METHODS AND TOOL FOR MAINTENANCE OF HARD SURFACES, AND A METHOD FOR MANUFACTURING SUCH A TOOL

Abstract

A method is disclosed for treating or maintaining a hard surface comprising a stone or stone-like material, the method comprising treatment of the surface with a flexible pad, in the presence of abrasive particles, bonded to the pad, on a contact surface between the pad and the hard surface, wherein the abrasive particles comprise diamond particles, and the treatment is performed in the absence of an effective amount of crystallization agent on the contact surface. The treatment is performed on a substantially regular basis, such as daily, weekly or monthly, and the treatment is performed using a pad comprising an open, lofty, three dimensional non-woven webs of fibers. A tool for use in the method is also provided, as well as a floor-surfacing machine comprising such a tool and a method for manufacturing such a tool. Furthermore, methods for treating or maintaining hard, smooth surfaces such as wood, polymer material, lacquer, linoleum, gelcoat, glass and automotive enamel are disclosed.

Claims

1. (canceled)

2. A method for maintaining a hard, smooth floor surface comprising a polymer material, the method comprising: treating the hard, smooth floor surface with a flexible pad comprising an open, lofty, three dimensional non-woven web of fibers, in the presence of abrasive particles, bonded to the pad, on a contact surface between the pad and the hard, smooth floor surface, wherein the abrasive particles comprise diamond particles of an average diameter of 0.1 to 30 μm, preferably 0.1 to 15 μm or 3 to 6 μm, and wherein treating the hard, smooth floor surface is performed using said pad having: abrasive particles bonded thereto only in a vicinity of the contact surface, the fibers of the flexible pad are bonded to each other by a primary binder and/or via melt-bonding, and have the abrasive particles bonded thereto by a secondary binder, the abrasive particles are present throughout the secondary binder, a first portion of the flexible pad has the abrasive particles present in a first concentration, and a second portion of the flexible pad has the particles present in a second, lower concentration, and said second concentration is zero, such that the second portion is free from the abrasive particles, and wherein the flexible pad has a disc-shaped body having a thickness and a first surface, the abrasive particles being present on said first surface and down to a depth from said first surface, which depth is less than said thickness, such that said first portion is at said first surface and said second portion is at a second surface, opposite said first surface.

3. The method as claimed in claim 2, wherein the abrasive particles comprise at least one of natural diamond particles, industrial diamond particles and coated diamond particles.

4. The method as claimed in claim 2, wherein the treating step is performed using a pad having a density of less than 40 kg/m.sup.3, preferably 20-35 kg/m.sup.3.

5. The method as claimed in claim 2, wherein the pad, while in contact with the hard surface, is caused to move in relation to the hard surface.

6. The method as claimed in claim 2, wherein the pad, while in contact with the hard surface, is caused to rotate at a rotational speed of 50-300 rpm, preferably of 100-1500 rpm.

7. The method as claimed in claim 2, wherein the hard, smooth polymer floor surface has a hardness less than about 3 Mohs, preferably less than about 2 Mohs and most preferably less than about 1 Mohs.

8. The method as claimed in claim 2, wherein the method is performed using a scrubber/dryer combination floor surfacing machine.

9. The method as claimed in claim 2, wherein the treating step is performed in the absence of surface-improving agents on the contact surface.

10. The method as claimed in claim 2, wherein the abrasive particles comprise diamond particles of an average diameter between 0.1 and 15 μm and preferably between 3 and 15 μm.

11. The method as claimed in claim 2, wherein the treating step is performed in the absence of liquid on the contact surface.

12. The method as claimed in claim 2, wherein the treating step is performed in the presence of water on the contact surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0075] FIGS. 1a-1b show a pad according to a first embodiment.

[0076] FIGS. 2a-2b show a pad according to a second embodiment.

[0077] FIGS. 3a-3b show enlarged photographs of a pad according to the present disclosure, before and after the binder and abrasive particles have been applied.

[0078] FIGS. 4a-4b show a diagram of a pad according to the first embodiment, and an enlargement of a portion of the pad.

[0079] FIG. 5 is a sectional view of a floor surfacing machine on which a pad according to the disclosure is mounted.

DESCRIPTION OF EMBODIMENTS

[0080] The description will first focus on a tool suitable for use in the method for maintenance of hard surfaces, subsequently on the method for manufacturing the tool, and finally on the use of the tool for maintenance of a hard surface.

[0081] Referring to FIG. 1a, there is shown a pad 1 made up from an open, lofty three dimensional non-woven web of fibers 2. A first surface of the pad 1 has a portion P1 presenting abrasive particles bonded to the web by means of a secondary binder, i.e. a binder having as a main purpose to bond fibers to the web. The pad 1 is circular in shape.

[0082] Referring to FIG. 2b, a cross section along the line S1-S2 in FIG. 1a is shown. As is indicated in FIG. 1b, the portion P1 presenting the abrasive particles is present at the first surface A and to a depth D, which is less than the thickness T of the pad 1. Hence, at the second surface B there is a portion P2, which is substantially free from the abrasive particles and the secondary binder.

[0083] When referring to “portions”, it is to be understood as a portions of the macrostructure of the pad 1 and not portions of the individual fibers.

[0084] Referring to FIGS. 2a and 2b, there is shown a similar pad 1, the difference being that there is a portion P2′ also at the first surface A, which portion P2′ is substantially free from the abrasive particles and the secondary binder.

[0085] In both embodiments, the abrasive particles are present throughout the secondary binder, and the fibers are bonded to each other by a primary binder and/or by being melt-bonded.

[0086] A description of the preparation of a pad 1 according to the embodiment discussed with reference to FIGS. 1a and 1b will now be given.

[0087] As a starting material, circular, disc shaped Glit/Microtron® Tan Floor Polishing Pad having a diameter of 20 inches (51 cm), a thickness of 28 mm and a weight of 157 grams was used. Such pads are available from Glit/Microtron, Wrens, Ga., USA. The starting density of the pad was thereby 27 kg/m.sup.3. FIG. 3a is a microscope photograph showing the pad prior to application of the polymer resin/abrasive particles.

[0088] From FIG. 3a, it can be seen that the fibers constituting the pad are held together at their points 10 of mutual contact by a primary polymer resin. The pad is flexible and resilient and comprises polyester and nylon fibers.

[0089] A homogenous polymer resin mixture was prepared, consisting of 200 g PA resin 52-68 phenol resin (available from Perstorp AB, Perstorp, Sweden), 100 g of T-ROD® ethanol (available from Alfort & Cronholm AB, Bromma, Sweden) and 20 g of LANDS LS600F 4-8 μm diamond particles (available from Lands Superabrasives, Co., New York, N.Y., USA). Just before application of the mixture, 60 g of 65% p-toluene sulfonic acid (PTS) was added as a hardener.

[0090] The resin mixture was sprayed onto a first one A of the surfaces of the polishing pad, using a standard-type compressed air spray gun (normally used for spraying paint).

[0091] The pad with the uncured resin thereafter weighed 173 grams. Subsequently, the pad was placed in a hot air oven at approximately 120° C. for approximately 20 minutes.

[0092] The pad has now assumed the appearance that can be seen from FIG. 3b, which is a microscope photograph. Globules or droplets 11 of the resin/particle mixture are formed along each fiber, also between the fibers' points of mutual contact. The droplets are so distributed that the fibers to which they are adhered are not entirely covered. A more clear illustration of this is found in FIGS. 4a-4b, which show a pad as described above with reference to FIGS. 1a-1b, and an enlargement of a portion of that pad (FIG. 4b), wherein droplets 11 of binder/particle mixture are attached to the fibers.

[0093] In order to evaluate the performance of the pad produced as described above, comparative tests were carried out in order to evaluate two different 20 inch (51 cm) pads, prepared as described above: a first one, referred to as “yellow”, having 7-12 μm silver coated diamond particles, and a second one, referred to as “green”, having 3-6 μm normal diamond particles. As a reference, two different commercially available pads were used: a 20 inch (51 cm) 3M™ 5200 Brown Stone Renew Pad and a 20 inch (51 cm) 3M™ 4000 Grey Stone Polish Pad were used, both available from 3M, St. Paul, Minn., USA.

[0094] The tests were made on two different surface types: Kolm{dot over (a)}rden marble (marble from the Kolmarden area outside Norrköping, Sweden) and K40 concrete. Each test was carried out on a surface of about 1 m.sup.2, using a Coor & Kleever Crystallizer 1250KG floor surfacing machine (available from Coor & Kleever, S.A., Barcelona, Spain) having a single carrier plate adapted for receiving a 20 inch floor pad and rotating at about 175 rpm. The test included polishing the surface for about 1 minute/m.sup.2. The surface gloss was measured at several spots on the area before and after each treatment using a Sanwal/Cenma IG-310 Glosschecker. The gloss value in the tables below constitute the average value for each area. High gloss is rated 80-90°. Semi gloss is rated 50-75°. Satin is rated 30-45°. Rubbed effect is rated 20-25°. Flat sheen is rated 5-15°.

[0095] Each surface was tested both dry and using water as a lubricant. Additionally, the concrete surface was tested using Coor Rosa/K-2 crystallizer (available from Coor & Kleever S.A., Barcelona, Spain) as lubricant, i.e. the crystallization chemical mentioned in EP-B-0 562 919 as comprising magnesium hexafluourosilicate as crystallization agent.

[0096] When testing the 3M™ pads, each surface portion was first treated with the brown pad and subsequently with the gray pad.

TABLE-US-00001 TABLE 1 Tests performed with water as lubricant on Kolmården marble Pad Brown Gray Green Initial gloss 17 17 10 Liquid Water Water Water Final gloss 17 35 30

TABLE-US-00002 TABLE 2 Tests performed without lubricant on Kolmården marble Pad Brown Gray Green Initial gloss 20 25 28 Liquid No No No Final gloss 25 30 50

[0097] From tables 1 and 2, it can be concluded that on marble, which is a relatively soft stone having a hardness of about 3-5 moh, and using water as a lubricant, the 3M™ pad combination (brown and gray) provide a slightly better effect, although both the gray and the green pads achieved values falling within the “satin” range. However, during dry conditions, the green pad achieved a remarkable improvement, reaching the semi-gloss range.

TABLE-US-00003 TABLE 3 Tests performed with water as lubricant on K40 concrete Pad Brown Gray Yellow Green Initial gloss 30 29 24 35 Liquid Water Water Water Water Final gloss 29 29 35 46

TABLE-US-00004 TABLE 4 Tests performed without lubricant on K40 concrete Pad Brown Gray Yellow Green Initial gloss 29 34 30 48 Liquid No No No No Final gloss 34 35 48 58

[0098] From Tables 3 and 4, it is noted that in wet conditions and on K40 concrete, having a hardness of about 6-7 moh, the combination of brown and gray pads did not provide any measurable improvement at all, whereas the combination of yellow and green pads provided a distinct improvement. In dry conditions, a small improvement was noted for the surface treated with the combination of brown and gray pads, whereas a major improvement was noted for the surface treated by the combination of yellow and green pads.

TABLE-US-00005 TABLE 5 Tests performed with Coor Rosa/K-2 crystallizer as lubricant on K40 concrete Pad Gray Green Initial gloss 41 35 Liquid VMC-Pink VMC-Pink Final gloss 45 51

[0099] From table 5, it is noted that some effect is achievable with a gray pad using Coor Rosa/K-2 crystallizer as lubricant on K40 concrete, and that a somewhat better effect is achievable with the green pad using Coor Rosa/K-2 crystallizer as lubricant.

[0100] All in all, it is concluded that the pad according to the present disclosure provides a noticeable improvement as compared with the prior art. The improvement is particularly noticeable during dry conditions and on concrete.

[0101] FIG. 5 is a sectional view of a floor surfacing machine 20 on which a pad 1 according to the present disclosure is mounted so as to define a contact surface 9 with the hard surface 8, which in this example is a floor surface. The pad 1 is mounted on a driven, rotatable carrier plate 4, which is typically journalled in bearings and thus rotatable relative to a machine body 5, on which a motor unit 6 is arranged. In this embodiment, the machine has a handle 7, and is thus adapted for being held/pushed/pulled by a walking operator. It is recognized that in other embodiments the floor surfacing machine 20 may be e.g. a ridable vehicle fitted with a carrier plate 4 that is adapted for receiving the pad 1.

[0102] The pad 1 and method described above can be used for everyday cleaning/maintenance of polished hard surfaces, such as stone, concrete or terrazzo floor surfaces using a floor surfacing machine such as a scrubber/dryer combination machine, e.g. the Nilfisk CR1300; a single disc floor maintenance machines (low speed or high speed), e.g. the Nilfisk 510B or 545; a burnisher, e.g. the Nilfisk SDH5120, BHS5120 or BHS7014, all of which are available from Nilfisk-Advance, Stockholm, Sweden.

[0103] The treatment of the floor surface is typically performed by causing the pad, when in contact with the floor surface, to rotate in a plane parallel with the floor surface. Typical rotational speeds are from 50 rpm to 3000 rpm. However, lower or higher rotational speeds are not excluded.

[0104] As is clear from the above, a first embodiment of the pad according to the present disclosure comprises an open, lofty, three dimensional non-woven web, including a plurality of fibers, which are adhered to each other at their points of mutual contact by means of a primary binder, and in which abrasive particles are mixed with a secondary binder and applied only to a first surface of the pad, such that the pad is only partially impregnated by the binder/particle mixture. Alternatively, or additionally, the fibers may be melt-bonded to each other.

[0105] In a second embodiment of the pad, binder/particle mixture is only applied to parts of said first surface. This can be achieved by masking those parts of the surface to which the binder/particle mixture should not be applied.

[0106] In a third embodiment, the pad is entirely impregnated with the binder/particle mixture, e.g. by using such squeeze rollers as are described in EP-B-0 562 919. In a variant of this embodiment, a relatively thin impregnated woven or non-woven pad is attached to a thicker carrier pad in order to provide the flexibility. According to variants of this embodiment, a substantially two-dimensional woven or non-woven web is attached to a thicker carrier pad.

[0107] In a fourth embodiment, a three dimensionally woven or knitted pad may be used, whereby the binder/particle mixture is applied as described above.

[0108] In a fifth embodiment, the abrasive particles are present in the material of the pad. In a first alternative, the pad is a non-woven fiber pad substantially as described above, with the diamond particles included in the fiber material. In a second alternative, the pad is a polymer foam pad with the diamond particles included in the foamed polymer material.

[0109] In a sixth embodiment, the pad is a polymer foam pad, to a surface of which a binder/particle mixture is applied as described above.

[0110] The present disclosure is not limited to the use of phenol resin. Other examples of suitable resins are melamine, urea, epoxy and polyester resins.

[0111] Furthermore, the hardener may be selected from any hardener suitable for the type of resin selected. Also it is possible not to include the hardener, e.g. by allowing the pad to cure at a higher temperature and/or for a longer period of time.

[0112] Also, the solvent (ethanol was used in the example) is provided merely to reduce the viscosity of the mixture and thereby to facilitate spraying thereof. Any suitable solvent may be used, and the solvent may also be excluded, provided that the method of application so allows.

[0113] The abrasive particles preferably include diamond. However, floor treatment pads may be produced according to the principles set forth above using other types of abrasive particles, or combinations thereof, as well, e.g. those mentioned in EP-B-0 562 919. In particular silver coated diamond particles have proven to provide good results as well. Naturally, the diamond particles may be combined with other types of abrasive particles.

[0114] It is understood that the pad 1 having secondary binder and abrasive particles as described above may be attached to a disc or plate having an arbitrary connector for being connected to a carrier plate of the surfacing machine, or that the pad may be directly connectable to the surfacing machine by means of a Velcro-type hook arrangement provided on the carrier plate, the hooks of which engage the fibers of the pad 1. Hence, the maintenance tool may be composed of the pad with the primary binder, the secondary binder and the abrasive particles, possibly with the addition of dyes or printed areas providing information on the type of pad, manufacturer, trademark etc.

[0115] Alternatively, or additionally, the pad may be provided with a backing layer.

[0116] Further tests were performed using applicant's yellow and green pads, described above, as well another pad, referred to as “white”, having 15-30 μm diamond particles, but otherwise corresponding to the yellow and green pads described above. As a reference, a 3M® 5100 Red Buffer Pad, available from 3M, St. Paul, Minn., USA, was used.

[0117] In a first additional test, the applicant's pads were tested on an oiled oak parquet surface. Gloss values of the floor was measured, before and after treatment, at five spaced apart points using the gloss meter referred to above, whereby an average gloss value was calculated after processing with each pad type. The results are shown in Table 6.

TABLE-US-00006 TABLE 6 dry polishing of oiled oak parquet Pad 3M ® red White Yellow Green Initial gloss 6.0 6.0 6.0 6.0 Liquid No No No No Final gloss 20.2 17.0 26.0 31.4

[0118] From Table 6, it can be seen that a gloss improvement from a silk matt surface (6.0) is achievable, in particular when using the yellow and white pads, which both provide a very shiny surface. The white pad provided a shiny surface, whereas the 3M® red pad provided a shiny, though somewhat blotchy surface. It was noticed that the white, yellow and green pads provided a very clean floor.

[0119] In a second additional test, the applicant's pads were tested for wet polishing of an oiled oak parquet surface. Gloss values of the floor was measured, before and after treatment, at five spaced apart points using the gloss meter referred to above, whereby an average gloss value was calculated after processing with each pad type. The results are shown in Table 7.

TABLE-US-00007 TABLE 7 dry polishing of oiled oak parquet Pad White Yellow Green Green Initial gloss 6.8 6.8 6.8 6.8 Liquid Water Water Water No Final gloss 0.0 0.0 0.0 22.8

[0120] From Table 7, it can be seen that starting from a silk matt surface, the white and yellow pads provided an entirely matt surface, with some grinding residue being noticeable in the water. The green pad, on the other hand provided a matt, entirely smooth surface. Dry polishing with the green pad provided a shiny and clean surface, entirely free from oil film. It was noticed that the white, yellow and green pads provided a very clean floor. It was also noted that dry polishing of the flooring using the white, yellow or green pads subsequent to the wet polishing, provided gloss values similar to those of Table 6.

[0121] Hence, it is concluded that the pad disclosed herein may be used for grinding and/or polishing wood surfaces, such as wood floor surfaces, deck surfaces (on e.g. patios or boats), wall surfaces, interior moldings, doors, baseboards etc.

[0122] In a third additional test, the applicant's pads were tested for dry polishing of an Amtico® vinyl tile flooring, available from Amtico International, Coventry, UK, processed with flooring wax to a shiny finish. Initially, the surface had multiple scuff marks. Gloss values of the floor was measured, before and after treatment, at five spaced apart points using the gloss meter referred to above, whereby an average gloss value was calculated after processing with each pad type. The results are shown in Table 8.

TABLE-US-00008 TABLE 8 dry polishing of Amtico ® vinyl flooring Pad Gloss Comment None 24.8 Shiny surface, multiple scuff marks 3M ® red 24.8 Shiny surface, scuff marks remaining White 16.4 Clean, matt surface, no scuff marks Yellow 19.4 Clean surface, no scuff marks Green 24.4 Very shiny, clean surface

[0123] From Table 8 it is noted that the 3M® red pad, while maintaining the shiny floor surface, did not remove all scuff marks. The white pad removed the scuff marks, at a loss in shininess. With the yellow pad, a more shiny surface was obtainable, with all scuff marks being removed. The green pad provided a surface having practically the same shine as the initial surface, although the scuff marks were entirely removed. It was noticed that the white, yellow and green pads provided a very clean floor.

[0124] In a fourth additional test, the applicant's pads were tested for wet polishing of the Amtico® vinyl tile flooring, processed with flooring wax to a shiny finish. Initially, the surface had multiple scuff marks. Gloss values of the floor was measured, before and after treatment, at five spaced apart points using the gloss meter referred to above, whereby an average gloss value was calculated after processing with each pad type. For reference, dry polishing using the green pad was performed. The results are shown in Table 9.

TABLE-US-00009 TABLE 9 wet polishing of Amtico ® vinyl flooring Pad Liquid Gloss Comment None None 24.0 Shiny surface, multiple scuff marks 3M ® red Water 24.8 Shiny surface, some scuff marks remaining White Water 15.2 Clean, matt surface, no scuff marks Yellow Water 19.0 Clean surface, somewhat more shiny Green Water 20.4 Clean surface Green None 26.8 Very shiny, clean surface

[0125] From Table 9, it is noted that the 3M® red pad once more failed to remove all scuff marks from the floor surface, although providing a shiny surface. The white pad provided a clean, matt surface, whereas the yellow pad provided a clean, slightly more shiny surface. The result from the green pad, when used for wet polishing was moderately better than that of the yellow pad. Once more, the green pad when used in dry conditions provided a very shiny, clean surface. It was noticed that the white, yellow and green pads provided a very clean floor.

[0126] In a fifth additional test, the applicant's pads were tested for dry polishing of a linoleum floor surface. The initial surface had been treated with flooring wax. Gloss values of the floor was measured, before and after treatment, at five spaced apart points using the gloss meter referred to above, whereby an average gloss value was calculated after processing with each pad type. The results are shown in Table 10.

TABLE-US-00010 TABLE 10 dry polishing of linoleum surface Pad Liquid Gloss Comment None None 19.0 3M ® red None 21.0 No noticeable change White None 12.8 The surface is matted Yellow None 21.5 The surface is perceived as more shiny than reference Green None 26.3 Very shiny and clean surface

[0127] From Table 10, it is noted that whereas the white pad provides a matter surface, the 3M® red pad only provides a slight improvement, whereas the surface processed with the yellow pad is perceived as more shiny than the reference surface. The green pad provides a very shiny and clean surface. It was noticed that the white, yellow and green pads provided a very clean floor.

[0128] In a sixth additional test, the applicant's pads were tested for wet polishing of a linoleum floor surface. The initial surface had been treated with flooring wax. Gloss values of the floor was measured, before and after treatment, at five spaced apart points using the gloss meter referred to above, whereby an average gloss value was calculated after processing with each pad type. The results are shown in Table 11.

TABLE-US-00011 TABLE 11 wet polishing of linoleum surface Pad Liquid Gloss Comment None Water 19.0 3M ® red Water 7.3 Very matt surface after scouring White Water 3.5 The polished surface removed by scouring Yellow Water 7.0 The polished surface removed by scouring, matt finish maintained Green Water 9.8 Somewhat more shiny than after yellow pad, matt finish

[0129] From Table 11, it is noted that the 3M® red pad provides a very matt surface, while the white pad provides a matt surface, and completely removes the polished surface. The yellow pad provides a matt finish, while removing the polished surface. The green pad provides a slightly more shiny finish as compared with the yellow pad. It was noticed that the white, yellow and green pads provided a very clean floor. It was also noted that dry polishing of the flooring using the white, yellow or green pads subsequent to the wet polishing, provided gloss values similar to those of Table 10.

[0130] Hence, the pad may be used for grinding and/or polishing linoleum and plastic floors, e.g. floors having a surface comprising vinyl, polyurethane, epoxy, acrylic or other plastic material. In particular, the pad is suitable for dry polishing of such surfaces.

[0131] In a seventh additional test, the applicant's pads were tested for dry polishing of a lacquered parquet floor surface. In this test, an additional pad, termed “Orange” and having diamond particles of 2-4 micron was used. Gloss values of the floor was measured, before and after treatment, at five spaced apart points using the gloss meter referred to above. The results are shown in Table 12.

TABLE-US-00012 TABLE 12 polishing of lacquered parquet surface Pad Green Orange Orange Initial gloss 40 40 47-50 Liquid None None None Final gloss 47-51 58-60 56-59

[0132] From Table 12, it is noted that the pads can be used for cleaning/polishing lacquered surfaces as well. Using the orange pad provides an additional gloss increase, regardless of whether it is performed on a surface having an initial gloss value of 40 or of 47-50.

[0133] Hence, it is concluded that the pad disclosed herein may be used for grinding and/or polishing lacquered surfaces, e.g. lacquered wood surfaces, such as wood parquet floor and other lacquered surfaces (on e.g. patios or boats), wall surfaces, interior moldings, doors, baseboards etc.

[0134] According to another embodiment, the pad may be used for polishing polymer surfaces, e.g. so-called “gelcoat” surfaces, that are found on fiber-reinforced plastic structures, such as boats etc., and which typically comprise resin and optionally pigments.

[0135] According to yet another embodiment, the pad may be used for grinding and/or polishing glass surfaces, such as e.g. automobile windows/windscreens, in order to remove small scratches etc.

[0136] According to yet another embodiment, the pad may be used for grinding and/or polishing automobile bodies, and even for polishing painted surfaces on automobile bodies, i.e. automotive enamel.

[0137] Whereas the methods disclosed herein are suitable for regular treatment or maintenance, they can also be used for ad hoc polishing or grinding treatment.