JP2003061753A - Manufacturing method of brush - Google Patents

Abstract

PROBLEM TO BE SOLVED: To estimate a warping deformation of a base board due to the shrinkage accompanying the cooling-solidification of a filler which is filled on the back surface side of the base board, and obtain a desired final shape of the base board. SOLUTION: In this manufacturing method for a brush 10, the final shape of the base board 11, which is obtained after the cross section in the longitudinal direction of the base board 11 has been warp-deformed due to the shrinkage accompanying the cooling-solidification of the filler 19 being filled on the back surface side of the base board 11, is estimated. Then, a primary molded shape by a die 20 of the base board 11 is formed into a corrected molded shape by which the final shape is obtained by estimating the warp-deformation amount of the base board 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a brush such as a toothbrush having a bristle implant portion and a handle portion.

[0002]

2. Description of the Related Art In a method of manufacturing a toothbrush, a method of fixing a hair bundle of hairs inserted in a hair bundle insertion hole has generally been a method of using a metal member called a flat wire. With this method, the device can be simply constructed, but it is difficult to reduce the thickness of the bristles (hereinafter referred to as the head) of the toothbrush because of the use of the metal member. Therefore, when thinning the head portion, a method that does not use a flat wire is used. There are the following three methods, but each method has advantages and disadvantages, and they are used according to the purpose of use.

(1) Type I (for example, Japanese Patent Publication No. 616725, U
SP4635313) A method of integrally manufacturing the handle part of the toothbrush by inserting the hair bundle into the hair bundle insertion hole of the molding die (cavity) having the hair bundle insertion hole, filling the hair bundle base with a plastic material . In this method, due to the structure of the cavity, when the molding pressure is increased, the plastic material easily leaks from the gap between the hair bundle insertion holes.

(2) Type II (eg, USP5458400, Japanese Patent Laid-Open No. 9-182632) A hair bundle is inserted into a preformed substrate having a large number of hair bundle insertion holes, and the substrate on which the hair bundle is inserted Is placed in a mold and the opening of the substrate is filled with a plastic material.
This method has more steps for molding the substrate, but since the hair bundle is planted in the substrate and there is a close contact portion between the substrate and the hair bundle when filling the plastic material, compared to Type I Leakage of the filler from between the substrate and the hair bundle is unlikely 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]

SUMMARY OF THE INVENTION The present invention aims to provide a brush of high quality by the type II method. In the type II method, a filling material is filled in a filling recess formed on the back side of a preformed substrate. At that time, the filling material shrinks due to cooling and solidification after filling, and the substrate also deforms due to the shrinking stress of the filling portion. As a result, an unexpected warp deformation occurs in the final shape of the substrate to which the filler is adhered, and further, an unexpected change occurs in the bristle implantation angle with respect to the handle of the bristle bundle fixed to the substrate. Although the substrate itself has already been molded and its contraction has been completed, if the head portion of the brush is made thin, the substrate must be made thin, and the bending rigidity of the substrate becomes small. Therefore, the deformation of the head portion of the brush becomes significant.

An object of the present invention is to plan a warp deformation of the substrate due to shrinkage accompanying cooling and solidification of the filling material with which the back side of the substrate is filled, and to obtain a desired final shape of the substrate.

Another object of the present invention is to obtain a desired bristle angle with respect to the handle in the hair bundle fixed to the substrate.

[0009]

According to a first aspect of the present invention, a substrate is formed by a mold, a hair bundle is inserted into a hair bundle insertion hole provided in the substrate, and the hair bundle is planted. Is positioned in the molding apparatus, the filler discharged from the injection port of the molding apparatus is filled around the base of the hair bundle on the back side of the substrate, and the hair bundle is fixed to the substrate provided on the tip side of the handle. A method for manufacturing a brush, in which the final shape of the substrate obtained by warping and deforming the cross section along the longitudinal direction of the substrate due to shrinkage accompanying cooling and solidification of the filler filled on the back side of the substrate The primary molded shape by the mold is a corrected molded shape in which the final shape can be obtained by planning the warp deformation amount of the substrate.

The term "hole axis" used in the hair bundle insertion hole in the present specification means the direction along the length of the hair when the hair is held in the hair bundle insertion hole. means.

In the present specification, the phrase "front side of the substrate" refers to the face on the side of the substrate where the bristle tufts protrude when the product becomes a toothbrush product, and the phrase "back face of the substrate" refers to a toothbrush product. This is the surface on the opposite side to the side on which the bristle tufts protrude from the substrate.

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

"Cross section along the longitudinal direction of the substrate" means a cross section of a toothbrush product which is parallel to the plane when the bristle bundle is placed on the plane so as to face downward. 1, 4, 5, and 10 are sectional views taken along the longitudinal direction.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) (FIGS. 1 to 1)
1) The toothbrush manufacturing method is shown below together with the operation of the apparatus. (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 the head 14 integrally formed with the handle 12 via the neck 13. As shown in FIG. 2, the head 14 has a rear surface filling recess 1 surrounded by a rising wall 15 provided on the outer edge of the rear surface.
6, a plurality of hair bundle insertion holes 17 are formed through the substrate surface 16B of the bristle implanting portion 16A defined within the range of the back filling recess 16, and the hair bundles 18 are provided in the respective hair bundle insertion holes 17. Allows flocking.

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 back surface filler 19 has good adhesiveness to the back surface, and the bending strength of the head 14 can be enhanced. However, the substrate 11 is provided with the rising wall 15 only at a part of the outer edge of the head 14, or the rising wall 15 is provided.
It does not have to include.

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 if the necessary strength and durability such as 10 can be secured. Hair bundle 1
As the bristles of No. 8, those made of a resin satisfying the performance of the toothbrush, for example, polyamide such as nylon or polyester such as polybutylene terephthalate can be adopted.

(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 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 forming the tip shape of the extruding pin 51 to be described later into substantially the same shape (fitting shape) as the hole bottom shape of the hair bundle shaping hole 32, the formability of the tip portion of the hair bundle 18 can be improved.

(3) The hair bundle 18 is picked by the sleeve 40 that houses 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 for molding (FIG. 3).

(4) hair bundle end face melting device 60
As shown in FIG. 3, the base end surface of the hair bundle 18 coming out of the hair bundle insertion hole 17 on the back side of the substrate 11 is melted or melt-pressed to close the hair bundle insertion hole 17 on the back side of the substrate 11. The (sheet-shaped) fusion surface 18A (FIG. 5) is formed. The melting surfaces 18A of the bristle bundles 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.

The hair bundle end face melting device 60 includes a heating element, hot air, a laser, and an ultrasonic vibrating element. (5) Substrate 11 with hair bundle 18 inserted and hair bundle holding jig 3
0 is conveyed to the molding apparatus 70 and positioned on the mold 71 (FIGS. 6 and 7).

(6) The back filling material 19 discharged from the inlet 72 (gate) of the die 71 of the molding apparatus 70 by the filling device 80 is filled with the back filling material 19 by the die 71 on the back surface of the substrate 11.
Of the hair bundle 18 on the back side in (the melting surface 18A)
The bristle bundle 18 is fixed to the substrate 11 by injecting and adhering it into the space (the space of the back surface filling concave portion 16) formed in the periphery (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, and the toothbrush 10 is removed from the bristle bundle holding jig 30 (FIG. 9).

The mold (71) of this example need only be the mold on the side that fills the back recess, and the manufacturing cost of the mold can be reduced.
In addition, the structure is relatively simple and maintainability is good. Further, the bristle bundle holding jig may adopt a form that constitutes a part of a mold (cavity).

As the filling device 80, an injection molding machine 81 can be adopted. The injection molding machine 81 shown in FIGS. 8 to 10 has the injection cylinder and the injection plunger arranged vertically, but may be arranged horizontally. The gate system of the injection port 72 of the molding apparatus 70 may be a cold runner system or a hot runner system.

Further, in the above embodiment, the substrate 11 in which the back filling concave portion 16 formed in the head 14 is filled with the secondary filling material is illustrated, but since the back filling is performed only in the head 14, the filling amount is set. Is small, and since the secondary filling material is filled in the recess 16 having substantially the same thickness, the handle 1
Molding conditions (conditions such as filling pressure, temperature, filling speed, etc.) can be set regardless of the shape such as 3. 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 recessed portion 16 of the head 14 is such that the outer wall surface is provided all around, the leakage of the filler material from the head 14 in which the recessed portion 16 is formed can be surely prevented and the filler material can be prevented. The filling pressure required for adhesion can be applied with high precision. Therefore, the substrate 11 forms the recess 16 in the head 14. Therefore, as a more preferable form of the concave portion 16, the concave portion 16 is formed in the head 14 and the vicinity thereof, and
This is a form having an outer wall surface on the entire circumference of the recess 16.

Further, the mold 71 has a recess 1 for back filling.
Since only the mold for filling 6 is required, the structure is relatively simple and maintainability is good.

The material used as the filler 19 may be the same as or different from that of the substrate 11, and may be a hot melt adhesive or an elastomer.

The filler 19 strengthens the adhesive force between the substrate 11 and the bristle bundle 18 so that the filling material 19 and the constituent material of the substrate 11 and the bristle bundle 18 have an adhesive property by heat bonding or chemical bonding (primer). Is used to heat the substrate 11 and the mold 71.
It is preferable to raise the temperature to increase the thermal adhesiveness and to raise the melting temperature of the filler 19 itself when it is injected. In addition, the higher the injection pressure of the filling material 19 is, the higher the substrate 11 and the hair bundle 1 are.
Adhesive strength with 8 is enhanced, and appearance (sink) is improved. The substrate 11 also partially mixes the constituent materials of the bristle bundle 18 and the filling material 19 in order to strengthen the adhesive force with the bristle bundle 18 and the filling material 19, or the constituent materials of the bristle bundle 18 and the filling material 19. And a material having adhesiveness such as thermal adhesiveness or chemical adhesiveness can be blended.

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

However, in the first embodiment, the above (1) to
In (6), the molded shape of the substrate 11 and the bristle implantation angle of the bristle bundle 18 are corrected as follows.

(A) The above is formed in the back filling recess 16 of the substrate 11.
Assuming the final shape of the substrate 11 obtained by warping and deforming the cross section along the longitudinal direction of the substrate 11 due to the shrinkage of the filling material 19 filled in (6) during cooling and solidification, the substrate 11 in the above (1) is assumed. The primary molding shape by the metal mold 20 is set as a correction molding shape in which the final shape is obtained by planning the warp deformation amount of the substrate 11. In this embodiment, the substrate 11
Of the mold for the substrate 11 so that the final shape of the cross section along the longitudinal direction of the substrate is straight on the front side of the substrate (the side where the bristle bundles are present as the form of the toothbrush) (FIG. 10D). The primary molding shape of No. 20 was a convex shape on the back surface of the substrate 11 (FIGS. 10A and 10B).

(B) The installation portion 31 of the hair bundle holding jig 30 used in the above (2) to (6) is made to follow the primary molding shape of the substrate 11. Further, the hair bundle shaping hole 32 of the hair bundle holding jig 30.
Correction for canceling the change of the hair transplantation angle (angle formed by the central axis of the bristle bundle 18 with respect to the longitudinal direction of the handle 12) of the bristle bundle 18 to the handle 12 due to the warp deformation of the substrate 11. Set in the hole axis direction. In the present embodiment, in order to make the bristle tuft angle of the hair tuft 18 relative to the handle 12 a right angle (FIG. 10 (D)), the correction hair axial direction of the hair tuft shaping hole 32 of the hair tuft holding jig 30 is corrected. The installation unit 31 (board 11
The angle correction was set individually in the direction orthogonal to the (front surface of) (FIG. 10 (C)).

(C) According to the above (a) and (b), the final shape of the cross section along the longitudinal direction of the substrate 11 is made straight on the front side of the substrate (the side on which the bristle bundle is present in the form of a toothbrush). , The toothbrush 10 that makes the bristle tuft angle of the bristle tuft 18 relative to the handle 12 at a right angle can be obtained (FIG. 10).
(D)).

Further, in the first embodiment, shrinkage caused on the outer surface 19A of the filling material 19 due to the shrinkage of the filling material 19 filled in the back surface filling concave portion 16 of the substrate 11 in the above (6) due to cooling and solidification (see FIG. 11). (B)), the molding surface 73 corresponding to the outer surface 19A of the filling material 19 in the mold 71 of the molding apparatus 70 is corrected to a curved bulging shape (R-shaped) that can offset this sink mark. As a result, the filling material 19 is formed so that the portion where the sink mark is to occur is thicker than the final shape, and a desired shape, for example, a flat shape (FIG. 11A) is obtained on the outer surface 19A in the final shape after the occurrence of the sink mark. You can

Therefore, according to the first embodiment, there are the following effects. The warp deformation of the substrate 11 due to contraction due to cooling and solidification of the filler 19 filled on the back surface side of the substrate 11 is planned.
The desired final shape of the substrate 11 can be obtained by correcting the primary molding shape by the mold 20 in the direction opposite to the warp deformation.

The installation portion 31 of the hair bundle holding jig 30 is made to follow the primary molding shape of the substrate 11, and the hair bundle holding jig 3
By setting the hole axis direction of the hair bundle shaping hole 32 of 0 to the correction hole axis direction capable of canceling the change in the bristle angle of the hair bundle 18 with respect to the handle 12 due to the warp deformation of the substrate 11, A desired bristle angle for the handle 12 can be obtained with the bristle bundle 18 fixed to 11.

It is possible to make the final shape of the substrate 11 (in this embodiment, the front surface of the substrate on the side in contact with the hair bundle holding jig) straight so that the bristle tuft angle of the hair bristle 18 with respect to the handle 12 becomes a desired right angle. .

(Second Embodiment) (FIG. 12) (a) The final shape of the substrate 11 (in this embodiment, the shape of the front surface of the substrate on the side in contact with the installation portion 31 of the hair bundle holding jig) is straight. In order to do so (FIG. 12 (D)), the primary molding shape of the substrate 11 by the mold 20 is adjusted to the center point 10 on the front side of the substrate 11 (the side on which the bristle tufts are present in the form of the toothbrush).
1 has an R shape and an approximate R shape, that is, the shape of the lower mold 22 side of the substrate 11 is the center point 1 in the lower mold 22 side direction.
An R shape 101A having 01 was included (including a composite shape including an approximate R) (FIGS. 12A and 12B).

(B) In order to make the bristle tuft angle of the bristle tuft 18 with respect to the handle 12 oblique to the outside of the tip of the substrate 11 (FIG. 12 (D)), the bristle tuft holding jig 30 The correction hole axis direction (angle a in FIG. 12C) of each hair bundle shaping hole 32 is an acute angle (for example, on the most distal end side) with respect to the mounting portion 31 (front surface of the substrate 11) at the tip side of the mounting portion 31. Hair bundle shaping hole 3
The angle correction was individually set in the direction of 2 ° (88 degrees or less) (FIG. 12 (C)).

(C) According to the above (a) and (b), the final shape of the substrate 11 (in this embodiment, the shape of the front surface of the substrate on the side in contact with the installation portion 31 of the hair bundle holding jig) is made straight. Handle 1
It is possible to obtain the toothbrush 10 in which the bristle tuft 18 has an angle of flocking with respect to 2 toward the outside of the tip of the substrate 11 (for example, the tilt angle C in FIG. 12D is 2 degrees or more) (FIG. 12).
(D)).

According to the second embodiment, the final shape of the substrate 11 (in this embodiment, the shape of the substrate front surface on the side in contact with the installation portion 31 of the hair bundle holding jig) is straight, and the handle 12 is used.
The bristle bristle 18 can be slanted to the outside with respect to the tip of the substrate 11. When the bristle tuft angle (c-part angle) of the bristle tuft 18 with respect to the axis orthogonal to the longitudinal direction of the handle 12 is inclined at an inclination angle of 2 degrees or more,
It is possible to easily obtain the toothbrush 10 that easily reaches the back teeth.

(Third Embodiment) (FIG. 13) (a) The final shape of the substrate 11 (in this embodiment, the shape of the front surface of the substrate on the side in contact with the installation portion 31 of the hair bundle holding jig) is the substrate 11.
In order to obtain a shape having a center R of R and an approximate R in the back direction of FIG. 13 (FIG. 13D), the primary molding shape of the substrate 11 on the side of the lower mold 22 by the mold 20 was changed to the straight shape 102A (FIG. 13). (A), (B)).

(B) In order to make the bristle tuft angle of the bristle bundle 18 with respect to the handle 12 oblique to the outside of the tip of the substrate 11 (FIG. 13 (D)), the bristle bundle holding jig 30 The correction hole axial direction of each hair bundle shaping hole 32 is set to the installation portion 31 (the substrate 1
1 is set on the side orthogonal to the front surface (see FIG. 13).
(C)).

(C) According to the above (a) and (b), the final shape of the substrate 11 is the center R of the R and the approximate R in the rear surface direction of the substrate 11.
The hair bundle 1 for the handle 12 has a shape having two.
It is possible to obtain the toothbrush 10 in which the bristle implantation angle of 8 is inclined toward the outside of the tip of the substrate 11 (for example, the tilt angle C of FIG. 13D is 2 degrees or more) (FIG. 13D).

According to the third embodiment, the final shape of the substrate 11 is the center R of the R and the approximate R in the rear surface direction of the substrate 11.
Hair bundle 18 for the handle 12
The flocking angle of can be made to be oblique toward the outside of the tip of the substrate 11. When the bristle tuft 18 has an angle of flocking (c-part angle) with respect to the axis orthogonal to the longitudinal direction of the handle 12 with a tilt angle of 2 degrees or more, the toothbrush 10 that allows the tuft 18 to easily reach the back teeth is facilitated. Obtainable.

Further, the form of the substrate 11 and the form of the bristle bundle 18 of the first to third embodiments can be formed by individual combinations.

In the first to third embodiments, the filler 1 is used.
The amount of warp deformation that is expected in the substrate 11 at the time of shrinkage due to cooling and solidification of 9 is generated by the following control.

(1) The thickness of the flocked portion 16A of the substrate 11 is changed in the longitudinal direction of the substrate 11, and the cross-sectional area of the filler 19 is changed in the longitudinal direction of the substrate 11. For example, the amount of warp deformation of the substrate 11 is increased on the tip side by reducing the thickness of the flocked portion 16A on the tip side of the substrate 11 and increasing the cross-sectional area of the filler 19.

(2) The height of the rising wall 15 of the substrate 11 is changed in the longitudinal direction of the substrate 11. For example, the height of the rising wall 15 is lowered on the tip side of the substrate 11, and the warp deformation amount of the substrate 11 is increased on the tip side.

(3) Mold 71 for filling the filling material 19
The cooling temperature of the filling material 19 is changed in the longitudinal direction of the substrate 11 by setting the cooling means provided in. For example, the substrate 11
The cooling temperature of the filling material 19 is lowered on the front end side, and the warp deformation amount of the substrate 11 is increased on the front end side.

(4) Filler 19 is made of a material having a large amount of heat shrinkage,
For example, by using polypropylene, it is possible to increase the amount of warp deformation to be planned for the substrate 11. Polypropylene is a crystalline resin and has a relatively large amount of heat shrinkage from melting to solidification.

In the present invention, the melting device 5 is used in the step of melting the base of the bristle bundle 18 planted on the substrate 11.
After the substrate 11 is warped and deformed by the heat contraction of the substrate 11 due to the heat generated by 0 and the heat contraction when the melted molten mass is cooled, the substrate 11 is further warped and deformed by the filler 19 filled on the back surface side. It also includes forms in which

[0056]

As described above, according to the present invention, the warp deformation of the substrate due to the shrinkage due to the cooling and solidification of the filling material with which the back side of the substrate is cooled can be planned, and the desired final shape of the substrate can be obtained. . Further, according to the present invention, it is possible to obtain a desired bristle angle with respect to the handle in the hair bundle fixed to the substrate.

[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 is a schematic view showing a hair bundle end face melting device.

FIG. 5 is a schematic view showing a melted surface forming state of a hair bundle.

FIG. 6 is a schematic diagram showing a state in which a substrate is transported to a molding apparatus.

FIG. 7 is a schematic view showing a state of positioning a substrate on a mold.

FIG. 8 is a schematic diagram showing a resin injection state by a molding apparatus.

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

FIG. 10 is a schematic diagram showing changes in the molded shape of the substrate and the bristle implantation angle of the bristle bundle.

FIG. 11 is a schematic diagram showing a corrected shape of the sink mark of the filling material.

FIG. 12 is a schematic diagram showing changes in the molding shape of the substrate and the bristle implantation angle of the bristle bundle of the second embodiment.

FIG. 13 is a schematic diagram showing changes in the molding shape of the substrate and the bristle implantation angle of the bristle bundle of the third embodiment.

[Explanation of symbols]

10 Toothbrush (brush) 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 19 Filling material 20 mold Hair bundle holding jig for 30 31 Installation Department Hair bundle shaping hole for 32 18A melting surface 19 Filling material 40 sleeve 50 hair bundle planting device 51 Extrusion Pin Hair bundle end face melting device for 60 70 Molding equipment 71 mold 72 Inlet (gate) 80 filling device 81 injection molding machine

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // B29L 31:42 B29L 31:42 F term (reference) 3B202 AA06 BA02 BE13 DB01 EA01 EF10 EG03 HA02 4F202 AH72 AM35 CA11 CB01 CB12 CD22 CK06 CK25 4F206 AH72 AM35 JA07 JB12 JQ81

Claims (7)

[Claims] 1. A substrate is molded by a mold, a hair bundle is inserted into a hair bundle insertion hole provided in the substrate, the substrate having the hair bundle is planted is positioned in a molding device, and the molding device is injected. A method for manufacturing a brush, in which a filling material discharged from an inlet is filled around the base portion of a bristle bundle on the back side of a substrate, and the bristle bundle is fixed to the substrate provided on the tip side of the handle. By assuming the final shape of the substrate obtained by warping and deforming due to the shrinkage of the filling material filled in the side due to cooling and solidifying, the primary molding shape of the substrate by the mold is set to the above warping deformation amount of the substrate. A method for manufacturing a brush having a corrected molded shape that can obtain the final desired shape. 2. The hair bundle holding jig and the substrate when holding the hair bundle in the hair bundle shaping hole of the hair bundle holding jig in the step of filling the back surface side of the substrate with the filling material. The installation part as the grounding surface of the hair is made to follow the primary molding shape of the substrate, and the axis direction of the hair bundle shaping hole of the hair bundle holding jig is set to the hair transplant angle for the hair bundle due to the warp deformation of the substrate. The method of manufacturing a brush according to claim 1, wherein the correction hole axial direction capable of canceling the change is set. 3. The cross section along the longitudinal direction of the substrate when the final desired shape of the cross section along the longitudinal direction of the substrate is such that the front side of the substrate is straight and the bristle tuft angle with respect to the handle is at a right angle. The primary molding shape of is a R or substantially R shape having a center point on the front side of the substrate, and the correction hole axis direction of the hair bundle shaping hole of the hair bundle holding jig is set relative to the installation portion. The method for manufacturing a brush according to claim 2, wherein the brushes are set in a direction orthogonal to each other. 4. The final desired shape of the cross section along the longitudinal direction of the substrate is such that the front side of the substrate is straight and the bristle tuft angle with respect to the handle is oblique toward the outside of the tip of the substrate. The primary molding shape of the substrate is an R shape having a center point on the front side and a substantially R shape, and the correction hole axial direction of the hair bundle shaping hole of the hair bundle holding jig is set to the installation portion. The method of manufacturing a brush according to claim 2, wherein the setting portion is set in a direction that forms an acute angle on the tip side of the installation portion. 5. The final desired shape of the cross section along the longitudinal direction of the substrate is defined so that the shape on the front surface side of the substrate is R in the rear surface direction of the substrate.
And when the bristle tuft angle to the handle is slanted outward toward the tip of the substrate, the front side of the primary molding shape of the cross section along the longitudinal direction of the substrate is straightened. 3. The method for producing a brush according to claim 2, wherein the hair-bundle shaping hole of the hair-bundle holding jig is set to have a correction hole axis direction orthogonal to the installation portion. 6. A brush manufactured by the manufacturing method according to claim 1. 7. A mold used for carrying out the manufacturing method according to claim 1.