U.S. patent application number 15/503955 was filed with the patent office on 2017-09-07 for toothbrush and method for manufacturing toothbrush.
The applicant listed for this patent is Yohei TSUJI. Invention is credited to Hitoshi NAKAMURA, Seiichi TAKIGAWA.
Application Number | 20170251796 15/503955 |
Document ID | / |
Family ID | 55439836 |
Filed Date | 2017-09-07 |
United States Patent
Application |
20170251796 |
Kind Code |
A1 |
NAKAMURA; Hitoshi ; et
al. |
September 7, 2017 |
TOOTHBRUSH AND METHOD FOR MANUFACTURING TOOTHBRUSH
Abstract
Provided are a toothbrush in which a tapered surface is formed
on a tip part of synthetic resin fibers forming a brush and a fiber
surface including the fiber tip part is coated with minerals and
the toothbrush is provided with a bristle tip (fiber) having
appropriate bending strength, and a manufacturing method of the
toothbrush. The toothbrush 1 includes a brush in which a mineral
component layer is formed on a surface of a synthetic resin fiber
4. The synthetic resin fiber 4a having a tapered surface 4a1 which
is formed in a range of 1 mm to 8 mm from a tip occupies 90% or
more of the synthetic resin fibers 4 (4a, 4b), and bending strength
of the brush at a position of 1 mm from a leading edge of the brush
3 (the synthetic resin fibers 4 (4a, 4b)) is 0.60 N/cm.sup.2 to
2.00 N/cm.sup.2.
Inventors: |
NAKAMURA; Hitoshi;
(Yokohama-shi, JP) ; TAKIGAWA; Seiichi;
(Yokohama-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TSUJI; Yohei |
Minoh-shi, Osaka |
|
JP |
|
|
Family ID: |
55439836 |
Appl. No.: |
15/503955 |
Filed: |
August 31, 2015 |
PCT Filed: |
August 31, 2015 |
PCT NO: |
PCT/JP2015/074775 |
371 Date: |
February 14, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A46B 15/00 20130101;
A46D 1/00 20130101; A46D 1/0207 20130101; A46D 1/04 20130101; A46D
9/06 20130101; A46B 11/0068 20130101; A46B 2200/1066 20130101; A46D
9/02 20130101; A46D 1/05 20130101; A46B 9/04 20130101; A46D 1/0276
20130101 |
International
Class: |
A46B 9/04 20060101
A46B009/04; A46D 1/05 20060101 A46D001/05; A46D 1/04 20060101
A46D001/04 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 2, 2014 |
JP |
2014-177837 |
Claims
1. A toothbrush comprising: a brush in which a mineral component
layer is formed on a surface of a synthetic resin fiber, wherein a
tapered surface is formed on the synthetic resin fiber in a range
of 1 mm to 8 mm from a tip and the synthetic resin fiber having the
tapered surface occupies 90% or more of the synthetic resin fibers
forming the brush, and bending strength of the brush at a position
of 1 mm from a leading edge of the brush is 0.60 N/cm.sup.2 to 2.00
N/cm.sup.2.
2. The toothbrush according to claim 1, wherein irregularities are
formed on the tapered surface.
3. A manufacturing method of the toothbrush according to claim 1,
comprising the steps of: bundling the synthetic resin fibers to
produce a synthetic resin fiber assembly; immersing the synthetic
resin fiber assembly in a solution bath in which a soluble liquid
is accommodated; moving the synthetic resin fiber assembly up and
down from an upper side of a polishing/rubbing body; making the
synthetic resin fiber assembly come into contact with a
polishing/rubbing blade for a predetermined time; dissolving and
swelling a surface of the synthetic resin fiber; and scrubbing off
the surface of the synthetic resin fiber by the polishing/rubbing
blade, to form the tapered surface.
4. The manufacturing method of the toothbrush according to claim 3,
wherein after the step of forming the tapered surface, the
synthetic resin fiber assembly is immersed in mineral water to form
a mineral component layer.
Description
TECHNICAL FIELD
[0001] The present invention relates to a toothbrush and a
manufacturing method of the toothbrush, and particularly, to a
toothbrush in which a surface of synthetic resin fibers forming a
brush is coated with minerals and a manufacturing method of the
toothbrush.
BACKGROUND ART
[0002] There are conventionally sold toothbrushes in which a
surface of synthetic resin fibers forming a brush is coated with
mineral components. The mineral components with which the surface
of the fibers forming the brush is coated are as described, for
example, in PTL 1 to have various effects such as water repellency
and prevention of attachment or reproduction of bacteria, and the
toothbrush coated with the mineral components has an advantage that
toothpaste is not necessary and cleaning in the mouth is made to be
possible.
[0003] Incidentally the synthetic resin fibers coated with the
mineral components generally adopt nylon fibers each of which is
formed in a so-called columnar shape. Accordingly, a relatively
flat and wide parts of tooth such as a tooth face or gum is easy to
be brushed, but there is a problem in that when the face is brushed
excessively, the gum is damaged by an edge portion between an end
face (upper face) and a side face of the columnar fiber. In
addition, the tip part of the columnar fiber is difficult to enter
in a narrow location such as the tooth face or periodontal pocket,
creating a problem of leaving such portions unbrushed.
[0004] As a method for solving the foregoing problems, for example,
as shown in PTL 2, a tapered processing is disclosed in which a
tapered surface is formed on the tip part of the synthetic resin
fiber by chemical treatment to narrow the tip part of the columnar
fiber. The tapered processing can be also applied to the toothbrush
in which the surface of the synthetic resin fibers forming the
brush is coated with mineral components.
[0005] The toothbrush that is subjected to the tapered processing
and is coated with the mineral components enables the tip part of
the fiber to enter the narrow location such as the tooth face or
periodontal pocket, and can brush the tooth face, the gum, and
portions between teeth without unbrushed portion being left.
CITATION LIST
Patent Literature
[0006] PTL 1: Unexamined Patent Application Publication No.
2004-237248 [0007] PTL 2: Unexamined Patent Application Publication
No. 2010-233781
SUMMARY OF INVENTION
Technical Problem
[0008] Incidentally, in the toothbrush in which the surface of the
synthetic resin fibers forming the brush is coated with the mineral
components, the surface of the nylon fiber is made smooth by the
chemical treatment and the coated mineral component is easy to drop
out, therefore arises a technical problem in that it is impossible
to obtain the function of the water repellency or prevention of
attachment or reproduction of bacteria for a long period of
time.
[0009] The tapered surface formed on the tip part of the synthetic
resin fiber is formed to the extent of 2 mm to 5 mm in view of a
size of the periodontal pocket or the like.
[0010] In a case of forming the tapered surface by the chemical
treatment, the tapered surface becomes longer by a capillary force
than an expected tapered surface length and also the fiber tip
becomes narrow, and this leads to the weakening of bending strength
of the bristle tip (tip part of the fiber). Therefore, arises a
technical problem in that the bristle tip (tip part of the fiber)
gets bent against the wide and nearly flat sections such as the gum
portion or the tooth face and the cleaning capability is
insufficient.
[0011] To solve the technical problems, the inventors have eagerly
studied toothbrushes in which the surface of the synthetic resin
fibers forming the brush is coated with the minerals, and
manufacturing methods for the toothbrushes. The inventors have
studied toothbrushes in which a tapered surface having a
predetermined length can be obtained on the premise that the
tapered processing of the tip part of the fiber is carried out with
mechanical polishing, the surface of the fiber becomes rough,
fixation of mineral components improves, and it is possible to
obtain the function of the water repellency or prevention of
attachment or reproduction of bacteria for a long period of
time.
[0012] Incidentally the inventors have had the following findings.
In a case where the tapered surface is mechanically formed on the
tip part of the fiber made of the synthetic resin using polishing
processing only, the tip part of the fiber cannot enter the narrow
location such as the tooth face or the periodontal pocket when the
length of the tapered surface is 1 mm or shorter. In that case, the
bending strength of the bristle tip (tip part of the fiber) is
strong, the flexibility is not obtained and feeling of use is not
good. On the other hand, the inventors have had the following
findings. As the length of the tapered surface is longer than 1 mm,
the tip part of the synthetic resin fiber is more excessively
polished, the fiber (bristle tip) is bent more than the tooth brush
subjected to tapered processing by the chemical treatment, whereby
the cleaning capability becomes insufficient and durability in use
degrades.
[0013] The inventors have discovered a manufacturing method of the
toothbrush based upon the above findings as described hereinafter.
At least the tapered processing of the fiber tip part is performed
with the mechanical polishing in a state where the synthetic resin
fiber is dissolved and swelled before the process of coating the
synthetic resin fiber with the mineral component; as a result, the
tapered surface having a predetermined length can be obtained. In
addition, fixation of the coated mineral component can be improved,
the bristle tip (tip part of the fiber) having the appropriate
bending strength is provided, and it is possible to allow the
bristle tip (tip part of the fiber) to enter the narrow location
such as the tooth face or periodontal pocket to brush the tooth
face, and the gum and the interdentium.
[0014] The present invention has an object of providing a
toothbrush in which a tapered surface is formed on each tip part of
synthetic resin fibers forming a brush and a mineral component
layer is formed on a fiber surface including the fiber tip part,
the toothbrush being provided with a bristle tip (fiber) having
appropriate bending strength, and a manufacturing method of the
toothbrush.
Solution to Problem
[0015] In order to achieve the above object, the present invention
provides a toothbrush including: a brush in which a mineral
component layer is formed on a surface of a synthetic resin fiber,
wherein the synthetic resin fiber having a tapered surface occupies
90% or more of the synthetic resin fibers forming the brush and the
tapered surface is formed in a range of 1 mm to 8 mm from a tip,
and bending strength of the brush in a position of 1 mm from a
brush leading edge is 0.60 N/cm.sup.2 to 2.00 N/cm.sup.2.
[0016] Since the synthetic resin fibers having the tapered surface
occupies 90% or more of the synthetic resin fibers forming the
brush and the tapered surface is formed in a range of 1 mm to 8 mm
from the tip, it is possible to allow the tip part of the fiber to
enter the narrow location such as the tooth face or periodontal
pocket to obtain a sufficient cleaning capability.
[0017] In addition, since the bending strength of the brush in a
position of 1 mm from the brush leading edge is in a range of 0.60
N/cm.sup.2 to 2.00 N/cm.sup.2, the appropriate bending strength of
the bristle tip (tip part of the fiber) can be obtained and a good
feeling of use with the soft feeling (flexibility) can be
obtained.
[0018] Furthermore, it is possible to improve a removal effect of
dirt such as dental plaque accumulated in narrow locations such as
interdentium or periodontal pockets in between teeth and gums, in
wide locations such as tooth faces or the like, and a soft brush
touch on sensory sensitive locations such as the periodontal pocket
or the gum can be obtained, thus making it possible to obtain a
toothbrush of good feeling of use.
[0019] Here, irregularities are preferably formed on the tapered
surface. In this way, in a case where irregularities are formed on
the tapered surface, the fixation of the mineral component layer is
improved, it is possible to obtain the effect of the mineral
component for a long period of time.
[0020] In order to achieve the above object, the present invention
provides a manufacturing method of the toothbrush, including the
steps of: bundling the synthetic resin fibers to produce a
synthetic resin fiber assembly; immersing the synthetic resin fiber
assembly in a solution bath in which a soluble liquid is
accommodated; moving the synthetic resin fiber assembly up and down
from an upper side of a polishing/rubbing body; causing the
synthetic resin fiber assembly to come into contact with a
polishing/rubbing blade for a predetermined time; dissolving and
swelling a surface of the synthetic resin fiber; and scrubbing off
the surface of the synthetic resin fiber by the polishing/rubbing
blade, to form the tapered surface.
[0021] In this way, the tapered surface is formed by dissolving and
swelling the surface of the synthetic resin fiber, and scrubbing
off the surface of the synthetic resin fiber by the
polishing/rubbing blade. Therefore even if the tapered surface
having a length of 1 mm or longer is formed, the brush having an
appropriate bending strength can be obtained without excessive
polishing to the tip part of the synthetic resin fiber. That is, it
is possible to easily manufacture the toothbrush in which the
tapered surface is formed in a range of 1 mm to 8 mm from the tip
and the bending strength of the brush in a position of 1 mm from
the brush leading edge is in a range of 0.60 N/cm.sup.2 to 2.00
N/cm.sup.2.
[0022] Here, after the step of forming the tapered surface, the
synthetic resin fiber assembly is preferably immersed in mineral
water to form a mineral component layer. That is, the tapered
surface is formed by dissolving and swelling the surface of the
synthetic resin fiber, and scrubbing off the surface of the
synthetic resin fiber by the polishing/rubbing blade. Therefore the
surface roughness of the tapered surface becomes large, the
fixation of the mineral component layer thereon is improved and the
durability thereof improves.
Advantageous Effects of Invention
[0023] According to the present invention, the present invention
can provide the toothbrush in which the tapered surface is formed
on the tip part of the synthetic resin fibers forming the brush and
the mineral component layer is formed on the fiber surface
including the fiber tip part, the toothbrush being provided with
the bristle tip (fiber) having the appropriate bending strength,
and the manufacturing method of the toothbrush.
BRIEF DESCRIPTION OF DRAWINGS
[0024] FIG. 1 is a side view illustrating a toothbrush according to
an embodiment of the present invention.
[0025] FIG. 2 is a side view illustrating synthetic resin fibers
forming the brush illustrated in FIG. 1.
[0026] FIG. 3 is a schematic configuration diagram illustrating a
manufacturing apparatus used in a manufacturing method for the
toothbrush according to the present invention.
[0027] FIG. 4 is an enlarged view illustrating an essential part of
the manufacturing apparatus illustrated in FIG. 3.
[0028] FIG. 5 is a schematic diagram illustrating a
polishing/rubbing body used in the manufacturing apparatus
illustrated in FIG. 3.
[0029] FIG. 6 is a perspective view illustrating an example of a
synthetic resin fiber processed by the manufacturing apparatus
illustrated in FIG. 3.
[0030] FIG. 7 is a perspective view illustrating another example of
a synthetic resin fiber processed by the manufacturing apparatus
illustrated in FIG. 3.
[0031] FIG. 8 is a schematic diagram illustrating a manufacturing
process of a toothbrush.
[0032] FIG. 9 is a side view schematically illustrating a
measurement apparatus for measuring bending strength of a
brush.
[0033] FIG. 10 is a side view explaining a measurement method by
the measurement apparatus in FIG. 9.
DESCRIPTION OF EMBODIMENTS
[0034] Hereinafter, an explanation will be made of an embodiment of
the present invention with reference to the drawings. FIG. 1 is a
side view illustrating a toothbrush according to an embodiment of
the present invention. In the figure, a toothbrush is denoted by
reference sign 1, a handle of the toothbrush 1 is denoted by
reference sign 2 and a brush provided at the tip part of the handle
of the tooth brush 1 is denoted by reference sign 3. The brush 3 is
formed by implanting fiber bundles 3A formed of a plurality of
synthetic resin fibers 4 at plural locations of the tip part of the
handle 2 of the toothbrush 1.
[0035] An example of a material of the synthetic resin fibers 4
forming the brush 3 may include a polyester resin such as
polybutylene terephthalate, polyethylene terephthalate,
polytrimethylene terephthalate, polybutylene terephthalate,
polyethylene naphthalate or polybutylene naphthalate, a polyolefin
resin such as polyethylene or polypropylene, a polyamide resin such
as nylon 6, nylon 610 or nylon 612, an acrylate resin, a
polyurethane resin, a polyacethale resin, a polycarbonate resin, a
polyether resin, a polyphenylene resin or a polyvinyl resin.
[0036] The synthetic resin fiber having approximately 0.10 mm to
0.25 mm in diameter can have appropriate flexibility and a
suppression effect of bending or broken, and therefore can be used
suitably as a brush of a toothbrush. The above diameter is a
diameter of a columnar part (part where a tapered surface 4a1 is
not formed).
[0037] The number of the fibers in one bundle formed by assembling
the synthetic resin fibers 4 can be set as needed, but 40 to 70
fibers can be typically used as the number of fibers protruding out
of one implant hole 2a (refer to FIG. 8(c)). The number of the
fiber bundles 3A implanted in the tip part of the handle 2 in the
tooth brush 1 can be set as needed, but typically 10 to 25 implant
locations can be preferably adopted as the number of the fiber
bundles 3A.
[0038] The synthetic resin fibers 4 forming the brush 3 include
tapered fibers 4a each having diameter formed to be gradually
smaller toward the tip and a tip part on which a taper, tapered
surface 4a1 is formed, and columnar non-tapered fibers 4b each
having a tip part on which a taper, tapered surface is not formed
and an end face 4b1.
[0039] Moreover, 90% or more in number of the entire synthetic
resin fibers is composed of the tapered fibers 4a on each of which
the tapered surface is formed. Furthermore, the brush 3 may be
formed by the tapered fibers 4a only.
[0040] A length X of the tapered surface 4a1 formed on the tapered
fiber 4a is formed in a range of 1 mm to 8 mm. This is set in a
range of 1 mm to 8 mm in consideration of a size of a periodontal
pocket or the like (responding to a periodontal pocket having a
periodontal disease).
[0041] Since the brush 3 thus configured includes a great number of
the tapered fibers 4a, the bending strength can increase toward the
rear side from a tip part 3a through a tapered part 3b and to a
straight body part 3c, which can improve feelings of use.
[0042] That is, the tip part of the tapered fiber 4a can be allowed
to enter the narrow locations such as the interdentium, and the
periodontal pocket in between the tooth and the gum. Since the
bending strength can increase toward the rear side through the
tapered part 3b to the straight body part 3c, it is possible to
achieve easy removal of dirt such as dental plaque accumulated in
the wide location such as the tooth face, and further, a soft brush
touch on sensory sensitive location such as the periodontal pocket
or the gum, and good feelings of use.
[0043] For this purpose, the tapered fibers 4a preferably occupy at
least 90% or more of the brush 3 as a whole.
[0044] In addition, it is preferable that in the brush 3, as
illustrated in FIG. 1, the bending strength in a position of 1 mm
from the tip part 3a of the brush 3 toward a direction of the
handle is in a range of 0.60 to 2.00 N/cm.sup.2.
[0045] Here, the reason why the bending strength in the position of
1 mm from the tip part 3a of the brush 3 toward the direction of
the handle is set as a reference is that a clearance between the
tooth and the gum corresponding to the periodontal pocket is 1 mm
to 2 mm for healthy persons, and the bending strength at the time
when the tip of the brush 3 (synthetic resin fiber) enters the
clearance has an influence on an entering extent of the synthetic
resin fiber into the clearance and the feelings of use of the tooth
brush.
[0046] In a case where the bending strength is in a range of 0.60
to 2.00 N/cm.sup.2, it is possible to achieve easy removal of dirt
such as dental plaque accumulated in the wide location such as the
tooth face, and furthermore, a soft brush touch on sensory
sensitive location such as the periodontal pocket or the gum, and
the good feelings of use.
[0047] Here, the bending strength is a magnitude in strength to be
measured by a measurement method as described hereinafter.
[0048] Setting the bending strength of the toothbrush 3 to have a
range of 0.60 to 2.00 N/cm.sup.2 at the position of 1 mm from the
tip part 3a of the toothbrush 3 toward the direction of the handle
is achieved by suitably defining quality of material of the
synthetic resin fiber 4, a diameter of the fiber 4, a mixing ratio
of the tapered fibers 4a and the non-tapered fibers 4b, a length of
the tapered surface 4a1 of the tapered fiber 4a (refer to a
reference sign X in FIG. 2), the number of the fibers 4 forming one
fiber bundle 3A, the number of the fiber bundles 3A forming the
brush 3, a shape of the brush 3 and a shape (a diameter and length)
of an entire brush.
[0049] Each surface of the synthetic resin fibers 4 forming the
brush 3 is subjected to coating processing with mineral components,
and a mineral component layer is formed on the surface (not
shown).
[0050] The component of the mineral component layer can be set as
needed; the mineral component having, for example, calcium 15 to 20
(mg/L), magnesium 2.5 to 3.0 (mg/L), strontium 0.04 to 0.05 (mg/L),
potassium 2.9 to 4.6 (mg/L), iron<0.1 (mg/L), sodium 14 to 21
(mg/L), silicon 2.3 to 6.7 (mg/L), aluminum<2.5 (mg/L),
copper<0.02 (mg/L) or zinc<0.01 (mg/L), which are described
in PTL 1, can be used as a primary component.
[0051] For forming the mineral component layer, after the synthetic
resin fiber 4 is immersed in mineral water containing the above
mineral components, the synthetic resin fiber 4 is applied with a
cloth or a brush, or heated to a temperature of 50.degree. C. or
higher, or placed under a pressure environment of 0.15 MPa or more
or the like. Thereby the mineral component layer can be formed on
the surface of the synthetic resin fiber 4.
[0052] Next, an explanation will be made of a manufacturing method
of the toothbrush according to the present invention with reference
to FIG. 3 to FIG. 8.
[0053] First, as illustrated in FIG. 3, a fiber assembly 5 is
produced by bundling the synthetic resin fibers 4 having a
predetermined length by a predetermined number. Next, the produced
fiber assembly 5 is attached on a holder 11, and the synthetic
resin fibers 4 of the fiber assembly 5 are subjected to tapered
processing.
[0054] The tapered processing uses a soluble or swelling treatment
liquid to the synthetic resin fiber 4, and is performed while
swelling and polishing/rubbing the synthetic resin fiber 4. The
treatment liquid in use differs in each kind of the synthetic resin
fiber; for example, in a case of a polyester resin fiber, a sodium
hydroxide solution is generally used, and in a case of a polyamide
fiber, a mixed liquid of meta-cresol and a calcium chlorite and
methanol solution is used.
[0055] The tapered processing of the synthetic resin fibers using
this treatment liquid will be explained with reference to FIG. 3 to
FIG. 5 by taking a case of using nylon fibers as an example.
[0056] In this processing method, as denoted by reference signs
10A, 10B, and 10C, a work processing apparatus in which a plurality
of solution baths are serially arrayed is used. In a case of this
processing method, as each treatment liquid used for
polishing/rubbing and cleaning of nylon fibers, a saturated calcium
chloride and methanol solution is used as a soluble liquid of the
first solution bath 10A, a mixing liquid of calcium chloride 15%
(by weight) and methanol 85% (by weight) is used as a soluble
liquid of the second solution bath 10B, and methanol (100%) is used
as a cleaning liquid in the cleaning liquid bath 10C.
[0057] A polishing/rubbing body 12 for polishing and rubbing the
nylon fibers of the nylon fiber assembly 5 is provided in each of
the first solution bath 10A and the second solution bath 10B. The
polishing/rubbing body 12 includes polishing/rubbing blades 13 in a
thin plate-shaped disk type, a rotational shaft 14 on which a
plurality of the polishing/rubbing blades 13 are arrayed in
parallel by predetermined intervals, and a spacer 15 arranged in
every interval of the polishing/rubbing blades 13.
[0058] At least a part of the polishing/rubbing body 12 (the
polishing/rubbing blades 13) is arranged to be submerged in the
soluble liquid bath. The polishing/rubbing body 12 is arranged also
in the cleaning bath 10C, but since the cleaning liquid has a
non-swelling property to nylon fibers, the polishing/rubbing are
hardly performed in this section.
[0059] In a case of processing the nylon fiber assembly 5 attached
on the tip of the holder 11 with this apparatus, while the holder
11 on which the nylon fiber assembly 5 is attached is being moved
up and down from an upper side of the polishing/rubbing body 12,
and being moved from the paper deep side to the paper near side
FIG. 3 (left-right direction in FIG. 5), the nylon fiber assembly 5
is made come into contact with the polishing/rubbing blade 13 for a
predetermined time.
[0060] When the soluble liquid in the first solution bath 10A
adheres to the nylon fiber assembly 5, the surface of the nylon
fiber is dissolved and swelled, and is scrubbed off by the
polishing/rubbing blade 13.
[0061] That is, as illustrated in FIG. 5, since a combing blade 13a
in a saw tooth shape is formed on the polishing/rubbing blade 13,
the polishing/rubbing blade 13 comes into contact with the fibers
of the nylon fiber assembly 5 to comb the fibers to repeat the
dissolution and rubbing. At this time, by controlling a velocity of
the up and down movement of the nylon fiber assembly 5 and the
moving velocity thereof from the paper deep side to the paper near
side in FIG. 3 (in the left-right direction in FIG. 5), the nylon
fibers forming the nylon fiber assembly 5 are processed in a
tapered shape. An entire shape of the nylon fiber assembly 5 is
formed in a tapered shape to become thinner toward the tip
part.
[0062] The polishing/rubbing blade 13 may be fixed, but the
polishing/rubbing blade 13 may be formed to rotate by the up and
down movement of the nylon fiber assembly 5 and the movement of the
nylon fiber assembly 5 from the paper deep side to the paper near
side in FIG. 3 (in the left-right direction in FIG. 5). In
addition, by the up and down movement of the nylon fiber assembly 5
and the lateral movement of the nylon fiber assembly 5 from the
paper deep side to the paper near side in FIG. 3 (in the left-right
direction in FIG. 5), the nylon fiber is processed in the tapered
shape, but the nylon fiber may be processed in the tapered shape by
moving the nylon fiber assembly 5 up and down without the above
lateral movement of the nylon fiber assembly 5.
[0063] Next, the nylon fiber assembly 5 is moved to the second
solution bath 10B to move up and down and again come into contact
with the polishing/rubbing body 12 for a predetermined time. The
polishing/rubbing in the second solution bath 10B produces a
polishing and rubbing amount in addition to the polishing and
rubbing amount of the first solution bath 10A, and a basic function
is the same as that of the first solution bath 10A.
[0064] That is, when the velocity of the up and down movement of
the nylon fiber assembly 5 is controlled, the nylon fibers forming
the fiber assembly 5 each are formed as the fiber 4a having the
tapered surface 4a1 as illustrated in FIG. 6.
[0065] Finally the nylon fiber assembly 5 moves to the cleaning
bath 10C and comes into contact with the polishing/rubbing body 12
for a predetermined time to clean the fibers 4a, thus completing
the processing of one end of the nylon fiber assembly 5.
[0066] In the method as already described, by controlling the
movement (movement distance) of the synthetic resin fiber assembly
5 in the upper-lower direction and the movement of the synthetic
resin fiber assembly 5 from the paper deep side to the paper near
side in FIG. 3 (in the left-right direction in FIG. 5), a plurality
of beaded projecting portions 4a2 are formed on a surface part of
the tapered surface 4a1 in an axial direction of the fiber. At this
time, a recessed portion 4a3 is formed between the adjacent
projecting portions 4a2. That is, the projecting portion and
recessed portion alternately and sequentially appear in the axial
direction of the fiber by the beaded projecting portions 4a2 and
recessed portions 4a3.
[0067] In the method as already described, by rotating the
polishing/rubbing body 12, further moving the synthetic resin fiber
assembly 5 up and down while rotating it, and controlling
rotational velocities of the polishing/rubbing body 12 and the
synthetic resin fiber assembly 5 as well, a shape of the tapered
surface may be further controlled (refer to virtual line arrows in
FIG. 3 and FIG. 5). On this occasion, since the polishing/rubbing
body 12 itself rotates, it is unnecessary to move the synthetic
resin fiber assembly 5 (holder 11) from the paper deep side to the
paper near side in FIG. 3 (in the left-right direction in FIG. 5)
as described before, and the synthetic resin fiber assembly 5 may
be moved up and down while rotating.
[0068] Further in the same way, the other end of the synthetic
resin fiber assembly 5 is also subjected to the processing of
forming the tapered surface 4a1.
[0069] In addition, after the synthetic resin fiber 5 is immersed
in mineral water containing the above mineral components, the
synthetic resin fiber 5 is applied with a cloth or a brush, or
heated to a temperature of 50.degree. C. or higher, or placed under
a pressure environment of 0.15 MPa or more or the like. Thereby the
mineral component layer can be formed on the surface of the
synthetic resin fiber 5.
[0070] After performing the above processes, the synthetic resin
fiber assembly 5 is dried, thereby forming the mineral component
layer on the surface of the synthetic resin fiber assembly 5.
[0071] As described above, since the tapered surface 4a1 is formed
by the rubbing of the saw-tooth shaped combing blade 13a, the
surface roughness becomes greater than before the processing.
Therefore it is easier to form the mineral component layer and the
mineral component layer is formed to be hard to drop off (good in
fixation).
[0072] Particularly in the synthetic resin fiber 4 in which the
recessed portion and projecting portion are alternately arranged by
the beaded projecting portion 4a2 and recessed portion 4a3, the
mineral components can be more firmly attached thereon.
[0073] Subsequently as illustrated in FIG. 8(a), there is prepared
a fiber bundle in which the number of the tapered fibers 4a
occupies at least 90% or more of the entire fibers, as illustrated
in FIG. 8(b), a central part of the fiber bundle is bent to form a
U-letter shape, and the central part is inserted/fixed in the
implant hole 2a formed in the handle 2 together with an engagement
element 2b such as a wire, thus completing the toothbrush 1 (refer
to FIG. 8(c)).
[0074] Next, an explanation will be made of the measurement method
of the bending strength of a brush.
[0075] A measurement apparatus schematically illustrated in FIG. 9
is used for the measurement. The measurement apparatus is provided
with a stand portion 21 erected on a base platform 20 as an
elevating mechanism. A groove portion 21a linearly extending up and
down is formed in the stand portion 21, and a slider 22 is
provided, capable of going up and down along the groove portion 21a
by a screw mechanism or the like. MX-500N made by IMADA CO., LTD
can be used as the elevating mechanism.
[0076] The slider 22 is provided with a load meter 26 for measuring
loads applied on a gauge head 25. MODLDS2-2N made by IMADA CO., LTD
can be used as the load meter 26.
[0077] As illustrated in the figure, the gauge head 25 of the load
meter 26 is arranged for the tip to project laterally (horizontal
direction), and before measuring the load, as illustrated in FIG.
10(a), the brush 3 is arranged such that the brush 3 of the
toothbrush 1 as a measured body is positioned downward of a tip
surface 25a of the gauge head 25. The tooth brush 1 is configured
to be horizontally movable by a fixing tool (not shown) and capable
of changing an initial position of the brush 3. A vertical
direction of the fixing tool is configured to be fixed and not to
move.
[0078] On the other hand, the gauge head 25 of the load meter 26 is
configured to be movable in a vertical direction and not to move in
a horizontal direction. The fixing tool is moved in the horizontal
direction to position the tip surface 25a of the gauge head 25
right above a position at a predetermined distance d (1 mm) in a
vertical direction to the handle from the tip part 3a of the brush
3, and the arrangement is defined as an initial position.
[0079] The reason why the predetermined distance d is set to 1 mm
is to consider that a clearance between a tooth and a gum of a
healthy person is generally in a range of 1 mm to 2 mm as described
before.
[0080] In the measurement apparatus of this construction, in a case
of measuring the bending strength of the brush 3, the load meter 26
goes down together with the slider 22 from a state of the initial
position illustrated in FIG. 10(a).
[0081] As a result, the gauge head 25 of the load meter 26 goes
down, and, as illustrated in FIG. 10(b), the gauge head 25 comes
into contact with the tip side of the brush 3 from above, bringing
in a state where the tip side of the brush 3 is pressed and bent.
The tip side of the brush 3 is pressed against the tip surface 25a
of the gauge head 25.
[0082] In this state, a horizontal predetermined load F acts on the
gauge head 25; a load measurement value is displayed on a display
window 26a of the load meter 26. The maximum value of this
measurement value is defined as a value of the bending strength.
When the load meter 26 further goes down, as illustrated in FIG.
10(c), the brush 3 becomes in a state of being separated from the
gauge head 25. In the toothbrush 3 according to the present
invention, the maximum value (value of the bending strength) of the
load measurement value displayed on the display window 26a of the
load meter 26 is in a range of 0.60 to 2.00 N/cm.sup.2.
EXAMPLES
[0083] (Experiment 1)
[0084] Nylon fiber was used as a material of synthetic resin fiber
in a brush, and a length of the fiber was set to 7 mm, 10 mm and 12
mm, and the fibers having a diameter of 0.10 mm, 0.18 mm and 0.25
mm were used. A length of the tapered fiber from the tip part of
the tapered surface was set to 1.0 mm, 5.0 mm and 8.0 mm, and a
mixing ratio of the tapered fiber was set to 80%, 85%, 90% and 100%
of the entirety. The number of the fibers forming one bundle of the
fibers was set to 40 to 70, and the bundle number forming the brush
was set to 10 to 25. A planar shape of the brush was set to a
rectangular shape; a length of the brush in a longitudinal
direction of a handle was set to 10 mm to 25 mm, and a length of
the brush in a lateral direction of the handle was set to 7 mm to
13 mm.
[0085] In regard to the brush in which the length of the fiber was
set to 7 mm to 12 mm; the diameter thereof was set to 0.10 mm to
0.25 mm; the length of the tapered fiber from the tip part of the
tapered surface was set to 1 mm to 8 mm, and the mixing ratio of
the tapered fiber was set to 90% or more of the entirety. It was
confirmed that the brush allows the bristle tip (tip part of the
fiber) to enter the narrow location such as the tooth face or
periodontal pocket and to brush the tooth face, the gum, and the
interdentium without leaving unbrushed portion.
[0086] (Experiment 2)
[0087] Next, in regard to the brush in which the length of the
fiber was set to 7 mm to 12 mm; the diameter thereof was set to
0.10 mm to 0.25 mm; the length of the tapered fiber from the tip
part of the tapered surface was set to 1 mm to 8 mm, and the mixing
ratio of the tapered fiber was set to 90% or more of the entirety,
having shown good feeling of use in Example 1; the number of the
fibers forming one bundle of the fibers was set to 40 to 70; the
bundle number forming the brush was set to 10 to 25; the planar
shape of the brush was set to the rectangular shape; the length of
the brush in the longitudinal direction of the handle was set to 10
mm to 25 mm; the length of the brush in the lateral direction of
the handle was set to 7 mm to 13 mm; and the bending strength of
the toothbrush in a position of 1 mm away from the leading edge of
the toothbrush was measured.
[0088] As a result, in a case where the number of the fibers
forming one bundle of the fibers is set to 42 to 48; the bundle
number forming the brush is set to 22; the planar shape of the
brush is set to the rectangular shape; the length of the brush in
the longitudinal direction of the handle is set to 20 mm and the
length of the brush in the lateral direction of the handle is set
to 10.8 mm; the bending strength is in a range of 0.60 to 2.00
N/cm.sup.2; the bristle tip (tip part of the fiber) has appropriate
bending strength and soft feelings and as described before, the
brush allows the bristle tip (tip part of the fiber) to enter the
narrow location such as the tooth face or periodontal pocket to
brush the tooth face, the gum, and the interdentium without leaving
unbrushed portion.
[0089] (Experiment 3)
[0090] Nylon fiber were used as a material of the synthetic resin
fiber to produce a toothbrush subjected to mineral coating
treatment, and nylon fibers having the tapered surface formed by
the above manufacturing method were used to produce a toothbrush
subjected to mineral coating treatment. Endurance tests of both the
toothbrushes were conducted.
[0091] As a result, the toothbrush that used the nylon fiber having
the tapered surface formed by the above manufacturing method and
was subjected to the mineral coating treatment allows to obtain an
effect of the mineral coating treatment for longer hours.
REFERENCE SIGNS LIST
[0092] 1 TOOTHBRUSH [0093] 2 HANDLE OF TOOTHBRUSH [0094] 2a IMPLANT
HOLE [0095] 2b ENGAGEMENT ELEMENT [0096] 3 BRUSH [0097] 3a TIP PART
[0098] 3b TAPERED PART [0099] 3c STRAIGHT BODY PART [0100] 4
SYNTHETIC RESIN FIBER [0101] 4a TAPERED FIBER [0102] 4a1 TAPERED
SURFACE [0103] 4b NON-TAPERED FIBER [0104] 4b1 END FACE [0105] X
TAPERED SURFACE LENGTH
* * * * *