TECHNICAL FIELD

Embodiments presented herein relate to wire saws, to methods for manufacturing wires for wire saws and to manufacturing devices for manufacturing wire saw wires.

BACKGROUND

A wire saw uses an elongated carrier, such as a wire or cable, for cutting or selectively abrading materials. Wire saws may be continuous where the elongated carrier is arranged in a loop, or they may be non-continuous, where the carrier has open ends.

Wire saws in general provide a cutting action via an abrasion effect rather than via saw teeth. The abrasion effect may be enhanced by bonding abrasive particles to the carrier, such as abrasive beads.

It is preferred to obtain an efficient cutting process and a resulting smooth cut with a minimum of artefact marks, such as scratch marks, wire marks, bead marks, and other residual patterns.

It is known to increase the speed of the wire to reduce artefact marks left by the wire saw. This however reduces the life span of the wire. Thus, there is a need for improved wires for wire saws which do not generate excessive artefact marks.

SUMMARY

An object of embodiments herein is to provide an improved wire for a wire saw, a manufacturing process for manufacturing improved wire saws, and a manufacturing device for obtaining improved wires. This object is obtained by a wire for a wire saw comprising an elongated carrier and a plurality of abrasive elements bonded to the carrier. The abrasive elements are arranged at respective locations along the carrier. The abrasive elements have respective widths and/or compositions. Notably, a distribution of the abrasive element widths and/or a distribution of the abrasive element compositions is randomized or irregular.

The abrasive element width can be defined in different ways, e.g., along an extension direction of the wire, or along a direction orthogonal to the extension direction. Thus, a randomization of element widths may be accomplished in at least two ways.

According to aspects, the above-mentioned abrasive element composition is determined by any of; abrasive particle size distribution, abrasive particle concentration, bond strength, bond wear resilience, and resulting cutting force. Thus, abrasive elements may be configured with different compositions and arranged randomly along the wire, which yields a wire having abrasive elements with randomized composition along the wire.

According to aspects, a distribution of the abrasive element locations along the carrier is also randomized.

Advantageously, residual patterns or marks, such as scratch marks and resonance patterns, left by the disclosed wire are minimized or even avoided due to the randomization of element widths and/or compositions. The residual patterns are further reduced by randomization also of abrasive element locations along the carrier.

Advantageously, the cutting performance of the disclosed wire is improved compared to known wires. The disclosed wire, e.g., provides an increased production rate in terms of sqm/hour as the differences in abrasive element widths give reduced contact surface between the wire and the material to be cut.

It is known that, for avoiding residual marks from a wire saw, an operator may increase the peripherical speed of the wire to speeds, e.g., on the order of 34 m/sec. The disclosed wire, however, requires no increase in peripheral speed to avoid or reduce residual marks. Instead the peripheral speed can remain around, e.g., 30-31 m/sec. Advantageously, the life-span of the wire is thereby prolonged compared to running the wire saw at increased speed, energy consumption during operation of the saw is reduced. Furthermore, component wear, such as rubber line wear and bearings wear, is reduced.

The skilled person may think that the largest width elements would simply get worn out faster and thus that all abrasive elements would reach uniformly the same width. It has, however, been realized that an initial variation in element width introduced on purpose will be maintained even in the context of an abrasive element consumption along their width while offering benefit to the cut. Similarly, a variation in composition of the abrasive elements will also induce slight differences among the behaviour of the various abrasive elements constituting the wire saw. This again improves the wire saw action by breaking up the detrimental periodicity that results in marking as well as varying width resulting from varying wear-out rate of the mixed abrasive elements.

Almost any material can be cut without residual marks by the disclosed saw. Quartzites for example are a class of materials that are very hard. They can be cut consecutively by the disclosed wire. Previously, it was common to alternate between cutting hard and more soft materials, which is not necessary when operating the disclosed wire saw.

In general, parameters of the cutting process are more easily determined due to relaxed requirements on cutting process optimization which arise due to the above- mentioned randomization of element widths, compositions, and optionally also element locations along the carrier.

The object is also obtained by a method of manufacturing a wire for a wire saw. The method comprises configuring an elongated carrier for receiving a plurality of abrasive elements, mixing abrasive elements of varying width and/or compositions in a container, and bonding abrasive elements randomly selected from the container onto the carrier. This way a wire is obtained where a distribution of abrasive element widths and/or compositions is randomized.

According to aspects, the method also comprises bonding abrasive elements onto the carrier at randomized locations along the carrier.

Hereby a wire is obtained associated with the above-mentioned advantages in a cost-efficient and reliable manner.

The object is furthermore obtained by a manufacturing device for manufacturing a wire. The device comprises a carrier feed module arranged to configure an elongated carrier for receiving a plurality of abrasive elements, a container comprising a mix of abrasive elements of varying width and/or composition, and a bonding module arranged to bond abrasive elements randomly selected from the container onto the carrier.

Hereby, manufacturing of a wire associated with the above-mentioned advantages is enabled in a cost-efficient and reliable manner.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the element, apparatus, component, means, step, etc." are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.

BRIEF DESCRIPTION OF THE DRAWINGS

The inventive concept is now described, by way of example, with reference to the accompanying drawings, in which: Figure 1 illustrates a wire according to embodiments;

Figure 2A illustrates a wire according to prior art;

Figure 2B illustrates a wire according to embodiments;

Figure 3A shows an example wire according to embodiments; Figure 3B shows an example abrasive element according to embodiments;

Figure 3C shows an example abrasive element according to embodiments;

Figure 4A is a graph exemplifying measured abrasive element widths;

Figure 4B is a graph exemplifying an abrasive element width distribution;

Figure 5A is a graph exemplifying measured abrasive element widths; Figure 5B is a graph exemplifying an abrasive element width distribution;

Figure 5C is a graph exemplifying an abrasive element width distribution;

Figure 6 is a flow chart illustrating methods according to the disclosure;

Figure 7 schematically illustrates a manufacturing device for manufacturing a wire according to embodiments; and Figure 8 is a graph exemplifying an abrasive element width distribution.

DETAILED DESCRIPTION

The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of the inventive concept are shown. This inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. Like numbers refer to like elements throughout the description. Any step or feature illustrated by dashed lines should be regarded as optional.

A problem with using wire saws for abrasive operation is that resonance effects may arise in the saw wire. These resonance effects tend to leave marks in the cut surface which marks are undesired. It has been realized that by randomizing one or more properties of abrasive elements arranged on the wire, these resonance effects can be broken up and thus reduced. Properties of abrasive elements which can be randomized in a cost-effective manner comprise abrasive element dimension, i.e. widths measured in different directions, and abrasive element composition in terms of, e.g., abrasive particle size and concentration.

Figure 1 illustrates a wire 100 comprising an elongated carrier 120. The elongated carrier may, e.g., be a wire or a cable, or any other flexible elongated object durable enough for a cutting operation. The wire also comprises a plurality of abrasive elements 110a, 110b, 110c, llOd bonded to the carrier. These abrasive elements may, e.g., be in the form of beads. The abrasive elements may, according to some aspects, be formed from an abrasive material, or they may be coated with a layer of abrasive material. Each of the abrasive elements has a composition in terms of, e.g., abrasive particle size distribution, abrasive particle concentration, bond strength, bond wear resilience, and resulting cutting force. According to some aspects, the abrasive elements comprise a diamond particle matrix. Abrasive elements having compositions suitable for use with wire saws are known and will not be discussed in more detail herein.

When the abrasive elements are brought in contact with a piece of material, and moved in relation to the material, a cutting action is obtained. The cutting action is either abrasive or erosive or comprises a combination of abrasion and erosion. The abrasive elements have respective widths 111a, 111b, 111c, llld, 112a, 112b, 112c, 112d, and possibly also respective compositions. Herein, abrasive element width is defined in two directions; A first abrasive element width 111a, 111b, 111c, llld is defined by the physical extension of the abrasive element in a direction E orthogonal to an extension direction D of the elongated carrier 120. A second abrasive element width 112a, 112b, 112c, 112d is defined in the extension direction D. The first abrasive element width may also be referred to as bead girth, while the second abrasive element width may be referred to as abrasive element length.

The width of an abrasive element, and the determining or measuring of width, i.e., first and second widths, will be discussed in more detail below.

Notably, a distribution of the abrasive element nominal widths and/or compositions at manufacturing is randomized. The randomization of abrasive element nominal widths and/or compositions at manufacturing enables a particularly efficient cutting action with a minimum of residual marks left on the material by the wire, since resonance effects during abrasive operation are reduced by the randomization. Thus, advantageously, any residual patterns or marks, such as scratch marks and resonance patterns, left by the disclosed wire are minimized. Also, the cutting performance of the disclosed wire is improved compared to known wires due to the randomization of the distribution of the abrasive element widths.

It is appreciated that randomization of element widths and randomization of element composition are separate randomizations and may be practiced separately and independently from each other. Randomization of element location is as already noted independent from the randomization of widths and/or composition.

To summarize, the disclosed wire saw wires may according to one example reduce resonance effects by having abrasive elements with variation in girth, i.e., a varying first width. The disclosed wires may according to another example reduce resonance effects by having abrasive elements with variation in length, i.e., a varying second width. The disclosed wires may according to a further example reduce resonance effects by having abrasive elements with variation in composition, e.g., by arranging abrasive elements with varying bond strengths on the wire. The disclosed wires may, according to yet another example, reduce resonance effects by having abrasive elements configured on the wire at varying distances.

An abrasive element having a relatively large first width value, such as abrasive element 110b shown in Figure 1, will be in contact with a material to be abraded in a manner differently from an abrasive element having a relatively small first width value, such as abrasive element 110a. The abrasive element 110b may exert an abrasive effect on the material to be cut, while abrasive element 110a may exert a more erosive effect on the material.

According to aspects, the first width values defined by physical extension of the abrasive element in direction E 111a, 111b, 111c, llld comprise nominal width values at manufacturing of x mm, and x+y mm, where 3 mm < x < 8 mm, and where y < 0,3 mm, preferably 0,1 mm < y < 0,3 mm.

It is appreciated that the difference y in diameter, in some scenarios, should be kept below 0,3 mm, since a too large difference in diameter will cause severe mechanical stress on the larger abrasive elements.

According to a non-limiting preferred example, first width values 111a, 111b, 111c, llld, associated with the abrasive elements 110a, 110b, 110c, llOd comprise nominal width values at manufacturing of the wire of approximately 6,0 mm, and 6,3 mm.

According to another non-limiting example, first width values 111a, 111b, 111c, llld, associated with the abrasive elements 110a, 110b, 110c, llOd comprise nominal width values at manufacturing of the wire of approximately 6,33 mm, and 6,51 mm. According to yet another non-limiting example, first width values 111a, 111b, 111c, llld, associated with the abrasive elements 110a, 110b, 110c, llOd comprise nominal width values at manufacturing of the wire of approximately 5,0 mm, and

5.3 mm.

According to yet another non-limiting example, first width values 111a, 111b, 111c, llld, associated with the abrasive elements 110a, 110b, 110c, llOd comprise nominal width values at manufacturing of the wire of approximately 7,0 mm, and

7.3 mm.

A mode value of a data sample distribution, in general, is a value in the distribution which appears often, i.e., appears with high frequency. Thus, a peak in any distribution is a mode value. A distribution of data samples may be unimodal, in which case the distribution has a single peak, or the distribution may be multimodal, in which case the distribution has more than one peak. Multimodal distributions will be discussed in more detail below in connection to Figure 4b. It is appreciated that modes may not appear clearly in a distribution plot, such as a histogram, until a large enough data set has been sampled. Thus, even if no clear modes can be seen in an initial histogram with few data samples, clear modes may appear once the histogram has stabilized after collecting a large enough data set.

According to some aspects, the first width values of a first group of abrasive elements are distributed around a mode value of 6,0 mm, and the first width values of a second group of abrasive elements are distributed around a mode value of 6,3 mm. It is appreciated that such distribution of width values may comprise a natural variation in width, or a man-made variation in width values. If such abrasive element width values are analyzed in a histogram, the histogram will be multimodal, i.e., have two modes, one close to 6,0 mm, and another close to 6,3 mm.

According to some other aspects, the first width values of a first group of abrasive elements are distributed around a mode value of 6,33 mm, and the first width values of a second group of abrasive elements are distributed around a mode value of 6,51 mm. Again, it is appreciated that such distribution of width values may comprise a natural variation in width, or a man-made variation in width values. If such abrasive element width values are analyzed in a histogram, the histogram will be multimodal, i.e., have two modes, one close to 6,33 mm, and another close to 6,51 mm.

Similar distributions may be used to describe second width values of the disclosed abrasive elements.

Consequently, according to some aspects, the width values of abrasive elements of the wire disclosed herein are distributed according to at least one distribution having at least two modes. For instance, the first width values may be associated with a first distribution while the second width values may be associated with a second distribution.

According to aspects, the modes of a width distribution correspond to nominal width values of a wire type at manufacturing.

There are additional advantages associated with randomly distributing abrasive element widths. For instance, a smooth cutting action with a reduced amount of residual marks is obtained because large width abrasive elements remove material by means of an abrasive process, while smaller width abrasive elements mainly remove material by means of an erosive process.

In other words, according to aspects, the abrasive elements comprise elements having a first width value above an average width value of the abrasive elements, configured for abrasive operation. The abrasive elements may also comprise elements having a first width value below an average width value of the abrasive elements, configured for erosive operation.

The larger width elements may correspond to elements having a first nominal width value at manufacturing, and the smaller width elements may correspond to elements having a second nominal width value at manufacturing. In other words, widths of the larger elements can be located around a first mode of a width distribution, while widths of the smaller elements can be located around a second mode of the width distribution. The abrasive elements are arranged at respective locations 122a, 122b, 122c, 122d along the carrier. According to some aspects, the abrasive element locations 122a, 122b, 122c, 122d are measured as distances from a reference location R, 121, associated with the elongated carrier 120 to the respective abrasive element in the direction D along the carrier. Inter-element distances 130 may be determined independently of the reference location as distances between successive elements bonded to the carrier.

According to some aspects, a distribution of the abrasive element locations is also randomized. The randomization of abrasive element locations enable a further improvement in cutting action with further reduction in residual marks left on the cut material by the wire saw. It is appreciated that randomization of element widths and randomization of element location are separate randomizations and may be practiced separately and independently from each other.

It is furthermore appreciated that, herein, the term randomized is given a broad interpretation, as will now be discussed; According to some aspects, a randomized distribution comprises a distribution where a repetitive pattern of values is absent. In other words, the distribution along the elongated carrier is non-repetitive. For instance, a distribution of nominal widths which repeats according to a given pattern is not randomized in the present meaning. Also, a distribution of locations along a wire which follows a given pattern is also not a randomized pattern according to the present meaning.

According to some other aspects, a randomized distribution comprises a distribution having a frequency domain representation with flat amplitude. This essentially means that no main frequency component can be detected in a frequency domain representation of a distribution. For instance, a repetitive pattern such as 1,2, 3, 1,2, 3, 1,2, 3, 1,2, 3 will exhibit a main frequency component when analyzed in frequency domain. However, a randomized distribution, according to the present interpretation, will appear with essentially flat amplitude distribution in frequency domain.

It is appreciated that some randomization will reduce resonance effects, i.e., a fully randomized abrasive element pattern may not be necessary.

According to some further aspects, a randomized distribution of the abrasive element nominal widths comprises a distribution where a nominal width of a next element in a sequence of widths cannot be determined based on information about widths of previous or future elements.

Similarly, according to some aspects, a randomized distribution of the abrasive element locations comprises a distribution where a location of a next element in a sequence of locations cannot be determined based on information about locations of previous or future elements.

It is appreciated that a pre-determined irregular sequence of abrasive elements of a first and a second type may be arranged on the carrier with the same effect of breaking up resonances during abrasive operation. There are many such pre determined sequences which can be used, and which differ from regular sequences such as '1,2, 1,2, 1,2, 1,2, 1,2'.

For example, resonance effects are reduced in a wire comprising an elongated carrier 120 and a plurality of abrasive elements 110a, 110b, 110c, llOd bonded to the carrier, if the plurality of abrasive elements comprises elements of a first type and elements of a second type different from the first type, and if the abrasive elements are arranged at respective locations 122a, 122b, 122c, 122d along the carrier such that a location on the carrier of an element of the first type is sequentially adjacent to a location on the carrier of another element of the first type. Herein, 'sequentially adjacent' means that one abrasive element is arranged next to another abrasive element on the carrier without any abrasive elements in-between. A section of carrier without any abrasive elements is present between the two sequentially adjacent elements. The different types of abrasive elements can be, e.g., elements of different widths measured along direction E or D, or elements having different compositions, as discussed above.

Consequently, it is appreciated that a randomized distribution may be obtained by arranging abrasive elements on the carrier according to an irregular but pre- determined sequence of abrasive element types.

The width values of abrasive elements of the first type may be different on average, or in distribution, from width values of the abrasive elements of the second type.

The composition, as discussed above, of the abrasive elements of the first type may be different in average or in distribution, from the abrasive elements of the second type.

A preferred irregular sequence of abrasive element types may be determined by means of computer simulation of wires having different abrasive element sequences.

Another way to describe a randomized and/or irregular distribution of abrasive elements is to define a sequence as an irregular sequence configured to reduce a resonance effect associated with the wire.

Thus, there is disclosed herein a wire 100 for a wire saw, comprising an elongated carrier 120 and a plurality of abrasive elements 110a, 110b, 110c, llOd bonded to the carrier in a sequence. The plurality of abrasive elements comprising elements of at least a first and a second type, wherein elements of the first type has a different width and/or composition compared to elements of the second type, and wherein the sequence is an irregular sequence configured to reduce a resonance effect associated with the wire.

There are different ways to describe such irregular sequences, for instance;

According to aspects, the sequence comprises a plurality of sub-sequences, wherein a first sub-sequence of N beads has different bead type proportion and/or different bead type ordering compared to a second sub-sequence of N beads adjacent to the first sub-sequence.

According to aspects, N=2*number of types of beads bonded to the carrier. According to a preferred example, N=4. According to aspects, a number X of consecutively bonded beads of the first type in the sequence is not repeatedly followed by the same number X of beads of another type, where X<2*number of types of beads bonded to the carrier.

According to aspects, a first sub-sequence of Y beads is different from a subsequent and adjacent sub-sequence of Y beads, wherein Y=2*number of types of beads, and a bead of one type is not repeatedly followed by an equal number of beads of another type at one or more locations in the sequence.

Consequently, an irregular abrasive element configuration, or a randomized abrasive element configuration on the elongated carrier can be described in many different ways, all having the same technical effect of reducing resonance effects during use of the wire saw.

Figure 2A illustrates a wire according to prior art. Here beads 210 are arranged bonded to a carrier 220. The beads are all the same width and of the same composition and arranged equally spaced on the carrier. This wire is likely to cause a resonance pattern on the cut material. This wire is also likely to exhibit a non- optimal cutting efficiency. Figure 2B illustrates a wire according to embodiments. Here the abrasive elements 110a, 110b are shown with different nominal widths 111a, 111b, 112a, 112b which nominal widths have been randomized to provide a cutting action with a reduced amount of residual marks. Due to the randomization of element nominal widths, resonance effects are reduced, whereby a smooth cutting action is obtained with a reduced amount of unwanted marks and scratches, such as resonance patterns.

The abrasive element compositions may also be randomized in order to reduce resonance effects. For instance, different elements may be configured with different abrasive particle sizes, abrasive particle concentrations, bond strengths, and bond wear resilience. To exemplify, suppose a mix of different abrasive element compositions is used; One type of element A, having a size distribution d, with harder bond and bigger abrasive particle size, in higher concentration. A relatively high cutting force will be applied to these elements. Another type of element B, having the same size distribution d, but with softer bond and smaller abrasive particle sizes in lower concentration. A relatively low cutting force will be applied to these elements compared to the elements of type A. This difference in applied cutting force will be randomly distributed along the wire, and therefore reduce resonance effects. Figure 3a shows an example wire 300 according to embodiments. According to this example the elongated carrier 120 is a wire enclosed in a sheath. The width values of the abrasive elements 110a, 110b, 110c, llOd, here shown as approximately cylindrical beads, is randomized.

In general, if the abrasive elements have cylindrical shapes, the first width of an abrasive element may be determined as the diameter of the cylinder in a straight forward manner, using, e.g., a caliper or other equivalent measuring tool. Similarly, in case the abrasive elements are spherically shaped, then the first width may be determined as the diameter of the spherical shape. A rectangular shape abrasive element will be associated with a first width value corresponding to a cross-section measure of the abrasive element. However, the skilled person will appreciate that abrasive elements 110 may not always be perfectly symmetrical, e.g., cylindrical or i6 spherical, even at manufacturing, but may instead have a slightly asymmetrical shape, e.g., due to imperfections in production or due to a sharpening process applied to the abrasive elements during manufacturing. Therefore, a measure of the first width of an abrasive element, or bead, may vary over a range depending on where on the abrasive element the measurement is made, and how the measurement is made. This is illustrated in Figure 3b, which shows an example abrasive element 110 having a slightly distorted cylindrical shape. This is also illustrated in Figure 3c, which shows an example abrasive element having a smaller diameter value in a center section 311 and a larger diameter value at end sections 312a, 312b.

The second width, i.e., the length of an abrasive element can also be measured by a caliper or the like. It is appreciated that also the second width may vary according to how the measurement is done.

Consequently, for the same abrasive element 110, a first measure of width D1 made using, e.g., a caliper, may be smaller than a second measure of width D2 taken on the same abrasive element using the same caliper. However, regardless of measurement method, a randomization of abrasive element widths will be apparent to the skilled person from analysis of the width measurements, as long as the same measurement method is used for all abrasive elements.

First width may be measured in several different, equally valid ways, all representing physical extension of the abrasive elements in a direction E orthogonal to the extension direction D of the elongated carrier 120. For instance;

According to some aspects, the first width of an abrasive element is measured as a distance value D2 corresponding to the largest distance value measured in any direction E orthogonal to the elongation direction D of the carrier 120.

According to some other aspects, the first width of an abrasive element is measured as a distance value D2 corresponding to the smallest distance value measured in any direction E orthogonal to the elongation direction D of the carrier 120. According to some further aspects, with reference to Figure 3b, the first width W1 of an abrasive element is measured as a value corresponding to an average value or median value determined as the average or median, respectively, of a distance value D1 corresponding to the smallest distance value measured in any direction E orthogonal to the elongation direction D of the carrier 120 and a distance value D2 corresponding to the largest distance value measured in any direction E orthogonal to the elongation direction D of the carrier 120.

With reference to Figure 3c, the first width W2 of an abrasive element 110 may also be measured as a value corresponding to an average value or median value determined as the average or median, respectively, of a distance value D3 corresponding to a distance value measured in direction E orthogonal to the elongation direction D of the carrier 120 at a first end section 312a of the abrasive element, a distance value D4 corresponding to a distance value measured in direction E orthogonal to the elongation direction D of the carrier 120 at a center section 311 of the abrasive element, and a distance value D5 corresponding to a distance value measured in direction E orthogonal to the elongation direction D of the carrier 120 at a second end section 312b of the abrasive element.

According to further aspects, the width of an abrasive element is measured as a value corresponding to an average value or median value determined as the average or median, respectively, of distance values measured in the elongation direction (for second widths) or measured in the direction E orthogonal to the elongation direction D of the carrier 120(for first widths) at regular intervals along the abrasive element.

With reference to Figure 3b, as an alternative to measuring using, e.g., a caliper, first width may also be determined from circumference 312 or girth of an abrasive element 110. A larger first width element then has larger circumference value than a smaller first width element. A randomization of first width values naturally also comprises a randomization of circumference or girth values. Second width may also be measured in several different, equally valid ways, all representing physical extension of the abrasive elements in the extension direction D of the elongated carrier 120, as will be realized by the skilled person. For instance;

According to some aspects, the second width of an abrasive element is measured as a distance value corresponding to the largest distance value measured in the elongation direction D of the carrier 120.

According to some other aspects, the second width of an abrasive element is measured as a distance value corresponding to the smallest distance value measured in the elongation direction D of the carrier 120. The first and/or second width of an abrasive element may also be measured by projecting a shadow of the abrasive element onto a surface and measuring the extension of this projection or shadow along a direction corresponding to the extension direction D or along a direction corresponding to the direction E orthogonal to the elongation direction D of the carrier 120. According to some aspects, the nominal first and/or second width of an abrasive element is defined prior to use of the wire saw. Consequently, it is appreciated that the nominal width of an abrasive element at manufacturing is independent of abrasive element wear after manufacturing. It is also appreciated that a randomization of abrasive element geometries may inadvertently be obtained from use of the wire due to wear, to a smaller extent or in such a way that the skilled person won't even notice it. However, the wire disclosed herein is associated with a randomized nominal width distribution when new. Advantageously, an operator need not wait for the wire abrasive element widths to be randomized due to wear before obtaining the advantages associated with the present wire. Figure 4a illustrates a sequence of measurements of abrasive element first widths, here bead widths 400. The bead widths are plotted versus bead number, in sequence along a carrier. The nominal widths at manufacturing have been randomized along the extension direction D of the carrier. Here, the widths are distributed around two nominal first width values 411, 412, at approximately 6,33 mm and 6,51 mm.

Figure 4b illustrates a histogram 450 over the width data from Figure 4a. The y-axis of a histogram, in general, shows frequency, i.e., how often a value occurs relative to other values. It is appreciated that the distribution illustrated by the histogram is multimodal, i.e., is has two modes. A first mode 451 is seen at 6,3 mm and a second mode 452 is seen at 6,5 mm, corresponding to approximate nominal first width values of the wire at manufacturing.

Figure 5a illustrates the results of a measurement campaign where abrasive elements of a wire according to prior art and a wire according to the present teaching was measured. The measured first width values in mm are plotted vs. bead number and labelled with triangles 511 for the prior art wire and with squares 512 for the wire proposed herein, i.e., the new type of wire. The prior art wire has abrasive elements with a single nominal width, while the new type of wire has abrasive elements with two different nominal widths. The abrasive element widths of the new wire have been randomized.

The distribution of abrasive element first widths of the prior art wire, i.e., measurement values 511, is plotted in a histogram in Figure 5b. It is noted that the distribution is unimodal, with mode value at approximately 6,3 mm, corresponding approximately to the single nominal width.

The distribution of abrasive element first widths of the new wire disclosed herein, i.e., measurement values 512, is plotted in Figure 5c. It is noted that the distribution is multimodal, with mode values 510, 520 at approximately 6,1 mm and at 6,25 mm, corresponding approximately to the different nominal widths of abrasive elements on the new wire.

A plot of second widths, exemplified in Figure 8, looks similar to that shown in Figure 5c but shows different mode values relating to length instead of girth. The plot 800 shows a first mode 810 around 6,95 mm and a second mode around 7.15 mm. Given that Full Width at Half Maximum (FWHM) of preferred length distributions is typically 0.2mm, a difference of more than 0.3mm between the 2 maximum peaks of the series being mixed to break resonance, combined or not with first width randomization seems desirable.

Thus, according to some aspects, a first nominal second width at manufacturing is about 7 mm, and a second nominal width at manufacturing is about 7,3 mm.

According to aspects, the second width values defined by physical extension of the abrasive element in direction D 112a, 112b, 112c, 112d comprise nominal width values at manufacturing of z mm, and z+w mm, where 5 mm < z < 8 mm, and where w < 1 mm, and preferably where 0,1 mm < w < 0,5 mm.

It is furthermore noted that the first width distribution of the new wire, see Figure 5c, has an increased spread, or statistical deviation from a mean width value, compared to the prior art wire. This is due to the multimodal width distribution indicating more than one nominal width value. In Figure 5b, most widths are within a range of 0,15 mm between approximately 6,20 mm and 6,35 mm. In Figure 5c, a large part of first widths is spread from 6,00 mm up to 6,30 mm, i.e., a range of 0,3 mm. The same is true for the second width, illustrated in Figure 8.

Consequently, according to aspects, less than 80% of first width values of the new wire type is comprised within a range of 0,25 mm.

Figure 6 is a flow chart illustrating methods according to the disclosure. There is shown a method of manufacturing a wire. The method comprises configuring SI an elongated carrier for receiving a plurality of abrasive elements, mixing S2 abrasive elements of varying width and/or composition in a container, and bonding S3 abrasive elements randomly selected from the container onto the carrier. This way, a wire is obtained where a distribution of abrasive element widths and or compositions is randomized. Consequently, the above-mentioned advantages are obtained. As an alternative to mixing abrasive elements of varying width and/or composition in a container, the abrasive elements may be placed in other means of supply, such as a tube or cartridge, in a random fashion.

According to aspects, the bonding S3 comprises bonding S31 abrasive elements onto the carrier at randomized locations, thereby obtaining a wire where the distribution of abrasive element widths and the distribution of abrasive element locations are both randomized.

According to other aspects, the method comprises bonding S32 according to a pre configured randomized inter-element distance sequence. This sequence is, according to some aspects, determined by experimentation or analysis, and programmed into a memory of a manufacturing device.

According to some other aspects, the abrasive elements of varying width comprise elements having first width value above an average width value of the abrasive elements, configured for abrasive operation.

According to some further aspects, the abrasive elements of varying width comprise elements having first width value below an average width value of the abrasive elements, configured for erosive operation.

The mixing S2 of abrasive elements of varying first width in a container may, according to some aspects, comprise mixing S21 varying first widths selected from a set of pre-configured widths. For instance, mixed widths may be selected from nominal first width values of 6,0 mm and 6,3 mm.

The mixing S2 of abrasive elements of varying width in a container may also, according to other aspects, comprise mixing S22 varying widths selected from a pre configured distribution of widths.

Figure 7 schematically illustrates a manufacturing device 700 for manufacturing a wire 100 according to the present teaching. The manufacturing device 700 comprises a carrier feed module 710 arranged to configure an elongated carrier 120 for receiving a plurality of abrasive elements 110a, 110b, 110c. The manufacturing device also comprises a container 720 comprising a mix of abrasive elements of varying width and/or composition, and a bonding module 730 arranged to bond abrasive elements randomly selected from the container onto the carrier. This way a wire 100 for a wire saw is obtained where a distribution of abrasive element width and/or composition is randomized.

According to aspects, the bonding module 730 is also arranged to bond abrasive elements onto the carrier at randomized locations. This way a wire for a wire saw 100 is obtained where a distribution of abrasive element widths and/or compositions, and a distribution of abrasive element locations are all randomized.

According to aspects, the container 720 comprises a mix of abrasive elements having at least two different nominal first width values and/or at least two different nominal second width values.

According to further aspects, the container 720 comprises a mix of abrasive elements having nominal width values distributed according to a distribution having at least two modes.

The inventive concept has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended patent claims.

In summary, there has been disclosed herein a wire 100, 300 comprising an elongated carrier 120 and a plurality of abrasive elements 110a, 110b, 110c, llOd bonded to the carrier. The abrasive elements are arranged at respective locations 122a, 122b, 122c, 122d along the carrier and the abrasive elements have respective widths 111a, 111b, 111c, llld, 112a, 112b, 112c, 112d. A distribution of the abrasive element widths is randomized. According to aspects, a distribution of the abrasive element locations along the carrier is randomized.

According to aspects, the width of an abrasive element is defined by a physical extension of the abrasive element in a direction E orthogonal to an extension direction D of the elongated carrier 120.

According to aspects, width values 111a, 111b, 111c, llld, 112a, 112b, 112c, 112d associated with the abrasive elements 110a, 110b, 110c, llOd comprise two different nominal width values at manufacturing.

According to aspects, a distribution of the abrasive element nominal widths at manufacturing is randomized.

According to aspects, a difference between any two nominal width values at manufacturing is at least 3,5%.

According to aspects, width values 111a, 111b, 111c, llld, 112a, 112b, 112c, 112d associated with the abrasive elements 110a, 110b, 110c, llOd comprise nominal width values at manufacturing of 6,0 mm, and 6,3 mm.

According to aspects, the width values are distributed according to a distribution having at least two modes.

According to aspects, less than 80% of width values are comprised within a range of 0,25 mm.

According to aspects, the initial width of an abrasive element is defined by a measure taken prior to use of the wire. The initial width of an abrasive element is independent of abrasive element wear after manufacturing.

According to aspects, the elongated carrier 120 comprises a wire or a cable.

According to aspects, the plurality of abrasive elements comprises one or more abrasive beads. According to aspects, the abrasive element locations 122a, 122b, 122c, 122d are measured as distances from a reference location 121 associated with the elongated carrier 120 to the respective abrasive element in the direction D along the carrier.

According to aspects, a randomized distribution comprises a distribution where a repetitive pattern of values is absent.

According to aspects, a randomized distribution comprises a distribution having a frequency domain representation with flat amplitude.

According to aspects, the abrasive elements comprise elements having a width value above an average width value of the abrasive elements, configured for abrasive operation.

According to aspects, the abrasive elements comprise elements having a width value below an average width value of the abrasive elements, configured for erosive operation.

There was also disclosed herein a method of manufacturing a wire. The method comprises configuring SI an elongated carrier for receiving a plurality of abrasive elements, mixing S2 abrasive elements of varying width in a container, and bonding S3 abrasive elements randomly selected from the container onto the carrier. This way a wire is obtained where a distribution of abrasive element widths is randomized.

According to aspects, the bonding S3 comprises bonding S31 abrasive elements onto the carrier at randomized locations.

According to aspects, the mixing of abrasive elements of varying width comprises mixing S23 abrasive elements having two different nominal width values.

There was furthermore disclosed herein a manufacturing device 700 for manufacturing a wire 100. The device comprises a carrier feed module 710 arranged to configure an elongated carrier 120 for receiving a plurality of abrasive elements 110a, 110b, 110c, a container 720 comprising a mix of abrasive elements of varying width, and a bonding module 730 arranged to bond abrasive elements randomly selected from the container onto the carrier. This way a wire is manufactured where a distribution of abrasive element widths is randomized. According to aspects, the bonding module is further arranged to bond the abrasive elements onto the carrier at randomized locations.

According to aspects, the container 720 comprises a mix of abrasive elements having at least two different nominal width values.

According to aspects, the container 720 comprises a mix of abrasive elements having nominal width values of 6,0 mm and 6,3 mm.

According to aspects, the container 720 comprises a mix of abrasive elements having nominal width values of 5,0 mm and 5,3 mm.

According to aspects, the container 720 comprises a mix of abrasive elements having nominal width values of 7,0 mm and 7,3 mm. According to aspects, the container 720 comprises a mix of abrasive elements having a first nominal width value of x mm, and another nominal width value of x+y mm, where 3mm<x<8mm and where y<0,3mm.