphic image of an embodiment of an abrasive area pattern having 148 abrasive areas according to the present invention.

Fig. 16 is an illustration of an embodiment of an alternative abrasive pattern that is a transpose of the abrasive pattern of fig. 15, in accordance with the present invention.

Fig. 17 is an illustration of an embodiment of abrasive regions in the form of spirals and arcs based on the pattern of fig. 16.

FIG. 18 is a graphic image of an exemplary embodiment of an abrasive area pattern having 344 abrasive areas according to the present invention.

FIG. 19 is an illustration of an exemplary embodiment according to the present invention as a transpose of the abrasive area pattern of FIG. 18.

FIG. 20 is an illustration of an exemplary embodiment according to the present invention as a backup pad in cooperation with the aperture pattern of FIG. 19.

FIG. 21 is a cross-sectional view of an embodiment of a coated abrasive according to the present invention.

The use of the same reference symbols in different drawings indicates similar or identical items.

Detailed Description

In one embodiment, an abrasive article includes a coated abrasive having a plurality of abrasive regions arranged in a pattern having a controlled non-uniform distribution. The pattern can be any pattern with controlled non-uniform distribution, including a radial pattern, a spiral pattern, a phyllotactic pattern, an asymmetric pattern, or a combination thereof. An example of a combined pattern is a spiral lattice pattern. The pattern may be partially, substantially or completely asymmetric. The pattern may cover (i.e., be distributed over) the entire abrasive article, may cover substantially the entire abrasive article (i.e., greater than 50% but less than 100%), may cover multiple portions of the abrasive article, or may cover only a portion of the abrasive article.

Controlled "non-uniform distribution" means that the pattern has a controlled asymmetry (i.e., controlled randomness) such that, although the distribution of abrasive regions can be described or predicted by radial, spiral, or phyllotactic equations, for example, the pattern exhibits at least partial to complete asymmetry.

The controlled asymmetry may be a controlled reflection asymmetry (also referred to as mirror symmetry, line symmetry, and bilateral symmetry), a controlled rotation asymmetry, a controlled translation symmetry, a controlled slip reflection symmetry, or a combination thereof. An example of an uneven distribution may be demonstrated for a radial, spiral, or phyllotactic pattern with rotational symmetry of first order, meaning that this pattern does not have rotational symmetry because the pattern repeats itself only once during a 360 ° rotation around its center. In other words, if two copies of the same exact pattern are disposed directly over each other and one copy remains constant while the second copy is rotated 360 ° about its center, all abrasive areas of the two copies are aligned only once during the 360 ° rotation.

Typically, all of the abrasive areas of the pattern (i.e., the entire pattern) are smoothed with a controlled asymmetry. However, it is contemplated that patterns according to embodiments of the present invention also include the following patterns: wherein only a portion of the total abrasive area of the pattern (i.e., a portion of the pattern) possesses a controlled asymmetry. This may occur, for example, by combining a portion or fully random pattern of a uniformly distributed pattern with a controlled non-uniform distributed pattern or stroking a portion or fully random pattern of a uniformly distributed pattern instead of a controlled non-uniform distributed pattern such that only a portion of the abrasive area of the resulting pattern has a controlled non-uniform distribution. The portion of the total abrasive area having controlled non-uniformity can be quantified as a discrete number, or a fraction, percentage, or ratio of the total number of abrasive areas of the pattern. In an embodiment, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, at least 99.5%, at least 99.9% of the abrasive regions of the pattern possess a controlled asymmetry. The portion of the abrasive region of the pattern possessing the controlled asymmetry can be within a range including any pair of the previous upper and lower limits. In particular embodiments, about 50% to about 99.9%, about 60% to about 99.5%, about 75% to about 99% of the pattern possesses a controlled non-uniform distribution.

In another embodiment, the pattern possesses a controlled asymmetry over at least about 5 abrasive regions, at least about 10 abrasive regions, at least about 15 abrasive regions, at least about 20 abrasive regions, at least about 25 abrasive regions, or at least about 50 abrasive regions. In another embodiment, the pattern possesses a controlled asymmetry over no greater than about 100,000 abrasive regions, no greater than about 10,000 abrasive regions, no greater than about 5,000 abrasive regions, no greater than about 2,500 abrasive regions, no greater than about 1,000 abrasive regions, no greater than about 750 abrasive regions, or no greater than about 500 abrasive regions. The number of abrasive regions possessing a controlled asymmetry can be within a range including any pair of the previous upper and lower limits.

As described above, the pattern of embodiments of the present invention may be any pattern with a controlled non-uniform distribution, including a radial pattern, a spiral pattern, a phyllotactic pattern, an asymmetric pattern, or a combination thereof. An example of a combined pattern is a spiral lattice pattern. It is recognized that the spiral lattice pattern can be classified as a radial pattern, a spiral pattern, a phyllotactic pattern, and an asymmetric pattern. The radial pattern may be any pattern that appears to radiate from a central point, such as spokes radiating from the hub of a wheel.

In an embodiment, the spiral pattern may be any curve or collection of curves radiating from a central point on the abrasive article and extending progressively farther apart as it rotates about the central point. The center point may be located at or near the center of the abrasive article, or alternatively, away from the center of the abrasive article. There may be a single helix or multiple helices (i.e., multiple helices). The spirals may be discrete or continuous, separate or combined. The separate spirals may radiate from different central points (i.e., each spiral has its own central point), may radiate from a common central point (i.e., each spiral shares a central point), or a combination thereof. The spiral pattern may include: an archimedean screw; euler spiral, cowy spiral, or gyroid spiral; a Fermat spiral; a hyperbolic spiral; a chain spiral; a logarithmic spiral; fibonacci helices; a golden spiral; or a combination thereof.

In one embodiment, the pattern may be a phyllotactic pattern. As used herein, "phyllotactic pattern" means a pattern associated with phyllotaxis. Phyllotaxis is the arrangement of lateral organs such as leaves, flowers, scales, florets and seeds in many kinds of plants. Many phyllotactic patterns are characterized by naturally occurring phenomena with distinct patterns of arcs, spirals, and threads. The pattern of seeds in the head of a sunflower is an example of this phenomenon. As shown in fig. 3 and 4, multiple arcs or spirals, also referred to as skew lines, may have their origin at a center point (C) and travel outward while other spirals originate to fill the gaps left by the inner spiral. See Jean for "phyllotaxy: systematic study of plant morphogenesis [ page 17 ]. The spiral pattern arrangement can often be considered as radiating outward in both clockwise and counterclockwise directions. As shown in fig. 4, these types of patterns have distinctly opposite diagonal pairs, which may be represented by (m, n), where the number of spirals or arcs radiating in a clockwise direction at a distance from the center point is "m" and the number of spirals or arcs radiating in a counter-clockwise direction is "n". Further, the angle between two consecutive spirals or arcs at their center is referred to as the divergence angle "d". The inventors have surprisingly found that phyllotactic patterns are useful for creating new patterns for abrasive articles, particularly coated abrasive articles.

In an embodiment, the pattern has a number of clockwise spirals and a number of counter-clockwise spirals, wherein the number of clockwise spirals and the number of counter-clockwise spirals are fibonacci numbers or multiples of fibonacci numbers. In a particular embodiment, the number of clockwise spirals and the number of counter-clockwise spirals are, as a pair (m, n): (3, 5), (5, 8), (8, 13), (13, 21), (21, 34), (34, 55), (55, 89), (89, 144) or multiples of these pairs. In another embodiment, the number of clockwise spirals and the number of counter-clockwise spirals are the lucas number or a multiple of the lucas number. In a particular embodiment, the number of clockwise spirals and the number of counter-clockwise spirals are, as a pair (m, n): (3, 4), (4, 7), (7, 11), (11, 18), (18, 29), (29, 47), (47, 76) or (76, 123) or multiples of these pairs. In another embodiment, the number of clockwise spirals and the number of counterclockwise spirals are any number that converges on the golden ratio equal to the sum of the square root of 1 plus 5 divided by 2: (1 + √ 5)/2, which is equal to about 1.6180339887. In a particular embodiment, the ratio of the clockwise spiral to the counterclockwise spiral is approximately equal to the golden ratio.

As already mentioned above, it has essentially been observed that the seeds of sunflower plants are arranged in a helical phyllotactic pattern. In one embodiment, the pattern is a sunflower pattern.

Sunflower patterns have been described by a Vogel model, which is a type of "fibonacci spiral" or spiral in which the divergence angle between successive points is a fixed fibonacci angle close to the golden angle equal to 137.508 °.

Fig. 6 and 7 illustrate the Vogel model, which is:

(equation 1)

Wherein:

n is the serial number of the florets, counting from the center outwards;

is the angle between the reference direction and the position vector of the nth floret in the polar coordinate system originating at the center of the capitalized inflorescence, such that the divergence angle α between the position vectors of any two consecutive florets is constant and at 137.508 ° with respect to the sunflower pattern;

r is the distance from the center of the capitate inflorescence and the center of the nth floret; and

c is a constant scaling factor.

In an embodiment, the pattern is described by a Vogel model or a variation of a Vogel model. In a particular embodiment, the pattern is described by a Vogel model, wherein:

n is the number of abrasive regions, counting outward from the center of the pattern;

is the angle between the reference direction and the position vector of the nth abrasive region in the polar coordinate system originating at the center of the pattern, such that the divergence angle between the position vectors of any two consecutive abrasive regions is a constant angle α;

r is the distance from the center of the pattern to the center of the nth abrasive region;

and c is a constant scaling factor.

As described above, stroking describes all, substantially all, or a portion of the abrasive area of the pattern by (i.e., conforming to) a Vogel model. In one embodiment, the entire abrasive area of the pattern is described by a Vogel model. In another embodiment, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 99% of the abrasive area is described by a Vogel model.

In another embodiment, a suitable spiral or phyllotactic pattern may be generated from the x and y coordinates of any phyllotactic pattern, such as a Vogel model or other suitable pattern with controlled non-uniform distribution, including radial patterns, spiral patterns, phyllotactic patterns, asymmetric patterns, or combinations thereof. In one embodiment, the x and y coordinates of the spiral or phyllotactic pattern are transposed and rotated to determine the x 'and y' coordinates of the spiral or phyllotactic pattern, where θ is equal to π/n (in radians) and n is any integer according to the following equation:

the generated transposed and rotated coordinates (x 'and y') may be rendered, for example, by using Computer Aided Drafting (CAD) software to generate a spiral or phyllotactic pattern. A particular embodiment of a transposed phyllotactic pattern is shown in fig. 16 and 19, fig. 16 being a transpose of the phyllotactic pattern of fig. 15, and fig. 19 being a transpose of the phyllotactic pattern of fig. 18.

The inventors have surprisingly discovered that phyllotactic patterns are useful for creating new patterns that improve the performance of abrasive articles, including fixed abrasive articles, such as bonded abrasive articles and coated abrasive articles. In particular, phyllotactic patterns are useful for creating new abrasive area patterns for coated abrasive articles. The phyllotactic pattern helps solve the competing problems of achieving high removal rates of the surface material while still achieving acceptable surface quality, reducing the amount of abrasive dust loading on the abrasive surface, and maintaining high durability and long service life of the abrasive. This is partly surprising in at least the following respects. First, the phyllotactic pattern of the present embodiments unexpectedly provides an improvement in superior chip removal coverage and a more complete hybrid distribution of chip extraction sites (e.g., open areas, passages, and/or channels) and abrasive regions (e.g., in the form of individual abrasive dots, elongated nodes, semi-continuous arcs, threads, spirals, and combinations thereof, as described and shown herein) on the face of the abrasive, even when the total abrasive area is less than that of the prior art pattern. Second, the phyllotactic patterns of the present examples unexpectedly provide at least equivalent superior abrasive performance (e.g., cumulative material cut) with and without the application of vacuum, even when the total abrasive area is less than that of the prior art patterns. Third, as discussed in more detail later in this application, the effectiveness and performance of embodiments of the present invention may be even further enhanced when paired with a cooperating backup pad and vacuum system.

As can be appreciated, important aspects of pattern design for coated abrasive articles include: the percentage of total abrasive surface area, the ratio of total abrasive surface area to open area, the predicted location and extent of coverage of the abrasive region when the abrasive article is in use (e.g., rotational movement in an orbital sander, oscillating movement in a sheet sander, continuous lateral movement in a belt sander), the scaling factor, the number of abrasive regions, the angle of divergence between the abrasive regions, the size and shape of the abrasive region, the distance between adjacent abrasive regions, and the distance between the outermost abrasive region and one or more edges of the coated abrasive article.

Size of abrasive disk

Abrasives of various sizes are commonly used by industry and commercial consumers, typically ranging from about a few tenths of an inch in diameter to several feet in diameter. The patterns of the present invention are suitable for use on most any size abrasive, including various standard size abrasive discs (e.g., 3 inches to 20 inches). In one embodiment, the abrasive article is a circular disc having a diameter of at least about 0.25 inches, at least about 0.5 inches, at least about 1.0 inches, at least about 1.5 inches, at least about 2.0 inches, at least about 2.5 inches, or at least about 3.0 inches. In another embodiment, the abrasive article is a circular disc having a diameter of no greater than about 72 inches, no greater than about 60 inches, no greater than about 48 inches, no greater than about 36 inches, no greater than about 24 inches, no greater than about 20 inches, no greater than about 18 inches, no greater than about 12 inches, no greater than about 10 inches, no greater than about 9 inches, no greater than about 8 inches, no greater than about 7 inches, or no greater than about 6 inches. In another embodiment, the abrasive article ranges in size from about 0.5 inches in diameter to about 48 inches in diameter, about 1.0 inch in diameter to about 20 inches in diameter, and about 1.5 inches in diameter to about 12 inches in diameter.

Total potential surface area

The size and shape of the abrasive article determines the total potential surface area of the abrasive article. For example, a 1 inch diameter abrasive disc has a total potential surface area of 0.7854 square inches. As another example, a rectangular sheet of abrasive material measuring 2 inches by 3 inches has a total potential surface area of 6 square inches.

Total open area

The total open area affects the amount of abrasive dust extracted. Generally, as the amount of open area increases, the amount of swarf extraction also increases, which tends to maintain or sometimes improve the material removal rate (i.e., "cut" rate) of the abrasive article during use. However, increasing the amount of open area also directly decreases the amount of available abrasive area, which somewhat slows down the material removal rate. In one embodiment, the total open area is equal to the sum of the areas of all open areas on the face of the abrasive article. In other words, the total open area is equal to the total potential surface of the abrasive article minus the total abrasive area (i.e., the sum of all abrasive areas). Thus, depending on the amount of abrasive area desired, the total amount of open area can range from about 15% to about 95.5% of the total potential surface area. In an embodiment, the total open area is at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, or at least about 80% of the total potential surface area of the abrasive article. In another embodiment, the total open area is not greater than about 95.5%, not greater than about 95%, not greater than about 94.5%, not greater than about 94%, not greater than about 93.5%, not greater than about 93%, not greater than about 92.5%, not greater than about 92%, not greater than about 91.5%, not greater than about 91%, not greater than about 90.5%, or not greater than about 90%. The amount of total open area can be within a range including any pair of the previous upper and lower limits. In another embodiment, the total open area ranges from about 65% to about 93%, about 70% to about 92%, about 75% to about 91%, or about 80% to about 90%. The total open area may be considered a discrete amount rather than a percentage. For example, a five inch abrasive disc may have a total open area ranging from about 2.95 square inches to about 18.75 square inches.

Total abrasive surface area

The total abrasive surface area affects the amount of surface material removed. Generally, as the total abrasive surface area increases, the amount of surface material removed increases. Also, in general, as the amount of surface material removed increases, the tendency for swarf to build up increases and the surface roughness tends to increase. In one embodiment, the total abrasive surface area of the coated abrasive is equal to the total potential surface of the abrasive article (i.e., the abrasive surface area if no pores are present) minus the total open area (i.e., the sum of all open areas). Thus, depending on the amount of open area desired, the amount of total abrasive surface area may range from about 4.5% to about 85% of the total potential surface area. In an embodiment, the total abrasive area is at least about 4%, at least about 4.5%, at least about 5%, at least about 5.5%, at least about 6%, at least about 7.5%, at least about 8%, at least about 8.5%, at least about 9%, at least about 9.5%, or at least about 10% of the total potential surface area of the abrasive article. In another embodiment, the total abrasive area is not greater than about 85%, not greater than about 80%, not greater than about 75%, not greater than about 70%, not greater than about 65%, not greater than about 60%, not greater than about 55%, not greater than about 50%, not greater than about 45%, not greater than about 40%, not greater than about 35%, not greater than about 30%, not greater than about 25%, or not greater than about 20%. The amount of total abrasive area can be within a range including any pair of the previous upper and lower limits. In another embodiment, the total abrasive area ranges from about 7% to about 35%, about 8% to about 30%, about 9% to about 25%, or about 10% to about 20%. The total abrasive area may be considered a discrete amount rather than a percentage. For example, a 5 inch disk may have a total abrasive surface area ranging from about 0.88 square inches to about 16.69 square inches.

Ratio of total abrasive surface area to total open area

In one embodiment, the ratio of total abrasive surface area to total open area is at least about 1: 199, at least about 1: 99, at least about 1: 65.7, at least about 1: 49, at least about 1: 39, at least about 1: 29, at least about 1: 19, or at least about 1: 9. In another embodiment, the ratio of total abrasive surface area to total open area is not greater than about 1: 0.05, not greater than about 1: 0.1, not greater than about 1: 0.2, not greater than about 1: 0.3, not greater than about 1: 0.4, not greater than about 1: 0.5, not greater than about 1: 0.6, not greater than about 1: 0.7, not greater than about 1: 0.8, not greater than about 1: 0.9, or not greater than about 1: 1. The ratio of total abrasive surface area to total open area can be within a range including any pair of the previous upper and lower limits.

Number of abrasive regions

The number of abrasive regions affects the total amount of open area and the total amount of abrasive area. In addition, the number of abrasive areas affects the density and distribution of abrasive coverage on the surface of the abrasive article, which in turn directly affects the surface material removal rate and swarf extraction efficiency of the abrasive article. In an embodiment, the number of abrasive regions is at least about 5, at least about 10, at least about 15, at least about 18, or at least about 21. In another embodiment, the number of abrasive regions is not greater than about 100,000, not greater than about 50,000, not greater than about 10,000, not greater than about 1,000, not greater than about 800, not greater than about 750, not greater than about 600, or not greater than about 550. The number of abrasive regions can be within a range including any pair of the previous upper and lower limits. In another embodiment, the number of abrasive regions ranges from about 21 to about 10,000, about 25 to about 1,000, about 30 to about 750, or about 35 to about 550. In particular embodiments, the number of abrasive regions is in a range of about 21 to about 550.

Divergence angle

The divergence angle is 137.3 ° for fig. 8a, 137.5 ° for fig. 8c, 137.6 ° for one embodiment, the divergence angle is at least about 30 °, at least about 45 °, at least about 60 °, at least about 90 °, or at least about 120 ° for another embodiment, the divergence angle is less than 180 °, such as not greater than about 150 °, the divergence angle may be within a range including any pair of the previous upper and lower limits, in another embodiment, the range of divergence angles is from about 90 ° to about 179 °, about 120 ° to about 150 °, about 130 ° to about 139 °, or about 135 ° to about 137 °, in a particular embodiment, the divergence angle is determined by the divergence ratio of 360 ° to 360 ° in a particular range, such as 360.32 ° to 360 ° in a particular range, 360 ° to 360.6 ° to 360 ° in a particular range, such as 360.6 ° to 360 ° to 360.2 ° to 360 ° in a particular embodiment.

Distance from edge of abrasive

Depending on the geometry of the abrasive article and its intended use, the overall dimensions of the pattern may be determined. The distance from the center of the pattern to the outermost abrasive region may extend to a distance contiguous with the edge of the abrasive article. Thus, the edge of the outermost abrasive region may extend to or intersect the edge of the abrasive article. Alternatively, the distance from the center of the pattern to the outermost abrasive region may extend to a distance that allows a certain amount of space between the edge of the outermost abrasive region and the edge of the abrasive article to be free of abrasive regions. The minimum distance from the edge of the outermost abrasive region can be specified as desired. In one embodiment, the minimum distance from the edge of the outermost abrasive region to the outer edge of the abrasive article is a particular distance, identified as a discrete length or as a percentage of the length of the face of the abrasive article in which the pattern appears. In an embodiment, the minimum distance from the edge of the outermost abrasive region to the outer edge of the abrasive article may be at least about zero (i.e., the edge of the outermost abrasive region intersects or is continuous with the edge of the abrasive article) to about 15% of the length of the face of the abrasive article.

Size of abrasive region

The size of the abrasive region is determined, at least in part, by the total amount of abrasive area desired for the abrasive article. The size of the abrasive region may be constant throughout the pattern, or may vary within the pattern. In one embodiment, the size of the abrasive area is constant. In another embodiment, the size of the abrasive region varies with the distance of the abrasive region from the center of the pattern.

Scaling factor

The scaling factor affects the overall size and dimensions of the pattern. The scaling factor may be adjusted such that the edge of the outermost abrasive region is within a desired distance of the outer edge of the abrasive article.

Distance between nearest adjacent abrasive regions

Along with considerations of the number and size of abrasive regions, the distance between the centers of nearest adjacent abrasive regions may be determined. The distance between the centers of any two abrasive regions varies with other design considerations. In an embodiment, the shortest distance between the centers of any two abrasive regions never repeats (i.e., the center-to-center spacing is never exactly the same distance). This type of spacing is also an example of controlled asymmetry.

Pattern coverage-acceptable outliers

As can be appreciated, the pattern need not be applied to the abrasive article in its entirety or in a continuous manner. Portions of the pattern may be applied or skipped so that the various sections or sectors of the face of the abrasive article do not carry the entire pattern. In one embodiment, one-half, one-third, one-fourth, one-fifth, one-sixth, one-seventh, one-eighth, one-ninth, or one-tenth of the pattern may be skipped. In another embodiment, the pattern may be applied to only one or more concentric annular regions of the abrasive article. In another embodiment, it is possible to skip one or more of the abrasive regions that typically occur in a series of abrasive regions along an individual arc or spiral arm of the pattern. In an embodiment, every nth or multiple of nth abrasive region may be skipped. In another embodiment, individual abrasive regions, groups of abrasive regions, or abrasive regions according to a particular numerical progression may be skipped. Conversely, it is also possible to incorporate a certain amount of additional abrasive area into the pattern. The addition or subtraction of abrasive areas may be considered an anomaly of the pattern, and a certain amount of anomaly (positive or negative) of the pattern may be acceptable. In an embodiment, the acceptable amount of anomalies of the pattern may range from 0.1% to 10% of the total abrasive area of the abrasive article.

Shape of abrasive region

The amount of coverage can be affected by the shape of the abrasive region. The abrasive regions may be regular or irregular in shape. In one embodiment, the shape of the abrasive region may be in the form of: a stub, a regular polygon, an irregular polygon, an ellipsoid, a circle, an arc, a spiral, a thread, a lattice, or a combination thereof. In particular embodiments, the abrasive region has a circular shape. In another embodiment, the shape of the abrasive region may be in the form of one or more lines, arcs, spirals, or convolutions having a controlled non-uniform distribution as described herein. The one or more lines, arcs, spirals, or convolutions may have a plurality of line intersections.

The abrasive region can be configured such that adequate removal of swarf can occur with or without the addition of a vacuum to the back of the abrasive article. In one embodiment, the abrasive region is in the form of a helical or diagonal line extending radially outward from the center of the abrasive article. The helical or diagonal lines may be configured to create air flow channels in the open areas between the abrasive regions. In another embodiment, the abrasive regions are formed to resemble a spiral lattice. The pores may be located within an open area enclosed by the lattice. It is believed that the presence of open areas in fluid connection with the outer edge of the abrasive article or with the apertures in the abrasive article open to the vacuum source, or both, facilitates removal of the swarf. These abrasive areas and open areas configured to create airflow paths channel the abrasive dust such that it is ejected from the abrasive areas by centrifugal force or directly into the pores of the vacuum system, thus preventing the entrainment of abrasive dust in the abrasive areas on the face of the abrasive article and any open fiber layers (e.g., layers of hook and loop material) that may be attached to the back side of the abrasive article.

In an embodiment, the pattern of abrasive regions may comprise regular polygons, irregular polygons, ellipsoids, arcs, spirals, phyllotactic patterns, or combinations thereof. The pattern of abrasive regions may comprise radiating arcs, radiating spirals, or a combination thereof. The pattern of abrasive regions may comprise a combination of inner and outer radiating spirals. The pattern of abrasive regions may comprise a combination of clockwise radiating spirals and counterclockwise radiating spirals. The abrasive regions may be discrete or discontinuous from one another. Alternatively, one or more of the abrasive regions may be fluidly connected.

The number of radiating arcs, radiating spirals, or combinations thereof may vary. In an embodiment, the number of radiating arcs, radiating spirals, or a combination thereof can be no greater than 1000, such as no greater than 750, no greater than 500, no greater than 250, no greater than 100, no greater than 90, no greater than 80, or no greater than 75. In an embodiment, the number of radiating arcs, radiating spirals, or a combination thereof may be no less than 2, such as no less than 3, no less than 5, no less than 7, no less than 9, no less than 11, no less than 15, or no less than 20. In an embodiment, the number of radiating arcs, radiating spirals, or a combination thereof may be from 2 to 500, such as from 2 to 100.

The width of the abrasive region can vary. The width of the abrasive region may be constant or varying or a combination thereof. In one embodiment, the width of the abrasive region may be in the range of a fixed length. In one embodiment, the width of the abrasive region may vary from 0.1mm to 10 cm. In another embodiment, the width of the abrasive region is related to the desired size of the adjacent open area of the abrasive article. In an embodiment, the width of the abrasive region is not less than 1/10, for example, not less than 1/8, 1/6, 1/5, 1/4, 1/3, or 1/2, the size of the open area of the coated abrasive. In an embodiment, the width of the abrasive region is no greater than 10 times the size of the open area of the coated abrasive, such as no greater than 8 times, no greater than 6 times, no greater than 5 times, no greater than 4 times, no greater than 3 times, no greater than 2 times the size of the open area of the coated abrasive. In one embodiment, the width of the abrasive region is approximately equal to the size of the open area of the coated abrasive.

In another embodiment, the abrasive region can be shaped and configured to form a plurality of airflow paths disposed in a pattern. The pattern of airflow paths may include regular polygons, irregular polygons, ellipsoids, arcs, spirals, phyllotactic patterns, or combinations thereof. The pattern of air flow paths may comprise a radiating arcuate path, a radiating helical path, or a combination thereof. The pattern of air flow paths may comprise a combination of inner and outer radiating spiral paths. The pattern of air flow paths may comprise a combination of clockwise radiating spiral paths and counter-clockwise radiating spiral paths. The airflow paths may be discrete or discontinuous from one another. Alternatively, one or more of the airflow paths may be fluidly connected.

The number of radiating arc-shaped paths ("arcs"), radiating spiral paths, or combinations thereof may vary. In an embodiment, the number of radiating arc-shaped paths, radiating spiral paths, or a combination thereof may be no greater than 1000, such as no greater than 750, no greater than 500, no greater than 250, no greater than 100, no greater than 90, no greater than 80, or no greater than 75. In an embodiment, the number of radiating arc-shaped paths, radiating spiral paths, or a combination thereof may be no less than 2, such as no less than 3, no less than 5, no less than 7, no less than 9, no less than 11, no less than 15, or no less than 20. In an embodiment, the number of radiating arc-shaped paths, radiating spiral paths, or a combination thereof may be 2 to 500, such as 2 to 100.

The width of the airflow path may vary. The width of the airflow path may be constant or varying or a combination thereof. In an embodiment, the width of the airflow path may be in the range of a fixed length. In an embodiment, the width of the airflow path may vary from 0.1mm to 10 cm. In another embodiment, the width of the air flow path is related to the size of the coated abrasive area. In an embodiment, the width of the air flow path is no less than 1/10, for example, no less than 1/8, 1/6, 1/5, 1/4, 1/3, or 1/2, the size of the abrasive region of the coated abrasive. In an embodiment, the width of the air flow path is no greater than 10 times the size of the abrasive area of the coated abrasive, such as no greater than 8 times, no greater than 6 times, no greater than 5 times, no greater than 4 times, no greater than 3 times, no greater than 2 times the size of the abrasive area of the coated abrasive. In one embodiment, the width of the air flow path is approximately equal to the size of the abrasive area of the coated abrasive.

The air flow path may have one or more cavities, apertures, passages, holes, openings, or combinations thereof disposed along or within the air flow path that extend through the body of the abrasive article. In one embodiment, each air flow path has at least one hole disposed therein extending through the body of the abrasive article.

Shape and construction of abrasive articles

The shape of the abrasive article can be any shape that accommodates the desired pattern of abrasive areas and is dictated by the given abrasive construction process and material. In one embodiment, the abrasive article is a bonded abrasive article. In one embodiment, the abrasive article is a coated abrasive article. In particular embodiments, the abrasive article is one of a sheet, a belt, or a circular disc.

FIG. 1 shows a top view of an embodiment of a coated abrasive article 100, the coated abrasive article 100 having a plurality of abrasive regions 101 arranged in a pattern having a non-uniform distribution, wherein the pattern is a phyllotactic spiral pattern (commonly referred to as a "sunflower" pattern) conforming to the Vogel model. The open area 103 surrounds the abrasive area. The coated abrasive is in the shape of a substantially planar (i.e., substantially flat) circular disc.

Fig. 21 shows a side view of a coated abrasive article 2100, the coated abrasive article 2100 comprising a backing 2101 having a first major surface 2103 and a second major surface 2105. Abrasive layer 2107 is disposed on the first major surface of the backing. The abrasive layer may include multiple layers, including a binder layer 2109, also referred to as a primer coat. The plurality of abrasive particles 2111 can be dispersed within, impregnated into, or rest on the binder layer, or a combination thereof. A pattern of abrasive regions 2113 is present on the surface of the backing. One or more open areas 2115 are stroked adjacent to the abrasive region. A size coating 2117 may optionally be disposed on the adhesive layer. A top size coat 2119 may optionally be disposed over the size coat. The back coating 2121 can be disposed on a second major surface (i.e., non-abrasive side) of the backing layer. The fastening layer 2123 may be disposed on the back coating, or alternatively may be disposed directly onto the second major side of the backing. In particular embodiments, the coated abrasive article 2100 may optionally be attached to a backup pad (not shown) or a vacuum system (not shown).

Back lining

The backing may be flexible or rigid. The backing can be made of any number of various materials, including those conventionally used as backings in the manufacture of coated abrasives. An exemplary flexible backing includes: a polymeric film (e.g., a primer film), such as a polyolefin film (e.g., polypropylene comprising biaxially oriented polypropylene), a polyester film (e.g., polyethylene terephthalate), a polyamide film, or a cellulose ester film; a metal foil; a net; foams (e.g., natural sponge materials or polyurethane foams); cloth (e.g., cloth made of fibers or yarns including polyester, nylon, silk, cotton, polyester cotton, or rayon); paper; vulcanized paper; vulcanized rubber; vulcanizing the fiber; a non-woven material; combinations thereof; or a treated version thereof. The cloth backing may be woven or stitch bonded. In particular examples, the backing is selected from the group consisting of: paper, polymeric film, cloth, cotton, polyester cotton, rayon, polyester, vulcanized rubber, vulcanized fiber, metal foil, and combinations thereof. In other examples, the backing comprises a polypropylene film or a polyethylene terephthalate (PET) film.

The backing may optionally have at least one of a saturant, pre-size layer, or back size layer. The purpose of these layers is usually to seal or protect the yarns or fibers in the backing. At least one of these layers is typically used if the backing is a cloth material. The addition of the pre-size layer or the backsize layer may additionally result in a "smoother" surface on the front or back side of the backing. Other optional layers known in the art may also be used (e.g., tie layers; see U.S. patent No. 5,700,302(Stoetzel et al), the disclosure of which is incorporated herein by reference).

The cloth treatment material may include an antistatic material therein. The addition of an antistatic material may reduce the tendency of the coated abrasive article to accumulate static electricity when sanding wood or wood-like materials. Additional details regarding antistatic backings and backing treatments can be found, for example, in U.S. patent nos. 5,108,463(Buchanan et al), 5,137,542(Buchanan et al), 5,328,716(Buchanan), and 5,560,753(Buchanan et al), the disclosures of which are incorporated herein by reference.

The backing may be a fiber reinforced thermoplastic such as described in U.S. Pat. No. 5,417,726(Stout et al), or an endless, endless belt such as described in U.S. Pat. No. 5,573,619(Benedict et al), the disclosure of which is incorporated herein by reference. Likewise, the backing may be a polymeric substrate having hook stems protruding therefrom, such as described in U.S. Pat. No. 5,505,747(Chesley et al), the disclosure of which is incorporated herein by reference. Similarly, the backing may be an endless fabric such as described in U.S. Pat. No. 5,565,011(Follett et al), the disclosure of which is incorporated herein by reference.

Abrasive layer

The abrasive layer may be formed from one or more coatings and a plurality of abrasive particles. For example, the abrasive layer comprises primer coat _09 and can optionally comprise a size coat or a supersize coat. The abrasive layer typically comprises abrasive particles disposed on, embedded within, dispersed within, or a combination thereof.

Abrasive particles

The abrasive particles may comprise essentially single phase inorganic materials such as alumina, silicon carbide, silica, ceria, and harder high performance superabrasive particles such as cubic boron nitride and diamond. Additionally, the abrasive particles may comprise a composite particulate material. These materials may comprise aggregates which may be formed by a slurry treatment route which comprises removal of the liquid carrier by volatilization or evaporation, leaving a green aggregate, optionally followed by high temperature treatment (i.e., firing) to form a usable fired aggregate. Further, the abrasive region can comprise an engineered abrasive comprising a macrostructure and a particular three-dimensional structure.

In an exemplary embodiment, abrasive particles are blended with a binder formulation to form an abrasive slurry. Alternatively, the abrasive particles are applied to the binder formulation after the binder formulation is coated on the backing. Optionally, a strokable functional powder is applied to the abrasive region to prevent the abrasive region from sticking to the patterning tool. Alternatively, the pattern may be formed in the abrasive region in the absence of the functional powder.

The abrasive particles may be formed from any one or combination of abrasive particles including silica, alumina (fused or sintered), zirconia/alumina oxide, silicon carbide, garnet, diamond, cubic boron nitride, silicon nitride, ceria, titania, titanium diboride, boron carbide, tin oxide, tungsten carbide, titanium carbide, iron oxide, chromia, flint, emery for example, the abrasive particles may be selected from the group consisting of silica, alumina, zirconia, silicon carbide, silicon nitride, boron nitride, garnet, diamond, co-fused alumina zirconia, ceria, titanium diboride, boron carbide, flint, emery, aluminum nitride, and blends thereof.

The abrasive particles may also have a particular shape. Examples of such shapes include rods, triangles, pyramids, cones, solid spheres, hollow spheres, or the like. Alternatively, the abrasive particles may be randomly shaped.

In an embodiment, the abrasive particles can have an average particle size of not greater than 800 microns, such as not greater than about 700 microns, not greater than 500 microns, not greater than 200 microns, or not greater than 100 microns. In another embodiment, the abrasive particle size is at least 0.1 microns, at least 0.25 microns, or at least 0.5 microns. In another embodiment, the abrasive particle size is from about 0.1 microns to about 200 microns, and more typically from about 0.1 microns to about 150 microns or from about 1 micron to about 100 microns. The particle size of the abrasive particles is typically specified as the longest dimension of the abrasive particles. In general, there is a range distribution of particle sizes. In some examples, the particle size distribution is tightly controlled.

Primer coat-binder

The primer coating or the binder of the size coating may be formed from a single polymer or a blend of polymers. For example, the binder may be formed from an epoxy, an acrylic polymer, or a combination thereof. Additionally, the binder may include fillers, such as nano-sized fillers or a combination of nano-sized and micro-sized fillers. In a particular embodiment, the binder is a colloidal binder, wherein the formulation that is cured to form the binder is a colloidal suspension comprising particulate filler. Alternatively or additionally, the binder may be a nanocomposite binder comprising submicron particulate fillers.

The binder generally comprises a polymer matrix that binds the abrasive particles to the backing or compliant coating (if present). Typically, the binder is formed from a cured binder formulation. In one exemplary embodiment, the binder formulation includes a polymer component and a dispersed phase.

The binder formulation may include one or more reactive or polymeric compositions for preparing the polymer. The polymer composition may comprise monomeric molecules, polymeric molecules, or a combination thereof. The binder formulation may further comprise a component selected from the group consisting of: solvents, plasticizers, chain transfer agents, catalysts, stabilizers, dispersants, curing agents, reaction media, and agents for affecting the fluidity of the dispersion.

The polymer composition may be formed into a thermoplastic or thermoset. For example, the polymer composition may include monomers and resins for the formation of: polyurethanes, polyureas, polymeric epoxies, polyesters, polyimides, polysiloxanes (silicones), polymeric alkyds, styrene-butadiene rubbers, acrylonitrile-butadiene rubbers, polybutadienes or reactive resins generally used in the manufacture of thermoset polymers. Another example includes an acrylate or methacrylate polymer composition. The precursor polymer composition is typically a curable organic material (i.e., a polymeric monomer or material that is capable of polymerizing or crosslinking over time upon exposure to heat or other energy sources such as electron beam, ultraviolet light, visible light, or upon addition of a chemical catalyst, moisture, or other agent that causes the polymer to cure or polymerize). Examples of precursor polymer compositions include reactive compositions for forming: amino polymers or aminoplast polymers, such as alkyl urea-formaldehyde polymers, melamine-formaldehyde polymers, and alkyl benzoguanamine-formaldehyde polymers; acrylate polymers including acrylate and methacrylate polymers, alkyl acrylates, epoxy acrylates, acrylated urethanes, acrylated polyesters, acrylated polyethers, vinyl ethers, acrylated oils, or acrylated silicones; alkyd polymers, such as polyurethane alkyd polymers; a polyester polymer; a reactive polyurethane polymer; phenolic polymers, such as resole and novolac polymers; phenolic/latex polymers; epoxy polymers, such as bisphenol epoxy polymers; an isocyanate; isocyanurates; a polysiloxane polymer comprising an alkylalkoxysilane polymer; or a reactive vinyl polymer. The binder formulation may comprise monomers, oligomers, polymers, or combinations thereof. In particular embodiments, the binder formulation includes monomers of at least two types of polymers that can crosslink when cured. For example, the binder formulation may include an epoxy resin composition that forms an epoxy/acrylate polymer when cured and an acrylate composition.

Additive-grinding aid

The abrasive layer may further comprise a grinding aid to increase buffing efficiency and cut rate. Useful grinding aids can be inorganic based, such as halide salts, e.g., sodium cryolite and potassium tetrafluoroborate; or organic based, such as chlorinated paraffin, e.g., polyvinyl chloride. Particular embodiments include cryolite and potassium tetrafluoroborate with particle sizes ranging from 1 to 80 microns, and most typically from 5 to 30 microns. The supersize coat may be a polymer layer applied over the abrasive particles to provide glaze and load-blocking properties.

Back coat-compliant coating

The coated abrasive article may optionally include a compliant coating and a back coating (not shown). These coatings may function as described above and may be formed from binder compositions.

Method of manufacture-coated abrasive article

For methods of making coated abrasive articles having a pattern of abrasive regions, the backing can be dispensed from a roll and coated with a binder formulation dispensed from a coating apparatus. Exemplary coating equipment includes a die coater, a blade coater, a curtain coater, a vacuum die coater, or a die coater. The coating process may comprise a contact or non-contact process. These methods include two-roll coating, three-roll reverse coating, roll-knife coating, slot-die coating, gravure coating, spin-print coating, extrusion coating, spray-application coating, or combinations thereof.

In one embodiment, the binder formulation may be provided in a slurry comprising the formulation and abrasive particles. In alternative embodiments, the binder formulation may be dispensed separately from the abrasive particles. The abrasive particles may be provided after coating the backing with the binder, after partial curing of the binder formulation, after patterning of the binder formulation (if present), or after complete curing of the binder formulation. The abrasive particles may be applied, for example, by techniques such as electrostatic coating, drop coating, or mechanical spraying.

In another embodiment, the backing coated with binder and abrasive particles can be embossed, die cut, laser cut, or a combination thereof to form the shape of the coated abrasive (e.g., a disk) or pattern of pores, if present, cut through the coated abrasive.

In another embodiment, the backing may be selectively coated with a binder to leave uncoated regions that are subsequently coated with abrasive particles to form abrasive regions. For example, the adhesive may be printed onto the backing, such as by screen printing, offset printing, rotary printing, or flexographic printing. In another example, the adhesive may be selectively applied using gravure coating, slot die coating, mask spraying, or the like. Alternatively, a photoresist or UV curable mask may be applied to the backing and developed to mask portions of the backing, such as by photolithography. In another example, the wet-out compound may be applied to the backing prior to applying the adhesive.

Method of use-grinding a workpiece

For methods of abrading a workpiece, the workpiece may be contacted with a coated abrasive. The coated abrasive can be rotated relative to the workpiece. For example, a coated abrasive can be mounted on an orbital sander and contacted to a workpiece. While abrading the workpiece, material abraded from the workpiece may accumulate in open areas between or adjacent to the abrasive areas. By movement of the coated abrasive during use, accumulated material can be expelled from the face of the coated abrasive. Alternatively, the abrasive article may be equipped with a vacuum system. The vacuum system may include a backup pad configured to function in cooperation with an abrasive article.

Standby pad

As can be appreciated, a backup pad designed to correspond to a coated abrasive having a controlled non-uniform distribution of abrasive areas can be successfully used in conjunction with conventional coated abrasives as well as certain coated abrasives having a controlled non-uniform distribution of abrasive areas. The inventors have surprisingly found that backup pad embodiments can provide excellent swarf removal and facilitate improved abrasive performance for conventional abrasives.

In an embodiment, the backup pad may have a pattern of air flow paths cooperatively adapted to operate with a coated abrasive having a controlled non-uniform distribution pattern. As previously described, this backup pad may be used in conjunction with conventional perforated coated abrasives to facilitate swarf removal and abrasive performance.

In an embodiment, the backup pad may include a pattern of air flow paths, wherein the pattern of air flow paths is generated from x and y coordinates of the controlled uneven distribution pattern. The controlled uneven distribution pattern used to create the backup pad air flow pattern may be the same or different than the pattern of the coated abrasive used with the backup pad. In one embodiment, the controlled non-uniform distribution pattern is the same as the pattern of the coated abrasive used with the backup pad. In another embodiment, the controlled non-uniform distribution pattern is different from the pattern of the coated abrasive used with the backup pad.

In an embodiment, the backup pad may be cooperatively adapted to operate with a coated abrasive having a phyllotactic pattern according to the coated abrasive embodiments described herein. The backup pad cooperates with the coated abrasive having a phyllotactic pattern when the backup pad includes a plurality of openings, a plurality of cavities, a plurality of channels, a plurality of passages, or a combination thereof, configured in a pattern designed to facilitate suction and removal of swarf from the working surface through the pores of the coated abrasive having a phyllotactic pattern during the abrading process. The openings, cavities, channels, passages, or combinations thereof may define airflow paths that are positioned along, within, or through the backup pad, or combinations thereof. The airflow path facilitates improved suction and removal of swarf from the working surface through the pores of the coated abrasive during the abrading process. In an embodiment, the pattern of openings, cavities, channels, passages, or combinations thereof may be in the form of: regular polygons, irregular polygons, ellipsoids, arcs, spirals, phyllotactic patterns, or combinations thereof. In another embodiment, the airflow path may be in the form of: regular polygons, irregular polygons, ellipsoids, arcs, spirals, phyllotactic patterns, or combinations thereof.

The pattern may then be used to define a radiating arc and a spiral channel, as well as a circular channel that may intersect the arc and spiral channel, or a combination thereof. The annular, arcuate, spiral or combined channels may then be cut into a suitable material, for example in the form of grooves, cavities, apertures, channels or other paths, to form a cooperative backup pad.

In certain embodiments, the airflow path of the backup pad is stroked to fully match the porosity of the coated abrasive. It is to be understood that the airflow path matches the aperture when at least a portion of the area of the aperture coincides or aligns with a portion of the airflow path. In an embodiment, the air flow path of the corresponding backup pad matches at least 5%, at least 10%, at least 15%, at least 20%, at least 25% of the apertures. In an embodiment, the airflow path of the corresponding backup pad may match at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 55%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 100% of the pores of the coated abrasive.

It is appreciated that certain backup pad spirals and sequencing air flow patterns exhibit some quality of alignment with the coated abrasive's pattern of apertures, particularly when the air flow pattern is based on the transposing and rotation of the coordinates of the coated abrasive's area. In one embodiment, the airflow pattern of the backup pad matches most to nearly all of the coated abrasive pores when the backup pad is at a particular phase or degree of rotation relative to the coated abrasive. The backup pad is referred to as a single-alignment (also referred to as 2-fold alignment) backup pad when the backup pad's airflow path matches the pores of the coated abrasive when rotated 90 ° or 180 ° compared to the coated abrasive and a majority to almost all of the pores of the coated abrasive match at least one of the backup pad's airflow paths.

In an embodiment, the backup pad may include or be adapted to include an alignment indicator. The alignment indicator may be a mark, device, indentation, appendage, collar, protrusion, or a combination thereof to indicate the degree of alignment of the backup pad with the coated abrasive. In a particular embodiment, the alignment indicator may be a mark.

While described as cooperating with embodiments of the abrasive articles described herein, these backup pads may also be used with standard prior art perforated coated abrasives. It has been unexpectedly discovered that backup pads having multiple openings, multiple cavities, multiple channels, or combinations thereof forming suitable spiral or phyllotactic pattern airflow paths have improved swarf removal, can facilitate abrasive cutting performance, and extend abrasive life of both standard prior art perforated coated abrasives and coated abrasives having perforated phyllotactic patterns.

The backup pad may be flexible or rigid. The backup pad can be made of any number of various materials or combinations of materials, including those materials conventionally used in backup pad manufacture. The backup pad may be made of a monolithic unitary construction or a multi-piece construction such as a multi-layer construction or a concentric layer construction. The backup pad is preferably a resilient material such as a flexible foam. Suitable foams may be polyurethane, polyester polyurethane, polyether polyurethane; natural or synthetic rubbers, such as polybutadiene, polyisoprene, EPDM polymers, polyvinyl chloride (PVC), polychloroprene or styrene/butadiene copolymers; or a combination thereof. The foam may be open cell or closed cell. Additives such as coupling agents, toughening agents, curing agents, antioxidants, reinforcing materials, and the like may be added to the foam formulation to achieve desired properties. Stroke dyes, pigments, fillers, antistatic agents, flame retardants and scrims may also be added to the foam or other resilient material used to make the backup pad.

Particularly useful foams include Toluene Diisocyanate (TDI)/polyester and diphenylmethane diisocyanate (MDI)/polyester foams. In one embodiment, the backup pad is made of a resilient open-cell polyurethane foam formed as the reaction product of a polyether polyol and an aromatic polyisocyanate. In another embodiment, the backup pad may be foam, vulcanized rubber, or any combination thereof.

It should be noted that not all of the activities described above in the general description or the examples are required, that a portion of a particular activity may not be required, and that one or more additional activities may be performed in addition to those described. Again, the order in which activities are listed is not necessarily the order in which the activities are performed.

In the foregoing specification, concepts have been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense, and all such modifications are intended to be included within the scope of present invention.

As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having" or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of features is not necessarily limited to only those features but may include other features not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, "or" refers to an inclusive or and not to an exclusive or. For example, any one of the following satisfies condition a or B: a is true (or present) and B is false (or not present), a is false (or not present) and B is true (or present), and both a and B are true (or present).

Also, the use of "a" or "an" is used to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is not so meant.

Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. The benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced, however, are not to be construed as a critical, required, or essential feature or feature of any or all the claims.

After reading the specification, one skilled in the art will appreciate that certain features that are, for clarity, described herein in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any sub-combination.

Further, reference to values stated in ranges includes each and every value within that range. When the term "about" or "approximately" precedes a numerical value, such as when describing a numerical range, it is intended that the exact numerical value be included as well. For example, a numerical range beginning with "about 25" is intended to also include ranges that begin exactly at 25.

Item 1. an abrasive article comprising:

a coated abrasive having a plurality of abrasive regions arranged in a pattern,

wherein the pattern has a controlled non-uniform distribution, an

Wherein the pattern is at least one of a radial pattern, a spiral pattern, a phyllotactic pattern, an asymmetric pattern, or a combination thereof.

Item 2. the abrasive article of item 1, wherein the pattern is a spiral pattern.

Item 3. the abrasive article of item 2, wherein the spiral pattern is one of an archimedean spiral, an euler spiral, a fermat spiral, a hyperbolic spiral, a interlocking spiral, a logarithmic spiral, a fibonacci spiral, a golden spiral, or a combination thereof.

Item 4. the abrasive article of item 3, wherein the pattern has a controlled asymmetry.

Item 5. the abrasive article of item 4, wherein the controlled asymmetry is at least a partial rotational asymmetry about a center of the pattern.

Item 6. the abrasive article of item 5, wherein the rotational asymmetry extends to at least 51%, at least 70%, or at least 85% of the abrasive region of the pattern.

Item 7. the abrasive article of item 5, wherein the rotational asymmetry extends to at least 20 abrasive regions, at least 50 abrasive regions, or at least 100 abrasive regions of the pattern.

Item 8. the abrasive article of item 5, wherein the pattern is rotationally asymmetric about the center of the pattern.

Item 9. the abrasive article of item 1, wherein the pattern is a phyllotactic pattern.

Item 10 the abrasive article of item 9, wherein the pattern is a helical phyllotactic pattern.

Item 11 the abrasive article of item 10, wherein the pattern has a number of clockwise spirals and a number of counterclockwise spirals, wherein the number of clockwise spirals and the number of counterclockwise spirals are fibonacci numbers or multiples of fibonacci numbers.

Item 12 the abrasive article of item 11, wherein the number of clockwise spirals and the number of counterclockwise spirals are lucas numbers or multiples of lucas numbers.

Item 13 the abrasive article of item 11, wherein the number of clockwise spirals and the number of counterclockwise spirals are in a ratio that converges on the golden ratio.

Item 14. the abrasive article of item 10, wherein the helical phyllotactic pattern has a controlled asymmetry.

Item 15 the abrasive article of item 10, wherein the helical phyllotactic pattern is a sunflower pattern.

Item 16. the abrasive article of item 11, wherein the pattern is described in polar coordinates by the following equation:

(equation 1)

Wherein:

n is the number of abrasive regions, counted from the center of the pattern outwards;

is the angle between the reference direction and the position vector originating from the nth abrasive region in the polar coordinate system at the center of the pattern such that the divergence angle between the position vectors of any two consecutive abrasive regions is a constant angle α;

r is the distance from the center of the pattern to the center of the nth abrasive region; and c is a constant scaling factor.

Item 17. the abrasive article of item 16, wherein at least about 51%, at least about 70%, at least about 85% of the abrasive region conforms to equation 1.

Item 18 the abrasive article of item 16, wherein the pattern has a divergence angle in polar coordinates ranging from about 100 ° to about 170 °.

Item 19. the abrasive article of item 16, wherein the pattern has a divergence angle of 137.508 °.

Item 20. the abrasive article of item 16, wherein at least about 80%, at least about 85%, at least about 90% of the total abrasive area conforms to equation 1.

Item 21 the abrasive article of item 16, wherein the plurality of abrasive regions ranges from about 5/10/20 abrasive regions to about 500/1000/10,000 abrasive regions.

Item 22 the abrasive article of item 16, wherein the pattern covers substantially an entire face of the abrasive article.

Item 23. the abrasive article of item 16, wherein an edge of the outermost abrasive region of the pattern intersects an edge of the abrasive article.

Item 24. the abrasive article of item 16, wherein an edge of an outermost abrasive region of the pattern is at least a particular distance from the edge of the abrasive article.

Item 25 the abrasive article of item 16, wherein the pattern covers only a portion of the face of the abrasive article.

Item 26. the abrasive article of item 16, wherein the pattern covers periodic portions of the face of the abrasive article.

Item 27 the abrasive article of item 16, wherein the total open area of the pattern is about 15% to about 99.5% of the surface potential surface area of the abrasive article.

Item 28. the abrasive article of item 16, wherein the total abrasive surface area ranges from about 4.5% to about 85% of the total potential surface area.

Item 29 the abrasive article of item 16, having the shape of a disc.

Item 30. the abrasive article of item 16, wherein the abrasive regions have a shape selected from one of a short line segment, a polygon, an ellipsoid, a circle, an arc, a spiral, a thread, a spiral lattice, or a combination thereof.

Item 31. a coated abrasive article comprising:

a backing layer having a first major side and a second major side; and

an abrasive layer disposed on the first major side of the backing layer,

wherein the abrasive layer comprises a plurality of abrasive areas arranged in a pattern having a controlled non-uniform distribution and is at least one of a radial pattern, a spiral pattern, a phyllotactic pattern, an asymmetric pattern, or a combination thereof.

Item 32. a method of making an abrasive article, comprising:

disposing an abrasive layer on a backing;

wherein the abrasive layer comprises a plurality of abrasive areas arranged in a pattern having a controlled non-uniform distribution, the pattern being at least one of a radial pattern, a spiral pattern, a phyllotactic pattern, an asymmetric pattern, or a combination thereof.

Item 33. a coated abrasive article comprising:

a plurality of abrasive regions disposed on a major surface of the coated abrasive article, wherein the abrasive regions are configured to form a plurality of airflow paths comprising arcs, spirals, threads, phyllotactic patterns, or combinations thereof.

Item 34 the coated abrasive of item 34, wherein the pattern of air flow paths comprises a radiating arcuate path, a radiating helical path, or a combination thereof.

Item 35 the coated abrasive of item 34, wherein the pattern of air flow paths comprises a combination of inner radiating spiral paths and outer radiating spiral paths.

Item 36. the coated abrasive of item 34, wherein the pattern of air flow paths comprises a combination of clockwise radiating spiral paths and counterclockwise radiating spiral paths.

Item 37 the coated abrasive of item 34, wherein the pattern of air flow paths further comprises an annular air flow path intersecting the radiating arcuate path or radiating helical path, or a combination thereof.

Item 38. the coated abrasive includes a pattern of air flow paths, wherein the pattern of air flow paths is generated from x and y coordinates of a controlled non-uniform distribution pattern.

Item 39. the coated abrasive of item 38, wherein the x and y coordinates of the controlled non-uniform distribution pattern are transposed and rotated according to the following equation (equation 2) to determine the x 'and y' coordinates of the pattern of airflow paths, where θ is equal to pi/n in arcs and n is any integer:

item 40. the coated abrasive of item 39, wherein the controlled non-uniform distribution pattern is a phyllotactic pattern.

Item 41. the coated abrasive of item 40, wherein the controlled non-uniform distribution pattern is a Vogel equation.

Item 42. the coated abrasive of item 41, wherein n is any integer from 1 to 10.

Item 43. the coated abrasive of item 42, wherein n is 1, 2, 3, 4, 5, or 6.

Item 44. the coated abrasive of item 39, wherein the pattern of air flow paths comprises a plurality of openings, cavities, channels, passageways, or a combination thereof.

Item 45. an abrasive system, comprising:

a coated abrasive; and a backup pad, wherein the coated abrasive comprises a controlled non-uniform distribution pattern of abrasive areas, and wherein the backup pad comprises a plurality of air flow paths arranged in a pattern adapted to correspond with the abrasive areas of the coated abrasive.

Claims

1. An abrasive article, comprising:

a coated abrasive having a plurality of discrete abrasive regions on a flexible planar backing and adjacent open regions arranged in a pattern,

wherein the plurality of discrete abrasive regions comprise a plurality of abrasive particles dispersed in a polymeric binder layer on the backing,

wherein a size coating is located over the abrasive region and the open region,

wherein the pattern has a controlled non-uniform distribution,

wherein the pattern is a helical phyllotactic pattern,

wherein the pattern is described in polar coordinates by the following equation:

phi is n α, r is c n (equation 1)

Wherein:

φ is an angle between a reference direction and a position vector originating from an nth abrasive region in a polar coordinate system at the center of the pattern, such that a divergence angle between position vectors of any two consecutive abrasive regions is a constant angle α;

r is the distance from the center of the pattern to the center of the nth abrasive region; and is

c is a constant scaling factor and is,

wherein the pattern has a divergence angle in polar coordinates in the range of 137 to 138,

wherein at least about 80% of the total abrasive area conforms to equation 1,

wherein the total open area of the pattern is from 90% to 95.5% of the total potential surface area of the abrasive article,

wherein the pattern has a total abrasive surface area of 4.5% to 10% of the potential surface area of the abrasive article,

wherein each of the abrasive regions comprises a width of not less than 1/10 to not greater than 10 times the size of the adjacent open area of the abrasive article, and

wherein each of the abrasive areas comprises a width in a range of 0.1mm to 10 cm.

2. The abrasive article of claim 1, wherein the pattern has a divergence angle of 137.508 °.

3. The abrasive article of claim 1, wherein the plurality of abrasive regions ranges from 5 abrasive regions to 10,000 abrasive regions.

4. The abrasive article of claim 1, wherein the pattern covers substantially the entire face of the abrasive article.

5. The abrasive article of claim 1, wherein edges of an outermost abrasive region of the pattern intersect with edges of the abrasive article.

6. The abrasive article of claim 1, wherein an edge of an outermost abrasive region of the pattern is at least a particular distance from the edge of the abrasive article.

7. The abrasive article of claim 1, wherein the pattern covers only a portion of a face of the abrasive article.

8. The abrasive article of claim 1, wherein the pattern covers periodic portions of a face of the abrasive article.

9. The abrasive article of claim 1 having the shape of a disc.

10. The abrasive article of claim 1, wherein the abrasive regions have a shape selected from one of a short line segment, a polygon, an ellipsoid, a circle, an arc, a spiral, a thread, a spiral lattice, or a combination thereof.