Method for dry production of a sliding layer

Abstract

A method for dry production of a sliding layer on a flexible backing, in particular a backing that includes a textile or an abrasive backing, includes at least the following. A binder, or more particularly an adhesive such as a hot-applied adhesive or a hotmelt, is applied to a flexible backing. The binder is applied in dry form, such as via scattering, and is joined to the backing via exposure to heat to form a sliding layer on the backing and to hold the sliding layer at least one of on and in the backing. A lubricant, or more particularly a lubricant that includes graphite or PTFE, is applied to at least one of the backing and the binder.

Claims

1. A method for producing a lining for a sanding pad configured to slidingly engage an abrasive, the method comprising: forming a sliding layer via a dry production process that includes: applying a binder in dry form to a first face of a flexible backing; joining the binder to the flexible backing via exposure to heat to form a sliding layer on the flexible backing, and to hold the sliding layer at least one of in and on the flexible backing; and applying a lubricant to at least one of the flexible backing and the binder; wherein: a second face of the flexible backing opposite the first face is configured to connect to an accommodation face of a sanding pad, such that the flexible backing forms a lining on the accommodation face and such that the sliding layer is configured to slidingly engage an abrasive supported by the sanding pad; and the lining is free from abrasive material.

2. The method of claim 1, wherein the binder is applied as a powder.

3. The method of claim 1, further comprising: mixing the binder and the lubricant together prior to applying the binder and lubricant to the flexible backing; wherein the binder and lubricant are applied to the flexible backing as a mixture to form at least one of the first layer and the second layer of the sliding layer.

4. The method of claim 1, further comprising: forming a first layer of the sliding layer by either: applying a mixture of the binder and the lubricant to the flexible backing to form a first layer that consists of the binder and the lubricant; or applying the lubricant to the flexible backing so as to form a first layer of the sliding layer that consists of the lubricant.

5. The method of claim 4, further comprising: forming a second layer of the sliding layer by either (i) separately applying the binder and the lubricant to the first layer, or (ii) applying a mixture of the binder and the lubricant to the first layer, such that the second layer consists of the binder and the lubricant.

6. The method of claim 3, wherein the binder constitutes at least 10% of the mixture of the binder and the lubricant.

7. The method of claim 6, wherein the binder constitutes about 30% of the mixture of the binder and the lubricant.

8. The method of claim 1, further comprising: pressing the sliding layer onto the backing.

9. The method of claim 1, further comprising: after exposing at least one of the binder and the flexible backing to heat during the joining, removing heat from at least one of the sliding layer and the flexible backing.

10. A method of using a lining backing that includes an abrasive layer disposed on a first backing side, and a sliding layer disposed on a second backing side facing away from the first backing side, the sliding layer including (i) a first layer including a lubricant or a binder and the lubricant (ii) a second layer including the binder and the lubricant and (iii) a third layer including the lubricant and free from the binder, the binder applied to the backing in dry form and joined to and held on the backing via exposure to heat, and the lubricant applied to at least one of the backing and the binder, the method comprising: separably joining the lining backing to a sliding mechanism embodied as a sanding pad.

11. The method of claim 1, wherein the flexible backing includes a textile.

12. The method of claim 1, wherein the flexible backing is an abrasive backing.

13. The method of claim 1, wherein the binder is at least one of a hot-applied adhesive and a hotmelt.

14. The method of claim 1, wherein the binder in dry form is applied to the flexible backing via scattering.

15. The method of claim 1, wherein the lubricant includes or consists of graphite or PTFE.

16. A method for dry production of a sliding layer on a flexible backing, comprising: applying a binder in dry form to a flexible backing and applying a lubricant to at least one of the flexible backing and the binder to form a sliding layer on the flexible backing, wherein forming the sliding layer includes: forming a first layer of the sliding layer by either: applying a mixture of the binder and the lubricant to the flexible backing to form a first layer that consists of the binder and the lubricant; or applying the lubricant to the flexible backing so as to form a first layer of the sliding layer that consists of the lubricant forming a second layer of the sliding layer by either (i) separately applying the binder and the lubricant to the first layer or (ii) applying a mixture of the binder and the lubricant to the first layer, such that the second layer consists of the binder and the lubricant; and forming a third layer of the sliding layer by applying the lubricant to the second layer, such that the third layer consists of the lubricant; and joining the binder to the flexible backing via exposure to heat to form a sliding layer on the flexible backing, and to hold the sliding layer at least one of in and on the flexible backing.

17. The method of claim 16, wherein the binder is applied as a powder.

18. The method of claim 16, further comprising: mixing the binder and the lubricant together prior to applying the binder and lubricant to the flexible backing; wherein the binder and lubricant are applied to the flexible backing as a mixture to form at least one of the first layer and the second layer of the sliding layer.

19. The method of claim 18, wherein the binder constitutes at least 10% of the mixture of the binder and the lubricant.

20. The method of claim 19, wherein the binder constitutes about 30% of the mixture of the binder and the lubricant.

21. The method of claim 16, further comprising: pressing the sliding layer onto the backing.

22. The method of claim 16, further comprising: after exposing at least one of the binder and the flexible backing to heat during the joining, removing heat from at least one of the sliding layer and the flexible backing.

23. The method of claim 16, wherein the flexible backing includes a textile.

24. The method of claim 16, wherein the binder is at least one of a hot-applied adhesive and a hotmelt.

25. The method of claim 16, wherein the binder in dry form is applied to the flexible backing via scattering.

26. The method of claim 16, wherein the lubricant includes or consists of graphite or PTFE.

27. The method of claim 5, further comprising: forming a third layer of the sliding layer by applying the lubricant to the second layer, such that the third layer consists of the lubricant.

28. A backing for abrasive machining of a workpiece, comprising: a sliding layer disposed on a first backing side, the sliding layer consisting of a binder and a lubricant, the sliding layer including: a first layer including the lubricant or the binder and the lubricant; a second layer including the binder and the lubricant; and a third layer including the lubricant and free of the binder; wherein the binder was applied to the backing in dry form, and was joined to and held on the backing via exposure to heat, and the lubricant was applied to at least one of the backing and the binder.

29. The backing of claim 28, wherein the backing is an abrasive backing, and further comprises an abrasive layer disposed on a second backing side facing away from the first backing side.

30. The backing of claim 28, wherein: the backing is a lining backing that is free from abrasive material; and the lining backing is configured to connect to a sliding pad that is configured to support an abrasive such that the abrasive is slidably engaged with the sliding layer of the lining backing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages are apparent from the drawing description which follows. Depicted in the drawing are exemplary embodiments of the disclosure. The drawing, the description, and the claims contain numerous features in combination. The skilled person will also look individually at the features, judiciously, and will collate them to form rational further combinations.

(2) In the drawing

(3) FIG. 1 shows a sectional view of a backing,

(4) FIG. 2 shows a diagrammatic representation of the production method of the disclosure, and

(5) FIG. 3 shows a flow diagram of the method.

(6) In the figures which follow, components that are alike are given the same reference symbols.

DETAILED DESCRIPTION

(7) The following figures each pertain to a method for dry production of a sliding layer on a flexible backing. This backing may be implemented as an abrasive backing comprising an abrasive. The backing may be configured as a belt abrasive backing, more particularly as a wide-belt abrasive backing.

(8) In a first embodiment of the backing, the backing may be configured for friction-reduced sliding friction of an abrasive which moves relative to the backing, such as a belt abrasive, for example. In this case, the backing may be provided for accommodation in or with a sliding means, more particularly a sanding pad. The backing in this case may serve as a replacement part of the sliding means, more particularly of the sanding pad.

(9) The backing is intended to be accommodated in a hand-operated sanding device such as, for example, a manual sanding machine, or a fixed sanding device such as a belt sanding machine or a wide-belt sanding machine, for example, and to machine a workpiece, more particularly to sand it and/or polish it, or to guide, in a friction-reduced manner, an abrasive which moves relative to the backing. The sanding device in this case may have at least one sliding means configured as a sanding pad, as evident, for example, from application EP 1 716 972 A1, for pressing the backing onto a workpiece to be machined. The backing in this case may be configured as a continuous belt backing, more particularly wide-belt backing. The backing may alternatively be provided for sliding relative to the pressing means, in operation in or on a sanding device.

(10) FIG. 1 shows a sectional view of an abrasive 1 comprising a flexible backing 3, configured as an abrasive backing and having a first backing side 15 and a second backing side 17 facing away from the first backing side 15. The first backing side 15 of the backing 3 has a first backing face 16. The second backing face 17 of the backing 3 has a second backing face 18.

(11) The first backing side 15 may in particular be lined with a velour, with the result, for example, that the sliding layer 5 may be disposed on the first backing side 15 and/or on the velour of the first backing side 15 and may surround the same in order to permit a firm join of the backing to the sliding layer 5.

(12) The backing 3 has a textile. The textile in particular forms an underlayer for the sliding layer. The textile may be woven or knitted. The textile may comprise or consist of natural or synthetic fibers. The backing 3 may comprise or consist of a cotton material. Alternatively, the backing 3 may at least partly comprise or consist of a paper material. For the backing 3 it is also possible, however, to use other materials which appear to be rational to a skilled person.

(13) Adjoining the first backing face 16 of the backing 3 is a sliding layer 5 for sliding on a sliding means, such as a sanding pad, for example. The sliding layer 5 is joined, in particular fusionally, to the backing.

(14) In a first embodiment of the backing 3, the second backing face 18 of the backing 3 is adjoined by an abrasive layer 7 for machining or sanding of a workpiece. In this first embodiment, the backing 3 serves as an abrasive backing 3a, more particularly for operation in a belt sanding device.

(15) In this embodiment, the abrasive layer 7 comprises an abrasive binder 83 and at least one abrasive element 85, in the form of abrasive grain, for the sanding of a workpiece surface. The abrasive layer 7, however, is not confined to this embodiment, but may be implemented as any abrasive layer 7, with at least one abrasive element 85, that is known from the prior art or appears rational to a skilled person. The abrasive element 85 may equally be designed as an edge, an angle or a sharpening suitable for the abrasive machining of workpieces. In this embodiment, the at least one abrasive element 85 is surrounded by an abrasive binder 83 in such a way that at least part of the at least one abrasive element 85 is in freely projecting form. The skilled person is already aware of various abrasive layers 7 on flexible backings 3, and here, therefore, no details will be addressed with regard to construction and composition of the abrasive layer 7.

(16) The abrasive backing 3a comprising the abrasive layer 7 and the sliding layer 5. In the first embodiment, the abrasive backing 3a is intended in particular for operation with a sanding device not shown in detail, such as a belt sanding machine, for example. In that case, the abrasive backing 3a is accommodated in the sanding device comprising a plurality of diverting rollers for tensioning and guiding the abrasive backing 3a. The diverting rollers here are in contact with the sliding layer 5 of the abrasive backing 3a, and guide the abrasive backing 3a at least partly around the diverting rollers. Additionally, the majority of sanding devices have a sliding means in the form of a sanding pad which is intended to be pressed onto the sliding layer 5 in order to press the abrasive layer 7 of the abrasive backing 3a against the workpiece to be machined, and to generate an erosive or abrasive action on the workpiece to be machined. With this embodiment it is possible for the sliding means in the form of a sanding pad to have no backing with a sliding layer.

(17) In a second embodiment of the backing 3b, the second backing face 18 of the backing 3b has no abrasive layer. The second backing face 18 in this case forms a fastening face 18 which is intended at least partly to cover a sliding means, forming a sanding pad 5, of a sanding device. The backing 3b here serves as a lining backing for the sanding pad. The backing 3b may be accommodated in or with the sanding pad. The sanding pad here has an accommodation region, not shown in detail, having an accommodation face. The sanding pad here accommodates the backing 3b in such a way that the second backing face 18 or backing face not provided with the sliding layer is facing the accommodation face of the accommodation region. The connection between the backing face 18 and the accommodation face of the accommodation region here may be a force-fit or frictional fit and/or fusional fit and/or form fit. In particular, the backing 3b may be joined firmly to the sanding pad, such as by means of a screw connection, a clamping connection and/or a tensioning connection, for example. Sanding pads of this kind may be found for example in application EP 1 716 972 A1.

(18) The backing 3b as well is suitable for accommodation in or with a sanding pad system, with the sanding pad system having at least one backing means, not shown in detail, for accommodating and fixing the backing 3b, and a sanding pad device able to join the backing means separably. For this purpose it is possible to use all sanding pads or sanding pad systems that are present on the market, with the backing 3b of the disclosure.

(19) Furthermore, provision may be made for the sliding means designed as sanding pad to be provided with the backing 3b and to press an abrasive backing 3a against a workpiece to be machined, in the operation of a sanding device.

(20) The sliding layer 5 has a joining face, which is joined to the first backing face 16, and a sliding face 5a, which faces away from the joining face. The sliding face 5a is intended to allow, with reduced friction, sliding on a sliding means in the form of a sanding pad, or of an abrasive in the form of a belt abrasive.

(21) The sliding layer 5 comprises a binder 10 and a lubricant 9 which consists of or comprises a graphite and/or PTFE material. The binder 10 is intended for joining the lubricant 9 to the backing 3.

(22) The sliding layer 5 has a first layer 21 which adjoins the first backing face 16 of the abrasive backing 3 and is joined, more particularly fusionally, to the backing face 16.

(23) The first layer 21 of the sliding layer 5 comprises the binder 10, which is intended to join the second layer 23 to the first backing face 16, more particularly by fusional means and/or by form fit.

(24) The sliding layer 5 has a second layer 23 which adjoins the first layer 21 and is disposed on a side of the first layer 21 that faces away from the backing 3.

(25) The second layer 23 of the sliding layer 5 comprises the binder 10 and the lubricant 9. The second layer 23 is intended in particular for joining the second layer 23 reliably to the first layer 21, more particularly by fusional means and/or by form fit and/or by way of intermolecular forces.

(26) The sliding layer 5 additionally has a third layer 25 which adjoins the second layer 23 and is disposed on a side of the second layer 23 that faces away from the first layer 21.

(27) The third layer 25 of the sliding layer 5 comprises the lubricant 9. The third layer 25 is intended to allow the sliding of a sliding means, such as of a conventional sanding pad, for example, with as little frictional resistance as possible, and so to prevent excessive heating both of the backing 3 and of the sliding means. In order to permit optimum sliding, the third layer 25 preferably has no binder 10.

(28) The binder 10 of the second layer 23 is intended for joining the third layer 25 by means, in particular fusionally and/or form-fittingly and/or by way of intermolecular forces.

(29) FIG. 2 illustrates diagrammatically the production of a backing 3 with a method of the disclosure. The method is shown in FIG. 3 on the basis of a flow diagram. The apparatus 29 used for this purposesee FIG. 2comprises an unwind station 31, from which a backing 3 in web form is unwound continuously in a step A, this backing 3 consisting of or comprising, for example, a textile or paper. In the step A, the backing 3 may already be provided with an abrasive layer 7 and already be in the form of an abrasive backing. In the case of a version of the backing 3 without an abrasive layer 7, such a layer may also be applied during the method or in a subsequent method to the second backing side 17 of the backing 3, the side facing away from the sliding layer 5, and may be joined fusionally and/or form-fittingly to the backing 3.

(30) In a scattering station 33, which is known per se, in a step B, which may be subdivided into a plurality of component steps, the sliding layer 5 is applied to the abrasive backing 3. Depending on the preferred embodiment, the sliding layer 5 may comprise a plurality of layers, which are applied, for example, in a sequential series, more particularly a first layer 21, a second layer 23 applied to the first layer 21, and a third layer 25 applied to the second layer 23. The compositions of the respective layers of the sliding layer 5 may be configured in accordance with the composition of the layers from FIG. 1. Here, in a first component step B1, the first layer, comprising or consisting of a binder, is applied or scattered onto the first backing side 15. In a second component step B2, the second layer 23, comprising or consisting of a binder 10 and a lubricant 9, is applied or scattered onto the first layer 21. In a third component step B3, the third layer 25, comprising or consisting of a lubricant, is applied or scattered onto the second layer 23. The scattering station 33 here may comprise a plurality of scattering modules 33a which perform the component steps B1, B2, and B3.

(31) Also possible is a sliding layer 5 comprising only one single layer or two layers.

(32) In the case of one embodiment, not shown in detail, with a sliding layer 5 comprising a single layer 21a, the layer 21a may in particular comprise or consist of a mixture of a binder 10 and a lubricant 9, this mixture being applied or scattered onto the first backing face 16 of the backing side 15 of the backing 3 by means of a single component step B2a of the scattering station 33. In this case, the scattering station 33 may advantageously be equipped with only a single scattering module 33a.

(33) In the case of a further embodiment not shown in detail, with a sliding layer 5 comprising two layers, a first layer 21b may comprise or consist of a binder 10, and a second layer 23b may comprise or consist of, in particular, a mixture of a binder 10 and a lubricant 9. The first layer 21b may take place by means of a component step B1b, by the first layer 21b being applied or scattered onto the first backing face 16 of the backing side 15 of the backing 3. The second layer 23b may take place by means of a component step B2b of the scattering station 33, by the second layer 23b being applied to the first layer 21b.

(34) By means of a heating station 35, in a downstream step C, the backing 3 and/or the sliding layer 5 are/is heated to a temperature of preferably 20-40 above the melting point of the binder, causing the binder to reach or exceed a binder melting temperature, in order to joinmore particularly fusionallythe backing 3 to the lubricant 9. By this means it is possible, for example, for the aggregate state of the binder to change, allowing the binder to flow into and fill pores and vacancies in the sliding layer.

(35) Additionally to the heating station 35 in step C, a pressing station 37 is provided in a step D, which compacts the sliding layer 5 and, in particular, presses it onto the backing 3, thereby compacting or consolidating the sliding layer 5. In this embodiment, step C is combined with step D, and so the pressing station 37 and the heating station 35 are configured integrally in order to achieve rapid throughput of the backing 3. In an alternative version, the step C and the step D may be configured sequentially one after another. By this means, the sliding layer 5, more particularly the binder of the sliding layer 5, is heated by means of the heating station 35 to a binder melting temperature, for example, and is compacted or consolidated, thereby causing the vacancies or cavities formed in the sliding layer in step B, during the scattering of the binder 10 and/or of the lubricant 9 onto the backing 3, to be filled with the binder 10, for example, in step D. As a result, a homogeneous microstructure may come about in the respective layers of the sliding layer 5. The pressing station 37 and the heating station 35 extend for 2 to 9 m, more particularly 3 to 8, preferably 4 to 7 m, more preferably 4 to 6 m, very preferably 4.5 to 5.5 m. The pressing station 37 may be any pressing station which appears rational and suitable to a skilled person in particular for compacting or compressing a sliding layer 5 on a flexible abrasive backing 3.

(36) Although no water is added to the backing 3 and/or to the sliding layer 5, it is possible in the heating station 35 and/or during the heating of the backing 3 and/or the sliding layer 5 for liquid to escape from the binder and/or the lubricant 9, this liquid having been absorbed via the ambient atmospheric moisture, for example, or having been taken up in the base material of the binder 10 or of the lubricant 9.

(37) In a step E which follows step C or step D, a cooling station 39 is provided, which cools the backing and the sliding layer; as a result, the temperature and optionally the aggregate state of the binder 10 changes from liquid to solid, and so the sliding layer and the backing are converted into an end state. In this embodiment, step D of the pressing station 37 and step E of the cooling station 39 overlap one another or are performed simultaneously. Alternatively or additionally, step E may also take place after step D.

(38) In a further step F subsequent to the preceding steps A to D, it is optionally possible for there to be a cleaning station 41 provided, which, by means for example of a brush rotating over the sliding layer, in particular, cleans residues arising from the operation from the backing 3 and/or the sliding layer 5, for example, and ensures that the sliding layer has a uniform and/or smooth sliding face.