Abrasive disc, refiner comprising abrasive disc and method for producing abrasive disc

Abstract

The present invention relates to an abrasive disc (10) for a refiner for dissociating lignocellulosic material, the abrasive disc (20) comprising a refining surface (40) having a plurality of teeth (20) separated by grooves (30), where each tooth (20) has a tooth width (w) and a tooth height (h), the tooth height being a height from an adjacent groove bottom to an upper end of the tooth, and where the width (w) of the tooth is greater than the width (w) of the tooth and the height (h) of the tooth is greater than the width (w) of the tooth. According to the invention, at least one tooth of the abrasive disc has a tooth width of 1.5 mm or less and a tooth height of at least 5 mm, at least one groove (30) of the abrasive disc has a groove width (gw) of 1.5 mm or less, at least one of the teeth (20) comprises a tooth opening (23) in the form of a through hole extending through the tooth (20) from one groove (30) to an adjacent groove (30). The invention also relates to a refiner comprising at least one abrasive disc, and to a method for producing an abrasive disc.

Description

TECHNICAL FIELD

[0001] The present invention relates to a refiner plate for a refiner for refining lignocellulosic material. The invention also relates to a refiner comprising such a refiner plate and a method for manufacturing the refiner plate. BACKGROUND

[0002] Disc refiners are commonly used in the pulp industry for refining lignocellulosic material used in the production of fibrous material such as paper and board.

[0003] A disc refiner comprises two or more opposing refining elements, at least one of which is rotatable. The rotatable refining element can be referred to as a rotor or rotor-side plate, while the non-rotatable or stationary refining element can be referred to as a stator or stator-side plate. Between the refining elements is a refining gap, where the material to be refined is ground against the refining surfaces. The refining surfaces of the refining elements comprise a plurality of knives separated by grooves, which are used to refine the lignocellulosic material during use.

[0004] In some applications, the rotor-side plate and the stator-side plate are circular plates, which are mounted on one stationary frame element and one rotating frame element in the refiner, so that they face each other during use. Typically, the stator-side plate and the rotor-side plate are divided into a number of smaller plate segments, each covering a sector of the frame element, which when mounted together form a circular plate. At least one of these circular plates typically has an opening in the centre for insertion of lignocellulosic material, so that the material enters from the centre and is transported in a radial direction during refining.

[0005] The plates are typically very susceptible to wear during use, resulting in the need for frequent replacement. To prolong the service life of the refiner plates and to improve their refining capacity, it is desirable to provide plates with higher density, having a finer pattern, with an increased total length of the refining surface knives, which is referred to as the total cutting edge length. To this end, it is also desirable to provide narrow grooves to achieve a high density arrangement of the refiner knives.

[0006] However, when such refiner plates are cast using conventional sand moulds, the draw angle of the mould results in an increased thickness of the knife bottom, which in turn results in increasingly narrow grooves in the knife bottom. Such narrow grooves are particularly susceptible to clogging, which in turn severely limits the refining capacity of the knives on lignocellulosic material.

[0007] Patent US7419112B2 discloses an attempt to solve this problem, where grooves of different widths are arranged to increase the flow of material along the refiner plate.

[0008] However, there is still a need for further improvements in this field. SUMMARY

[0009] It is an object of the present invention to eliminate or at least minimize the above-mentioned problems. This is achieved by a refiner plate, a refiner comprising a refiner plate and a method of manufacturing a refiner plate according to the appended independent claims.

[0010] The refiner plate of the present invention is suitable for use in a refiner for disintegrating lignocellulosic material, the refiner plate comprising a refining surface having a plurality of tines separated by grooves, wherein each tine has a tine width and a tine height, said tine height being the height from the bottom of an adjacent groove to the upper end of said tine. Furthermore, at least one tine of the refiner plate has a tine width of 1.5 mm or less and a tine height of at least 5 mm. Furthermore, at least one groove of the refiner plate has a groove width of 1.5 mm or less. Furthermore, at least one of the tines comprises a tine opening extending through the tine from one groove to an adjacent groove, said tine opening being a through hole through the tine.

[0011] Thereby, a refiner plate with narrow tines and deep grooves is achieved, which provides a finer pattern with increased cutting edge length, improving the refining effect compared to prior art refiner segments. Furthermore, the tine height is at least 5 mm, increasing the lifetime of the refiner plate as the tines can withstand more wear before needing to be replaced. Providing narrow grooves results in a higher density of refiner tines, thereby increasing the total cutting edge length of the refiner plate.

[0012] By providing a tine opening, steam and / or lignocellulosic material can flow through, reducing the risk of, and even avoiding, clogging or blocking in the grooves. This is particularly advantageous in locations where the groove width is small, as the risk of clogging of the groove increases as the groove width decreases. By providing at least one, but preferably a plurality of tine openings, clogging of the grooves can be minimized or even eliminated, thereby improving the refining effect of the lignocellulosic material and ensuring efficient steam flow and lignocellulosic material transport.

[0013] Suitably, the at least one tine has a tine width of less than 1 mm, preferably less than 0.7 mm, more preferably less than 0.5 mm. In this way, an even finer pattern can be achieved, thereby further increasing the cutting edge length.

[0014] Furthermore, the at least one tine has a tine height of at least 10 mm, preferably at least 15 mm, more preferably at least 20 mm. In this way, the lifetime of the refiner plate is further increased as the tines can withstand more wear before needing to be replaced.

[0015] Suitably, at least one groove has a groove width of 1 mm or less, preferably 0.7 mm or less, more preferably 0.5 mm or less. This significantly increases the total cutting edge of the grinding disc because the cutting teeth can be positioned very close together. In some embodiments, the groove width can be as small as 0.1 mm.

[0016] Suitablely, the average tooth width of the multiple cutting teeth is 1.5 mm or less, or the average tooth height is 5 mm or more. This allows for the creation of fine patterns with narrow teeth that can withstand severe wear.

[0017] Suitablely, each of two adjacent cutting teeth includes at least one cutting tooth opening, and the cutting tooth opening of one of these cutting teeth is non-aligned with the cutting tooth opening of the other cutting tooth. Thus, steam and / or lignocellulose material can flow through the cutting teeth, and due to the misalignment of the openings, the material is guided to flow both along the groove and through the cutting tooth opening, thereby improving flow.

[0018] Furthermore, misalignment of the cutter openings can be achieved by varying the height of the groove bottom between the two cutter teeth or by different radial positions. This distribution of cutter openings allows steam and / or lignocellulosic material to flow efficiently through the cutter openings and along the grooves.

[0019] Suitablely, at least one of these cutting teeth includes multiple cutting tooth openings. This further improves flow and reduces the risk of blockage in the trench.

[0020] In some embodiments, at least half of the cutting teeth include at least one cutting tooth opening. This ensures efficient flow of the lignocellulosic material throughout the grinding disc.

[0021] Suitably, each of two adjacent cutting teeth includes at least one cutting tooth opening, and the cutting tooth opening of one cutting tooth is aligned with the cutting tooth opening of the other cutting tooth to form a flow channel. In this way, steam and / or lignocellulose material can flow through the flow channel and efficiently pass through the grinding disc without flowing along the grooves.

[0022] Suitablely, the grinding disc forms circular sectors with a central angle of 10° to 360°. Thus, the present invention covers both fine grinding discs configured as individual portions forming the entire grinding disc and fine grinding discs formed from circular sectors that can be combined to form the grinding disc.

[0023] The present invention also includes a fine grinding mill having at least one grinding disc according to the invention. Thus, the fine grinding mill can demonstrate the advantages of the grinding disc when finely grinding lignocellulosic materials.

[0024] The present invention also includes a method for manufacturing the grinding disc of the present invention. The method includes providing production data for the grinding disc, providing the production data to a 3D printer, and 3D printing a pattern for the grinding disc.

[0025] By using this method to manufacture grinding discs, it is possible to obtain very fine patterns and grooves for the cutting teeth of a fine grinding mill. Traditional manufacturing methods use molds to produce grinding discs for fine grinding mills, which severely limits the density of the cutting teeth on the grinding disc, thereby limiting the total cutting edge length of the grinding disc.

[0026] Furthermore, by 3D printing the grinding disc, cutting tooth openings can be formed on the disc to achieve the advantages disclosed herein. These cutting tooth openings, preferably forming channels through multiple fine grinding mill teeth, or being misaligned to encourage flow both along and through the fine grinding mill teeth, are impossible to achieve using methods of manufacturing grinding discs via molds or other known prior art techniques.

[0027] Many additional benefits and advantages of the present invention will be readily understood by those skilled in the art in light of the detailed description below. Attached Figure Description

[0028] The invention will now be described in more detail with reference to the accompanying drawings, in which:

[0029] Figure 1 A perspective view of a grinding disc or a portion thereof according to a first embodiment of the present invention is disclosed;

[0030] Figure 2 It was disclosed in an illustrative manner. Figure 1 Side view of the grinding mill teeth and grooves of the grinding disc;

[0031] Figure 3 A perspective view of the cross-section of the grinding disc of the second embodiment is disclosed, showing the opening of the cutting teeth;

[0032] Figure 4 A top view of the grinding mill cutter teeth is disclosed, showing the opening of the cutter teeth;

[0033] Figure 5 An embodiment of the profile of the blade opening is disclosed;

[0034] Figure 6 A perspective view of the grinding disc portion according to the second embodiment is disclosed, showing the flow channel formed by the opening of the cutting teeth in the fine grinding mill;

[0035] Figure 7 A perspective view of the grinding disc according to the second embodiment is disclosed, showing more flow channels formed by the openings of the cutting teeth; and

[0036] Figure 8 The method according to the present invention is disclosed.

[0037] All figures are schematic and not necessarily drawn to scale. They generally show only the parts necessary to illustrate the various embodiments, while other parts may be omitted or are merely illustrative. Unless otherwise indicated, any reference numerals appearing in multiple figures refer to the same object or feature in the figures. Detailed Implementation

[0038] Figure 1 A grinding disc 10 for a disc-type fine grinding mill according to a first embodiment of the present invention is disclosed. The term "grinding disc" is used to refer to a circular sector of a fine grinding mill grinding disc, the central angle of which is 10° to 360°. Therefore, the grinding disc of the present invention can be a circular grinding disc, or it can be a circular sector of a grinding disc, so that multiple grinding discs can be combined to form a circular fine grinding mill grinding disc.

[0039] If the included angle of the grinding disc is less than 360°, the grinding disc is defined by an edge in the circumferential direction of the circular sector. It is particularly important to note that such edges are not limited to the radius of the circle, but can have any straight or curved shape, as long as they can connect the inner periphery to the outer periphery.

[0040] In use, the grinding disc 10 is typically mounted in a disc grinder (not shown) and is used to grind lignocellulosic materials by acting as grinding discs within a pair of grinding discs arranged facing each other, wherein at least one of the grinding discs in the pair is arranged to rotate. Generally, the grinding discs arranged to rotate in the disc grinder are called rotor-side grinding discs, while the grinding discs arranged to be stationary are called stator-side grinding discs.

[0041] As used herein, the term "lignocellulosic material" refers to a material comprising lignin, cellulose, and hemicellulose. An example of such a material is wood, and other examples include other agricultural or forestry waste. When lignocellulosic materials are ground in a disc grinder, the material is typically fed into the grinder through an opening at the center of one of the grinding discs and ground while moving radially outward between the discs.

[0042] As used herein, the term "opposite" or "opposing," when referring to the grinding discs of a disc grinding mill, refers to grinding discs arranged facing each other and sharing a common central axis, about which at least one grinding disc can rotate. Generally, when the grinding discs are stationary, the opposing grinding discs are arranged such that the grinding zone of one disc directly faces the grinding zone of the other, and during the rotation of the rotor-side grinding discs around the central axis, the grinding zone of the rotor-side grinding discs directly passes through the relative positions of the grinding zones of the stator-side grinding discs.

[0043] Figure 1A grinding disc 10 is disclosed, which is a circular sector with arcuate edges 11, 12. The grinding disc 10 is also defined by an inner peripheral edge 13 and an outer peripheral edge 14. On the grinding disc 10, a plurality of fine grinding mill teeth 20 are arranged on a base 15. These teeth 20 are separated by grooves 30, which may extend all the way to the base 15, or, viewed from the fine grinding surface 40 defined by the upper ends 21 of the teeth 20, the depths of which may vary. In some embodiments, the grinding disc 10 includes teeth 20 distributed across the entire grinding disc 10, but in other embodiments, there may be portions without teeth 20 at all. In some such embodiments, portions without teeth 20 may be arranged between portions with teeth 20, or, alternatively or supplementally, portions without teeth may be arranged at the inner peripheral edge 13 and / or the outer peripheral edge 14.

[0044] Each of the cutting teeth 20 extends at least partially in the radial direction D, i.e., from the inner periphery 13 toward the outer periphery 14. The fact that the cutting teeth 20 extend at least partially in the radial direction should be understood as meaning that the extensions of the cutting teeth 20 have a radial component, but they may also have a component perpendicular to the radial direction.

[0045] The grinding disc 10 may also include at least one mounting opening 16 for mounting the grinding disc 10 in a fine grinding mill. In other embodiments, the mounting of the grinding disc 10 may be carried out in any other manner and may optionally include other features or details that facilitate or enable the mounting. Such features or details are well known to those skilled in the art, as are the ways in which the grinding disc 10 is mounted and used in a fine grinding mill.

[0046] In use, the cutting teeth 20 cut the material through the edge 22 at the upper end 21, thereby finely grinding the lignocellulosic material (see...). Figure 2 The edge 22, referred to as the leading edge 22, is the edge 22 at the upper end 21 facing the predetermined rotation direction R. The cutting edge length of the grinding disc 10 is defined as the total length of the leading edges of the teeth 20 divided by the radius r of the grinding disc 10, that is, the line connecting a point on the inner periphery 13 to the nearest point on the outer periphery 14. It is well known in the art that the finishing effect is improved when the cutting edge length is increased by providing a fine pattern consisting of more closely spaced narrow teeth 20.

[0047] Each tooth 20 has a tooth width w and a tooth height h. The tooth width w is preferably measured at the widest portion of the tooth 20, while the tooth height h is the height from the bottom of the groove 30 adjacent to the tooth 20 to the upper end 21 of the tooth 20, i.e., from the bottom of the groove 30 to the finishing surface 40. In some embodiments, multiple teeth may have the same tooth width w and tooth height b, but in other embodiments, they may vary depending on the tooth 20. Furthermore, in some embodiments, for a single finishing mill tooth 20, the tooth height h measured in each of the adjacent grooves 30 may be the same (i.e., the grooves 30 may have the same or substantially the same depth), but in other embodiments, the tooth height h may vary depending on the adjacent grooves 30 used to measure the tooth height h. In such embodiments, when the tooth height h of the tooth 20 is mentioned herein as having any given length, it should be understood as the tooth height h measured in at least one of the adjacent grooves 30 having that length.

[0048] In the grinding disc 10 of the present invention, the tooth width w of at least one cutting tooth 20 is 1.5 mm or less, and the tooth height h is at least 5 mm. This makes the cutting tooth 20 both narrow, enabling fine patterns to be formed, thus providing a longer cutting edge length on the grinding disc 10, and high, ensuring a longer service life of the grinding disc 10. In some embodiments, the tooth width w of at least one cutting tooth 20 is less than 1 mm, preferably less than 0.7 mm, more preferably less than 0.5 mm. This ensures the formation of finer patterns on the grinding disc 10. In some embodiments, the tooth width 2 of at least one cutting tooth 20 is 0.2 mm.

[0049] Furthermore, in some embodiments, the tooth height h is at least 10 mm, preferably at least 15 mm, and more preferably at least 20 mm. This ensures an increased service life for the grinding disc 10, thereby reducing the frequency of replacement of worn grinding discs.

[0050] Furthermore, in the grinding disc 10 of the present invention, at least one groove in the groove 30 has a groove width gw of 1.5 mm or less. This narrows the groove 30, thereby increasing the density of the cutting teeth 20, and consequently significantly increasing the total cutting edge length of the grinding disc 10. In some embodiments, the groove width of at least one groove is 1 mm or less, preferably 0.7 mm or less, more preferably 0.5 mm or less. Additionally, the groove width of at least one groove in the groove 30 may be 0.2 mm.

[0051] Advantageously, the multiple grooves 30 can have the groove width gw described above. Furthermore, the groove width gw can vary along a single groove 30, or can be varied such that the groove width gw of one groove 30 is different from the groove width gw of another groove 30 of the grinding disc 10.

[0052] The design of the cutting teeth 20 and grooves 30 of the grinding disc 10 of the present invention makes the grinding disc 10 particularly suitable for low-concentration fine grinding, wherein the slurry concentration is typically in the range of 3% to 5%.

[0053] In some embodiments, the average tooth width of a plurality of grinding mill teeth 20 in at least a portion of the grinding mill disc 10 is 1.5 mm or less, or the average tooth height is 5 mm or more. Similarly, the average groove width of a plurality of grooves 30 in at least a portion of the grinding mill disc 10 is 1.5 mm or less. This ensures that fine patterns can be achieved across the entire grinding disc 20, thereby enhancing the aforementioned advantages. In other embodiments, all grinding mill teeth 20 of the grinding disc 10 have an average tooth width of 1.5 mm or less, or an average tooth height of 5 mm or more, and all grooves have an average groove width of 1.5 mm or less.

[0054] In such embodiments, the average tooth width, average tooth height, and average groove width can preferably be the same as the tooth width w and tooth height h of a single tooth 20 and the groove width gw of a single groove 30.

[0055] In a first embodiment, at least one of the cutting teeth 20 includes a cutting tooth opening 23 that extends through the cutting tooth 20 from one adjacent groove 30 to another adjacent groove. This is in Figure 4 As shown, the tooth opening 23 is indicated by a dashed line, and two of the teeth 20 include the tooth opening 23, but the other tooth 20 does not. The tooth opening 23 can have any suitable cross-sectional shape, such as circular, elliptical, rectangular, or any other shape. Figure 5 One embodiment is shown in which the toothed opening 23 has an elongated lower portion and a gradually narrowing upper portion, which is a suitable shape, but many other shapes are possible. The toothed opening 23 has an opening width ow and an opening height oh, the dimensions of which can be varied as needed to obtain a toothed opening 23 with suitable dimensions, thereby allowing steam and / or lignocellulose material to pass through the toothed opening 23. Furthermore, the size and shape of the toothed opening 23 provided on the same grinding disc 10 can differ from any other toothed opening 23.

[0056] The opening 23 is defined as an opening extending through the tooth 20 to establish a connection between the groove 30 on one side of the tooth 20 and the groove 30 on the other side of the tooth 20. The opening 23 is defined by the material of the tooth 20; specifically, it is defined by the material of the tooth 20 around its entire circumference, meaning the opening 23 is not in the form of a notch, groove, or indentation. Furthermore, an advantage of the opening 23 is that it is located within the tooth 20, rather than beneath it.

[0057] The purpose of the tooth opening 23 is to allow lignocellulosic material and / or steam to pass through during fine grinding, thereby facilitating transport across the grinding disc 10. It also serves to minimize or even eliminate the risk of reduced fine grinding efficiency due to clogging of the grooves 30 on the grinding disc 10, as it allows lignocellulosic material and steam to move not only along the grooves 30 but also from one groove 30 to another through the tooth opening 23. Particularly advantageous is that the tooth opening 23 is provided as a through-hole within the tooth 20, rather than a groove penetrating the tooth 20, or even an interruption structure of the tooth 20, because this allows any number of tooth openings 23 to be provided on the grinding disc 10 without reducing the fine grinding area provided by the tooth 20. If the tooth opening 23 were instead provided as an interruption structure or groove in the tooth 20, this would significantly reduce the area available for fine grinding of the lignocellulosic material, thereby also reducing the fine grinding efficiency of the grinding disc 10.

[0058] like Figure 4 As shown, when tooth openings 23 are provided in adjacent cutting teeth 20, they may be misaligned, causing them to not overlap or only partially overlap. This can be achieved by offsetting the tooth openings 23 relative to each other, or offsetting along the distance direction between the upper end 21 of the cutting tooth 20 and the grinding surface 15 (i.e., the distance direction between the upper end 21 of the cutting tooth 20 and the bottom of the groove 30 between the cutting teeth 20 of the grinding mill), or offsetting radially D, or offsetting in both of the above directions. Figure 4 floor plan and Figure 3 The perspective views all reveal this type of misaligned blade opening 23, in which, Figure 3 Multiple blades 20 with blade openings 23 are shown. Misalignment or offset of the blade openings 23 means that the flow of lignocellulose material and steam cannot travel in a straight line through the blades 20, but is instead forced to cross the grinding disc 10 to find other paths.

[0059] Preferably, at least half of the blades 20 include at least one blade opening 23, which allows the material to flow efficiently through the grinding disc 10 when used for fine grinding of lignocellulosic materials.

[0060] Figure 6A grinding disc 10 is disclosed, having a flow channel 24 formed by cutter tooth openings 23 distributed in the cutter teeth 20. In such a flow channel 24, the height of the cutter tooth openings 23 may be offset, but they are aligned in the radial direction D or in a direction at an angle relative to the radial direction D to provide a suitable flow direction. Figure 6 In the flow channel 24, the flow channels are distributed with gaps between them. These flow channels may include some portions of the blades 20 with missing blade openings 23, or blades 20 with misaligned blade openings 23 to form the flow channels 24.

[0061] Figure 7 One embodiment of the grinding disc 10 is disclosed, wherein the flow channels 24 are arranged more closely to further improve the flowability of material through the grinding disc 10. The advantage of arranging the tooth openings 23 as flow channels 24 is that it facilitates the transport of steam and / or lignocellulose material within the flow channels 24, thereby improving its transport from the inner periphery to the outer periphery through the grinding disc 10. Suitably, at least some of the flow channels 24 are arranged in a natural flow direction at an angle relative to the radial direction D to further improve the transport of steam and / or lignocellulose material within the flow channels 24. The natural flow direction is the primary flow direction that traverses the grinding disc 10 as it rotates in the rotational direction R.

[0062] In some embodiments, the blade openings 23 may be arranged vertically within the same blade 20, and suitably, the flow channels 24 penetrating multiple blades 20 may also be arranged vertically, such that their extending directions are parallel to each other or at a certain angle, but at different heights. It is particularly advantageous to arrange the flow channels 24 closer to the outer periphery 14, because the risk of clogging of the grooves 30 increases there.

[0063] In some embodiments, the groove 30 is configured with a smaller groove width gw near the outer periphery 14, but a larger groove width near the inner periphery 13. This allows for a higher density of the cutting teeth 20, resulting in a longer cutting edge length near the outer periphery. It is also advantageous to position the cutting tooth opening 23 near the outer periphery 14 to avoid clogging at the groove 30.

[0064] The present invention also includes a fine grinding mill comprising at least one grinding disc 10 according to any embodiment of the invention. The grinding disc 10 can be used as a rotor-side grinding disc or a stator-side grinding disc; alternatively, two grinding discs 10 according to the invention can be used together, one as a rotor-side grinding disc and the other as a stator-side grinding disc. Where the central angle of the grinding disc 10 is less than 360°, a plurality of grinding discs 10 are combined to form a circular grinding disc in the fine grinding mill. In some embodiments of the fine grinding mill, different embodiments of the invention can be used as both stator-side and rotor-side grinding discs.

[0065] It is difficult, if not impossible, to manufacture the grinding disc 10 with narrow cutting teeth 20 disclosed herein using known existing manufacturing methods (typically sand casting, although other manufacturing methods are also known and used). The cutting tooth 20 size achieved by the present invention benefits from additive manufacturing technology, which has not been previously applied to the manufacture of blades 10 for fine grinding mills. Furthermore, the cutting tooth opening 23, as described above, cannot be manufactured by casting, but is formed using the manufacturing method of the present invention described below.

[0066] Now refer to Figure 8 A method for manufacturing grinding discs according to the present invention is described.

[0067] The method includes providing production data for the 101 grinding disc 10 according to any of the embodiments disclosed herein.

[0068] Generally, in this disclosure, production data can be provided in any suitable data type. Typically, 3D printable models can be created using computer-aided design (CAD) software packages, via 3D scanners, or through ordinary digital cameras and photogrammetry software. 3D printing models created using CAD result in reduced errors and can be corrected before printing, allowing for verification of the object's design prior to printing. Therefore, CAD data is preferred in this disclosure.

[0069] In one specific embodiment of this disclosure, a 3D model of a grinding mill disc is created using a CAD software package. The 3D model, generated by the CAD program, is a mathematical expression stored in a first data file with a suitable file format, such as an STL file. Suitable CAD software packages include, for example, Pro / Engineer and SolidWorks. Optionally, but preferably, the data in the first and second data files is checked for errors and defects using a suitable software package (e.g., a package provided by EOS Additive Manufacturing Solutions). Besides correcting errors in the data files, it is important that all geometries in the grinding mill disc model are reproducible and suitable for subsequent manufacturing steps. Based on the geometry integrated in the grinding mill sector and the selected specific 3D printer and 3D printing software, the data contained in the data file is mathematically sliced ​​into layers, with a virtual slice thickness, for example, 0.01 mm.

[0070] The method also includes providing production data to the 3D printer.

[0071] Generally, in this disclosure, the printing step can be performed using any suitable type of 3D printer. Preferred printing materials are selected from metals or metal alloys. The invention is not limited to specific printing materials.

[0072] The method also includes 3D printing the pattern of the 103 grinding disc 10.

[0073] Therefore, the data file after mathematical stratification and slicing is input into a suitable 3D printer software package, and a 3D printer is used to print a fine grinding disc. Different 3D printing technologies can be used, but the preferred technology is the so-called Direct Metal Laser Sintering (DMLS), which uses a yttrium (Yb) fiber laser emitted into a bed of metal powder.

[0074] It should be noted that the features from the various embodiments described herein can be freely combined unless it is explicitly stated that such a combination would be inappropriate.

Claims

1. A refining plate for a refiner for disintegrating lignocellulosic material, the refining plate (10) comprising a refining surface (40) having a plurality of teeth (20) separated by grooves (30), wherein each of the teeth (20) has a tooth width (w) and a tooth height (h) being the height from the bottom of an adjacent groove (30) to the upper end of the tooth (20), wherein the tooth width (w) of at least one tooth (20) of the refining plate (10) is 1.5 mm or less and the tooth height (h) is at least 5 mm, and wherein further the groove width (gw) of at least one groove (30) of the refining plate is 1.5 mm or less, at least one of the teeth (20) comprises a tooth opening (23) extending through the tooth (20) from one groove (30) to an adjacent groove (30), the tooth opening (23) being a through hole through the tooth (20). The tooth width (w) of at least one tooth (20) is less than 1 mm, preferably less than 0.7 mm, more preferably less than 0.5 mm. characterized in that The tooth height (h) of at least one tooth (20) is at least 10 mm, preferably at least 15 mm, more preferably at least 20 mm.

2. The abrasive sheet of claim 1, wherein, The groove width (gw) of at least one groove (30) is 1 mm or less, preferably 0.7 mm or less, more preferably 0.5 mm or less.

3. The abrasive sheet of claim 1 or 2, wherein, The average tooth width of the plurality of teeth (20) is 1.5 mm or less and the average tooth height is 5 mm or more, or the average groove width of the plurality of grooves (30) is 1.5 mm or less.

4. The abrasive segment of any of the preceding claims, wherein, Both adjacent teeth (20) each comprise at least one tooth opening (23), and wherein the tooth opening (23) of one of the teeth (20) is misaligned with the tooth opening (23) of the other tooth (20).

5. The abrasive sheet according to any one of the preceding claims, wherein, The tooth opening (23) is misaligned by being different in height from the bottom of the groove (30) between the two teeth (20), or by being different in position in the radial direction (D).

6. The abrasive sheet according to any one of the preceding claims, wherein, At least one of the teeth (20) comprises a plurality of tooth openings (23).

7. The abrasive sheet of claim 6, wherein, At least half of the teeth (20) comprise at least one tooth opening (23).

8. The abrasive sheet of claim 6 or 7, wherein, Both adjacent teeth (20) each comprise at least one tooth opening (23), and wherein the tooth opening (23) of one of the teeth is aligned with the tooth opening (23) of the other tooth to form a flow channel (24).

9. The abrasive sheet according to any one of the preceding claims, wherein, The refining plate (10) forms a circular sector having a central angle of 10° to 360°.

10. The abrasive sheet according to any one of the preceding claims, wherein, The refining plate (10) is made by additive manufacturing.

11. The abrasive sheet according to any one of the preceding claims, wherein, 13. A refiner comprising at least one refining plate (10) according to any one of claims 1 to 12.

12. The abrasive sheet according to any one of the preceding claims, wherein, 14. A method for manufacturing a refining plate according to any one of claims 1 to 12, comprising: - providing production data of the refining plate (10), - supplying the production data to a 3D printer, and - manufacturing the refining plate (10) by additive manufacturing. ​ - 3D printing the pattern of the abrasive sheet. - 3D printing the pattern of the abrasive sheet.

Images