Method for maintenance of hard surfaces

Technical field

The subject of the invention is a method and tool for the maintenance of hard surfaces, mainly concrete floor (cement), terrazzo and granite but also marble and limestone surfaces. Particularly, the present invention relates to a maintenance method suitable for daily use to maintain a polished, hard floor surface.

Background of the invention

In connection with the cleaning or light polishing of floor surfaces, it is known to use a disc in the form of a three-dimensional nonwoven material. The disk is usually supplied in the form of a circular disk-shaped element which is detachably mounted on a circular support plate and which, when used, is put into rotation in a plane parallel to the floor surface in such a way that when the disk is brought into contact with the floor surface , it is slightly compressed by the pressure arising between the floor surface and the support plate. The support plate is usually set in motion by means of a motor and can be mounted on a support frame which can be adapted to be pushed or pulled by a walking operator or which can be constructed as a self-propelled vehicle.

Such discs are made of fibers of an organic material, for example polyamide and / or polyester, especially polyethylene terephthalate. In some cases, the fibers include natural fibers, such as walnut or coconut fibers.

The disc fibers are interconnected at their common points of contact by so-called molten bonding, in which the fibers are subjected to heat, which causes a slight melting of the outer part of the fibers, and thus contributes to their interconnection.

Alternatively or additionally, the fibers can be interconnected at their common contact points by impregnating the disc with a polymer resin, hereinafter referred to as "base binder".

The method of producing this type of nonwoven discs is well known, for example from US-A-3,537,121, US-A-4,893,439, EP-A-0 397 374, GB-A-1 348 526 and EP-A-0 562 919 and including does not require additional detailed explanation.

US-A-3,537,121 discloses wheels for polishing surfaces of aluminum, plastic, wax and the like. US-A-3,537,121 also discloses a method for making these targets. In US-A-3,537,121, the disc is treated with a binder mixed with abrasive particles by passing the disc between two wringing rollers, one of which is partially immersed in a container with a mixture of binding resin and abrasive particles, after which the disc is cured or dried . Thus, US-A-3,537,121 provides for a disk that is completely impregnated with binder and abrasive particles.

US-A-4,893, 439 discloses a disk for polishing floor or aluminum surfaces. The disc consists of fibers of organic material and is a high, open non-woven structure and contains a binder connecting abrasive particles with fibers. The disc shown in US-A-4,893,493 has larger voids than the disc shown in US-A-3,537,121, which means that it has an increased ability to absorb dirt and can therefore be used for a longer period of time. The wheel disclosed in US-A-4,893,493 is also completely impregnated using binder and abrasive particles.

EP-A-0 397 374 discloses a disk for floor polishing machines, which is also completely impregnated using binder and abrasive particles.

Discs of the above type are often used for so-called "glossing", i.e. dry polishing (often everyday) of very lightly worn surfaces, using high speed (1500-3000 rpm) and with relatively low pressure to renew the surface This type of treatment is commonly used for both vinyl and marble flooring. Discs suitable for these purposes are available from 3M® under the name "3M ™ Floor Discs" and are not effective or are not very effective on very hard floor surfaces such as terrazzo or concrete, which have been used for a long time.

EP-A-0 562 919 discloses a non-woven polymer fiber disc that is completely impregnated with an adhesive containing a mixture of curable plastic resin and abrasive particles ranging from 0.1 pm to 30 pm. Examples of curable resins include phenol resin, acrylic resins, melamine resin and urea resin. As one of a number of other acceptable examples of abrasive particles, diamond is mentioned.

However, according to EP-A-0 562 919, the disc disclosed in this application is suitable for use on marble floor surfaces and only in combination with chemicals used for crystallization, which means that this treatment must be carried out in the presence of a liquid containing an acid forming salt.

EP-A-0 562 919 also envisages a disc obtained by passing a nonwoven disc through a clamp between the wringing rollers, one of which is partially immersed in the binder / abrasive particles mixture, in such a way that the binder and abrasive particles through the cylinder surface are put into the shield.

Because the target disclosed in EP-A-0 562 919 is intended for use in the presence of crystallization chemicals, the method described in EP-A-0 562 919 is actually a vitrification method used to improve the stain resistance and durability of the marble floor. This method is not suitable for daily maintenance, because the method uses special chemicals used for crystallization, including acids, which are reacted with calcium present on the floor surface to produce an insoluble calcium salt. This method is usually used once in connection with the initial manufacture of a polished marble floor and then at intervals of 6 to 12 months. Thus, the method described in EP-A-0 562 919 is too complicated for everyday use.

Blades of the type shown in EP-A-0 562 919 are sold by 3M® under the names "3M ™ 5200 Brown Stone Renew Pad" and "3M ™ 4,000 Gray Stone Polish Pad" and are used to process marble in the presence of chemical substances. crystallization at relatively low speeds (less than 250 rpm).

The requirement to use the chemicals used for crystallization makes the polishing work more complicated, because chemicals are to be applied to the surface with the possible subsequent removal of excess chemicals, which also contributes to the extension of the polishing time. The manipulation and application of chemical substances is also a potential danger to the environment in general and to the working environment in particular.

It is also known to obtain a polished stone or concrete surface by using tools containing grinding or polishing elements made of plastic resin mixed with abrasive particles, i.e. diamond particles. Because such elements are fixed on a usually rotating plate, they do not have the ability to compensate for unevenness in the floor, which may lead to uneven floor surface treatment or to scratching or staining of the floor surface when the element is to contact the surface with increased pressure. . Yet another problem is that debris such as grains of sand, small stones or metal can stick to the elements or near the elements and cause scratching of the floor surface. Finally, this type of tool requires a special mechanism capable of creating more pressure on the contact surface between the tool and the floor surface.

WO 03/075734 discloses a disc-shaped cleaning device comprising a nylon scouring material which is placed on a rigid disc in which grinding elements containing industrial diamonds are placed in the cavities of the active scrubbing surface. An unfavorable circumstance associated with the device disclosed in WO 03/07534 is that it does not eliminate the risk of crumbs sticking into the grinding elements or in the vicinity of the grinding elements. Yet another drawback is that the tool is complicated and therefore more easily damaged, and more difficult and expensive to manufacture.

For this reason, there is a need for an improved and simplified method and tool for the daily maintenance of hard surfaces. Preferably, the method should be uncomplicated in use, for example by persons who are not specifically trained in the preparation of the floor surface, and the method should be suitable for use with conventional floor surface maintenance equipment, for example polishing machines and the like. Tool making should also be easy, not too expensive and tools should be durable.

Summary of the Invention

The object of the present invention is to provide an improved technical method that completely or partially eliminates the problems associated with prior methods and targets. Particularly, it is an object of the invention to provide a method for treating a hard surface that is easier to use and that allows comparable or better results to be obtained than when using methods of the prior art.

The invention is based on the idea that abrasive particles in the form of diamond particles make it possible to obtain a polishing effect that is much larger than achievable with those abrasive particles which are for example represented in EP-A-0 562 919 and that this polishing effect is great that eliminates the need to use chemicals used for crystallization.

The invention is defined by the appended independent claim. Embodiments are included in the dependent claims and in the following description and drawings.

Thus, a method is provided for the maintenance of hard floor surfaces, including stone or stone-like material, i.e. a method whose features are set out in claim 1. 1.

The term "diamond" is believed to include natural diamond as well as synthetic diamond and diamond particles that are coated with any coating, for example, a silver coating.

By the term "effective amount" is meant an amount that is sufficient to achieve a measurable refinement of gloss as compared to the same treatment using a liquid containing no crystallization agent at all. For a single maintenance operation, the amounts considered effective are from 1 liter to 2 liters of crystallization agent (containing from 2% to 30% by weight, for example magnesium hexafluorosilicate) per 50 m² floor surface. Hence, amounts considered to be temporarily effective range from about 0.4 g of magnesium hexafluorosilicate per m²'floor surface. It is known, however, that a diluted crystallization agent, for example in a ratio of 1: 100, when used repeatedly is also effective, for example in combination with daily or weekly maintenance. Hence, the amounts considered effective in regular preservation are in the range of 0.004 g magnesium hexafluorosilicate per m2² floor surface. It is known that there are other types of crystallization agents, for example, zinc hexafluorosilicate, hydrofluoric acid and oxalic acid. Thus, it may be necessary to adapt the values ​​given above to the chosen suitable type of crystallization agent.

The combination of a flexible disk and diamond particles allows the surface to be leveled and the pressure applied to the disk evenly distributed. Due to the disc's flexibility, this combination also significantly reduces the risk of diamonds scratching the surface.

The use of diamond particles as abrasive particles to polish hard stone surfaces ensures an effect equal to or better than that obtained with traditional abrasive particles, both in wet and dry conditions. Particularly, the use of diamonds makes it possible to dispense with the crystallization agent and thus eliminate manipulation of the agent.

Maintenance work can, in principle, be carried out in the absence of a liquid on the contact surface, i.e. in principle in dry conditions or in the presence of water on the contact surface, i.e. in wet conditions. Particularly, maintenance work can be carried out in the presence of water and a cleaning agent on the contact surface, thus perfectly combining it with daily maintenance / cleaning work.

In one embodiment, the abrasive particles are joined to the disk by a secondary binder. Thus, there is no need to add abrasives during floor maintenance.

More specifically, the abrasive particles can only be attached to the disc near the contact surface. This is advantageous because the abrasive particles present in the parts of the disc that are not in contact with the hard surface do not perform any function and can therefore be considered wasted.

The average diameter diameter of the abrasive particles may be from 0.1 pm to 30 pm, preferably from 0.1 pm to 15 pm and most preferably from 10 pm to 15 pm.

Abrasive particles may include at least one type of particle among natural diamond particles, industrial diamond particles, and coated diamond particles.

The disc used includes an open, high, three-dimensional nonwoven fiber material. Such materials are available at relatively low costs and with standard dimensions adapted to existing surface treatment machines.

The specific weight of the disc may be below 40 kg / m³, preferably from 20 kg / m³ up to 35 kg / m³. Thus, the disk contains a relatively large amount of voids to which waste, dust and particles can migrate during maintenance work. Thus, dust is predominantly contained in the shield rather than spread around the workplace, thus eliminating the need for additional dust collection equipment. By allowing waste migration into the disc, the risk of surface scratches is also reduced.

This method is particularly suitable for use on stone or stone-like surfaces whose Mohs hardness is about 5, preferably

6-7. Examples of such surfaces include concrete, plaster, granite and the like.

During contact with the hard surface, the disc can be put into rotation at a rotation speed of 50 rpm to 3000 rpm, preferably 100 rpm to 1500 rpm.

Short description of the drawings

Figs la and Fig. 1b show a target according to a first embodiment.

Fig. 2a and Fig. 2b show the target according to a second embodiment.

Figures 3a and 3b show enlarged photographs of the wheel of the present invention, before and after application of the binder and abrasive particles.

Fig. 4a and Fig. 4b show a diagram of the disc according to the first embodiment and an enlarged part of this disc.

Fig. 5 shows a cross-sectional view of a floor surface treatment machine with the disk according to the invention mounted.

Description of the embodiment

First, the description will focus on a tool that can be used in a hard surface maintenance method, then a tool manufacturing method, and finally on a hard surface maintenance tool.

Referring to Fig. La, the drawing shows a disk 1 made of an open, high, three-dimensional nonwoven fiber material 2. The first surface of the disk 1 has a part P1 presenting abrasive particles associated with the nonwoven material by means of a secondary binder, i.e. the binder whose main the goal is to combine the fibers with the nonwoven material. The disk 1 has a circular shape.

Referring to Fig. Ib, this drawing shows a cross-section along the line S1-S2. As shown in Fig. Ib, the part P1 presenting the abrasive particles is in the first surface A and occupies a space to a depth D which is smaller than the thickness T of the disk 1. Hence, in the second surface B there is a part P2 in which essentially there are no abrasive particles and secondary binder.

By the term "parts" is meant parts of the macrostructure of the disk 1 and not parts of the individual fibers.

Referring to Fig. 2a and Fig. 2b, a similar disk 1 is shown in these drawings, with the difference that there is part P2 'there, also in the first surface A, in which part P2' there are essentially no abrasive particles and binder secondary.

In both forms, the abrasive particles are found in the entire secondary binder and the fibers are connected to each other with a primary binder and / or are joined in a molten state.

Now, a description will be given of the production of the disk 1 according to the embodiment discussed with reference to Fig. La and Fig. Ib.

As a raw material, a circular, disk-shaped disc for polishing a light brown Glit / Microtron® floor with a diameter of 20 inches (51 cm), a thickness of 28 mm and a weight of 157 g was used. These types of discs are available from Glit / Microtron, Wrens, GA, USA. The initial specific gravity of the disc was 27 kg / m³. Fig. 3a is a microscopic photograph showing a disk before using the polymer resin / abrasive particles. In Fig. 3a it can be seen that the filaments forming the target are connected at their points of mutual contact by a basic polymeric resin. The disc is flexible and resilient and contains polyester and nylon fibers.

A homogeneous polymer resin mixture was prepared, which consisted of 200 g PA resin, 52-68 phenol resin (available from Perstorp AB, Perstorp, Sweden), 100 g T-RÓD® ethanol (available from Alfort & Cronholm AB, Bromma, Sweden) and 20 g of LS600F diamond particles 4-8 pm (available from Lands Superabrasives, Co., New York, NY, USA). Just before applying the mixture, 60 g of 65% p-toluenesulfonic acid (PTS) as hardener was added.

The resin mixture was sprayed onto the first surface A, from the surface of the polishing wheel, using a standard compressed air spray gun (usually used for spray painting). The disc together with the uncured resin weighed 173 g. Then, the disc was placed in a hot air oven at 120 ° C for about 20 minutes.

After this treatment, the shield assumed the appearance shown in Fig. 3b, which is a microscopic photograph. The beads or droplets 11 of the resin / particles mixture are formed along each fiber as well as between the points of mutual contact of the fibers. The droplets are so dispersed that the fibers they adhere to are not completely covered. A more vivid illustration of this is found in Fig. 4a and Fig. 4b, which show the target as described above with reference to Figs. La and Fig. 1b and an enlarged part of this target (Fig. 4b) in which the droplets 11 of the resin / particles mixture adhere to the fibers.

In order to test the operation of the dial produced as described above, comparative tests were carried out to evaluate two different 20-inch (51 cm) targets produced as described above: the first target, defined as "yellow", containing silver-coated diamond particles 7-12 pm and a second disc, described as "green", containing normal diamond particles 3-6 pm. As a reference, two different blades were commercially available: a 3M ™ 5200 Brown Stone Renew Pad 20 inch (51 cm) was used and a 3M ™ 4000 Gray Stone Polish Pad gray, both available from 3M, St. Paul, MN, USA.

The tests were carried out on two different types of surface: on Kolmarden marble (marble from the Kolmarden area near Norrkóping, Sweden) and on K40 concrete. Each test was carried out on an area of ​​about 1 m², using a Coor & Kleever Crystallizer 1250 KG floor surface processing machine (available from Coor & Kleever, SA, Barcelona, ​​Spain), having a single support plate adapted to receive a 20 inch (51 cm) floor blade at a speed of about 175 rpm. The test involved polishing the surface for about 1 minute / m2². Surface gloss was measured at several locations in the area before and after each treatment using a Sanwal / Cenma IG-310 Glosschecker meter. The gloss value in the following tables is the average value for each area. High gloss is estimated at 80 ° -90 °. Satin is estimated at 30 ° -45 °. The wiping effect is estimated at 20 ° -25 °. The flat glow is estimated at 5 ° -15 °.

Each surface was tested both dry and using water as a lubricant. In addition, the concrete surface was tested using Coor Rosa / K-2 crystallization agent (available from Coor & Kleever SA, Barcelona, ​​Spain), i.e. the crystallization agent listed in EP-B-0 562 919, because it contained magnesium hexafluorosilicate as a crystallization agent.

When the 3M ™ discs were tested, each part of the surface was first treated with a brown disc and then with a gray disc.

Table 1: Tests carried out on Kolmarden marble, using water as a lubricant

<td>Shield</td><td>Brown</td><td>grey</td><td>green</td>

<td>Initial gloss</td><td> 17</td><td> 17</td><td> 10</td>

<td>Liquid</td><td>water</td><td>water</td><td>water</td>

<td>Final gloss</td><td> 17</td><td> 35</td><td> 30</td>

Table 2: Tests carried out on Kolmarden marble, without the use of grease

<td>Shield</td><td>Brown</td><td>grey</td><td>green</td>

<td>Initial gloss</td><td> 20</td><td> 25</td><td> 28</td>

<td>Liquid</td><td>lack</td><td>lack</td><td>lack</td>

<td>Final gloss</td><td> 25</td><td> 30</td><td> 50</td>

Based on the data in Tables 1 and 2, it can be concluded that on marble, which is a relatively soft stone with a hardness of approx. 3-5 on the Mohs scale and using water as a lubricant, a combination of 3M ™ discs (brown and gray) it produces a slightly better effect, although both the gray and the green shield result in values ​​in the "satin" range. In dry conditions, however, a significant improvement was achieved with the green shield, achieving a range of silky gloss.

Table 3: Tests carried out on K40 concrete, using water as a lubricant

<td>Shield</td><td>Brown</td><td>grey</td><td>yellow</td><td>green</td>

<td>Initial gloss</td><td> 30</td><td> 29</td><td> 24</td><td> 35</td>

<td>Liquid</td><td>water</td><td>water</td><td>water</td><td>water</td>

<td>Final gloss</td><td> 29</td><td> 29</td><td> 35</td><td> 46</td>

Table 4: Tests carried out on K40 concrete, without using grease

<td>Shield</td><td>Brown</td><td>grey</td><td>yellow</td><td>green</td>

<td>Initial gloss</td><td> 29</td><td> 34</td><td> 30</td><td> 48</td>

<td>Liquid</td><td>lack</td><td>lack</td><td>lack</td><td>lack</td>

<td>Final gloss</td><td> 34</td><td> 35</td><td> 48</td><td> 58</td>

Based on the data in Tables 3 and 4, it can be noted that in wet conditions and on K40 concrete, whose hardness on the Mohs scale is about 6-7, the combination of the brown disc and the gray disc did not cause any measurable improvement, while the combination of the yellow shield and the green shield resulted in a clear improvement. In dry conditions, a slight improvement was noted for the surface treated with the combination of the brown disc and the gray disc, while more improvement was noted for the surface treated with the combination of the yellow disc and the green disc.

Table 5: Tests carried out on K40 concrete using Coor Rosa / K-2 crystallization agent as a lubricant

<td>Shield</td><td>grey</td><td>green</td>

<td>Initial gloss</td><td> 41</td><td> 35</td>

<td>Liquid</td><td>VMC-Pink</td><td>VMC-Pink</td>

<td>Final gloss</td><td> 45</td><td> 51</td>

Based on the data in Table 5, it can be noted that some effect can be achieved with a gray disc and using the agent used for crystallization Coor Rosa / K-2 as a grease on K40 concrete, and that a slightly better effect can be achieved with the green disc and using the agent used for Coor Rosa / K-2 crystallization as a grease.

Generally, it should be noted that the wheel of the invention is a significant improvement over the wheel of the prior art. The improvement is particularly noticeable in dry conditions and on concrete.

Fig. 5 is a cross-sectional view of the floor surface processing machine 20 to which the disk 1 according to the invention is attached in such a way as to define the contact surface 9 with the hard surface 8, which is for example the floor surface. The disk 1 is mounted on a driven, rotatable support plate 4, which is usually transversely mounted and thus rotates relative to the machine body 5 on which the drive unit 6 is mounted. In this embodiment, the machine has a handle 7 and is thus adapted to be held / pushed / pulled by a walking operator. It is allowed that in other embodiments, the floor surface treatment machine 20 may be, for example, a self-propelled vehicle with a support plate 4 mounted that is adapted to receive the disc

1.

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

The surface treatment of the floor is carried out by rotating the disc when it is in contact with the floor surface in a plane parallel to the floor surface. Typical speeds are between 50 RPM and 3000 RPM. However, lower and higher speeds are not excluded.

As is clear from the above description, the first form of the inventive wheel includes an open, high, three-dimensional non-woven fabric containing a plurality of fibers that are interconnected at their common contact points by means of a primary binder and in which the abrasive particles are mixed with a secondary binder and used only to the first surface of the target, so that it is only partially impregnated by the binder / particle mixture. Alternatively or additionally, the fibers can be interconnected in a molten state.

According to the second form of the wheel, the binder / particle mixture is applied only to a part of this first surface. This can be achieved by masking those parts of the surface to which the binder / particle mixture should not be used.

In a third embodiment, abrasive particles are present in the pad material. In a first alternative, the disk is a nonwoven fiber disk, in principle as described above, with diamond particles in the fibrous material.

The invention is not limited to the use of phenol resin. Other examples of suitable resins include melamine, urea, epoxy and polyester resins.

In addition, the hardener can be selected from any hardener suitable for the type of resin selected. It is also possible not to use a hardener, for example by subjecting the wheel to a curing process at elevated temperature and / or for an extended period of time.

A solvent is also used (ethanol is used in the example), simply to reduce the viscosity of the mixture and thus facilitate spraying. If the application method allows, any suitable solvent may be used, as well as the solvent may be excluded.

Abrasive particles include diamond. Based on the research, it was found that especially silver-coated diamond particles also give good results. Of course, diamond particles can be combined with other types of abrasive particles.

It is understood that the disk 1 having a secondary binder and abrasive particles, as described above, can be connected to a disk or a plate having any connector to be connected to the support plate of a surface treatment machine, or the disk can be adapted to be directly connected to a surface treatment machine , by means of a Velcro hook system mounted on a support plate, which hooks start thanks to the tool for the shield form with an abrasive particle binder, If the printed area is delivered to the manufacturer, its manufacturer, the shield can be equipped with a shield fiber 1. The server can be formed in 10 joints, secondary binder and not with the addition of dyes or other information about the type of goods and the like.

Differently or additionally a substrate.

HTC Sweden AB

Proxy:

80P21490PL00

EP 1 702 714 BI