Patent Application
20210046613
The application relates to a method and an apparatus for abrading. Further the application relates to an abrasive product and uses of the method, the apparatus and the abrasive product.
Abrading refers to a method for rubbing abrasive particles against a surface in order to treat or finish a surface. Surface treatment enables achieving a desired result relating to surface smoothness, roughness, structure or design, for example. Finishing may comprise providing a surface texture, a polished surface or a mirror polish, for example. Typically more than one abrading phases are required in order to achieve the desired result. Abrading may include several different abrading phases. Different abrading phases may include anything between a coarse grit enabling removing lot of material and a finer grit enabling achieving a mirror polish.
An object of the application is to simplify a process for abrading a workpiece at different abrading phases, which utilize different abrasive properties.
A continuous abrasive product comprises predetermined length and number of predetermined kind of abrasive areas on an abrasive surface. An abrasive product comprises at least two abrasive areas of different abrasive properties. Different abrasive properties enable providing different surface roughness sequentially, using a single abrasive product. Different abrasive properties of a single abrasive product may enable forming a desired shape, surface pattern or surface finish to a workpiece using a single abrasive product, at a single tooling place, phase and/or machine.
According to an aspect of the invention an abrasive product comprises continuous longitudinal abrasive material including at least two longitudinally sequential different abrasive areas having different kind of abrasive properties. The continuous longitudinal abrasive product is feedable in an abrading zone of an abrading apparatus in order to arrange abrading sequentially with the corresponding at least two sequential different kind of abrasive areas.
According to another aspect of the invention an apparatus for abrading a workpiece comprises an abrading zone, wherein the workpiece is arranged to be abraded, and an arrangement configured to feed to the abrading zone an abrasive area of an abrasive product and to replace the abrasive area at the abrasive zone with an another abrasive area of the abrasive product. The another abrasive area, or an unused abrasive area, is different from the abrasive area, or the used abrasive area.
Still another aspect of the invention comprises a method for abrading a workpiece including arranging an abrasive area of an abrasive product at an abrading zone for abrading the workpiece, and replacing the abrasive area at the abrading zone with an another abrasive area of the abrasive product for abrading the workpiece. The another abrasive area is different from the abrasive area. The abrasive product comprises a continuous longitudinal abrasive product including at least two longitudinally sequential different abrasive areas having different kind of abrasive properties.
According to yet another aspect of the invention use of an abrasive product in an abrading apparatus comprises a continuous longitudinal abrasive product having a surface of at least two sequential different kind of abrasive areas along the longitudinal dimension of the abrasive product, wherein the at least two sequential different kind of areas have different kind of abrasive properties. The continuous longitudinal abrasive product is feedable to an abrading zone of the abrading apparatus such that the at least two sequential different kind of abrasive areas are feedable sequentially to the abrading zone.
In the following embodiments of the invention are described in more detail with the accompanying drawings of which:
The figures may not be in scale.
An abrasive product may be a flexible elongated sheet, which is arranged to be rolled up. The abrasive product may be a roll, a belt or comprise alike elongated form. An abrasive surface is arranged onto a backing. The abrasive surface comprise different kind of abrasive areas. An abrasive area may be arranged in contact with an object or a surface, which is to be a abraded. The abrasive surface and the surface to be abraded are arranged to move in relation to each other. The abrasive surface may be arranged to move, for example oscillate, back and forth, or roll to roll, while arranged in contact with the object/surface to be a abraded. The object/surface to be abraded may be arranged to move, for example spin or rotate, while in contact with the abrasive area.
A workpiece 10 is arranged at an abrading zone 105. An abrasive surface 104 of an abrasive material is fed onto the contact roll 102 in order for the abrasive surface 104 to be arranged in contact with the workpiece 10 at the abrading zone 105. The contact roll 102 is arranged to support an area of an abrasive surface 104 of the abrasive material and arrange it in contact with the workpiece 10. The contact roll 102 is arranged to move the abrasive material towards the workpiece 10 such that an abrasive area of the abrasive surface 104 of the abrasive material is arranged in contact with the workpiece 10. The contact roll 102 may be moved pneumatically. The contact roll is arranged to move towards and away from the workpiece 10. At the abrading phase the abrasive surface 104 and the workpiece 10, that are arranged in contact with each other, are arranged to move in relation to each other. The abrasive material is moveable from the roll of abrasive material 101 to the roll of used abrasive material 103 via a contact roll 102. The abrasive material may be arranged to move continuously and/or constantly over the contact roll 102. The abrasive material comprises different abrasive areas, having different abrasive properties. Continuous movement of the abrasive material having different abrasive areas enables abrading the workpiece with different kind of abrasive areas continuously. Different kind of sequential abrasive phases are implemented continuously, without breaks. The abrasive material may be designed in accordance to a desired end result of the different kind of abrading phases.
Sequential abrading phases may be arranged to change continuously, on the fly, without breaks. A different kind of abrasive area may be introduced to an abrading zone via roll-to-roll abrading method. A roll of abrasive product may comprise two, three or more sequential different kind of abrasive areas of predetermined length along longitudinal dimension of the roll. After all desired different abrading phases are accomplished, the movement is stopped. The contact roll is arranged to move away from the workpiece, thereby releasing contact between the abrasive material and the workpiece.
An abrading zone refers to a part of an abrading apparatus, where abrading is implemented. The abrading zone may comprise, at least partly, a part of the abrading apparatus arranged to receive a workpiece to be abraded. The abrading zone may comprise, at least partly, a moveable support for receiving an abrasive material. An abrasive surface of an abrasive product is arrangeable in contact with a workpiece at the abrading zone. The abrasive surface is arranged in contact with a workpiece with aid of the moveable support. The abrading is implemented at the contact area of the abrasive surface of the workpiece.
For abrading, a relative movement of the abrasive material and the workpiece is arranged. During abrading phase, the abrasive material and the workpiece are arranged to move in relation to each other. Moving may comprise one-way movement, two-way movement, reciprocating movement back and forth, rotation and/or oscillation. An abrading phase may comprise a predetermined abrading time. Both the workpiece and the abrasive surface on the contact roll may be arranged to rotate, optionally in different directions of rotation. The workpiece may be arranged to move against the abrasive surface. The abrasive surface may be arranged to move against the workpiece. The abrasive surface may be arranged to move with aid of the support. The workpiece may be arranged to rotate in relation to the abrasive surface, in order to abrade the surface of the workpiece by the abrasive surface. The workpiece may be arranged to oscillate with or without rotation movement. The abrasive surface may be arranged to reciprocate. The workpiece maybe arranged to rotate and/or the abrasive surface may be arranged to oscillate with the support in order to arrange abrading. Oscillation may comprise oscillation in one dimension in a plane, referring to a reciprocation along x-direction, or movement back and forth. Oscillation may comprise oscillation in two dimensions in a plane, referring to a movement along x- and y-directions or reciprocation in two dimensions.
An abrading phase may relate to a predetermined abrading result and/or to sequential use of a certain kind of abrasive areas of the abrasive product. An abrading phase may be changed to a different one by replacing a used abrasive area with another unused, different kind of abrasive surface. Sequential abrading phases relate to a predetermined kind of abrading result, and/or to a use of different kind of abrasive areas sequentially. The sequential abrasive areas differ in their abrasive properties with their neighbouring abrasive areas. A sequential abrading phase may be initiated by replacing the used abrasive surface with a different kind of abrasive surface. Sequential different abrading phases are enabled by providing a continuous abrasive product including different abrasive areas to an abrading apparatus. This enables different abrading phases to be implemented without replacing an abrasive product or changing an abrading machine to another one. With the abrasive product, two, three or more different abrading phases may be accomplished without interruptions. Multiple, different abrading phases may be accomplished as a single continuous process.
The abrasive areas 301, 302, 303 are arranged next to each other, sequentially, along longitudinal direction L of the abrasive surface of the abrasive product 300. In
Portions without abrasive grains between the abrasive portions, which comprise abrasive grains, enable providing channels between abrasive portions of an abrasive area. The channels between abrasive portions enable removing abraded material away from the abrading area. Blocking or clogging of abrasive material is reduced or avoided by removing material via channels. This provides longer service life for the abrasive area. Channels may aid in providing a flexible abrading product. If lubricant, like emulsion, water or oil, is used for abrading, removal of the lubricant from the abrasive area may be enhanced via channels.
An abrasive product 300 may comprise multiple sets of predetermined sequential abrasive areas.
abc illustrated different abrasive areas of an abrasive product. The abrasive product may comprise two or three or more different abrasive areas.
One or some of the sequential abrasive areas may comprise a pattern. One or some of the sequential abrasive areas may include dot-like abrasive areas. The sequential abrasive areas comprise different abrasive properties compared to their neighbouring abrasive area(s). The abrasive areas may comprise different type of grains and/or grains of a different size and/or grains at a different density on an area unit. The abrasive result is dependent on the abrasive area used. An abrasive area may comprise a pattern. An abrasive area may comprises a form of a fractal. The fractal may have congruent shapes and channel portions may comprise substantially constant widths. The form of the repeated units of the fractal may vary. The repeated units on the abrasive area may comprise self-similar or a congruent shapes. Congruent refers to figures or objects, which have the same shape and size. If the geometric shape is not symmetric, a mirror image of a shape may be used. A mirror image of a shape is also congruent to the original shape. Two congruent shapes may be next to each other in alternating order, for example as translations, rotations and reflections. Self-similar shapes refer to shapes which may differ in size but not in shape. Fractals are self-similar patterns, which may be exactly the same at every scale, or nearly the same at different scales. A two-dimensional surface of an abrasive area may be created by using the repetition of a geometric shape without overlaps or gaps.
The abrasive product may be rolled out from a roll 401. The abrasive product may be rolled between two rolls 401, 403. The two rolls may be the roll 401 of unused abrasive material and a roll 403 of used abrasive material. The roll 401 of unused abrasive material refers to a source of unused abrasive material. The roll 403 of used abrasive product may be arranged to collect used abrasive product. The rolls 401, 403 enable movement of the abrasive product between them. For example, a used abrasive surface at the abrading zone may be replaced by an unused abrasive surface of the same abrasive product by moving the abrasive product between the rolls.
Rolls of a roll-to-roll arrangement or one of them may be replaced by an arrangement enabling moving the abrasive material between the rolls. Instead of the roll of used abrasive material, the abrasive material may be pulled from the abrading zone to waste. A roll may be replaced by rolls, a nip between two rolls or alike arrangement suitable for moving the abrasive material towards and/or away from the abrasive zone. An abrasive product may be in form of a belt. The belt may be arranged to move with aid of rolls and guiding rolls.
An axle, a shaft or a bearing, for example a connecting rod or a driving bar, may be abraded in three different phases, where a three-phase machine tooling has been commonly used. For the three phases, three different machines have been be utilized. Alternatively, a machine with three separate abrading arms has been used. Use of different machines or arms requires moving the workpiece between different places of the corresponding abrading phases. In accordance to the present inventive aspects, three different machines may be replaced by a single one, or use of separate abrading arms may be avoided. An abrasive area of an abrasive material, which is arranged next to a workpiece to be tooled, is replaceable by another abrasive area of the abrasive material. When an abrading phase is accomplished, a used abrasive area is removed from the abrading zone, while new, unused abrasive area of the same abrasive product is fed to the abrading zone for the subsequent abrading phase. Feeding new different kind of abrasive area may be repeated continuously or multiple times, in order to arrange multiple sequential abrading phases. The abrasive product having different abrasive areas may be fed to abrading arrangement between different abrading phases, or as a start of an abrading phase, or continuously without any breaks between different abrading phases.
An abrasive product may be arranged in a form of a roll, a belt or a corresponding continuous structure. The abrasive product may be arranged to be pulled or rolled out from a roll. A support is configured to arrange an abrasive surface in contact with a workpiece, which is to be tooled via multiple different sequential abrading phases. A support may comprise a contact piece, a contact roll, an abrading support, an abrading base or alike. A support may comprise any form, for example it may comprise square or round plane, which is arranged to push an abrasive surface in contact with a workpiece. A back surface of an abrasive product, being opposite to the abrasive surface, is arranged next to the support. There is a friction between the back surface of the abrasive product and the support such that the abrasive product is arranged to move with the support or with aid of the support.
A contact between an abrasive material and a round object may be implemented via clamp shoes or a contact roll. The workpiece and the abrasive surface are arranged to move in relation to one another. Both the workpiece and the abrasive surface on the contact roll may be arranged to rotate, optionally in different directions of rotation. An abrasive surface on a contact roll may be moved while the abrasive surface is in contact with a surface of a workpiece. A workpiece may be arranged to move, for example rotate or oscillate, in order for it to be abraded.
Abrading is applicable for plane-like, contoured or curved surfaces, for example. Abrading may be implemented for cylindrical or round objects, like shafts. In addition to round surfaces, also flat, plane-like surfaces may be abraded. A square shaped support may press the abrasive product in contact with a workpiece, wherein the support is arranged to move or reciprocate along a plane, in x-direction and/or y-direction. The contact area between the workpiece and the abrasive surface of the abrasive material may be the same or smaller than a size of a support surface, which is arranged to press the abrasive surface on it in contact with the workpiece. Size of the support surface refers to a surface area of the support, onto which an abrasive material is arranged to be placed. The size of the support surface corresponds to a size of a tooled or abraded surface of the workpiece. For example, the abrasive product may have width of 50 mm. If the support surface comprising a diameter of 25 mm is used for pressing the abrasive surface in contact with the workpiece, the workpiece is tooled at the contact area, being of width of 25 mm in accordance to the size of the support surface. When clamp shoes are utilized, the abrasive surface may be pressed around a round-shaped workpiece. Clamp shoes may conform shape and size of the round-shaped workpiece, like a shaft. In addition, the contact area is dependent on an interior surface area of the clamp shoes. Dimensions of the interior surface of the clamp shoes arrange the contact area for the abrasive surface with the workpiece.
After the abrading is accomplished, the abrading phase is stopped 505. Stopping 505 includes stopping the relative movement of the abrasive surface and the workpiece. Abrading may be considered accomplished, when a desired abrasive result, relating to final result of abrading or current abrading phase, is achieved, when a predetermined time of the current abrading phase has expired, or when the abrasive surface tends to be worn out. After the abrading is stopped, the support is separated from the workpiece 506. In case the final abrading phase is accomplished and/or or all the predetermined abrading phases are accomplished and/or the predetermined end result of the workpiece is achieved, the workpiece is considered to be finished, and the abrading, as well as abrading phases, are stopped 507. The finished, tooled and/or final workpiece may be removed. If abrading is to be continued to another, sequential abrading phase, the method is continued from the phase 502, by feeding another abrasive surface of the abrasive material to the abrasive zone. The fed, another abrasive surface, which is replacing the previously used abrasive surface in the abrasive zone, may comprise different abrasive properties than the previously used. After the abrasive material with the another abrasive surface is fed 502 to the abrading zone, it is arranged in contact with the workpiece.
The abrasive material is arranged on the support, which is pressed towards the workpiece. The abrasive material is arranged in contact with the workpiece 503. Next, the abrading is started 504 and the workpiece is abraded. After the abrading is ready, the abrading is stopped 505 and the support is separated from the workpiece 506, causing the abrasive surface to loose contact with the workpiece. After this, readiness of the workpiece is considered again. After this, abrading may be stopped or new abrading phase may be started. Thus, a workpiece may be abraded with a single abrasive product, in accordance to different abrading phases, which may include abrading with different kind of abrasive surfaces. Phases 502-506 may be repeated two, three or more times for the same workpiece. This enables providing two, three or more different kind of abrading phases for the workpiece without changing tools, machine or places of abrading. This enables providing subsequent different abrading phases and/or switching from an abrading phase to another fast and effectively. The workpiece may be abraded and finished using a single abrasive product and machine.
In order to provide longer abrasion time with a certain kind of abrasive area, the abrasive surface may comprise multiple abrasive layers. With multiple abrasive layers longer abrasion time may be implemented. The multiple layers sustain wear and may be used for a longer period. When a layer of abrasive is worn out, new layer is revealed, which enables continuing abrading with the same kind of abrasive surface. Another alternative to enable longer abrasion time with a certain kind of abrasive area, is to provide increased length of the abrasive area on the abrasive surface. This enables a worn out abrasive area to be replaced by an unused same kind of abrasive area. Thus the same kind of abrasive area may be subsequently fed to the abrading zone. This enables abrading with the same kind of abrasive area subsequently twice or more. With continuous abrading, where the abrasive material is continuously fed on a contact roll at an abrading zone, lengths of different kind of abrasive areas along longitudinal abrasive product have effect on abrasion time with the different kind of abrasive areas. In addition to size of the abrasive areas, feeding speed of the abrasive material has effect on abrasion time with a certain kind of abrasive area.
The backing 601 may be flexible. Flexible backing material may comprise thermoplastic, paper, polymer, fabric, cloth foam, laminate or threads. The backing 601 may comprise film, metal film, plastic film, textile, a woven textile made from combustible fibers, a sheet comprising vulcanized fibers. The flexible backing material may conform according to a surface to be abraded. The backing layer 601 thickness may be from 50 to 250 micrometres, for example. This may provide a desired flexibility. An abrasive product may be an abrasive sheet, disc, roll, belt, band or alike continuous elongated form or part of such. The backing 601 comprising a polymer material may be modified to comprise desired properties. The backing 601 may be at the same time both flexible in order to conform with an abraded surface, and durable in order to withstand use in machine abrasion. Durability relates to properties like tensile strength, bending stiffness and/or elongation strength of the backing 601. The backing 601 comprising thermoplastic polymers enables processing by extrusion, co-extrusion, injection moulding or lamination. Thermoplastic polymers may be formed to have a precise composition, may be easy to mould and process and may enable providing a backing 601 with even quality. A thermoplastic polymer may be selected to comprise a combination of elastic and plastic properties which are suitable for the abrasive product.
An abrasive surface 602 or an abrasive layer is arranged onto a backing 601. Abrasive surface may comprise abrasive grains adhesively attached to the backing 601 via adhesive. Adhesive may comprise at least one of water based adhesive, solvent based adhesive, acrylic resin or formaldehyde resins. The backing 601 may be arranged to operate as an adhesive. The backing may comprise resin reinforced with fibers. The grains may be partially sunk in a plastic film, or in an organic and/or inorganic coating layer. Two or more abrasive layers may be arranged onto a backing 601. The abrasive surface 602 may comprise abrasive areas of several layers on top of each other. The abrasive layers may have similar size and/or shape, or the size and/or shape of the layers may differ. A fine abrasive layer may be arranged onto a predetermined area of a backing 601 and a coarse abrasive layer on top of the fine abrasive layer. Outermost of the abrasive layers may be disintegrated due to mechanical forces, like pressure or shear rate. There may be abrasive areas with multiple abrasive layers on top of each other. An abrasive area with more abrasive layers is less susceptible to wear compared to an abrasive article with a single abrasive layer. For example, longer time of use may be provided with an abrasive area having multiple abrasive layers, compared to an abrasive area having less abrasive layers.
The abrasive grains provided on the backing material may be selected for each application, for example according to the composition, grain size or surface treatment. Typical materials used as abrasive grains are hard minerals, which may be synthetic or natural. Minerals used as abrasive grains may comprise cubic boron nitride (c-BN), boron carbide (BC), aluminium oxide (Al2O3), titanium oxide (TiO2), iron oxide (Fe2O3), cerium oxide (CeO2), silicon carbide (SiC), zirconia alumina and diamond, such as synthetic diamond grains. In addition or alternatively abrasive grains may comprise ceramic grains or engineered grains.
The abrasive grains may be sized or unsized. Sized means that the grains have a specified average size and/or a specified size distribution. Grains may have average size of 3-260 micrometers. The smaller and finer grain particles, the finer surface finish is achievable. So-called coarse abrasive surface enables removing material in quicker manner, while in comparison, a finer abrasive surface enables a polished or even mirror polished end result. The specified size distribution may be relatively narrow. Unsized means that the grains have not been selected according to size. For example grain type may be used as a basis for a selection in addition or instead of grain size.
An abrasive product may refer to an abrasive material and/or an abrasive item and/or an abrasive article. An abrasive material may mean material, which comprises abrasive grains on an abrasive surface. An abrasive product may comprise sequential abrasive areas starting with an abrasive area of grain size of 120 micrometers, followed by an abrasive area of grain size of 80 micrometers, followed by an abrasive area of grain size of 18-20 micrometers.
An abrasive surface, comprising abrasive grains, is formed onto a backing. Adhesive may be provided onto the backing and abrasive grains may be provided onto the adhesive. Alternatively, a mix of adhesive and abrasive grains may be provided onto the backing. Abrasive areas may be formed onto a backing by using cylindrical rolls with engravings or printing methods, such as calendaring, gravure or intaglio printing or pressing. Printing enables punctilious manufacturing and smaller tolerances compared to traditional cutting methods. Different abrasive areas may be provided onto a backing by coating with a kiss roll or an engraved roll. Coating methods may enable providing different abrasive areas along longitudinal abrasive material sheet. Rolls may enable repeating certain kind of patterns or densities of adhesive/grains sequentially along longitudinal backing. Rolls enable providing for example certain density of adhesive/grains at a certain area(s) of the backing. Rolls may have holes at certain density in order to provide certain amount of adhesive/grains onto the backing.
Printing may be used to provide different types of abrasive surfaces and/or abrasive patterns onto the backing. Printing may comprise screen printing or other known methods. A pattern of at least one abrasive area may comprise fractal patterns. Printing may be used to provide a surface comprising repeated units. The surface may comprise at least two or more abrasive areas, which are next to each other in longitudinal dimension of the abrasive product. Printing method enables producing at least two different abrasive areas comprising different abrasive properties onto the backing layer such that the different abrasive areas are next to each other. While one kind of abrasive area ends along longitudinal abrasive sheet, the other kind of abrasive area begins.
Printing methods, like gravure, inkjet or other digital printing methods, may be used for applying abrasive, for example adhesive and/or grains, onto the backing. Printing may be used to match the two different abrasive areas and possible area between the two, at their desired places and shapes. Printing may enable providing abrasive areas and areas free of abrasive, as pre-determined. Printing may enable providing two different kind of abrasive areas along the longitudinal abrasive sheet. Printing may be used to print a predetermined kind of abrasive grains at certain length along the longitudinal dimension of the backing. Printing may be used to print abrasive grains at a predetermined density at certain length along the longitudinal dimension of the backing. Printing may be used to print abrasive grains of a predetermined size at certain length along the longitudinal dimension of the backing.
A printing method may comprise two separate printing stations, which may be located next to each other. The two different kind of abrasive areas may be printed simultaneously at the same printing station or sequentially at two separate printing stations. It is possible to print adhesive onto a backing at a first printing station and apply grains onto the adhesive at the second printing station. Adhesive may be printed as zones, lines or spots, for example. Formed abrasive areas correspond to size, zones, lines or spots of the adhesive. Density of the adhesive areas determines density of the grain areas. Amount of adhesive may have effect on certain size of grains to/not to become attached. Size of the grains may vary between the two different abrasive zones.
Abrasive materials may be used in different manufacturing processes for finishing operations to create desired surface finishes. When used for abrading, an abrasive surface of an abrasive product may last from only a couple of minutes to several hours, depending on the abrasive surface and the end application. Lifespan for an abrasive surface of a flexible abrasive product in an industrial use may typically be from few seconds to several minutes. Efficiency in industrial use may be enhanced by providing an unused abrasive surface of the same product in order to continue abrading with the same, a similar or a different kind of abrasive surface. No change of machine, abrasive arm or place is required.
An abrasive product may comprise pre-determined abrasive areas, of predetermined kind and of predetermined length along a longitudinal dimension of the abrasive product. An abrading process is determined in accordance to a desired abrading result. Abrading process may comprise adjustable parameters, like kind of abrasive areas utilized, the sequential abrading areas to be used, total time of abrading, time of abrading with a certain kind of abrasive area, speed of machine, a manner and a speed of a movement of a workpiece and/or an abrading support in relation to each other, speed of feeding in the abrasive material. Specifications of a workpiece to be abraded may be used to determine what kind of abrading phases are used and which ones are repeated for how long time. Finishing may comprise utilizing abrading area comprising a pattern. For example raster pattern may be desired on a surface of the workpiece.
An apparatus for abrading a workpiece may comprise a predetermined abrading phases. The abrading phases may be programmed to the apparatus. Abrading phases may include feeding sequential abrasive areas on a support and arranging the sequential abrasive areas in contact with a workpiece. An abrading may be started with an abrasive phase, where a workpiece is abraded by an abrasive area comprising abrasive grains of average size of 40 μm. After the abrading phase is accomplished, abrading may be continue with a subsequent abrasive phase, where the workpiece is abraded by an abrasive area of the same abrasive product comprising abrasive grains of average size of 20 μm. After the abrading phase is accomplished, abrading may continue with a subsequent abrasive phase, where the workpiece is abraded by an abrasive area of the same abrasive product comprising abrasive grains of average size of 9 μm. Predetermined end result of abraded workpiece may comprise abrading in three different phases including finishing with the abrasive area comprising abrasive grains of average size of 9 μm. Alternatively, predetermined end result of abraded workpiece may comprise further finishing or mirror finish. In this case, abrading may continue with a subsequent one or two abrasive phase(s), where the workpiece is further abraded by an abrasive area of the same abrasive product comprising abrasive grains of average size of 5 μm and/or 3 μm.
The abrasive product may comprise subsequent different kind of abrasive areas of predetermined lengths in accordance to desired subsequent abrading phases, desired result(s) of the phases as well as a desired end result. Time of abrading, with different kind of abrasive surfaces, may be adjusted for sequential abrading phases. Sequential abrading phases may comprise use of different abrasive surfaces, different abrading times, different kind of relative movement of an abrasive surface and a workpiece, different pressure of a support towards a workpiece. Abrading by oscillating is enabled by arranging a support to oscillate. The oscillation may be arranged in one or two directions. A contact roll may be arranged to oscillate in order to arrange abrading by oscillating of a workpiece via abrasive surface on the contact roll. Oscillating movement has effect on abrading result. A pressure between an abrading surface and a workpiece has effect on abrading result. The pressure may be arranged pneumatically. The pressure at a contact surface may be 0.04-2 N/mm2, or 0.03-1 N/mm2. In case abrading is arranged at least partly by rotating a workpiece, rotation speed of a workpiece has effect on abrading result. Rotation speed of a workpiece may be 50-200 rpm (rounds per minute), for example. Diameter of a workpiece and rotation speed of a workpiece have effect on rotation speed of the workpiece. Rotation speed of a workpiece may be 40-200 m/s, for example. In case of a continuous feed of abrasive material, the speed of feeding the abrasive material has effect on abrading result. Feeding speed of an abrasive material may be 40-70 mm/min, or 60-70 mm/min. In addition, abrading result is effected by manner of abrading, for example dry abrading or wet abrading, where in the latter oil, water or emulsion may be utilized. Contact area, hardness of a support and/or hardness of a workpiece may have effect on abrading result. Abrading phases are predetermined and programmed to an abrading machine before the abrading is started. The predetermined abrading phases and the used abrasive product with different abrasive areas enable automation of abrading for the desired end result, even when requiring two or multiple different abrading phases.
Abrading phases may comprise abrading with one or more rough abrasive surface in order to remove material efficiently from a surface of the workpiece. Abrading phases may continue by a finer abrasive surface in order to continue towards smoother abraded surface. Abrading phases may further continue by a fine(st) abrasive surface in order to provide a finished surface (for the workpiece) as an end result. Alternatively or in addition, a surface pattern may be provided for the workpiece surface. In addition to selection of different kind of abrasive surfaces, time of total abrading as well as time per abrading phase is predetermined. Abrading is effected by adjusting manner of the relative movement of the abrasive surface and the workpiece, as well as speed of movement.
Use of abrasive product comprising different abrasive areas of different abrasive properties enables different kind of abrading phases to be accomplished with the another kind of abrasive area of the same abrasive product. Instead of changing an abrasive product, for example a roll of abrasive, to a different kind of abrasive product; or instead of moving the workpiece to another machine; or instead of changing a place of abrading, an abrading phase is changeable to a next one by feeding a different sequential abrasive area of the same abrasive product to the abrasive zone. The abrasive area is pressed in contact with the workpiece at the abrasive zone and the next abrading phase may start. Different abrading phases may be repeated sequentially.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20185242 | Mar 2018 | FI | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/FI2019/050201 | 3/11/2019 | WO | 00 |
