JP2003135154A - Method of manufacturing toothbrush and toothbrush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the strength of adhesion of a packing material for immobilizing bristle tufts to a substrate disposed on the front end side of a handle. SOLUTION: The method of manufacturing the brush 10 comprises setting an injection port 72 of a molding device 70 to a part on the near side of the handle 12 connecting with a head 16A of the substrate 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toothbrush manufacturing method and a toothbrush manufactured by the manufacturing method.

[0002]

2. Description of the Related Art Conventionally, as a conventional technique for manufacturing a toothbrush, a method has been widely used in which a bristle bundle is inserted into a bristle bundle insertion hole and fixed by a metal member called a flat wire. Although this method can easily configure the device, it has the disadvantages that the thickness of the tooth-implanted portion of the toothbrush cannot be reduced, and that oblique hair implantation is difficult. On the other hand, as a method that does not use a flat wire,
There are the following three methods, and the actual situation is that they are used properly according to the purpose of use.

(1) Type I (for example, Japanese Patent Publication No. 616725, U
(SP4635313) Insert the hair bundle into the hair bundle insertion hole of the molding die (cavity) that has the hair bundle insertion hole, fill the hair bundle base with plastic material, and integrally manufacture the handle part of the toothbrush. Is the way to do it. In this method, the formation of the handle portion and the fixing of the hair bundle can be manufactured in the same step, but due to the configuration,
When the molding pressure is increased, the plastic material easily leaks between the hair bundle insertion hole of the mold (cavity) and the hair bundle.

(2) Type II (eg, USP5458400, Japanese Patent Laid-Open No. 9-182632) A hair bundle is planted on a substrate having a large number of preformed hair bundle insertion holes, and this hair bundle is planted. The substrate is placed in a mold and the opening of the substrate is filled with a plastic material.
Although this method increases the number of steps for molding the substrate, it is a method in which hair bundles for hair are once implanted in the substrate and there is a close contact portion between the substrate and hair bundle for hair, and then a plastic member is filled. As compared with Type I, the leakage of the filler from between the substrate and the bristle bundle is less likely to occur.

(3) Type III (for example, Japanese Examined Patent Publication No. 6-46962) A substrate having a hair bundle insertion hole for a hair bundle insertion hole portion and a hair bundle base portion are both heated and brought into close contact with each other. How to crimp a bundle. This method is likely to cause variations in quality in fixing the hair bundle.

[0006]

[Problems to be Solved by the Invention] Type I to Type
In any of the three methods of III, when the head portion of the toothbrush is thin, it is necessary to secure the strength of the head portion. Especially in Type II, after forming the substrate,
Since the opening of the substrate is filled with the filling material, it is necessary to secure sufficient adhesive strength between them. If this is insufficient, the adhesive force between the substrate and the filler is reduced due to the shrinkage of the filled filler, and the adhesive portion between the substrate and the filler is peeled off due to repeated bending stress during tooth brushing. In some cases, the strength is reduced and the substrate may be broken.
A broken substrate can damage the oral cavity, and a broken substrate is a fatal defect for a toothbrush.

The greatest feature of the present invention is that the adhesive strength is increased by the type II method. Further, since the hair bundle is planted in the substrate, the filling of the filler for fixing the hair bundle is performed. To create a high quality toothbrush that prevents the breakage of the substrate during tooth brushing, taking advantage of the type II advantage that the filler does not easily leak (burr) between the substrate and the bristle bundle. Was the task.

[0008]

According to a first aspect of the invention, a base of a hair bundle is arranged on a bristle portion of a substrate provided on a tip side of a handle, and the substrate on which the hair bundle is arranged is positioned in a molding device. A method of manufacturing a toothbrush in which a filler discharged from an injection port of a molding device is injected around a base portion of a bristle bundle arranged in a bristle portion of a substrate and bonded, and the bristle bundle is fixed to the substrate,
The injection port of the molding device is set at the handle-side portion that is continuous with the flocked portion of the substrate.

According to the above-described method for manufacturing a toothbrush, the injection port of the molding device is installed at a portion of the toothbrush near the handle which is continuous with the bristles of the toothbrush where the repeated bending stress of toothbrushing tends to concentrate, and the high temperature and high pressure immediately below the injection port are set. Thus, the strength of the toothbrush can be maintained by making the adhesive force between the substrate and the secondary filler strong.

In order to further enhance the above-mentioned adhesive effect, unevenness is provided on the surface of the substrate filled with the filler to increase the area of the bonded portion.

In order to obtain the same effect, at least a part of the rising wall surface of the filling recess (preferably in the vicinity of the neck portion) is directed in the direction in which the shrinkage of the filling material is large (usually in the longitudinal direction of the flocked portion). Add parallel surfaces.

Further, in order to maintain the strength of the substrate or the backside filling material alone when the adhesive strength is lowered, an R, taper or stepped stepped surface is provided at the edge of the backside filling recess to avoid stress concentration.

In the present specification, the wording "rear surface of substrate" means
It is the surface on the side opposite to the side from which the bristle tufts protrude in the substrate when it becomes a toothbrush product.

Further, the "R surface" in claim 4 means that the end surface has no edge and is in a state of being rounded, and the rounding processing of substantially R shape is also included. In the description of the third to fifth embodiments, the symbol “R30” used.
“R” in “1, R (301A, 301B, 301C)” has the same meaning. Further, “C” refers to a tapered chamfering process, and the symbols “C302, C302A, C302” used in the third to fifth embodiments.
The letter "C" at the beginning of "B, C302C" has the same meaning.

The "longitudinal direction of the handle" means the direction in which the handle extends from the substrate when the product is a toothbrush product. In FIG. 1, it is the direction of the long part of the handle on the paper surface.

The "molding device" according to the present invention means a filling machine for discharging a filling material, or an apparatus in which the filling machine is combined with other members such as a mold.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) (FIGS. 1 to 9) The preferred construction of a toothbrush manufacturing method and manufacturing apparatus is as follows. (1) The substrate 11 of the toothbrush 10 is molded by the substrate molding die 20 (upper mold 21 and lower mold 22) of FIG. In this embodiment, the substrate 11 is composed of a head 14 integrally formed with the handle 12 via the neck 13.

As shown in FIG. 2, the head 14 is provided with a back surface filling concave portion 16 surrounded by a rising wall 15 provided on the outer edge on the back surface side, and a flocked portion 16A defined within the range of the back surface filling concave portion 16 is formed. A large number of hair bundle insertion holes 1 on the substrate surface 16B
7 is formed so as to penetrate, and the hair tufts 18 can be transplanted into the hair tuft insertion holes 17.

The substrate 11 has a handle 12 (neck 13).
The back filling material 19 is secondarily filled in the back filling concave portion 16 of the head 14 after the step of implanting the head 14 which will be described later.
However, the flocking substrate 11 may be composed of only the head 14, and after the step of flocking the head 14, the back filling material for the back filling concave portion 16 of the head 14 and the handle 12 are provided.
The molding material for the (neck 13) may be integrally secondarily filled.

Since the substrate 11 is provided with the rising wall 15 which is continuous over the entire circumference of the outer edge of the head 14, the back filling recess 16 is provided.
The adhesion area of the back filler 19 to the back surface is widened, the adhesion is good, and the bending strength of the head 14 can be enhanced. However, substrate 1
The head 1 may be provided with the rising wall 15 only on a part of the outer edge of the head 14, or may not be provided with the rising wall 15.

As the resin constituting the substrate 11, any of polypropylene, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, polycarbonate, polymethylmethacrylate, unsaturated polyester, etc. may be adopted. It suffices that the properties such as the required strength and the durability of 10 can be secured, and that when the substrate 11 is molded, it should have moldable flow characteristics and thermal stability. Nylon, polybutylene terephthalate, or the like can be used as the bristle of the hair bundle 18.

(2) The substrate 11 is installed on the hair bundle holding jig 30. As shown in FIG. 3, the hair bundle holding jig 30 for the substrate 1
No. 1 installation part 31 and the board 11 installed in the installation part 31
The hair bundle shaping hole 32 connected to the hair bundle insertion hole 17 is provided.

The hair bundle holding jig 30 may be made of metal (iron, aluminum), plastic, or a composite of metal and plastic. Tetrafluoroethylene or the like is preferable as the plastic, and since this plastic has good slipperiness, insertion efficiency and quality of the hair bundle are improved. Further, it is preferable to coat the metal material with tetrafluoroethylene or the like, because both slipperiness and durability can be secured.

The hair bundle holding jig 30 has a hair bundle shaping hole 32.
The bottom surface of the hole is set to a shape to be applied to the tip of the hair bundle 18. By making the tip shape of the extruding pin 51, which will be described later, substantially the same as the hole bottom surface shape (fitting shape) of the hair bundle shaping hole 32, the shaping property of the tip portion of the hair bundle 18 can be improved.

(3) The hair bundle 18 is picked by the sleeve 40 that accommodates the hair bundle 18 (FIG. 3). Then, the bristle tuft implanting device 50 pushes the bristle tufts 18 accommodated in the sleeve 40 by the pushing pins 51, and
8 is planted in the hair bundle shaping hole 32 of the hair bundle holding jig 30 from the hair bundle insertion hole 17 of the substrate 11 installed in the hair bundle holding jig 30, and the base of the hair bundle 18 is fixed. The hair bundle is inserted into the hair bundle insertion hole 17 of the substrate 11, and the tip of the hair bundle 18 is pressed against the bottom surface of the hair bundle shaping hole 32 to shape the hair (FIG. 3).

(4) hair bundle end face melting device 60
As shown in, the base end surface of the bristle tuft 18 protruding from the bristle tuft insertion hole 17 on the back side of the substrate 11 is melted or melt-pressed to close the back tuft 11 to the back side of the substrate 11. A sheet-shaped melt-bonding surface 18A (FIG. 5) is formed.
The fusion fixing surfaces 18A of the bristle tufts 18 are not limited to those in which adjacent ones are continuously formed into a band shape as described above, but may be individually formed into a lump shape. As the hair bundle end face melting device 60, an ultrasonic vibrating body may be used in addition to the heating element.

(5) The substrate 11 in which the tufts 18 for hair are planted and the tuft holding jig 30 for the tuft are conveyed by the conveying device 200 to the positioning mechanism 201 in the molding device 70 and positioned (FIG. 6).

(6) The back filling material 19 discharged from the injection port 72 (gate) of the die 71 of the molding apparatus 70 by the filling device 80 is filled with the back filling material 19 of the substrate 11 by the die 71.
Of the hair bundle 18 on the back side of the
A) Space formed around (space of back-filling recess 16)
Then, the hair bundle 18 is fixed to the substrate 11 by injecting it into the substrate 11 (FIGS. 7 and 8).

(7) After the filling material 19 is solidified, the mold 71 is opened, the toothbrush 10 and the bristle bundle holding jig 30 are taken out (FIG. 9), and the toothbrush 10 is removed from the bristle bundle holding jig 30 (FIG. 9).

In the molding apparatus 70 (FIGS. 6 to 9), a vertical molding apparatus is used, and the positioning mechanism 2 is used.
01 shows an example in which the hair bundle holding jig 30 on which the substrate 11 is arranged is positioned and the back filling material 19 is injection-molded in the back filling recess 16 of the head 14. If 30 is sequentially conveyed into the molding apparatus 70, continuous molding can be efficiently performed. If necessary, a horizontal molding device may be adopted.

Further, in the above embodiment, the substrate 1 in which the back filling recess 16 formed in the head 14 is filled with the secondary filling material.
However, since only the head 14 is filled with the back surface, a small amount of filling is required. Further, since the secondary filling material is filled into the recess 16 having substantially the same thickness, the handle 13
The molding conditions (conditions such as filling pressure, temperature, filling speed, etc.) can be set regardless of the shape. On the other hand, for example, in the method of filling (secondarily filling) the head portion and a part of the handle portion, molding conditions corresponding to the shape of the handle portion other than the head portion are required. Comparing the two forms, it can be said that the present form is more stable in quality because the molding conditions suitable for the head 14 can be set.

Further, since the shape of the recess 16 of the head 14 is such that the outer wall surface is provided on the entire circumference, leakage of the filler from the head 14 in which the recess 16 is formed can be surely prevented, and the filler can be adhered. The required filling pressure can be applied with high precision. Therefore, the substrate 11 is not
Is formed. A more preferable form of the recess 16 is a form formed in the head 14 and the vicinity thereof, and further having an outer wall surface on the entire circumference of the recess 16.

Further, the toothbrush can be manufactured using only the mold 71 for filling the filling concave portion.
That is, since the toothbrush can be manufactured without using a mold other than the mold 71 for filling the filling recess, the structure of the molding apparatus is relatively simple and the maintainability is good.

The filler 19 is usually made of the same material as the substrate 11 (for example, polypropylene resin, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, polycarbonate, polymethylmethacrylate, unsaturated polyester resin). Etc.) is used. Although polypropylene resin is generally used as the toothbrush, polypropylene resin having physical properties different from those of the substrate 11 is used as the filler to improve moldability during filling (improve the fluidity of the filler. It is possible to achieve low pressure filling). In addition, if necessary, the substrate 1
A material different from the polypropylene resin of No. 1 (for example, a thermoplastic elastomer) can be used as a filler to impart elasticity to the toothbrush or to impart coloring to the toothbrush to impart a characteristic to the appearance. As the resin for the filler, it is preferable to select a resin having good adhesiveness to the substrate 11, but any of the above-mentioned resins shrinks after filling. Therefore, it can be said that the resin as the filler 19 has a property of reducing the adhesive force between the filler 19 and the substrate 11.

Therefore, in order to strengthen the adhesive force with the substrate 11 and the hair bundle 18, the filling material 19 is added to the substrate 11 and the hair bundle 18.
Of the compositional material and a material having good thermal adhesiveness or chemical adhesiveness, heating the substrate 11 or raising the temperature of the mold 71 to increase the thermal adhesiveness, and the melting temperature at the time of injecting the filler 19 itself. It is preferable to increase. Furthermore, it is preferable to increase the injection pressure of the filler 19 from the viewpoint of improving the adhesive force with the substrate 11 and the hair bundle 18 and improving the appearance (reducing sink marks). However, if the injection pressure is too high, the substrate 1
Since leakage of the filler (burrs) occurs between the 1 and the bristle bundle 18, it is necessary to set an appropriate pressure. In addition, as a method of strengthening the adhesive force, a method of injecting the filling material 19 after performing corona discharge treatment or plasma discharge treatment on the surface of the substrate 11 or a method of applying a primer agent on the surface of the substrate 11 may be used. good.

However, in the first embodiment, the above (5),
In (6), the injection port 72 of the molding device 70 is set to a region near the handle 12 that is continuous with the flocked portion 16A (back surface filling recess 16) of the substrate 11 (FIG. 7). The setting range of the injection port 72 with respect to the substrate 11 is as shown in FIG.
A range L1 closer to the handle 12 from the longitudinal center position 16C of A, more preferably a range L2 from the center of the flocked portion 16A to the narrowest position of the neck 13 and the position of the smallest cross-sectional area and its vicinity. It is preferable to set in.

According to this embodiment, there are the following effects. The filler 19 injected from the injection port 72 of the molding device 70 into the bristles 16A of the substrate 11 made of, for example, a thermoplastic resin.
(For example, a thermoplastic resin similar to that of the substrate 11) has a lower temperature and pressure on the filling end side, resulting in a lower thermal adhesive force with the substrate 11. The resin shrinkage after filling is large at the filling end portion where the filling pressure is difficult to be transmitted, and the shrinkage is caused by the filling material 1.
This causes a decrease in the adhesive force between the substrate 9 and the substrate 11. However, high temperature and high pressure are maintained near the injection port 72, the resin shrinkage is small, and the thermal adhesive force with the substrate 11 is high.

In this embodiment, the injection port 7 of the molding device 70 is used.
Since No. 2 is set on the handle 12 side portion connected to the flocked portion 16A of the substrate 11, a high thermal adhesive strength with the filling material 19 is secured at the handle 12 side portion of the substrate 11 where repetitive bending stress during tooth brushing is particularly large. It is possible to prevent peeling of the adhesive portion between the substrate 11 and the filler 19. Therefore, the substrate 11
The strength of the cross section where the filler 19 is adhered to is maintained stable, and the substrate 11 is not broken.

When the filling material 19 is injected by injection molding, the resin passing through the injection port 72 (gate portion) is heated to a high temperature due to shearing heat generation at the gate portion having a small passage diameter, and the injection temperature of the resin (the temperature of the injection cylinder). )
The high-temperature resin (filler 19) can be effectively injected into the portion of the substrate 11 on the side closer to the handle 12 where the heat adhesive force is most required, and the adhesive strength of the filler 19 can be improved. It should be noted that if the temperature of the injection cylinder is excessively increased, the physical properties of the resin are deteriorated, discolored, and carbides are generated, which is not appropriate.

(Second Embodiment) (FIG. 10) In the second embodiment, as in the first embodiment, a handle for connecting the injection port 72 of the molding device 70 to the flocked portion 16A (back surface filling concave portion 16) of the substrate 11. When it is set at the 12-side portion, as shown in FIG. 10, the injection direction of the injection port 72 is further removed from the hair bundle insertion hole 17 provided in the substrate surface 16B of the flocked portion 16A of the substrate 11.

According to the present embodiment, the pouring direction of the pouring port 72 for ejecting the high-temperature and high-pressure filling material 19 in the molding device 70 is set so that the bristle bundle insertion hole 17 for the bristle bundle 18 provided on the substrate 11 is formed. Removed from Therefore, the filler material 19 under the high temperature and high pressure conditions immediately below the injection port 72 is the hair bundle insertion hole 17 and the melt fixing surface 1.
It is possible to prevent the filler from leaking from between the portion where the base of the hair bundle 18 is planted and the substrate 11 by being transmitted to the 8A.

(Third Embodiment) (FIGS. 11 and 12) The third embodiment is different from the second embodiment in the following points. The base portion of the bristle bundle 18 on the substrate 11 (melt-bonding surface 18
A) A back filling recess 1 around which the filling material 19 is filled
In the contour of the bottom portion of No. 6, the handle side portion (in the present embodiment, the surface on the handle 12 side) is rounded R301 (FIG. 1).
1) or a chamfered C302 (FIG. 12) having a tapered shape.

According to this, the filling material 19 and the substrate 11 are
For example, when molding with thermoplastics, as described above, since the adhesion is thermal adhesion, the adhesive strength may decrease due to the filling temperature, the filling pressure, and the resin shrinkage after filling. . At that time, the shape of the substrate 11 is important for maintaining the main strength against bending, and in particular, the recess 1
Stress concentration occurs at the edge portion of 6. R as a countermeasure
Also, a tapered C is arranged to prevent breakage due to stress concentration.

Regarding R301 and C302, R
Is preferably 0.2 mm or more, C is 0.2 mm or more (including equivalent shape), R is 0.3 mm or more, and C is more preferably 0.3 mm or more (including equivalent shape).
It is preferable that C1 and C302 are as large as possible. A radius of 0.2mm means a radius of radius R of 0.2mm and a radius of 0.2mm.
2mm is the length of each of the two orthogonal sides chamfered at 45 °
It means 0.2 mm.

As a modified example of the third embodiment, the substrate 1
Around the base portion (melt-adhering surface 18A) of the bristle bundle 18 in FIG. 1, a step-like step surface is formed on the surface of the back filling concave portion 16 filled with the filling material 19 (in this embodiment, the surface closer to the handle 12). 303 is formed, and the handle 12 has the substantially parallel surfaces 101, 102 and the substantially orthogonal surface 103 with respect to the longitudinal direction,
104 was added (FIG. 13). The hair bundle insertion hole 17 for hair is provided on the substantially parallel surface 101, and the injection direction of the injection port 72 is set to the neck 13
The substantially orthogonal surface 103 is formed by the inner periphery of the rising wall 15 at the outer edge of the back surface filling recess 16, and the approximately orthogonal surface 104 is formed on the root side of the neck 13 toward the substantially parallel surface 102 on the side. According to this, since the surfaces of the substrate 11 to be filled with the filling material 19 are provided with the substantially parallel surfaces 101, 102 and the substantially orthogonal surfaces 103, 104 with respect to the longitudinal direction of the handle 12, they act through the handle 12 when brushing teeth. The adhesive surface is formed in both the parallel direction and the orthogonal direction with respect to the repeated bending stress, and the adhesive strength of the filler 19 can be improved.

In the above description, the R301, C302 and the stepped step surface 303 provided in the back surface filling recess 16 of the substrate 11 may be provided over a part or the entire circumference of the recess 16, but in the present embodiment. It was provided on the side closer to the handle 12 where repetitive bending stress when brushing teeth was particularly large. By adopting the form provided near the handle like this,
This is a preferable mode in which the strength of the substrate 11 is improved against the bending stress and bending is prevented.

(Fourth Embodiment) (FIG. 14) The effect of the third embodiment described above can be enhanced by combining some or all of them as necessary. FIG. 14 which shows 4th Embodiment is step-shaped step surface 303A and R.
In this example, (301A, 301B, 301C) and C302A are combined.

As a result, the step-like step surface 303A is formed.
Thus, the adhesive strength of the adhesive surfaces in both the parallel direction and the orthogonal direction with respect to the repeated bending stress acting through the handle 12 at the time of brushing teeth is improved, and R (301A, 301B, 301
C) and C302A can prevent stress concentration at each edge portion.

That is, as in the case of the fourth embodiment, the effect of the third embodiment is further enhanced by combining some or all of them with each other as necessary.

The combined surface such as R, C and stepped step surfaces provided in the back surface filling recess 16 of the substrate 11 is formed by the recess 1
Although it may be provided over a part or the entire circumference of No. 6, in the present embodiment, it is provided on the side closer to the handle 12 where repetitive bending stress during tooth brushing is particularly large. By adopting the form provided near the handle in this way, the substrate 1 is not affected by the bending stress.
1 is a preferable mode in which the strength is improved and breakage is prevented.

(Fifth Embodiment) (FIGS. 15 and 16) The fifth embodiment is different from the third embodiment in that the height of the rising wall 15 at the outer edge of the back surface filling recess 16 of the substrate 11 is set to the filling material. The height of the filling material 19 is lower than that of the filling wall 19, and the substantially parallel surface 102 is connected to the rising wall 15.
5 along the upper surface of the substantially parallel surface 102 and the upper surface of the substantially parallel surface 1
It is to be filled up by the height of 04.

That is, in the fifth embodiment, a substantially parallel surface 10 is formed with respect to the outer edge rising wall 15 of the back surface filling recess 16 of the substrate 11.
Formed 2.

When the back surface filling material 19 is filled in the substrate 11, the back surface filling material 19 shrinks after being filled in the substrate 11 (FIG. 16A) whose shrinkage has been completed, and as a result, the head 14 is warped. Occurs. In this state, shrinkage stress remains in the head 14, and the adhesive strength is reduced due to the residual stress due to shrinkage at the bonding interface between the rising wall 15 of the back filling recess 16 and the rising wall of the neck 13 and the filler 19 (FIG. 16).
(C)).

In particular, when a resin (for example, polypropylene) having poor adhesion to the melt-fixing surface 18A (for example, nylon (registered trademark)) of the hair bundle 18 is used as the filler 19, the adhesive force of the melt-fixing surface 18A is used. Is considered low. Therefore, the directions of large contraction X, Y (FIG. 15B,
The adhesive force of (C) is weak, and in order to improve this, in the present embodiment, the approximately parallel surface 102 is installed substantially parallel to the resin shrinking direction with respect to the rising wall 15 to enhance the adhesive force.

In the type II embodiment of the present case, the contact area between the filler 19 and the mold 71 is smaller than that of the type I, and the cooling efficiency is poor (the substrate 11 and the fusion fixing surface 18A are plastic members, It is harder to cool compared to (Fig. 16)
(B)). Therefore, the shrinkage of the filler 19 becomes large during the gradual cooling after the filling. This is particularly remarkable in the polypropylene resin having a relatively large shrinkage property.

The substantially parallel surface 102 is preferably provided in a direction substantially parallel to the X direction (longitudinal direction of the back surface filling concave portion 16) (FIG. 15) where contraction of the filling material 19 is the largest, but the Y direction (the aforementioned longitudinal direction). It may also be installed in a direction substantially orthogonal to the direction). Most preferably, it is formed on the entire circumference of the rising wall 15.

When the substantially parallel surface 102 is formed on a part of the rising wall 15, it is provided on the side of the handle 12 (neck 13 side) where the repetitive bending stress during tooth brushing is particularly large. Suppresses the decrease in power,
The breakage of the substrate 11 can be prevented.

The substantially parallel surface 102 of the fifth embodiment is not limited to a horizontal surface, but may be a combination of tapered surfaces, R surfaces and curved surfaces. Further, the first to fourth embodiments can be appropriately combined and configured.

(Sixth Embodiment) (FIG. 17) The sixth embodiment differs from the second embodiment in that a substrate 11 is used.
Around the base portion (melt-bonding surface 18A) of the bristle bundle 18 in the back filling recess 16 of
In the present embodiment, the uneven surface 121 is provided on the inner periphery of the rising wall 15 near the handle 12. The uneven surface 121 may be provided over the entire depth of the recess 16 on the inner periphery of the rising wall 15 (FIG. 17 (B)), or even in the middle of the depth of the recess 16 on the inner periphery of the rising wall 15. It may be provided (FIG. 17C). The concave-convex surface 121 is the back filling concave portion 1.
It can also be provided on the substrate surface 16B of No. 6.

According to this embodiment, since the surface of the substrate 11 filled with the filler 19 is provided with the uneven surface 121, the area of the adhesive portion between the substrate 11 and the filler 19 is increased to increase the adhesive strength of the filler 19. Can be improved. Further, when the filling material 19 flows on the surface of the substrate 11, the high temperature resin of the filling material 19 melts the tips of the convex portions provided on the surface of the substrate 11 to improve the adhesive strength (a plurality of convex portions are effective). . Note that the uneven surface is also effective if it is a minute uneven surface that roughens the surface of the substrate 11.

The concave-convex surface 121 provided in the back-filling concave portion 16 of the substrate 11 may be provided over a part or the entire circumference of the concave portion 16. However, in the present embodiment, a handle having a particularly large repeated bending stress during tooth brushing. It was provided on the 12th side. By adopting the configuration provided near the handle in this way, the adhesive strength between the substrate 11 and the filling material 19 can be improved, and a preferable configuration in which bending is prevented against the bending stress is provided.

(Seventh Embodiment) (FIG. 18) The seventh embodiment is different from the sixth embodiment in that the base of the hair bundle 18 (fusion fixing surface 18A) in the back filling recess 16 of the flocking substrate 11 is different. Around the periphery of the handle 12 and the neck 13 on the surface where the filler 19 is filled,
That is, the uneven surface 131 is provided.

(Eighth Embodiment) (FIG. 19) The difference between the eighth embodiment and the sixth embodiment is that the periphery of the base (melt-bonding surface 18A) of the bristle bundle 18 in the back filling recess 16 of the substrate 11 is different. , The surface of which the filler 19 is filled, and the base of the handle 12 and the neck 13
Through-hole 141 is provided, the diameter of the entrance side of the through-hole 141 (back side of the substrate 11) is the small diameter portion 141A, and the exit side of the through hole 141 (front side of the substrate 11) is the large diameter portion 14.
1B, the small diameter portion 141A is communicated with the back surface filling recess 16 by the communication groove 142.

According to this embodiment, as an application example of the uneven shape provided on the surface of the substrate 11 filled with the filling material 19, the through hole 141 penetrating the substrate 11 is provided, and the exit diameter of the through hole 141 is set. Is larger than the entrance side diameter of the through hole 141, and the lump of the filler material 19 (the large diameter portion 141B) that is molded within the exit side diameter of the through hole 141 serves as a stopper and prevents The adhesive strength can be improved.

In the substrate 11 of the present invention, the total width (filling width) of the substrate surface 16B sandwiched by the rising walls 15 on both sides in the width direction of the substrate 11 is the total width in which the hair bundle insertion holes 17 are provided. It is set to be larger than (brushing width) (for example, larger than the diameter of one hair bundle insertion hole 17 on one side in the width direction), and as a result, the area of the bonded portion between the substrate 11 and the filler 19 is increased, The adhesive strength of the filler 19 can be improved.

The filling device 80 of the present invention may be an applicator (air pump type, gear pump type, screw pump type, etc.) for hot melt adhesive or the like.

Further, according to the method for manufacturing a brush of the present invention, the base of the hair bundle is arranged in the front filling concave portion provided on the front side of the substrate, and the filler discharged from the injection port of the molding device is applied to the front side. What is injected into a filling recess, specifically, a method of manufacturing a brush for implanting a bristle tuft on a toothbrush substrate, wherein the tuft for tuft is planted in a tuft for shaping tufts in a jig for holding tufts for tufting. Then, the substrate is installed so that the front filling concave portion of the substrate surrounds the base of the hair bundle protruding from the hair bundle shaping hole of the hair bundle holding jig, and the substrate and the hair bundle holding jig are molded. Position it on the device and inject the hot melt adhesive into the space (the space for the front filling recess) formed around the base of the hair bundle by the substrate and the hair bundle holding jig to bond the hair bundle to the substrate. It can also be applied to those that are fixed.

[0068]

EFFECTS OF THE INVENTION Among the flocking methods that do not use a flat wire, in the type II flocking method that uses a molded plastic plate (substrate), adhesion of the joint surface portion between the substrate and the secondary filler forming the handle portion The force was improved and it was possible to secure sufficient strength when using the toothbrush.

[Brief description of drawings]

FIG. 1 is a schematic view showing a substrate and a molding die thereof according to a first embodiment.

FIG. 2 is a schematic view showing a main part of a substrate.

FIG. 3 is a schematic view showing a hair bundle holding jig and a hair bundle planting device.

[Fig. 4] Fig. 4 is a schematic view showing a fusing device for an end face of a hair bundle.

FIG. 5 is a schematic diagram showing a state in which a fused and fixed surface of a hair bundle is formed.

FIG. 6 is a schematic view showing a positioning state of a substrate on a molding apparatus.

FIG. 7 is a schematic diagram showing a state where a mold and a substrate are in contact with each other.

FIG. 8 is a schematic diagram showing a state of injecting a filler by a molding device.

FIG. 9 is a schematic view showing a state in which the toothbrush is removed from the bristle bundle holding jig.

FIG. 10 is a schematic view showing the arrangement of the hair bundle insertion holes of the substrate and the injection port of the molding apparatus of the second embodiment.

FIG. 11 is a schematic diagram showing a substrate of a third embodiment.

FIG. 12 is a schematic view showing a modified example of the substrate of the third embodiment.

FIG. 13 is a schematic diagram showing a modified example of the substrate of the third embodiment.

FIG. 14 is a schematic diagram showing a substrate of a fourth embodiment.

FIG. 15 is a schematic view showing a substrate of the fifth embodiment.

FIG. 16 is a schematic diagram showing a filling state of a filling material in the fifth embodiment.

FIG. 17 is a schematic diagram showing a substrate of a sixth embodiment.

FIG. 18 is a schematic diagram showing a substrate of a seventh embodiment.

FIG. 19 is a schematic view showing a substrate of the eighth embodiment.

[Explanation of symbols]

10 toothbrush 11 board 12 handles 13 neck 14 heads 15 rising wall 16 Back filling recess 16A Flocking part 16B board surface Hair bundle insertion hole for 17 Hair bundle for 18 18A Melt fixing surface (base) 19 Filling material 20 Substrate molding die Hair bundle holding jig for 30 31 Board installation part Hair bundle shaping hole for 32 40 sleeve 50 hair bundle planting device 51 Extrusion pin 60 melting equipment 70 Molding equipment 71 mold 72 Inlet (gate) 80 filling device 101, 102 substantially parallel surfaces 103, 104 Substantially orthogonal plane 112 Tapered surface 121, 131 uneven surface 141 through hole 141A small diameter part 141B Large diameter part 200 carrier 201 Positioning mechanism 301 R side 302 Tapered surface 303 Step surface

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3B202 AA06 AB10 AB15 AB19 BA02                       EG03 HA02                 4F202 AA11 AD16 AH72 CA11 CB01                       CB12 CK06

Claims (6)

[Claims] 1. A base for hair tufts is arranged at a hair-implanted portion of a substrate provided on the tip side of a handle, the substrate on which the tufts for hair are arranged is positioned in a molding device, and the filling is discharged from an injection port of the molding device. A method for manufacturing a toothbrush in which a material is injected around the base of a hair bundle arranged on the hair-implanted portion of the substrate and adhered to fix the hair bundle to the substrate, and the injection port of the molding device is attached to the hair-implanted portion of the substrate. The manufacturing method of the toothbrush set in the part near the continuous handle. 2. Around the base of the tuft of hair on the substrate,
The method for manufacturing a toothbrush according to claim 1, wherein at least a part of the surface filled with the filler is provided with an uneven shape. 3. The substrate has a filling concave portion for filling with a filling material, and at least a part of a rising wall portion of the concave portion is provided with respect to a longitudinal direction of the filling concave portion or a direction substantially orthogonal to the longitudinal direction. The method for producing a toothbrush according to claim 1 or 2, wherein the surfaces are substantially parallel to each other. 4. The substrate has a filling recess for filling with a filling material, and at least a part of a cross section of the rising wall provided in the recess in the recess depth direction has an R surface, a tapered surface, or 4. The method for manufacturing a toothbrush according to claim 1, wherein a step-like step surface in which a substantially orthogonal surface and a substantially parallel surface with respect to the longitudinal direction of the handle intersect with each other, or a configuration in which these are combined is provided. 5. When the substrate has a hair bundle insertion hole for implanting the base of the hair bundle, the injection direction of the injection port of the molding device is removed from the hair bundle insertion hole. The method for manufacturing a toothbrush according to any one of claims. 6. A toothbrush manufactured by the manufacturing method according to claim 1.