File, particularly nail file

Abstract: The file, the body (1) of which is provided on at least part of its surface (2) with a roughness varying from 10 to 100µm, is made of flat, pressed or hardened glass. The file can have a variety of geometrical shapes and cross sections. The roughening is preferably achieved by etching with a HF solution.

Description: Field of the invention The invention involves a file, particularly for nails, manufactured from glass Description of the prior art Nail files, which are among the principal components of the various sets of cosmetic equipment, are at the present time manufactured from various metals or their alloys, from paper or fabric with a rough finish, as the case may be. Since files destined for such purposes are often used in an environment with high humidity, for example during personal hygiene in the bathroom, it happens in some cases that they corrode or the material from which the file is made becomes moist resulting, on the one hand, in a deterioration in the appearance and, on the other, a dulling of the cutting edges of the file from the effects of corrosion and humidity and, thereby, a basic loss of effectiveness. If non-corroding materials are used in the manufacture of files, which is generally the case, then the disadvantage is the high price. The disadvantage of metal files in which the cutting edges are formed by mechanical means is also the limited "smoothness" of the file, and the fact that by mechanical means it is possible to produce only a limited degree of roughness of the abrasive surface. Likewise, it is simply not possible to produce a series of files with finely graded roughness. It is convenient, in the use of a file, that the side edges be functional, that is rough. Because metal files are flat and too thin, it is not practical to use their side edges to trim the nails. US-A-3,866,618 discloses a nail file, which consists of a sandwich consisting of emery paper or cloth mounted on resilient perforated plastic layer. In the center of the sandwich is an adhesive layer which provides rigidity. The adhesive layer is described as containing a hardener which can include glass powder. US-A-5,119,839 concerns an applicator to provide sealing material to a human nail. The sealing material is contained in an upper layer of a multi-layer elongate board. US-A-3,648,318 describes a brush in which the bristles can be made of glass fiber. The brush can also have compartments in its rear to hold a pen, a comb and a nail file, thus making a compact grooming set. Document CH 237277 published on April 15, 1945 discloses a file which it refers to as a "polishing file", made of a strip of glass into which a series of parallel teeth are cut by means of a grinding wheel. The teeth are continuous along their entire length and extend from one edge of the strip to the other. Such an arrangement has several serious disadvantages which would prevent successful commercial exploitation. The first is that a milled profile extending from one edge to the other would produce a line of weakness which in glass could lead to ready breakage along the line of machining. The second disadvantage is that the files are produced individually which is expensive and time consuming. Furthermore, such a file would only be effective to polish the upper surface of a fingernail. Any attempt to file the end of the nail would lead to difficulty because the finger nail would very easily fall into one of the grooves between the teeth and be guided rather than filed. It is known from document CA-A-2,142,949 to produce a nail file by electroplating diamond particles onto the top surface of a strip of fiberglass material. The diamond particles disclosed are in a range 30 to 1200 mesh which corresponds to 595 microns to 15 microns diameter. Assuming that the particles are submerged to a depth of approximately 50% as shown in Figure 4 of that document, the peak to valley depth would range from 297.5 microns to 7.5 microns. Average peak to valley depth can in practice be measured by a profilometer and is given by the parameter R z according to DIN 4768 and DIN-EN-ISO 4287. Powdered glass is used as the abrasive material on a finger nail board in document US-A-2,699,791, the substrate in this case is typically lemon wood. Diamond dust is the abrasive material in document DE-U-18 28 813 and it is embedded in a metal coating on a steel substrate. A steel substrate is also used in DE-U-19 71 152 which discloses guide grooves for finger nails and a hard powder to achieve the abrasive effect. The abrasive effect is obtained in the surface of a stainless steel plate in document US-A-4,422,465 by etching a random pattern of pits in the surface. This is achieved by a photographic masking using a photosensitive resin and then etching. The masking and etching technique produces pits with a concave profile due to the undercutting action beneath the photosensitive resin. The pits are etched to a depth of 10-80 microns which would correspond to a range of roughness measurement R z also of 10 microns - 80 microns if measured with a profilometer according to DIN-EN-ISO 4287 and DIN 4768. In the arrangements shown in this document and in document CA-A-2,142,949 discussed above it is also envisaged that the abrasive surface covers only a part of the surface of the file, leaving a handle portion free. All of these prior art techniques are rather complex in practice as well as suffering from the other deficiencies as mentioned above. In a different technology it is known from US-A-5,036,731 to use a strip of glass that has been etched or sanded in the bottom of a box as a honing surface for sharpening razor blades. It is reported however that completely smooth glass is preferable. Summary of the invention According to a first aspect of the invention there is provided a file, particularly for nails, manufactured from glass by acid engraving or sanding, sufficient to achieve a roughness on at least a part of the surface of the glass in the range which at its finest is suitable for polishing surfaces and at its coarsest is suitable for grinding, and a hardening process. The advantage of such a file is its absolute resistance to the environment in which it is used. It is significant too that, given its non-corroding properties, the abrasive surfaces can be kept clean by rinsing in water. It is important to note here the wide range of surface roughness that can be attained, varying from the smoothest finish for polishing and a coarsest surface for grinding. Typically these would correspond to numerical values of roughness of 10µm to a roughness of around 100µm respectively. The glass body of the file may have an oblong board shape and a point at one end at least. The advantage of such a shape for the glass body of the file is the ease of manipulation in use and, thanks to the point, its practical value for hand hygiene is increased. Another advantageous solution to be noted is the fact that the glass body of the file may be roughened along one whole side at least, having a V-shaped point at the end. The advantages of such a file are apparent both during use of the file and during its manufacture, when roughening of the whole surface is carried out without the need, for instance, to mask part of the surface during the roughening process by use of acid engraving for example. When the point is formed in a V shape, its symmetrical shape facilitates manipulation during use of the file in either the left or the right hand. A further advantageous feature is the fact that body of the file may be roughened along one whole side at least and may be ground to a sharp finish on at least one edge. The longitudinal edge formed on one side of the body of the file than further increases the functional possibilities of the nail file. It is possible to form the body of the file so that both edges are bevelled, while the bevelled edge at the end is at an oblique angle to the side edge, so that together they form a point. This variation further increases the wide range of uses for the file. Another advantageous arrangement for the shape of the body of the file, is when the surface of at least one of the edges and of one end of the body of the file is also roughened, further contributing to increasing its usefulness. To further improve performance, the edges of the body of the file may be rounded. These variations in the shape of the glass file further extend its usefulness for special cases of hand hygiene. From the point of view of production technology, it is an advantage if the body of the file can be formed from flat or pressed glass. All the various shapes of the file can have a glass body formed from hardened glass. The advantages of such a treated glass body are its increased stability and particularly increased safety in the event of breakage of the whole of the glass body by dropping etc. The hardening of the glass-bodied file gives it properties which are well-known in such treated glass. Brief description of the drawings The invention can be better described by means of the drawings, of which Figure 1 represents an "axonometric overview of the glass body of the file. Figure 2 presents a cross section of the glass body of the file with roughening on one surface. Figure 3 also shows a cross section of the glass body of the file with roughening on one side and rounded edges. Similarly, Figure 4 presents a cross section of the glass body of the file, both of whose edges are bevelled. Description of the preferred embodiments The file according to Figure 1 is formed from a glass body 1 , shown here in oblong board shape, with a roughening 4 on the surface 2 . The roughening 4 is produced by a wide variety of techniques, the choice depending upon the degree of roughness. To produce the smoothest finish, for example around 10 µm, a chemical process can be used, such as acid engraving with a hydrogen fluoride solution. Greater roughness, of around 100 µm for instance, can be produced mechanically, by sanding for example. Figure 2 shows a cross section of the glass body 1 of the file illustrated in Figure 1, with a roughened finish 4 along the whole of one surface 2 . Figures 3 and 4 illustrate further possible variants on the glass body 1 of the oblong board-shaped file. A cross section is shown of the glass body 1 of the file, with roughening 4 of one surface finish 2 , the glass body 1 of the file having rounded edges 3 , while the cross section in Figure 4 presents the glass body 1 of the file with edges 3 bevelled to a sharp finish, the glass body 1 of the file having a rough finish 4 on both surfaces 2 . Industrial use of the invention The glass-bodied file has been described from the point of view of its use as a nail file. This example of use, however, in no way excludes further possible uses in other fields, particularly given the wide range of roughness which can be achieved in the glass-bodied file. A file produced according to this invention with a low degree of roughness, that is to say the finest, can be used in polishing surfaces, for example, while the coarsest can be used for grinding.

Claims: A file, particularly for nails, manufactured from glass by acid engraving or sanding sufficient to achieve a roughness (4) on at least part of the surface (2) of the glass in the range which at its finest is suitable for polishing surfaces and at its coarsest is suitable for grinding, and a hardening process. A file according to claim 1, wherein the glass is flat or pressed glass. A file according to claim 1 or 2, characterised by the fact that the body (1) of the file has an oblong board shape and at least at one of its ends a point (5). A file according to any of claims 1 to 3, characterized by the fact that the body (1) of the file is roughened at least along the whole of one side, while the point (5) at the end is V-shaped. A file according to any of claims 1 to 3, characterized by the fact that the body (1) of the file is roughened at least along the whole of one side and is bevelled to a sharp finish on at least one edge (3). A file according to claim 5, characterized by the fact that both edges (3) and at least one end of the body (1) of the file are bevelled, while the bevelled edge at the end is at an oblique angle to the side edge, so that together they form a point. A file according to claim 5, characterised by the fact that the surface of at least one of the edges (3) and of one end of the body (1) of the file is also roughened, and the edges (3) are preferably rounded. A method of producing a file, for example a nail file, comprising taking glass, for example, flat or pressed glass, roughening it on at least part of its surface (2) by acid engraving sufficient to achieve a roughness (4) on at least part of the surface (2) of the glass in the range which at its finest is suitable for polishing surfaces and at its coarsest is suitable for grinding and subjecting it to a hardening process.

Inventors: BLAZEK DALIBOR, BLAZEK, DALIBOR
Applicants: BLAZEK DALIBOR, BLAZEK, DALIBOR
Application year: 1998
Main classification: A45D29
IPC codes: A45D29, B23D71