JP2008155051A - Manufacturing method of brush - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a brush with low cost having bristle bundles with excellent aligning property and molding property, capable of reducing the thickness of a bristle implantation base part, complying with the production of many kinds in small quantities. <P>SOLUTION: The manufacturing method for the brush includes a process of arranging an bristle implantation base part having a plurality of implantation holes to a bristle holding tool having a concave part formed into a shape almost similar to the contour of the external shape of the bristle implantation base part, and an insertion part formed into a shape almost similar to the bristle implantation hole; and a process of forming molten lumps by inserting the bristle into the insertion part through the bristle implantation hole by making the insertion part communicate with respective bristle implantation holes, and fusing the parts of respective bristles protruding from the bristle implantation hole in a state that the bristle is held at the inside of the bristle implantation hole and the insertion part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a brush, and more particularly to a method for manufacturing a brush suitable for manufacturing a toothbrush and a hair bundle holding jig used therefor.

  As a prior art relating to a method for manufacturing a brush, for example, a technique described in Patent Document 1 below is known. In this technique, a flocking hole for bristles is formed in a part of a mold that forms a cavity, the bristles are inserted into the flocking holes, and resin is filled into the cavities for flocking.

  In this technique, molding is performed by directly inserting hairs into the flock holes provided in the mold, so that the molten resin oozes out between the hairs, forming burrs, and easily causing molding defects. In order to solve this problem, an attempt has been made to form an annular recess so as to surround the root portion of the hair bundle, but as a final form of the toothbrush, when the flocking base is thinned, the strength is reduced. In addition to this, water or the like easily accumulates in the annular recess, which is unsanitary. In addition, since a large number of expensive dies (“insert” in Patent Document 1 below) used for molding are required, this technique is not suitable for high-mix low-volume production.

  On the other hand, in Patent Document 2 described below, a substrate having a flock hole is disposed in a receiving mold having a space inside, and a hair is inserted into the flock hole and cut. The cut end portion of the hair is melted to form a molten lump, and a back cover is fitted so as to cover the molten lump to form a flocked portion.

  However, this technique only inserts the hair at the end of the flock hole, so that the tip of the hair bundle tends to spread during the formation of the molten lump. The tendency became strong and was not preferable. In addition, since the substrate is arranged so as to cover the space in the receiving mold, when the flocked portion is formed by injection molding so as to cover the molten mass, it is necessary to use the receiving mold as it is in terms of the strength of the substrate. This is also impossible, and it is necessary to transfer the substrate after forming the molten mass, resulting in a problem of low production efficiency.

JP-T-2001-513585 Japanese Patent Publication No. 50-14465

  Accordingly, an object of the present invention is to provide a method for manufacturing a brush that is excellent in the alignment and formability of the hair bundle, can be used at a low cost, and can be used for thinning of the flocked base and for low-volume production of various types of hair. It is another object of the present invention to provide a hair bundle holding jig suitable for use.

  The present invention provides a hair holding jig having a flocked base portion having a plurality of flocked holes, a recess formed in a shape substantially equivalent to the outline of the outer shape of the flocked base portion, and an insertion portion formed in a shape substantially equivalent to the flocked hole. Arranged through the insertion portion and each flocked hole, the hair previously introduced into the sleeve is pushed out by an extrusion pin and inserted into the insertion portion through the flocked hole, and the flocked hole and the insertion portion The object is achieved by providing a method for producing a brush comprising a step of melting a portion protruding from the flock hole in each of the hairs to form a molten mass while holding the hairs. It is a thing.

  According to the present invention, the hair bundles are excellent in alignability and moldability, can be manufactured at low cost, and can cope with thinning of the flocked base and high-mix low-volume production.

  Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings.

  FIG. 1 shows an embodiment of the hair bundle holding jig of the present invention. In FIG. 1, reference numeral 1 denotes a hair bundle holding jig, 11 denotes a toothbrush body, and 12 denotes a flocked base.

  As shown in FIG. 1, the hair bundle holding jig 1 includes a pedestal portion 2 on which a flocked base portion 12 having a plurality of flocked holes 12 a (see FIG. 2) is arranged, and a flocked base portion 12 arranged on the pedestal portion 2. Positioning means 3 for positioning.

  As shown in FIG. 2, the pedestal portion 2 has a plurality of hair insertion portions 20 that communicate with the flocked holes 12 a when the flocked base portion 12 is positioned on the pedestal portion 2. A hair holding mechanism 4 for holding the hair 13 inserted into each insertion portion 20 through the pores 12a is provided.

  The pedestal portion 2 is provided so as to be divided into three so as to divide the insertion portion 20 in the insertion direction of the hair 13. In the present embodiment, the pedestal portion 2 is provided with an upper plate portion 20a, an intermediate plate portion 20b disposed below the upper plate portion 20a, and a lower plate portion 20c fixed further below the upper plate portion 20a.

  The upper plate portion 20 a is provided with a recess 30 corresponding to the outer shape of the flocked base portion 12. The middle plate portion 20b is arranged via an elastic member (not shown) so as to be slidable within a predetermined range between the upper plate portion 20a and the lower plate portion 20c. The insertion portion 20 is biased so as to be intermittent. A known member such as a spring or a leaf spring can be used as the elastic member. A tip end portion of the insertion portion 20 is formed in the lower plate portion 20c. By replacing this portion, only the tip shape can be changed while the insertion direction of the insertion portion 20 remains unchanged.

  The insertion portion 20 is provided with an insertion direction in the same direction as the insertion direction of the flock hole 12a so as to communicate with the flock hole 12a of the flock base 12. The insertion opening of the insertion portion 20 is provided so as to gradually expand upward in a tapered shape, and when the hair 13 is inserted through the flocking hole 12a, the positioning of the flocking hole 12a and the insertion portion 20 is accurate. Even if it is not made, the hair can be smoothly inserted and the hair can be prevented from being caught at that time.

  The positioning recess 30 for positioning the flocked base 12 has a shape similar to the outer shape of the flocked base 12 in order to securely position and fix the flocked base 12 to the hair bundle holding jig 1. The size is preferably 0.05 to 0.2 mm larger than the flocked base. The concave portion 30 for positioning is preferably three-dimensionally formed with a positioning accuracy or higher corresponding to the flocked base portion 12, but as another form, it is convex and has two or three partial wall surfaces for positioning. A form such as fixing at a point or a combination of a concave portion and a convex portion can be appropriately selected.

  The cross-sectional shape in the direction orthogonal to the insertion direction of the insertion portion (excluding the tip portion) 20 is provided in a similar shape to the cross-sectional shape in the direction orthogonal to the insertion direction of the flock hole 12a. The insertion portion (excluding the tapered portion) 20 is preferably provided wider than the flocked hole 12a so as to have a gap of 0.05 to 0.2 mm between the inner periphery thereof and the inner periphery of the flocked hole 12a. If it is less than 0.05 mm, the insertion area is substantially too small due to the positioning accuracy of the flocked base, which may cause misinsertion of hair and poor hair raising. On the other hand, if the thickness exceeds 0.2 mm, the holding power of the hair becomes insufficient, and the alignment form of the hair ends tends to spread.

  Further, the hair bundle density in the insertion portion 20 is preferably 40 to 75%, particularly 50 to 70%, in order to maintain the shape of the hair bundle. When the hair bundle density is less than 40%, in the process of coating the molten mass by forming the molten mass or injection molding, turbulence of the hair, such as the tip of the hair bundle spreading, is likely to occur. When the hair bundle density exceeds 75%, each hair of the hair bundle is relatively displaced in the length direction at the time of inserting the hair bundle, and the form of the tip of the hair bundle cannot be formed accurately. In addition, some of the hairs are bent and problems during insertion tend to occur. The hair bundle density is a value obtained by dividing the cross-sectional area perpendicular to the length direction of the insertion portion 20 by the sum of the cross-sectional areas perpendicular to the length direction of each hair to be inserted into the insertion portion 20. Say.

  As shown in FIG. 3, the tip 20d in the insertion direction of the hair 13 of a part of each of the insertion portions 20 is shaped to align the tip of the hair 13 to be inserted in a predetermined alignment form. Is provided.

  In the present embodiment, the positioning means 3 includes the positioning recess 30 and a lock arm 31 that fixes the neck portion of the toothbrush main body 11, and holds the brush main body 11 securely. 20 and each flock hole 12a are connected with high accuracy. The lock arm 31 includes an arm 31a and a lock pin 31b that supports the arm 31a. A mechanism (not shown) that rotates the arm 31a around the lock pin 31b and the arm 31a can be moved up and down. A vertical movement mechanism (not shown) is arranged.

  When the brush body 11 is attached to the bristle holding jig 1, the lock arm 31 is rotated and moved so as not to interfere with the attachment of the brush body 11, and after the brush body 11 is attached, the lock arm 31 is moved to a predetermined position. The brush body 11 is fixed by the lock arm 31. The fixing is performed by lowering the arm 31a by the vertical movement mechanism and pressing the brush body 11.

  The hair holding mechanism 4 is provided so as to hold each hair 13 by moving the divided middle plate portion 20b in a shearing direction with respect to the hair 13 inserted into each insertion portion 20. ing. The thickness of the middle plate portion 20b is preferably 30 to 60% with respect to the length of the inserted hair. If the middle plate portion 20b is too thick, the position with a relatively high degree of freedom in the center in the longitudinal direction of the hair cannot be sheared and the holding state may become unstable. If it is too thin, a large shearing force is exerted on the hair. The hair may be deformed or damaged.

  In this embodiment, the middle plate portion 20b is urged by the elastic force of an elastic member (not shown), so that the bristle 13 inserted into the insertion portion 20 with the upper plate portion 20a is attached to the hair 13 The hair 13 can be held by applying a clamping force in the shear direction. The elastic force for urging the middle plate portion 20b is sufficient if it is about 1 to 5N. Moreover, in this embodiment, by changing a part or all of the upper plate portion 20a, the middle plate portion 20b, the lower plate portion 20c, and the tip portion 20d described later, which are some parts of the hair bundle holding jig. The hair-planting base 12, the hair-planting pattern, the length and thickness of the hair bundle, the alignment form of the hair tips, and the like can be easily changed at low cost.

  Next, the manufacturing method of the brush of this invention is demonstrated based on the manufacturing method of the toothbrush using the said bristle bundle holding jig 1 as the preferable embodiment.

  First, as shown in FIGS. 1 and 2, the toothbrush main body 11 having the flocked base portion 12 at the distal end thereof is arranged on the upper plate portion 20a of the pedestal portion 2, and the arm of the positioning means is arranged. Fix with 31a. Then, the intermediate plate portion 20b is pressed and slid against the elastic force of the elastic member, and is passed through the insertion portions 20 and the flock holes 12a.

Next, as shown in FIG. 2, a predetermined number of hairs 13 cut to a predetermined length are introduced into the sleeve 14 (the hair introduction part) in advance, and the hairs 13 are pushed out by the push pins 15 to be planted. It inserts into the pore 12a and the insertion part 20. Thus, it is preferable to insert the hair 13 from the flocked hole side of the flocked base 12 in the following points (1) to (3).
(1) Since there is no need to provide a taper on the hair bundle holding jig side of the flock hole, it is hygienic because moisture does not accumulate, resulting in a decrease in the strength of the flocked base due to a decrease in wall thickness and resin leakage during molding. Hateful.
(2) Since it is easy to set the cross section in the direction orthogonal to the insertion direction of the insertion portion and the cross section in the direction orthogonal to the insertion direction of the flocking hole to an optimum state, the insertion resistance at the time of insertion, the molten lump formation step In addition, the hair bundle is less likely to be disturbed due to the influence of the force acting on the hair bundle in the injection molding process, and insertion errors are less likely to occur.
(3) When the hair bundle insertion direction by the sleeve in this embodiment and the insertion direction of the flock hole and the insertion portion are inclined, the melt lump forming step is performed in a state where the hair bundle in the insertion portion is bent. Therefore, the orientation and alignment of the hair bundle for the final product can be improved.

  The bristles 13 can be made of any ordinary material and form conventionally used for toothbrush bristles without particular limitation. Examples of the material for the hair 13 include polyamide such as nylon, and polyester such as polybutylene terephthalate and polytrimethylene terephthalate. The length of the hair 13 is preferably 5 to 20 mm, and more preferably 8 to 18 mm. The thickness of the hair 13 is preferably 6 to 10 mil (127 to 254 μm), and more preferably 7 to 9 mil (178 to 229 μm).

  In the present embodiment, the outer surface of the sleeve 14 is subjected to electroless plating or surface treatment with polytetrafluoroethylene resin or the like from the viewpoint of suppressing resistance when the nozzle portion is inserted into a set of hairs. It is preferable to finish the surface by lubrication.

  As shown in FIG. 3, it is preferable to use the push pin 15 having a tip portion 15 a provided in a shape corresponding to the shape of the tip portion of the insertion portion 20. When the push pin 15 is inserted into the sleeve 14 and the hair 13 is pushed out, the rear end portion of the hair 13 is aligned by the front end portion 15a of the push pin 15, and the front end portion of the hair 13 is aligned in advance. After that, it is inserted into the insertion portion 20 through the flock hole 12a. Thus, before inserting the hair 13 into the insertion part 20, the alignment form of the front-end | tip part is previously arranged, The alignment form of the front-end | tip part of the hair 13 corresponded to the front-end | tip part 20d of the insertion part 20. A desired form can be obtained.

  After the insertion of the hair 13 for one insertion portion 20 is completed, the hair bundle holding jig 1 is moved so that the insertion portion 20 into which the hair 13 is inserted next is positioned at the insertion position. Thereafter, the hair 13 is inserted according to the above procedure. When the insertion of the hairs 13 into all the insertion portions 20 is finished, the pressing of the middle plate portion 20b by the hair holding mechanism 4 is released, and the hairs 13 inserted into the insertion portions 20 are held.

  Next, as shown to Fig.4 (a), the bristle bundle holding jig 1 is transferred to the process of forming a fusion soul with the toothbrush main body 11, and is positioned. And the part which protrudes from the said flock hole 12a in the said hair 13 is fuse | melted with the heat source 5, and as shown in FIG.4 (b), the flock hole 12a is plugged and the molten lump 130 is formed. Although there is no restriction | limiting in particular in the kind of the heat source 5, It is preferable to use the heater using a laser beam, a halogen light source, an ultrasonic wave, etc. from the point which can form a molten lump individually. The molten mass 130 may be formed alone or adjacent molten masses may be connected to each other.

  In this embodiment, since the flocked base 12 is used, even if the molten resin is temporarily leaked, it stays in the flocked hole 12a and does not impair the appearance of the product. In addition, since the insertion port of the flocked hole 12a is gradually expanded upward and is provided in a tapered shape, the flocked base 12 is made thin by forming the molten mass 130 using this portion. Also, it is possible to obtain the stability of hair raising. Further, when the molten lump 130 is formed, since the bristles are held and fixed by the bristles holding mechanism 4, it is possible to suppress the deviation of the bristles associated with the formation of the molten lump 130, and the obtained bristles The alignment form of the front end portions can be made favorable.

  Next, a flocked portion (head) is formed by covering the formed molten mass 130. In the present embodiment, as shown in FIG. 5, the brush body 11 is positioned with the hair bundle holding jig 1 with respect to the mold 60 of the molding device 6. At this time, molding is performed at a high injection pressure by pressing the flocked base 12 with the mold 60 and elastically or plastically deforming the flocked base 120 to improve the sealing property between the flocked base and the mold 60. Can do. In order to enhance this sealing property, it is preferable to provide the opening edge of the recess 12b on the back surface of the flocked base 12 in a flat manner.

  After positioning the bristle bundle holding jig 1 with respect to the mold 60 of the molding apparatus 6 as described above, the filler is injected between the flocked base 12 and the mold 60 through the inlet 61 from the filling apparatus 7. . Then, the flock 130 is coated to form a flocked portion (head) 110, and the hair 13 is fixed to the flocked base 12.

  It is preferable to use the same material as the flocked base 12 as the filler. Examples of such materials include polyethylene resin, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene polymer, polycarbonate, polymethyl methacrylate, and the like.

  As long as the desired adhesiveness is obtained with respect to the flocked base 12, the flocked base 12 and the filler can be formed of different materials. In this case, considering the adhesiveness between the flocked base 12 and the molten mass 130, it is preferable to select a material with good thermal adhesiveness and chemical adhesiveness between them. It is also effective for improving the adhesiveness to warm the flocked base 12, to increase the thermal adhesiveness by increasing the mold temperature, or to increase the melting temperature at the time of filling the filler itself. Furthermore, a method of injecting a filler after applying a corona discharge treatment or a plasma discharge treatment to the surface of the flocked base 12 or applying a primer agent is also effective for improving the adhesiveness.

  Thus, when the filler of a different material from the flocked base 12 is used, various characteristics can be provided to the obtained toothbrush. For example, elasticity can also be provided to the toothbrush obtained by using a polypropylene resin for the flocked base 12 and using a thermoplastic elastomer for the filler. Further, by changing the coloring between the flocked base 12 and the filler, it is possible to give a feature to the appearance.

  In the present embodiment, since the flocked hole 12a is blocked by the molten mass 130, the molten resin is prevented from leaking, and even if the molten resin is temporarily leaked, it remains in the flocked hole 12a, and the appearance of the product Will not be damaged.

  Moreover, in this embodiment, the flocking base 12 is arranged and supported stably in the recessed part 30 provided in the upper surface of the base part 2 of the hair holding jig 1, and each hair bundle is said hair Since it is held by the holding mechanism 4, even when the flocking base 12 is thinned, the flocking base 12 can be held by the hair holding jig 1, and bending of the flocking base 12 due to the injection pressure can be suppressed. It is also effective for the alignment of the hair bundles. For this reason, it is possible to produce a toothbrush with a thinner hair transplant.

  Moreover, in this embodiment, since the filler is injected between the flocking base 12 and the mold 60 of the molding apparatus to cover the molten mass, the filler is injected into the flocked base and the molten mass without a gap, and the flocked Solidified and integrated with the base and molten mass. For this reason, compared with the method (not shown) etc. which affix a plate-shaped plastic member to a hair transplant base part, a space does not generate | occur | produce inside a hair transplant part (head), and a water | moisture content penetrates in a head at the time of tooth brushing. It is hygienic because there is nothing.

  After completion of the injection molding, the hair holding mechanism 4 releases the holding hair 13 and releases the mold. Then, the brush body 11 is unfixed by the positioning means 3 and the toothbrush 10 is removed from the bristle holding jig 1 as shown in FIG. After performing post-processing such as trimming as necessary, the manufacture of the toothbrush is completed.

  Moreover, since the hair | bristle bundle holding jig 1 does not require severe precision compared with a shaping | molding die, it can be manufactured cheaply with materials, such as aluminum. Furthermore, since the hair bundle holding jig 1 is smaller and lighter than the molding die, conveyance between processes is easier than the molding die. Therefore, a large amount of hair bundle holding jig 1 is used, and the necessary amount corresponding to each process from the insertion process of the hair to the molding of the hair transplantation part in a state where the hair transplantation base is arranged and fixed to each hair bundle holding jig. By supplying, you can maximize the capacity of the entire facility. In addition, it is possible to build a flexible production system that can absorb the difference in production capacity generated in each process during a model change.

  As described above, according to the bristle bundle holding jig 1 of this embodiment and the method of manufacturing a toothbrush using the same, the bristle bundle is excellent in alignment and moldability, low in cost, and thin in the flocked base. It is possible to cope with the production and small variety production.

  The present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention.

  Further, according to the present invention, it is preferable to insert hairs (bundles) one by one using a sleeve as in the above embodiment, but a plurality of sleeves are used together to correspond to the hair transplantation pattern. The hair bundles can be inserted at once.

  According to the present invention, as in the above-described embodiment, the flocked base is disposed in a molding apparatus together with the hair bundle holding jig to form a cavity between the flocked base and the mold of the molding apparatus, and the cavity It is preferable to form a flocked portion by injecting a resin into the interior and coating the molten mass, but other methods, for example, bonding a plastic plate with an adhesive, ultrasonic wave, high frequency, etc. The flocked portion can also be formed by covering the molten mass by a method such as heat bonding with a plastic plate or a method of fitting a plastic plate.

  The present invention is particularly suitable for the production of toothbrushes as in the above embodiment, but can also be applied to the production of brushes other than toothbrushes, for example, the production of hair brushes, massage brushes, cleaning brushes and other various brushes. .

It is a figure which shows typically one Embodiment of the hair | bristle bundle holding jig of this invention, (a) is a top view, (b) is a side view. In one embodiment in which the method for manufacturing a brush of the present invention is applied to the manufacture of a toothbrush, a state in which the bristles introduced into the sleeve are pushed out by an extrusion pin and inserted into the insertion portion of the bristles holding jig is schematically shown. It is principal part sectional drawing shown in FIG. It is a figure which shows typically an example of each front-end | tip shape of the insertion part of an extrusion pin, the extruded hair, and the hair holding jig. It is principal part sectional drawing which shows the formation process of a molten lump typically, (a) is a figure which shows the state which has melt | dissolved the edge part of the hair with a heat source, (b) is the state in which the molten lump was formed. FIG. It is principal part sectional drawing which shows the filling process of a filler typically. It is principal part sectional drawing which shows typically the state which isolate | separated the toothbrush from the bristle bundle holding jig.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hair bundle holding jig 2 Base part 20 Insertion part 3 Positioning means 30 Recessed part 4 Hair holding mechanism 10 Toothbrush 11 Toothbrush main body 12 Flocking base 13 Hair 14 Sleeve 15 Extrusion pin

Claims (6)

  Disposing a flocking base having a plurality of flocking holes to a hair holding jig having a recess formed in a shape substantially equivalent to the outline of the flocking base and an insertion portion formed in a shape substantially equivalent to the flocking hole, Through the insertion portion and each flocked hole, the hair previously introduced into the sleeve is pushed out by an extrusion pin and inserted into the insertion portion through the flocked hole, and the bristles are inserted into the flocked hole and the insertion portion. A method for manufacturing a brush, comprising a step of melting a portion protruding from the flock hole in each of the hairs to form a molten lump while being held.   The method for manufacturing a brush according to claim 1, further comprising a step of forming a flocked portion by covering the formed molten mass.   The said hair transplant base part is arrange | positioned to a shaping | molding apparatus with the said hair | bristle bundle holding jig, resin is inject | poured between this mold base and the metal mold | die of this shaping | molding apparatus, The said molten lump is coat | covered. Brush manufacturing method.   The hair according to any one of claims 1 to 3, wherein a predetermined number of the hairs cut into a predetermined length are introduced into a hair introduction portion in advance, and the hair is delivered from the introduction portion and inserted into the insertion portion. A method for producing the brush according to claim 1.   The manufacturing method of the brush of Claim 4 with which the front-end | tip part of the delivery means which sends out hair is provided in the shape corresponding to the form of the front-end | tip part of the said insertion part.   The manufacturing method of the brush of Claims 1-5 which inserts the said hair in the said insertion part through the said flock hole from the said flocking base part side.