JPH0657176B2 - Toothbrush manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a toothbrush having a spherical tip on a bristle tip.

[Conventional technology]

In addition to the cleaning effect of the tooth surface and the interdental part that the toothbrush originally has, in order to enhance the massage effect on the gums, the technology of providing a spherical object at the bristle tip is already known, and for example, as such a toothbrush, No. 62-171938, No. 61-97923
No. etc. have been applied. The following method is known as a method for manufacturing a toothbrush having a spherical tip on the bristle tip.

That is, the bristles that are cut to the same length and supplied to the transfer conveyor one by one are transferred along the flow of the transfer conveyor, and flame is applied to both ends of the bristles from both sides of the conveyor, The tip is melted to make a sphere. Next, after bristles formed with spherical objects are bundled in a constant number, a metal piece called a flat wire is pressed against a substantially central portion in the longitudinal direction of the bristles bundle, and the bristles bundle is bent at approximately the central portion in the longitudinal direction at the same time. , The bristle folds are hammered together with the flat wire into the flock holes formed in the brush stand, and fixed to complete the toothbrush.

[Problems to be Solved by the Invention]

 However, the above manufacturing method has various problems.

First, as the first problem, the above manufacturing method has a problem that the tooth tips of the toothbrush are not aligned. That is, in the above-described manufacturing method, after bundling a predetermined number of bristles having spherical objects formed on both ends in advance, the bristles bundle is bent while sandwiching a flat wire, and at the same time, the bristles bundle is driven into the hair-implanting holes together with the flat wire. To align the bristles, it is necessary to align both ends of each bristle when bundling the bristles. It is also necessary to bend the bristle bundle accurately at the longitudinal middle position of the bristle bundle, but it is extremely difficult to align both ends of all bristles while maintaining high speed, and it is extremely difficult. It is technically difficult to strictly control the bending position of the. Even if the bending itself is performed strictly, the bending position may be displaced due to the impact at the time of high-speed driving into the flocked hole. If the toothbrush does not have a spherical object on the bristle tip, it is possible to align the bristle tips by setting the bristle length before implantation to a longer length and cutting the bristle tips after implantation. However, it is not possible to cut hair with a toothbrush having a spherical object formed on the tip of the hair. Thus, there is a fatal problem that the bristle tips are not aligned in the above manufacturing method, and the toothbrushes manufactured by such a manufacturing method have irregular bristle tips and are not aligned, and irregular bristle tips are formed. In addition to the fact that the desired brushing pressure cannot be obtained, it does not look good and cannot be used as a product.

A second problem is that the above-mentioned manufacturing method has a complicated manufacturing process, cannot follow existing equipment, and requires replacement or new installation of equipment. That is, in the above-mentioned manufacturing method, the bristles supplied in the form of a bundle are once separated, and spherical objects are formed at both ends thereof,
It is necessary to bundle the bristles again and implant them on the brush base, which is an extremely complicated process. Since the above-mentioned process is significantly different from the conventional toothbrush manufacturing process, the conventional toothbrush manufacturing process cannot be followed as it is, and when manufacturing the present toothbrush, it is necessary to introduce new equipment for all the processes. Further, the manufacturing of the toothbrush according to the above method requires more time than the conventional toothbrush, and there is a problem that productivity is low.

[Means for Solving the Problems]

The present invention has been made in view of the above circumstances, and it is possible to obtain a spherical object-containing toothbrush having a high commercial value in which the tips of the bristles are uniform or have a certain regularity and are even more useful. The present invention provides a method for manufacturing a toothbrush that does not significantly change the manufacturing process of a conventional toothbrush and that can be manufactured by simply adding a simple device to the conventional equipment, and that has excellent productivity. .

A method for manufacturing a toothbrush according to the present invention, which has solved such a problem, includes a bristling step of bending a bristle bundle at the center in the longitudinal direction and implanting a plurality of bristles on a brush base; and a tip height of the bristles planted on the brush base. An aligning hair-cutting step; a rounded-end rounding step of rounding the tips of the bristles cut off; a hair-cutting step, a cut-off step, and a rounded-end rounding step,
For semi-finished toothbrushes in which a plurality of bristle bundles are planted on the brush base and the bristle tips of the bristles are in a uniform state, the bristle tips thus planted have a temperature of at least that of the bristles. 40 ° C above melting point
And at 0 ℃ or less, and the air volume is 0.1m ³ /min~0.6m ³ / mi
n, adjust the wind speed in the range of 3.4m / s ~ 20m / s hot air,
0.05sec to 0.5se from the direction opposite to the bristle tip surface
The main steps are the hot air blowing step of spraying in the time range of c, thereby melting the bristle bristle tips almost at the same time and collectively forming spherical objects at the tips of the planted hair bundles.

In order to avoid that the melted hair tips are fused with each other, it is also appropriately adopted to provide a hair separating step after the hot air blowing step.

Further, in order to prevent the fusion of the fused hair tips and bring the shape of the spherical object formed close to a true sphere, when blowing hot air, each bristle is charged to the same polarity, and the bristle and the hot air nozzle are It is desired to charge the opposite polarity.

[Action]

In such a toothbrush manufacturing method, the bristles of the toothbrush produced through the manufacturing steps are followed by hot air in the bristle tips of the toothbrushes produced through the manufacturing steps as they are, up to the flocking step, the bristle cutting step, and the tip rounding step. By blowing for a certain period of time, the tips of the hair are melted to form spheres on the tips of the hair.

Since the hot air is blown from the direction opposite to the bristle tip surface, the hot air is blown almost uniformly over the entire tip surface of each bristle, and the size of the spherical object formed at the tip of the bristle is made uniform. You can Further, in the present invention, the temperature of the hot air to be blown is not lower than the melting point temperature of the bristle and is not higher than 400 ° C., so that there is a disadvantage that the molten beads formed at the tip of the bristle become too large and adjacent bristles are welded together. It does not occur, and the wind speed is 3.4
Since it is set in the range of m / s to 20 m / s, the shape of the spherical object formed on the bristle tip does not deviate from the usable range of the toothbrush. Moreover, the blowing time is set in the range of 0.05 sec to 0.5 sec and the air volume is set to 0.1
By ranged from m ³ /min~0.6m ^{3 /} min, can be realized spraying and stopping the hot air with a simple device shutter device or the like, yet the toothbrush having a spherical object with excellent productivity It can be provided.

When a hair blasting step is provided after the hot air blowing step, even if there are welded bristles, the bristles are separated by the hair blasting, so that defective products can be eliminated.

Further, when the bristles are charged to the same polarity and the bristles and the hot air nozzle are charged to different polarities, the bristles have the same polarity, so they try to repel each other and separate from each other. Since it will no longer be fused with the molten balls, it is possible to form a relatively large spherical object. Moreover, since each molten ball is pulled in the direction of the hot air nozzle having a different polarity, it is possible to suppress the deformation of the molten ball, which tends to be flat due to the wind pressure of the hot air.

〔Example〕

Next, details of the present invention will be described based on illustrated embodiments.
FIG. 1 is a process explanatory view showing an embodiment of a method for manufacturing a toothbrush according to the present invention. In the embodiment of the illustrated example, a bristle implantation step a for implanting bristles on a brush stand, a bristling step b for aligning bristle tips height after bristles, and a rounding step for rounding the bristles tips after bristling with a grinder or the like. c, a hot air blowing step d in which hot air is blown to the bristle tip after rounding to form a molten ball at the tip of the hair, cooling air is blown to the molten ball,
It comprises a cold air blowing step e for promoting the hardening of the molten balls, and a hair separating step f for separating the welded bristles by cutting the bristle tips that have been cooled and hardened. The hair-cutting step b to the hair-separating step f are processed in the same stage, and the transfer between the respective steps is performed by the same transfer conveyor. In the above manufacturing process, the hair transplanting process a and the hair cutting process b
Further, the tip rounding step c directly follows the conventional toothbrush manufacturing step. The hot air blowing step d, the cold air blowing step e, and the hair filing step f are steps added in the present invention, and the details of these steps d, e, and f are shown in FIG. 1 in the figure
Is a transfer conveyor for transferring the toothbrush 2 to each process,
The toothbrush 2 is fixedly arranged on the transfer conveyor 1 with the bristles facing upward by the holding means 3, for example.
The transfer conveyer 1 is fed at a predetermined pitch and is configured to be able to intermittently transfer the toothbrush 2 from the stop position X to Y sequentially to the next process. Above the stop position X, a hot air blowing device 5 with the hot air nozzle 4 facing downward is positioned at a fixed distance. The hot air blowing device 5 ejects hot air in conjunction with intermittent movement of the transfer conveyor 1, and is performed when the toothbrush 2 is transferred to a position below the hot air nozzle 4 and stopped. Further, a shutter device 6 is interposed between the hot air nozzle 4 and the toothbrush 2. This shutter device controls the passage time of the hot air intermittently ejected from the hot air nozzle by opening and closing to strictly adjust the hot air blowing time to the bristles 7, and its structure is shown in FIG. 3, for example. As described above, a structure is adopted in which the slide plate 11 having the opening 10 is stacked on the fixed plate 9 having the opening 8 and the slide plate 11 is moved with respect to the fixed plate 9 to close and open the opening 8. It

On the side of the hot air blowing device 5, a cold air blowing device 12 is arranged with a cold air nozzle 13 at its tip facing the bristles 7. In the embodiment shown in the figure, the cold air is blown from diagonally above the bristle 7.
Alternatively, as shown in FIG. 1, the toothbrush 2 may be sprayed vertically above the toothbrush 2 at the stop position after the transfer conveyor is moved forward by one pitch. The cold air blowing device 12 is controlled in conjunction with the hot air blowing device 5,
The timing of blowing cold air is set to be performed immediately after the blowing of hot air is stopped. The purpose of blowing cold air is to rapidly cool the molten ball, stabilize the spherical shape early, prevent the molten ball from deforming due to liquid sag, and shorten the processing time by accelerating curing, This step is for improving the productivity of the toothbrush, but the step is not always necessary and may be omitted as appropriate.

Above the next stop position Y, which is separated from the stop position X by a certain distance, a rotary brush 14 for separating hair is arranged. The rotating brush 14 has a structure in which a comb-shaped member 16 is provided around a rotating body 15, and by rotating the comb-shaped member 16 to blow the bristles 7, the fused bristles are separated from each other.

Using the toothbrush manufacturing method having the above-described structure, a toothbrush having a spherical object on the bristle tip is manufactured as follows. First, bristles are planted on a brush stand, and then bristles are cut to make the height of the bristles uniform, and then the bristles are rounded with a polishing plate or the like. The steps up to this point are exactly the same as the steps for manufacturing a conventional toothbrush, and the apparatus can follow the conventional apparatus as it is. The following steps are added in the present invention.
That is, the toothbrush that has been subjected to the rounding process is transferred by the transfer conveyor 1 to the hot air blowing step d arranged on the same stage. This transfer is performed intermittently at a constant pitch interval, and the moved toothbrush is accurately positioned at the processing position in each processing step. In this way, the hot air is blown to the toothbrush correctly positioned below the hot air blowing device 5. The blowing of the hot air is controlled in conjunction with the intermittent transfer of the transfer conveyor, and the hot air temperature, the hot air blowing amount,
The spraying time is strictly controlled. The shutter 6 interposed between the hot air nozzle 4 and the toothbrush allows or prohibits passage of the hot air, which is jetted from the hot air nozzle 4 and reaches the bristles 7, by opening and closing the shutter 6, and thereby the hot air blowing device 5 The hot-air blowing time, which has already been adjusted to a certain extent by, is managed more strictly. The hot air is blown onto the bristle bristle tip surface, and as a result, the bristle tip melts and a molten ball is formed on the bristle tip due to surface tension. Then
Cold air is blown from the cold air nozzle 13, and the molten balls are hardened into spherical particles. In the present embodiment, the hot air blowing time was adjusted by adjusting the opening / closing of the shutter 6. However, without using the shutter, the stop time of the toothbrush stopped below the hot air nozzle was adjusted, or the toothbrush was stopped. Instead, the lower part of the hot air nozzle may be passed at a constant speed, and the hot air blowing time may be controlled by adjusting the moving speed at the time of passage.

As long as the hot air temperature, air volume, and spraying time are strictly controlled, the molten balls grow to the maximum size within the range where they do not weld to the adjacent molten balls, but in some cases the molten balls grow too much. It may be deformed, and in this case, adjacent molten balls may be fused. These welded bristles are separated by subjecting them to a shaving process in the next step, and become independent and normal bristles.

What is shown as FIG. 4 is another embodiment of the present invention.
In the above-described embodiment, the conventional process including the flocking process a, the hair-cutting process b, and the tip-rounding process c, the hot air blowing process d, the cold air blowing process e, and the hair separating process f are arranged on the same stage, and the respective processes are interleaved. Was connected by a transfer conveyor, and online processing was performed as a series of operations from the hair transplanting operation to the hair separating operation. In the present embodiment, the hot air spraying step d ′, the cold air spraying step e ′, and the hair separating step f ′ are performed. The additional process is configured independently of the conventional process, and a toothbrush manufactured using an existing conventional apparatus is separately supplied to the hot air blowing process d ′ by an appropriate means, and a toothbrush having a spherical tip at the tip is subjected to off-line processing. It is intended to be made. According to this method, it is only necessary to newly install an additional step consisting of a hot air blowing step, a cold air blowing step, and a bristling step. Small capital investment for manufacturing.

What is shown as FIG. 5 is an embodiment which is appropriately added to the hot air blowing step. As described above, the adjacent bristles may be welded when the hot air is blown.
As shown in the figure, if the bristles are charged to the same polarity and the bristles and the hot air nozzle are charged to different polarities, the adjacent bristles are electrically repelled and try to separate from each other. You can reduce the risk of doing. Further, since the separation distance between the bristles can be increased, the maximum diameter of the formed spherical object can also be increased. Also, due to the influence of the stretching direction of the synthetic resin material forming the bristles and the influence of the wind pressure, the molten balls formed on the tips of the hair tend to have a flat shape, but when the bristles and hot air nozzles are charged to different polarities. Since the molten ball is pulled upward by the electric suction force, it is possible to prevent the spherical object from becoming flat.

Next, the present inventor changes the hot air treatment conditions such as the temperature of hot air, the air volume and the blowing time, and the size of the spherical object formed,
The shape was examined to derive preferable processing conditions. As a result, the hot air temperature does not melt if it is lower than the melting point temperature of the material of the bristle, and if it is too high, the melting balls become too large and the adjacent bristles are welded to each other.For example, in the case of nylon bristles, 230 ℃ ~ 400
It has been found that it is more preferable to set the temperature within the range of 260 ° C and further within the range of 260 ° C to 320 ° C. Further, since the wind speed acts as a wind pressure, it becomes a determining factor of the spherical object shape. As a result of the experiment, the wind speed is preferably in the range of 3.4 m / s to 20 m / s, and more preferably set to 5 m / s to 17 m / s.

The air volume and the blowing time are in a contradictory relationship, and the air volume must be increased if the blowing time is short. Since the shortening of the spraying time is directly reflected as the shortening of the time of the toothbrush processing step, the shorter spraying time is ideal from the viewpoint of improving productivity. However, since the minimum value of the spraying time depends on the opening / closing speed of the shutter 6, the spraying time is usually within the range of 0.05 sec to 0.5 sec, preferably 0.07 sec to 0.2 s.
It is desirable to set to ec, while the air volume is 0.1m ₃ / m
in~0.6m ³ / min, preferably 0.3m ³ /min~0.5m ³ / min,
It is desirable to set it in the range of.

FIG. 6 (a) shows the finished state of the toothbrush before the hot air treatment, and FIGS. 6 (b) and 6 (c) show the finished state of the spherical shape of the toothbrush treated with the hot air treatment under different hot air treatment conditions. The toothbrush before hot air treatment is made of nylon bristles with uniform bristles. The toothbrushes shown in FIGS. 6 (b) and 6 (c) are the results of hot air treatment with the hot air temperature set to 260 ° C. to 320 ° C. and the blowing time set to 0.07 sec to 0.2 sec. )
Shows as is the result of processing when setting air volume 0.4m ³ /min~0.6m ³ / min, air velocity in the 14m / s~20m / s (processing condition 1). On the other hand, FIG. 6 0.2m air flow rate is given by way of (c) ³ /min~0.4m ³ / min, air velocity 7m / s~14
It is a processing result when it is set within the range of m / s (processing condition 2). As a result, under treatment condition 1, the spheres formed at the tip of the bristles are small, the sphere diameter is uniform, and the hair lengths are substantially in the same plane, whereas under treatment condition 2, the sphere size is large. It was found that the hairs were uneven, and the hair length was also cut and cut. However, even in this case, the bristle length of each part constituting each bristle bundle is not in an irregular state, but the bristle length has regularity, and the spherical tip of the bristle is on a continuous curved surface. It is in a complete state.

Thus, it is understood that various modes of toothbrush can be obtained by considering the hot air treatment conditions. With a toothbrush having a uniform spherical diameter, there is no feeling of foreign matter during use, and plaque accumulated between the teeth can be effectively removed. On the other hand,
A toothbrush with a non-uniform sphere diameter and uneven bristles can be a toothbrush that has an excellent massage effect and can cope with various stains on tooth surfaces and teeth.

FIG. 7 is an appearance of a spherical object produced by the method of the present invention. In the present invention, since hot air is used as a heating means for the bristle, in addition to the effect of wind pressure on the molten ball, due to the influence of the stretching direction of the nylon bristles,
The spherical object that is formed will always have an elliptical shape in projection view that is flat in the length direction of the bristles. The "table" shows the variation in the shape of the spherical object when the spherical object was formed under the processing condition 1. As shown in FIG. 7, A, B, and C in the table are, respectively, A is the length of the ellipse in the longitudinal direction, B is the length of the ellipse in the lateral direction, and C is the diameter of the bristle. All are mm. n is the number of samples, and is the average value. The bristle to be measured is a nylon bristle manufactured by DuPont in the US and has a diameter of 8 mil (= 0.203 m).
Measurements were made for two types, one for m) and the other for 10 mil (= 0.254 mm).

As described above, according to the method for manufacturing a toothbrush of the present invention, a toothbrush having a spherical tip at the tip of the tooth, and the tip of the tip of the toothbrush being substantially aligned in a planar shape or a continuous curved surface can be manufactured by the conventional toothbrush manufacturing process. It can be easily obtained by adding a hot air spraying step and the like to the conventional step without changing.
Then, the size of the spherical object, the length of the bristle length, etc. can be freely changed only by changing the hot air condition, so that toothbrushes of various modes can be obtained with the same equipment. or,
In this embodiment, since cold air is blown to accelerate the hardening of the molten balls, the productivity is high and the welding of the adjacent bristles can be reduced. Further, in this embodiment, since the hair blasting step is provided after the cold air blowing step, the bristles can be separated even when the adjacent bristles are fused.

Further, in the hot air blowing step, when the bristles are charged to the same polarity and the bristles and the hot air nozzle are charged to different polarities, the bristles electrically repel each other and try to increase the gap between the bristles. Even when a molten ball having a relatively large diameter is formed, the molten ball is not welded. And since an electric attraction force acts between the bristles and the hot air nozzle, the spherical object should be made closer to a true spherical shape by suppressing the tendency of the elliptical shape in projection due to the influence of wind pressure and the stretching direction of the nylon bristles. You can

〔The invention's effect〕

The manufacturing method of the toothbrush according to the present invention, a hot air blowing step is provided subsequent to the conventional manufacturing step of the toothbrush, flocking processing,
Since the spherical object is formed at the tip of the bristle by blowing hot air against the bristle of the toothbrush after the hair cutting process and the tip rounding process, the spherical object formed on the bristle tip is substantially the same plane. Alternatively, it is possible to obtain a toothbrush having a bristle tip surface which is aligned in a continuous surface such as a continuous curved surface and has a substantially uniform bristle density. In this toothbrush, since the spherical object at the tip of each bristle exists in a continuous surface such as a substantially same plane or a continuous curved surface, it is possible to make the spherical bristle group come into contact with the tooth surface and the gingiva in a planar manner, and a high brushing pressure is applied. It can be exerted, and can exert an excellent tooth surface cleaning effect and gingival massage effect. In addition, it has a good look because it has uniform hair tips, and has a high commercial value. And the equipment for manufacturing such a toothbrush can follow the conventional equipment as it is, for example, the hot air blowing step can be continuously added to the next stage of the conventional apparatus, and a spherical object is formed. Toothbrush manufacturing can be realized with a small capital investment. In addition, hot air blowing is performed after bristles are planted on the brush base.Therefore, the hot air blowing process is provided separately from the conventional equipment, and the toothbrush made by the conventional equipment is stocked, and this is blown by appropriate means. It is also possible to transfer to a process and perform processing of forming a spherical object, and this transfer itself is also easy. As described above, the present invention forms a spherical object collectively on all of the bristles planted on the brush base by blowing hot air onto the toothbrush after the flocking. The production is remarkably simple and the productivity is remarkably high as compared with the one in which a spherical object is individually produced by applying a flame to each bristles, and then re-binding and bristling is performed on the brush base.

Further, in the present invention, the blowing of hot air to the bristle is performed from the direction opposite to the bristle tip surface,
The hot air can be blown onto the entire tip surface of each bristle substantially uniformly, and the size of the spherical objects formed on the hair tips can be made substantially constant.

Further, in the present invention, since the temperature of the hot air to be blown is not less than the melting point temperature of the bristle and not more than 400 ° C., the disadvantage that the molten balls formed at the tips of the tips of the hair become too large and adjacent bristles are welded to each other. Since it does not occur and the wind speed is set in the range of 3.4 m / s to 20 m / s, the shape of the spherical object formed on the bristle tip may deviate from the usable range as a toothbrush. Absent.
Moreover the blown by which the set and the air volume in the range of 0.05sec~0.5sec time in the range of 0.1m ³ /min~0.6m ^{3 /} min, a simple device such as a shutter device blowing and stopping the hot air It is possible to provide a toothbrush with a spherical object formed on the bristle tip with excellent productivity. Also, because hot air is blown from the direction opposite to the bristle bristles, it is possible to increase the distance between the bristles a little by the wind pressure during the blowing, thus preventing the fusion phenomenon of adjacent molten balls. Can be made more reliable.

Further, when the bristle blowing step is provided after the hot air blowing step as in the second aspect, even if the adjacent bristles are welded, they can be separated, so that defective products can be prevented.

Further, as described in claim 3, when the bristles are charged to the same polarity when the hot air is blown and the bristles and the hot air nozzle are charged to different polarities, the bristles are electrically repelled, so that the bristles are electrically repelled. The welding phenomenon of is reduced and relatively large spheres can be formed.
Since the bristles and the hot air nozzle are charged with different polarities, an electric attraction force acts between them to bring a spherical object, which tends to have an elliptical shape in projection, close to a true sphere.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an outline of a manufacturing apparatus for carrying out a method for manufacturing a toothbrush according to the present invention, FIG. 2 is an explanatory view of main parts of the manufacturing apparatus, FIG. 3 is an explanatory view of a shutter mechanism, and FIG. ，
FIG. 5 is another embodiment of the manufacturing apparatus, FIG. 6 (a) is an enlarged explanatory view of the essential parts showing the state of the toothbrush before the hot air treatment, and FIGS. 6 (b) and 6 (c) are the toothbrush after the hot air treatment. FIG. 7 is an enlarged explanatory view of a main part showing a state, and FIG. 7 is an explanatory view showing a projected shape of a spherical object. a: flocking step, b: hair cutting step, c: tip rounding step, d:
Hot air blowing step, e: Cold air blowing step, f: Buffing step, 1: Transfer conveyor, 2: Toothbrush, 3: Holding means, 4:
Hot air nozzle, 5: Hot air blowing device, 6: Shutter, 7:
Bristle, 8: opening, 9: fixed plate, 10: opening, 11: slide plate, 12: cold air blowing device, 13: cold air nozzle, 14: rotating brush, 15: rotating body, 16: comb-shaped member.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor, Rika Enokiya, 3-1, Asahi-cho, Takatsuki-shi, Osaka Sunstar Co., Ltd. (56) References JP 59-17307 (JP, A) Jitsuko Sho 59 -29568 (JP, Y2) Actual public Sho-58-39870 (JP, Y2)

Claims (3)

[Claims] 1. A bristling step of bending a bristle bundle at the center in the longitudinal direction and implanting a plurality of bristles on a brush stand, a bristling step of aligning the bristles height of bristles planted on the brush stand, and each bristled A rounded tip processing step of rounding the bristle tips, and a plurality of bristle bundles are planted on the brush stand obtained through the above-mentioned bristling step, bristling step and tip rounding step, and the bristle tip height is For semi-finished toothbrush products in a uniform state, at the bristle tip of the planted plant, the temperature is at least the melting point temperature of the bristle and 400 ° C or less, and the air volume is 0.1 m ³ / min-0.6m
Hot air with ³ / min and a wind speed adjusted to a range of 3.4m / s to 20m / s was applied for 0.05se from the direction opposite to the bristle tip surface.
Spraying in the time range of c to 0.5 sec, this causes the bristle bristle tips to melt almost at the same time, and the hot air blowing step of collectively forming spherical objects at the tips of the planted bristle bundles, and the main steps of the toothbrush Production method. 2. The method for manufacturing a toothbrush according to claim 1, further comprising a brushing step following the hot air blowing step. 3. The method for manufacturing a toothbrush according to claim 1 or 2, wherein the bristles are charged to the same polarity and the bristles and the hot air nozzle are charged to different polarities when the hot air is blown. .