ABRASIVE SYSTEM FOR POLYSTYRENE APPLICATIONS

The invention relates to an abrasive system for polystyrene applications. The invention relates to a kit of parts suitable for abrasion of a working surface with a power tool. The invention relates to a kit of parts suitable for abrasion of working surfaces of polymer materials, such as extruded polystyrene (XPS) insulation panels. The kit of parts comprises a backing pad arrangement and an abrading article.

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Description
CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to European Patent Application No. 23154228.3, filed on Jan. 31, 2023, the disclosure of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The invention relates to an abrasive system for polystyrene applications. The invention relates to a kit of parts suitable for abrasion of a working surface with a power tool. More precisely, the invention relates to a kit of parts suitable for abrasion of foamed polymer materials, such as extruded polystyrene (XPS) insulation panels.

BACKGROUND

Foamed polystyrene, such as expanded polystyrene (EPS) and extruded polystyrene (XPS), are commonly used for insulation purposes in construction, e.g., in exterior walls. Several panels are assembled adjacent to each other to cover a working area, e.g., a wall. In order to obtain a smooth and even surface to receive an external facing, joints between the individual insulator panels need to be abraded.

Foamed polystyrene materials, such as EPS and XPS, are very light materials with a specific gravity typically in the range of 10-100 kg/m3. Despite their low specific gravity, foamed polystyrene materials are typically rigid and stiff. Foamed polystyrene materials may be compression resistant with compressive strengths typically in the range of 50 kPa for EPS to 1000 kPa for XPS, measured according to the EN826 standard. The compression resistance enables the foamed polystyrene materials to be abraded by pressing an abrading article against the surface of said foamed polystyrene material by means of an abrasive tool, typically a machine-powered abrasive tool, such as an oscillating abrading apparatus such as a random orbit sander.

Abrasion of foamed polystyrene materials with conventional equipment to yield an even surface is difficult. As such, the material is easily abraded into abrasion debris, i.e., small particles or dust. The abrasion debris is prone to clog conventional abrading apparatuses. Abrasion debris of foamed polystyrene material gets very easily charged due to static electricity generated due to friction between the abrasive and the working surface. Typically, air flow is used to remove abrasion debris away from the working surface. The charged abrasion debris of foamed polystyrene material is difficult to remove using an air flow because of the tendency of the charged debris to stick or adhere to the working surface or to the surface of the abrading apparatus.

Foamed polystyrene materials may easily scratch when using conventional abrading apparatuses. Material may even be cut off from the working surface as large flakes. An abrading article, such as an abrasive disc, is typically attached to a backing pad by means of a Velcro type system. Despite the attachment, the abrading disc may slightly separate from the backing pad, especially near its perimeter. When abrading a light yet rigid material, such as foamed polystyrene, the edge of the abrading disc separated from the backing pad may hit the working surface at a non-parallel position, causing a sudden impact and cutting itself into the material being abraded. Thus, large flakes of the material may come off from the working surface. The separation of large flakes causes an uneven and poor abrasion result. Furthermore, the large flakes may clog the debris removal system of the abrading apparatus due to the tendency to adhere to surfaces because of static electricity.

SUMMARY

An object of the present invention is to overcome the drawbacks in the prior art. Another object of the present invention is to provide abrading products that are not clogged by polymer materials, such as foamed polystyrene. A yet further object of the present invention is to provide an abrading system with which polymer surfaces, such as foamed polystyrene panels, may be abraded to a high-quality finish.

These objects are attained with the invention having the characteristics presented below the independent claim. Some preferable embodiments are disclosed in the dependent claims.

The features recited in the dependent claims and in the description are mutually freely combinable unless otherwise explicitly stated.

The exemplary embodiments presented in this text and their advantages relate by applicable parts to all aspects of the invention, even though this is not always explicitly mentioned.

Hereafter, “polystyrene” and “foamed polystyrene materials” refer to foamed polystyrene materials typically utilized in insulator panel applications, i.e., to expanded polystyrene or extruded polystyrene. The materials have a specific gravity typically in the range of 10-100 kg/m3 and compressive strength typically in the range of 50-1000 kPa, the compressive strength measured according to the EN826 standard.

A typical kit of parts according to the present invention is suitable for abrasion of a working surface with a power tool. The kit comprises an abrading article and a backing pad arrangement comprising at least a backing pad, wherein

    • each of the backing pad arrangement and the abrading article individually comprise a surface having a diameter, and the surface diameter of the backing pad arrangement is larger than the surface diameter of the abrading article;
    • each of the backing pad arrangement and the abrading article individually comprise multiple peripheral openings, which peripheral openings on the backing pad arrangement and on the abrading article enable transport of debris from the working surface with air flow through the abrading article and the backing pad arrangement, wherein the air flow may be generated by suction pressure connected to the backing pad arrangement;
    • each peripheral opening on the abrading article is geometrically similar to a respective peripheral opening on the backing pad arrangement;
    • each peripheral opening spans an area that has a diameter, and the diameter of each peripheral opening on the abrading article is larger than or equal to the diameter of a respective peripheral opening on the backing pad arrangement;
    • the abrading article is configured to be concentrically aligned on the backing pad arrangement,
    • each peripheral opening on the abrading article is configured to be concentrically aligned with a respective peripheral opening on the backing pad arrangement, enabling transport of debris with air flow through the peripheral openings; and
    • the abrading article comprises a dense backing material that resists air flow through the material, such as paper or film,

such that when the backing pad arrangement and the abrading article are attached together for abrasion with a power tool, the perimeter of the backing pad arrangement and the perimeter of the peripheral openings on the backing pad arrangement are visible from beneath the abrading article, when viewed from the direction of the working surface.

Experimental research has indicated that the specific combination of the backing pad arrangement and the abrading article comprising peripheral openings makes abrading of polystyrene possible. The invention is typically used in a machine-powered abrading apparatus, i.e., a power tool. The invention is particularly suitable for use in an oscillating or reciprocating abrading apparatus, e.g., a random orbit sander.

Accurate alignment of the peripheral openings on the abrading article, such that sections of the backing pad arrangement as defined in the independent claim are visible from beneath the abrading article, enables the backing pad arrangement to function as a deflector for the abrading article, thus preventing or at least reducing the abrading article from cutting into the working surface, thereby minimizing the cutting of material as large flakes from the working surface. Thus, the present invention has the advantage of providing an even and smooth abrasion result even on polymer surfaces such as extruded polystyrene (XPS) panels.

Experimental research has indicated that by replacing a combination of a conventional backing pad and abrasive net with the combination described here, polystyrene surfaces can be abraded without clogging. Compared to a conventional abrasive net, the dense backing material of the abrading article in the present invention resists, prevents or at least drastically reduces air flow through the abrading article. With low to no air leakage through the backing material of the abrading article, the air flow may achieve a higher velocity near the peripheral openings compared to a conventional abrasive net. The higher velocity of the air flow enables the air flow to carry the light polystyrene debris towards the peripheral openings and further into a debris removal system of the abrading apparatus.

The placement of debris collection openings near the perimeter of an abrading apparatus has the advantage of improving debris removal efficiency. With the peripheral openings placed near the perimeter of the backing pad arrangement and the abrading article, an air flow may be provided from the perimeter of the backing pad arrangement and the abrading article towards the center of the apparatus. Thus, the amount of debris escaping the abrading apparatus via the perimeter is greatly reduced, leading to an improved debris removal efficiency.

An efficient debris removal improves working safety. Abrasion debris may have a detrimental impact on the worker's health, therefore it is of essential importance that debris is controllably and efficiently removed from the working surface and collected in a closed container. Debris removal can be achieved by connecting a device to the backing pad arrangement that generates suction, generating a pressure difference. The pressure difference generates an air flow towards the peripheral openings that are connected to suction points via outlet air conduits. The air flow transports debris from the working surface through the peripheral openings towards the suction points via outlet air conduits into a closed container.

The invention has a further advantage of enabling recycling of the collected abrasion debris. With an efficient debris removal and collection, a larger amount of the abrasion debris can be reused, e.g., in the manufacture of new polystyrene insulation panels or other products. Thus, the invention is compatible with the concept of circular economy.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 presents a cross-section of an abrading arrangement according to the present invention in Sx, Sz plane;

FIGS. 2A, 2B present backing pad arrangements according to the invention in Sx, SY plane;

FIGS. 3A, 3B present abrading articles according to the invention in Sx, SY plane;

FIGS. 4A, 4B present combinations of backing pad arrangement and abrading article according to the invention in Sx, SY plane; and

FIGS. 5A, 5B, 5C, and 5D present some possible arrangements of peripheral openings on the backing pad arrangement and abrading article according to the invention in Sx, SY plane.

 DETAILED DESCRIPTION

In the text, reference is made to the figures with the following numerals and denotations:

Sx, SY and Sz denote orthogonal directions. Center of the backing pad refers to a center point of the backing pad in the Sx, Sy plane.

    • 100 Abrading system
    • 200 Backing pad arrangement
    • 201 Central opening on the backing pad arrangement
    • 202 Peripheral opening on the backing pad arrangement
    • 203 Perimeter of the backing pad arrangement
    • 204 Perimeter of the central opening on the backing pad arrangement
    • 205 Perimeter of the peripheral opening on the backing pad arrangement
    • 206 Outlet opening on the backing pad arrangement
    • 300 Abrading article
    • 301 Central opening on abrading article
    • 302 Peripheral opening on abrading article
    • 303 Perimeter of abrading article
    • 304 Perimeter of central opening on the abrading article
    • 305 Perimeter of peripheral opening on the abrading article
    • 306 Outlet opening on the abrading article
    • 407 Radial zone
    • ν Direction of air flow

Referring to FIG. 1, a typical kit of parts comprises an abrading article 300 and a backing pad arrangement 200. The backing pad arrangement comprises at least a backing pad. The backing pad arrangement 200 and the abrading article 300 are configured to be attached to an oscillating or reciprocating abrading apparatus, e.g. a random orbit sander. Typically, the invention is used in a machine-powered abrading apparatus, i.e., a power tool.

The backing pad arrangement 200 may comprise a front side that is configured to receive the abrading article and a back side that is configured to be releasably attached on a power tool by a fixing member, for example by means of a screw. The backing pad arrangement may comprise several fixing members. The releasable attachment enables to replace a worn out backing pad quickly and conveniently for the user. The releasable attachment also increases the sustainability of the abrading apparatus because the entire abrading apparatus needs not be replaced when only a backing pad is worn out.

Referring to FIG. 1, the abrading article 300 comprises a front side that comprises an abrasive surface. The abrasive surface comprises an abrasive layer, the abrasive layer comprising abrasive grains that are fixed onto the abrasive layer. The abrading article also comprises a back side that is configured to be releasably attached on the backing pad arrangement, for example by means of a hook and loop type attachment system, a screw, or multiple screws. The releasable attachment enables to replace the abrading article quickly and conveniently for the user. The releasable attachment also increases the sustainability of the abrading apparatus because the entire abrading apparatus needs not be replaced when only the abrading article is worn out, or when changing from a coarse to fine abrasion or vice versa.

The abrading article 300 may further comprise an intermediate layer for increasing flexibility of the abrading article. The intermediate layer is arranged between the front side and the back side of the abrading article. The intermediate layer of the abrading article may increase the flexibility and adaptivity of the abrading article to contours of the working surface. Thus, an even and high-quality abrasion result may be achieved also on non-flat working surfaces.

In a typical kit according to the invention, each of the backing pad arrangement 200 and the abrading article 300 individually comprise a surface in the Sx, SY plane having a certain diameter. The surface diameter of the backing pad arrangement in the Sx, SY plane is larger than the surface diameter of the abrading article. For non-circular backing pad arrangements 200 and abrading articles 300, diameter of the surface in the Sx, SY plane refers to the longest possible distance between two points at the perimeter of the backing pad arrangement or the abrading article.

The diameter of the backing pad arrangement 200 and the surface diameter of the abrading article 300 is at least 170 mm, preferably in the range of 170-300 mm. The diameter of at least 170 mm may be considered as large for an abrading apparatus. The large diameter in an oscillating abrading apparatus brings about an advantage of large reciprocal movement, enabling a smooth and even abrasion result over large areas at once. Especially at joints or seams between individual polystyrene panels, a large abrading apparatus has the advantage of creating an even and high-quality result at one go.

The backing pad arrangement or the abrading article, or both the backing pad arrangement and the abrading article may comprise a central opening 201, 301 configured to convey air to the working surface. The central openings 201, 301 may be connected to an inlet air conduit within the abrading apparatus. The central opening may enhance air flow at the working surface, increasing efficiency of the debris removal.

Each of the backing pad arrangement 200 and the abrading article 300 further individually comprises multiple peripheral openings, which peripheral openings 202 on the backing pad arrangement and peripheral openings 302 on the abrading article enable transport of debris from the working surface with air flow through the abrading article and the backing pad arrangement. The peripheral openings 202 on the backing pad arrangement and the peripheral openings 302 on the abrading article are configured to be connected with outlet air conduits within the abrading apparatus. Referring to FIGS. 1-3A-3B, an air flow may be arranged at the working surface by connecting suction to the backing pad arrangement (200). Suction generates an air flow that transports debris from the working surface through the peripheral openings 202, 302 via outlet air conduits into a closed container. Thus, an air flow may be arranged at the working surface towards the peripheral openings by suction. Replacement air is configured to arrive at the working surface via the perimeter of the backing pad arrangement 203 and perimeter of the abrading article 303, and advantageously via the central opening 201 on the backing pad arrangement and the central opening 301 on the abrading article. The direction of the air flow ν is denoted in FIGS. 1 and 4B by arrows.

The abrading article 300 is configured to be concentrically aligned on the backing pad arrangement 200. Likewise, each peripheral opening 302a-h on the abrading article is configured to be concentrically aligned with a respective peripheral opening 202a-h on the backing pad arrangement, enabling transport of debris with air flow through the peripheral openings 202, 302. The peripheral openings 202 on the backing pad arrangement are connected to air conduits of the debris removal system of the abrading apparatus.

Each peripheral opening 302 on the abrading article is geometrically similar to a respective peripheral opening 202 on the backing pad arrangement. Likewise, the optional central opening 301 on the abrading article is geometrically similar to the optional central opening 201 on the backing pad arrangement. Similarity in course of this invention is defined as in Euclidean geometry: two openings are similar in shape if they have the same shape, i.e., a first opening has the same shape as the mirror image of a second opening. For example, the first opening can be obtained from the second opening by uniformly scaling (enlarging or reducing), possibly with additional translation, rotation and/or reflection.

The backing pad arrangement 200 may further comprise an intermediate pad in addition to the backing pad. The backing pad and the intermediate pad comprise peripheral openings and optionally a central opening. Each peripheral opening on the backing pad is geometrically congruent with a respective peripheral opening on the intermediate pad, i.e., they are similar and have a same size. The optional central opening on the backing pad and the optional central opening on the intermediate pad are likewise geometrically congruent. Congruence is defined as in Euclidean geometry: two openings are congruent if a first opening can be obtained from a second opening by translation, rotation, and/or reflection. The intermediate pad is configured to be releasably attached on the backing pad such that the peripheral openings and the optional central openings on the backing pad and on the intermediate pad are concentrically aligned. The releasable intermediate pad brings about cost savings and makes the abrading apparatus more sustainable, since it is often enough to replace a worn out intermediate pad instead of a complete backing pad arrangement. The backing pad may comprise a rigid and wear-resistant material, whereas the intermediate pad may comprise a more soft and flexible material, such as a foam material. The intermediate pad may thus be more flexible and adaptive to the contours of the working surface. Thus, an even and high-quality abrasion result may be achieved also on non-flat working surfaces.

Each peripheral opening 202, 302 spans an area in the Sx, SY plane that has a diameter. The diameter of each peripheral opening 302 on the abrading article is larger than or equal to the diameter of a respective peripheral opening 202 on the backing pad arrangement. Preferably, the diameter of each peripheral opening 302 on the abrading article is larger than the diameter of a respective peripheral opening 202 on the backing pad arrangement. Similarly, the optional central opening 201 on the backing pad arrangement and the optional central opening 301 on the abrading article each individually span an area in the Sx, SY plane that has a diameter. The diameter of the central opening 301 on the abrading article is larger than or equal to the diameter of the central opening 201 on the backing pad arrangement. In case of non-circular central openings 201, 301 or peripheral openings 202, 302, the diameter refers to the longest possible distance between two points at the perimeter of the central opening or peripheral opening, respectively.

Referring to FIGS. 2A-4B, the diameter of the peripheral openings 202 on the backing pad arrangement and the diameter of the peripheral openings 302 on the abrading article is at least 20 mm, preferably in the range of 20-30 mm. The diameter of at least 20 mm for a peripheral opening may be considered large. Abrasion debris and dust may effectively be collected through the large peripheral openings 202, 302.

The diameter of the optional central opening 201, 301 may be in the range of 30-50 mm, preferably in the range of 35-45 mm.

Referring to FIGS. 2A-3B, the central opening 301 comprises 1-6%, the peripheral openings 302 together comprise 5-15%, and the abrasive surface comprises 50-95%, preferably 75-90% of the surface area of the abrading article 300.

The geometrical similarity of the openings—both peripheral openings 202, 302 and the optional central openings 201, 301—on the backing pad arrangement 200 and on the abrading article 300, the concentric alignment and the carefully selected diameters result in the advantageous effect of enabling the backing pad arrangement to function as a deflector when abrading the working surface. This is illustrated schematically in FIG. 4A. When the backing pad arrangement 200 and the abrading article 300 are attached together for abrasion with a power tool, the perimeter 203 of the backing pad arrangement and the perimeter 205 of the peripheral openings 202 on the backing pad arrangement are visible from beneath the abrading article, when viewed from the direction of the working surface. The perimeter 204 of the optional central opening on the backing pad arrangement may also be visible from beneath the abrading article 300, when viewed from the direction of the working surface.

The deflector functionality of the backing pad arrangement 200 prevents the abrading article 300 from scratching the working surface. As illustrated in, e.g., FIGS. 1 and 4A, the first layer of material coming in contact with the working surface is the abrading article in most locations. However, near the perimeter 203 of the backing pad arrangement and the perimeter 303 of the abrading article, as well as near the perimeter 204, 304 of the optional central openings and near the perimeter 205, 305 of the peripheral openings, the first point of contact with the working surface is the backing pad arrangement. In a typical situation, the backing pad arrangement 200 is flexible, i.e., it is adaptive to contours of the working surface. Thus, when coming into contact with the working surface, the backing pad arrangement 200 compresses, forcing the abrading article 300 to remain in contact with the backing pad arrangement 200. In other words, the arrangement prevents the abrading article 300 from lifting off the surface of the backing pad arrangement 200. Therefore, the abrading article 300 cannot cut into the material being abraded, and the separation of material as large flakes is prevented.

The backing pad arrangement 200 may further comprise an intermediate pad. Thus, when the backing pad arrangement 200 and the abrading article 300 are attached together for abrasion with a power tool, the perimeter of the intermediate pad and the perimeter of the peripheral openings on the intermediate pad are visible from beneath the abrading article, when viewed from the direction of the working surface. In this situation, the intermediate pad functions as a deflector for the abrading article when abrading the working surface. Since the intermediate pad is of soft and flexible material, it can be compressed. When coming into contact with the working surface, the intermediate pad compresses, forcing the abrading article 300 to remain in contact with the intermediate pad and preventing the abrading article 300 from lifting off the surface of the intermediate pad.

Referring to FIG. 4A, the surface diameter of the backing pad arrangement 200 is larger than the surface diameter of the abrading article 300 by at least 1 mm, preferably by 1-6 mm, more preferably by 1.5-3 mm. The diameter of each peripheral opening 302 on the abrading article may be larger than the diameter of a respective peripheral opening 202 on the backing pad arrangement by at least 1 mm, preferably by 1-6 mm, more preferably by 1.5-3 mm. Referring to FIG. 4A, the diameter of the optional central opening 301 on the abrading article may be larger than the diameter of the optional central opening 201 on the backing pad arrangement by at least 1 mm, such as by 1-6 mm, more preferably by 1.5-3 mm. The differences in the diameters of especially the peripheral openings enable the backing pad to function as a deflector for the abrading article, enabling a smooth and even abrasion result.

The diameter of the optional central opening 201 on the backing pad may be equal to the diameter of the optional central opening 301 on the abrading article. Velocity of the air flow ν is smaller near the central opening 201, 301 than near the peripheral openings 202, 302. Thus, the abrading article 300 is not as prone to lift off from the backing pad arrangement near the central opening.

Referring to FIGS. 2A-5D, each of the backing pad arrangement 200 and the abrading article 300 individually comprises 5-10 peripheral openings 202, 302, preferably 6-8 peripheral openings 202, 302. Referring to FIG. 4A, the peripheral openings 202, 302 are radially equidistantly and symmetrically arranged around the center of each of the backing pad arrangement 200 and the abrading article 300. The equidistant and symmetric alignment of the peripheral openings 202, 302 enables efficient air flow at the working surface towards the peripheral openings 202, 302, enabling in turn an efficient dust and debris removal from the working surface into the debris removal system of the abrading apparatus.

Referring to FIG. 5D, the backing pad arrangement and the abrading article may comprise secondary outlet openings 206, 306 radially equidistantly and symmetrically arranged around the center of each of the backing pad arrangement 200 and the abrading article 300. Each secondary outlet opening spans an area in the Sx, SY plane that has a diameter, and the diameter of the secondary outlet openings 206, 306 is smaller than or equal to the diameter of the peripheral openings 202, 302. The secondary outlet openings 206, 306 need not be symmetrically aligned with the peripheral openings 202, 302. The secondary outlet openings 206, 306 may be connected to the debris removal system of the abrading apparatus. The secondary outlet openings 206, 306 contribute to transport of debris from the working surface with air through the abrading article and the backing pad arrangement. The diameter of each secondary outlet opening 306 on the abrading article is larger than or equal to the diameter of a respective secondary outlet opening 206 on the backing pad arrangement. Preferably, the diameter of each secondary outlet opening 306 on the abrading article is larger than the diameter of a respective secondary outlet opening 206 on the backing pad arrangement, such that when the backing pad arrangement and the abrading article are attached together for abrasion with a power tool, the perimeter of the secondary outlet openings 206 on the backing pad arrangement are visible from beneath the abrading article 300, when viewed from the direction of the working surface. For non-circular secondary outlet openings 206, 306, diameter of the opening refers to the longest possible distance between two points at the perimeter of the secondary outlet opening.

Referring to FIGS.-5A-5D, the peripheral openings 202, 302, the optional central openings 201, 301, and the optional secondary outlet openings 206, 306 on the backing pad arrangement 200 and on the abrading article 300 may take several different shapes. The peripheral openings 202, 302, the optional central openings 201, 301, and the optional secondary outlet openings 206, 306 may take, e.g., a circular, triangular, D-shaped or rectangular form. Not all openings on the backing pad arrangement 200 or the abrading article 300 need to be similar in shape, as illustrated schematically in FIG. 5C. It is sufficient that each opening on the abrading article 300 is geometrically similar to a respective opening on the backing pad arrangement 200 such that, when the abrading article is attached on the backing pad arrangement, the perimeter of the peripheral openings, and optionally, the perimeter of the optional central opening, and the perimeter of the optional secondary outlet openings on the backing pad arrangement are visible from beneath the abrading article 200, when viewed from the direction of the working surface. The peripheral openings 202, 302, the optional central openings 201, 301 and the optional secondary outlet openings 206, 306, are rounded and comprise no sharp edges. The rounded edges of the openings reduce or prevent the abrading article from cutting into the material being abraded, thus enabling a smooth and even abrasion result. The diameter of the backing pad arrangement 200, the diameter of the abrading article 300, the diameter of the peripheral openings 202, 302, the diameter of the central openings 201, 301, or the diameter of the secondary outlet openings 206, 306 refers to the longest possible distance between two points at the perimeter of the backing pad arrangement 200, abrading article 300, peripheral openings 202, 302, optional central openings 201, 301, or optional secondary outlet openings 206, 306, respectively.

The abrading article 300 may comprise a radial zone 407 of abrasive surface having a width of 10-30 mm. The radial zone 407, illustrated schematically with the dotting in FIG. 4B, extends from the perimeter 303 of the abrading article towards the center. The radial zone 407 comprises no openings. The radial zone 407 prevents or at least reduces debris leakage via the perimeter 303 of the abrading article. The backing pad arrangement 200 comprises a similar radial zone that does not comprise openings. Replacement air arrives at the working surface via the perimeter of the backing pad arrangement 203 and perimeter of the abrading article 303, i.e., through the radial zone 407. Replacement air arriving via the radial zone ensures that only a minor amount of debris escapes the working surface via the perimeter of the apparatus, thus enabling a very efficient debris collection at the debris removal system. Direction of air flow ν is illustrated in FIG. 4B with arrows.

The abrading article 300 comprises a dense backing material that resists air flow through the material, such as paper or film. Advantageously, the abrading article is of a material that resists air flow through the backing material such that air flow is configured to take place primarily between the abrading article and the working surface, and directed parallel to the working surface. Due to the arrangement of the openings, the air flow is directed towards the peripheral openings acting as outlet air conduits upon use, when suction is used to generate air pressure difference. As a contrast, in porous abrading articles, such as abrading nets, air tends to escape through the pores of the abrading article, whereby the abrading article is easily clogged by the light polystyrene debris abraded by the abrading apparatus. The present invention enables air to flow at the working surface towards the peripheral openings unidirectionally, ensuring an air flow parallel to the working surface. Air permeance of the backing material of the abrading article 300 may be measured using the Gurley method. In the Gurley method, the amount of time, in seconds, required for 300 cubic centimeters of air to pass through a 0.65 square centimeter area of a sample using a 1.39 Joules per meter force is measured. The Gurley apparatus and procedures for its use are known in the textile industry. For purposes of the present invention, a material shall be considered non-porous if it has a Gurley porosity that is at least 5 seconds per 300 cubic centimeters of air. The backing material may have a porosity of at least 5 s, preferably at least 50 s, more preferably at least 100 s, even more preferably at least 1000, such as at least 7000 or 10000 s, measured using the Gurley method. Density of the backing material of the abrading article 300 may be at least 500 kg/m3.

The backing material of the abrading article 300 is a material of low to no chargeability. Preferably, the backing material of the abrading article 300 is a material comprising natural fibers, more preferably a cellulose-based fiber material. A low chargeability reduces the tendency of the light polystyrene dust or debris to build up on the abrading article and to clog the abrading article.

The invention is further described by the following examples.

Example 1. A kit of parts for abrasion of a working surface with a power tool, the kit comprising an abrading article 300 and a backing pad arrangement 200 comprising at least a backing pad, wherein

    • each of the backing pad arrangement 200 and the abrading article 300 individually comprise a surface having a diameter, and the surface diameter of the backing pad arrangement is larger than the surface diameter of the abrading article;
    • each of the backing pad arrangement 200 and the abrading article 300 individually comprise multiple peripheral openings 202, 302, which peripheral openings 202 on the backing pad arrangement and peripheral openings 302 on the abrading article enable transport of debris from the working surface with air flow through the abrading article 300 and the backing pad arrangement 200, wherein the air flow may be generated by suction connected to the backing pad arrangement 200;
    • each peripheral opening 302 on the abrading article is geometrically similar to a respective peripheral opening 202 on the backing pad arrangement;
    • each peripheral opening 202, 302 spans an area that has a diameter, and the diameter of each peripheral opening 302 on the abrading article is larger than or equal to the diameter of a respective peripheral opening 202 on the backing pad arrangement;
    • the abrading article 300 is configured to be concentrically aligned on the backing pad arrangement 200,
    • each peripheral opening 302 on the abrading article is configured to be concentrically aligned with a respective peripheral opening on the backing pad arrangement 202, enabling transport of debris with air flow through the peripheral openings 202, 302; and
    • the abrading article 300 comprises a dense backing material that resists air flow through the material, such as paper or film,

such that when the backing pad arrangement 200 and the abrading article 300 are attached together for abrasion with a power tool, the perimeter of the backing pad arrangement 203 and the perimeter 205 of the peripheral openings on the backing pad arrangement are visible from beneath the abrading article 200, when viewed from the direction of the working surface.

Example 2. The kit according to example 1, wherein the backing pad arrangement 200 comprises a front side that is configured to receive the abrading article 300 and a back side that is configured to be releasably attached on a power tool, for example by means of a hook and loop type attachment system, a screw or multiple screws.

Example 3. The kit according to example 1 or 2, wherein the abrading article 300 comprises a front side that comprises an abrasive surface, the abrasive surface comprising an abrasive layer, the abrasive layer comprising abrasive grains fixed onto the abrasive layer, and a back side that is configured to be releasably attached on the backing pad arrangement 200, for example by means of a hook and loop type attachment system, a screw or multiple screws.

Example 4. The kit according to example 3, wherein the abrading article 300 further comprises an intermediate layer for increasing flexibility of the abrading article, the intermediate layer being arranged between the front side and the back side of the abrading article.

Example 5. The kit according to any of the preceding examples, wherein the backing pad arrangement 200 further comprises an intermediate pad, wherein

    • the backing pad and the intermediate pad comprise peripheral openings,
    • each peripheral opening on the intermediate pad is geometrically congruent with a respective peripheral opening on the backing pad, and
    • the intermediate pad is configured to be releasably attached on the backing pad such that and the peripheral openings on the backing pad and on the intermediate pad are concentrically aligned.

Example 6. The kit according to any of the preceding examples, wherein the surface diameter of the backing pad arrangement 200 and the surface diameter of the abrading article 300 is at least 170 mm, preferably in the range of 170-300 mm.

Example 7. The kit according to any of the preceding examples, wherein the diameter of the peripheral openings 202 on the backing pad arrangement and the diameter of the peripheral openings 302 on the abrading article is at least 20 mm, such as in the range of 20-30 mm.

Example 8. The kit according to any of the preceding examples, wherein the surface diameter of the backing pad arrangement 200 is larger than the surface diameter of the abrading article 300 by at least 1 mm, such as by 1-6 mm, preferably by 1.5-3 mm.

Example 9. The kit according to any of the preceding examples, wherein the diameter of each peripheral opening 302 on the abrading article is larger than the diameter of a respective peripheral opening 202 on the backing pad arrangement by at least 1 mm, such as by 1-6 mm, preferably by 1.5-3 mm.

Example 10. The kit according to any of the preceding examples, wherein each of the backing pad arrangement 200 and the abrading article 300 individually comprises 5-10 peripheral openings 202, 302, preferably 6-8 peripheral openings 202, 302, and wherein the peripheral openings 202, 302 are radially equidistantly and symmetrically arranged around the center of each of the backing pad arrangement 200 and the abrading article 300, enabling efficient air flow at the working surface towards the peripheral openings 202, 302.

Example 11. The kit according to any of the preceding examples 3-10, wherein the abrading article 300 comprises a radial zone 407 of abrasive surface having a width of 10-30 mm for preventing debris leakage via the perimeter 303 of the abrading article, the radial zone extending from the perimeter 303 of the abrading article towards the center.

Example 12. The kit according to any of the preceding examples, wherein the backing material of the abrading article 300 resists air flow through the backing material such that air flow is confined between the abrading article 300 and the working surface, and directed parallel to the working surface, the air flow being directed towards the peripheral openings 202, 302, the backing material having a porosity of at least 5 s, preferably at least 50 s, more preferably at least 100 s, even more preferably at least 1000, such as at least 7000 or 10000 s, measured using the Gurley method.

Example 13. The kit according to any of the preceding examples, wherein density of the backing material of the abrading article is at least 500 kg/m3.

Example 14. The kit according to any of the preceding examples, wherein the backing material of the abrading article 300 is a material of low to no chargeability, preferably the backing material of the abrading article is a material comprising natural fibers, more preferably a cellulose-based fiber material.

Example 15. The kit according to any of the preceding examples, wherein the backing pad arrangement 200 and the abrading article 300 further comprise secondary outlet openings 206, 306 radially equidistantly and symmetrically arranged around the center of each of the backing pad arrangement 200 and the abrading article 300, and wherein each secondary outlet opening spans an area that has a diameter, and the diameter of each secondary outlet opening 306 on the abrading article is larger than or equal to the diameter of a respective secondary outlet opening 206 on the backing pad arrangement, such that when the backing pad arrangement 200 and the abrading article 300 are attached together for abrasion with a power tool, the perimeter of the secondary outlet openings 206 on the backing pad arrangement are visible from beneath the abrading article 300, when viewed from the direction of the working surface.

Example 16. The kit according to any of the preceding examples, wherein the backing pad arrangement 200 or the abrading article 300, or both the backing pad arrangement 200 and the abrading article 300 further comprise a central opening 201, 301 configured to convey air to the working surface.

Example 17. The kit according to example 16, wherein both the backing pad arrangement 200 and the abrading article 300 comprise a central opening 201, 301, and the central opening 201 on the backing pad arrangement and the central opening 301 on the abrading article each individually span an area that has a diameter, and the diameter of the central opening 301 on the abrading article is larger than or equal to the diameter of the central opening 201 on the backing pad arrangement.

Example 18. The kit according to example 17, wherein the diameter of the central opening 301 on the abrading article is larger than the diameter of the central opening 201 on the backing pad arrangement by at least 1 mm, such as by 1-6 mm, preferably by 1.5-3 mm, such that when the backing pad arrangement 200 and the abrading article 300 are attached together for abrasion with a power tool, the perimeter 204 of the central opening on the backing pad is visible from beneath the abrading article 300, when viewed from the direction of the working surface.

Example 19. The kit according to any of examples 16-18, wherein the diameter of the central opening 201, 301 is in the range of 30-50 mm, preferably in the range of 35-45 mm.

Example 20. The kit according to example 5 and any of examples 16-19, wherein the central opening on the backing pad and the central opening on the intermediate pad are geometrically congruent.

Example 21. The kit according to any of examples 16-20, wherein the central opening 301 comprises 1-6%, the peripheral openings comprise 5-15%, and the abrasive surface comprises 50-95%, preferably 75-90% of the surface area of the abrading article 300.

Example 22. The kit according to any of the preceding examples, wherein the backing pad arrangement 200 and the abrading article 300 are configured to be attached to an oscillating or reciprocating abrading apparatus.

Example 23. The kit according to any of the preceding examples 1, 6-9, 15, or 17-19, wherein the diameter of the backing pad arrangement 200, the diameter of the abrading article 300, the diameter of the peripheral openings 202, 302, the diameter of the central openings 201, 301, or the diameter of the secondary outlet openings 206, 306 refers to the longest possible distance between two points at the perimeter of the backing pad arrangement 200, abrading article 300, peripheral openings 202, 302, central openings 201, 301, or secondary outlet openings 206, 306, respectively.

Claims

1. A kit of parts for abrasion of a working surface with a power tool, the kit comprising an abrading article and a backing pad arrangement comprising at least a backing pad, wherein wherein when the backing pad arrangement and the abrading article are attached together for abrasion with a power tool, the perimeter of the backing pad arrangement and the perimeter of the peripheral openings on the backing pad arrangement are visible from beneath the abrading article, when viewed from the direction of the working surface.

each of the backing pad arrangement and the abrading article individually comprise a surface having a diameter, and the surface diameter of the backing pad arrangement is larger than the surface diameter of the abrading article;
each of the backing pad arrangement and the abrading article individually comprise multiple peripheral openings, which peripheral openings on the backing pad arrangement and peripheral openings on the abrading article enable transport of debris from the working surface with air flow through the abrading article and the backing pad arrangement, wherein the air flow may be generated by suction connected to the backing pad arrangement;
each peripheral opening on the abrading article is geometrically similar to a respective peripheral opening on the backing pad arrangement;
each peripheral opening spans an area that has a diameter, and the diameter of each peripheral opening on the abrading article is larger than or equal to the diameter of a respective peripheral opening on the backing pad arrangement;
the abrading article is configured to be concentrically aligned on the backing pad arrangement,
each peripheral opening on the abrading article is configured to be concentrically aligned with a respective peripheral opening on the backing pad arrangement, enabling transport of debris with air flow through the peripheral openings; and
the abrading article comprises a dense backing material that resists air flow through the material,

2. The kit according to claim 1, wherein the abrading article comprises a front side that comprises an abrasive surface, the abrasive surface comprising an abrasive layer, the abrasive layer comprising abrasive grains fixed onto the abrasive layer, and a back side that is configured to be releasably attached on the backing pad arrangement, for example by means of a hook and loop type attachment system, a screw or multiple screws.

3. The kit according to claim 1, wherein the backing pad arrangement further comprises an intermediate pad, wherein

the backing pad and the intermediate pad comprise peripheral openings,
each peripheral opening on the intermediate pad is geometrically congruent with a respective peripheral opening on the backing pad, and
the intermediate pad is configured to be releasably attached on the backing pad such that and the peripheral openings on the backing pad and on the intermediate pad are concentrically aligned.

4. The kit according to claim 1, wherein the surface diameter of the backing pad arrangement and the surface diameter of the abrading article is at least 170 mm.

5. The kit according to claim 1, wherein the diameter of the peripheral openings on the backing pad arrangement and the diameter of the peripheral openings on the abrading article is at least 20 mm.

6. The kit according to claim 1, wherein the surface diameter of the backing pad arrangement is larger than the surface diameter of the abrading article by at least 1 mm, and/or wherein the diameter of each peripheral opening on the abrading article is larger than the diameter of a respective peripheral opening on the backing pad arrangement by at least 1 mm.

7. The kit according to claim 1, wherein each of the backing pad arrangement and the abrading article individually comprises 5-10 peripheral openings, and wherein the peripheral openings are radially equidistantly and symmetrically arranged around the center of each of the backing pad arrangement and the abrading article, enabling efficient air flow at the working surface towards the peripheral openings.

8. The kit according to claim 2, wherein the abrading article comprises a radial zone of abrasive surface having a width of 10-30 mm for preventing debris leakage via the perimeter of the abrading article, the radial zone extending from the perimeter of the abrading article towards the center.

9. The kit according to claim 1, wherein the backing material of the abrading article resists air flow through the backing material such that air flow is confined between the abrading article and the working surface, and directed parallel to the working surface, the air flow being directed towards the peripheral openings, the backing material having a porosity of at least 5 s, measured using the Gurley method.

10. The kit according to claim 1, wherein the backing pad arrangement and the abrading article further comprise secondary outlet openings radially equidistantly and symmetrically arranged around the center of each of the backing pad arrangement and the abrading article, and wherein each secondary outlet opening spans an area that has a diameter, and the diameter of each secondary outlet opening on the abrading article is larger than or equal to the diameter of a respective secondary outlet opening on the backing pad arrangement, such that when the backing pad arrangement and the abrading article are attached together for abrasion with a power tool, the perimeter of the secondary outlet openings on the backing pad arrangement are visible from beneath the abrading article, when viewed from the direction of the working surface.

11. The kit according to claim 1, wherein the backing pad arrangement or the abrading article, or both the backing pad arrangement and the abrading article further comprise a central opening configured to convey air to the working surface.

12. The kit according to claim 11, wherein both the backing pad arrangement and the abrading article comprise the central opening, and the central opening on the backing pad arrangement and the central opening on the abrading article each individually span an area that has a diameter, and the diameter of the central opening on the abrading article is larger than or equal to the diameter of the central opening on the backing pad arrangement.

13. The kit according to claim 11, wherein the diameter of the central opening is in a range of 30-50 mm.

14. The kit according to claim 1, wherein the backing pad arrangement and the abrading article are configured to be attached to an oscillating or reciprocating abrading apparatus.

15. The kit according to claim 1, wherein the diameter of the backing pad arrangement, the diameter of the abrading article, the diameter of the peripheral openings, the diameter of the central openings, or the diameter of the secondary outlet openings refers to the longest possible distance between two points at the perimeter of the backing pad arrangement, abrading article, peripheral openings, central openings, or secondary outlet openings, respectively.

Patent History
Publication number: 20240253185
Type: Application
Filed: Jan 24, 2024
Publication Date: Aug 1, 2024
Inventor: Stig FINNÄS (Sundby)
Application Number: 18/421,223
Classifications
International Classification: B24D 5/02 (20060101);