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1. Field of the Invention
The present invention relates, in general, to methods of manufacturing toothbrushes with needle-shaped bristles and toothbrushes manufactured using the methods and, more particularly, to a method of manufacturing a toothbrush with needle-shaped bristles which enhances the workability thereof, and a toothbrush with needle-shaped bristles having improved penetration ability and flexibility.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Generally, needle-shaped bristles, which have sharp ends and are set in a toothbrush, have superior flexibility and the ability to penetrate into gaps between teeth or into periodontal pockets, compared to normal bristles with end points which are round. Thus, recently, needle-shaped bristles have been set in almost all high quality toothbrushes.
In methods of manufacturing such needle-shaped bristles, there are methods: (i) in which end points of bristles are dissolved using a strong alkali chemical or strong acid chemical, (ii) in which bristles are ground using a grinder after a bristle setting process has been conducted, and (iii) in which bristles are partially tapered using the method (i) and are then additionally grounded using the method (ii).
High quality needle-shaped bristles, which are tapered such that the length of the tapered portions of the bristles are relatively long, that is, 5 mm or longer, and the thickness of end points of the bristles are approximately 0.01 mm, can be produced through the method (i). Because the tapered portions of these needle-shaped bristles are relatively long, the flexibility thereof increases. Furthermore, the end points of the bristles are relatively thin, so that the penetration ability is superior. However, it is very difficult to adjust the precise time required to dissolve the bristles. Also, there is the problem of an increased number of defective products.
In the case of the method (ii), the workability is increased, but because tapered portions of produced needle-shaped bristles are relatively short, that is, 2 mm, the flexibility is poor. As a result, there is a problem of damage to the gums of a user.
The method (iii) is advantageous in that it solves some problems of the methods (i) and (ii). This method (iii) was proposed in Korean Patent No. 261658 and Korean Patent No. 421454, which were filed by the inventor of the present invention. Korean Patent No. 261658 proposes a method, in which bristles are immersed and dissolved in a strong acid chemical or a strong alkali chemical until just before the length of the bristles is reduced and, thereafter, the partially tapered bristles are washed in water and dried, and then set in a head part of a toothbrush after being ground using a grinder. The needle-shaped bristles produced by this method are relatively long, that is, approximately 5 mm, so that the flexibility thereof is superior. However, because the thickness of the end points of the bristles ranges from 0.04 to 0.08 mm, that is, because the thickness of the end points is relatively large, the penetration ability is poor. If the grinding process is further conducted to reduce the thickness of the end points of the bristles, the length of the tapered portions of the bristles is reduced, thus resulting in poor flexibility.
Korean Patent No. 42154 is similar to Korean Patent No. 261658. In this case, bristles are ground such that the thickness of end points of bristles is 0.02 mm or less in order to enhance the penetration ability. However, this case is problematic in that, because the length of tapered portions of the bristles ranges from 2.8 to 3.5 mm, the flexibility is poor. Furthermore, there is a problem in that the number of defective products increases in this manufacturing process.
That is, it has been very difficult to produce needle-shaped bristles having both increased penetration ability and flexibility through the conventional immersion and grinding processes.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a toothbrush with needle-shaped bristles having improved penetration ability and flexibility. Another object of the present invention is to provide a method of manufacturing toothbrush with needle-shaped bristles in which a manufacturing process is simplified and the defective proportion is markedly reduced.
In an aspect, the present invention provides a method of manufacturing a toothbrush, including: setting needle-shaped bristles, partially tapered by immersing end points of the bristles in a chemical, in a head part of a toothbrush body; and grinding the needle-shape bristles using a drum grinder having protrusions. In another aspect, the present invention provides a method of manufacturing a toothbrush including: grinding a bundle of partially tapered needle-shaped bristles using a drum grinder having protrusions; and setting the bristles in a head part of a toothbrush body. The needle-shaped bristles of the toothbrush manufactured using the method of the present invention have end points ranging from 0.01 to 0.03 mm in thickness and tapered portions ranging from 3.5 to 8 mm in length.
As described above, the present invention provides a method of manufacturing a toothbrush with needle-shaped bristles which have end points ranging from 0.01 to 0.03 mm in thickness and tapered portions ranging from 3.5 to 8 mm in length. In the method of the present invention, because the manufacturing process is simplified, the production time and the defective proportion of bristles are markedly reduced.
Hereafter, the present invention will be described in detail.
A typical grinder has a structure shown in
As shown in
Intervals between protrusions 10 are not limited to a particular range, but a range from approximately 2 to approximately 5 mm is appropriate. Preferably, each protrusion 10 has a mountain top shape, a lower portion of which has a larger cross sectional area and an upper portion of which has a smaller cross sectional area. Alternatively, each protrusion 10 may have a cylindrical shape. In the case that each protrusion 10 has a mountain top shape, an end thereof is preferably rounded. The reason is that bristles to be machined may be undesirably cut by sharp end points of the protrusions.
Overall, each protrusion 10 has a mountain top shape but, more preferably, each protrusion 10 may have a slender base 11, as shown in
The slender bases 11 of the protrusions 10 serve to prevent ends of bristles from being excessively ground. The surface of each protrusion 10 is coated with grind stones in the same manner as that of the conventional grinder. The grinder may be constructed such that the grind stones are embedded in the surface of the grinder.
If the above-mentioned drum grinder having protrusions 10 is used, the thickness of end points of bristles can be reduced to a desired range despite maintenance of the length of tapered portions of the bristles. The reason is that the grinder having protrusions 10 can evenly grind end points of bristles to a length corresponding to the height of the protrusions 10, unlike a conventional drum grinder, which grinds only end points of bristles due to its planar surface. Furthermore, if the grinder having protrusions 10 rotates for a predetermined time and then rotates in reverse, relatively satisfactory bristles can be obtained.
However, to obtain more satisfactory bristles, a grinder, which is able to rotate even in a transverse direction, is required. A grinder having this structure is shown in
In a manufacturing method according to another embodiment of the present invention, a bundle of needle-shaped bristles, which were previously partially tapered, is ground by a drum grinder having protrusions 10 before being set in a head part of a toothbrush. “A bundle of needle-shaped bristles which were previously partially tapered” means a bundle of bristles made by partially dissolving end points of the needle-shaped bristles, each of which has a length ranging from 32 to 33 mm, using a chemical and by tying it in a cylindrical shape having a diameter ranging from 30 to 50 mm. Such a bundle of needle-shaped bristles is ground by the drum grinder having protrusions 10 and is then set in the head part of the toothbrush. This manufacturing method has the advantage of a reduction in the time required to grind the bristles. Particularly, the method is effective in manufacturing a toothbrush in which needle-shaped bristles, each of which is tapered, are set.
Several examples according to the present invention are as follows.
Partially tapered needle-shaped bristles were manufactured by immersing and dissolving end points of bristles in a chemical, such that the partially tapered needle-shaped bristles had end points ranging from 0.03 to 0.04 mm in thickness and tapered portions of 7 mm in length. Thereafter, the partially tapered needle-shaped bristles were set in a head part of a toothbrush. Subsequently, the bristles, which were set in the toothbrush, were tapered by grinding them at 200 rpm for four seconds using eight drum grinders, each of which has a structure of
The second example was conducted in the same method as the first example, but using a grinder of
This example was conducted in the same method as the first example, but using a typical drum grinder having no protrusions. In this case, the thicknesses of the end points of the manufactured needle-shaped bristles range from 0.015 to 0.02 mm. The lengths of the tapered portions of the needle-shaped bristles range from 2.7 to 3.2 mm.
A bundle of partially tapered needle-shaped bristles, each of which has a length of 33 mm, (the diameter of the bundle is 35 mm) was ground in the same manner as the second example, for 56 seconds (28 seconds for each end of the bundle), such that the partially tapered needle-shaped bristles have end points ranging from 0.01 to 0.02 mm in thickness and tapered portions ranging from 6 to 7 mm in length. Thereafter, the manufactured bundle of partially tapered needle-shaped bristles was set in a head part of a toothbrush, thus obtaining a toothbrush having the same shape as that of the second example.
However, in this example, one bundle of needle-shaped bristles can be set in fifty-eight toothbrushes. Therefore, the grinding time of the bristles is markedly reduced, to 0.97 seconds per toothbrush, compared to the second example, in which the grinding time of the bristles is 2 seconds per toothbrush.
Number | Date | Country | Kind |
---|---|---|---|
10-2004-0103171 | Dec 2004 | KR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/KR2004/003253 | 12/10/2004 | WO | 00 | 9/26/2007 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2006/062265 | 6/15/2006 | WO | A |
Number | Name | Date | Kind |
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5533227 | Ito et al. | Jul 1996 | A |
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6090488 | Kweon | Jul 2000 | A |
20020116778 | Kwon | Aug 2002 | A1 |
Number | Date | Country | |
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20080315669 A1 | Dec 2008 | US |