JP5290657B2 - toothbrush - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toothbrush with a structure capable of effectively preventing a resin injected into the back at molding of a bristle-planted part from oozing out on the surface from a gap between a bristle-planted hole and a bristle bundle without restrictions of a shape/size of the hole and a distance between the bundles. <P>SOLUTION: The toothbrush 10 is provided with the bristle-planted part 12 filled with a plurality of the bristle bundles 11 bundling up the bristles together. The part 12 includes a bristle-planted base 16 having a plurality of the bristle-planted holes 15, the bristle bundles 11 which are disposed in the holes 15 respectively and of which each one end 21 is heated-molten to be a molten solid 20 formed on the back 17 of the base 16 and a back mold layer 19 which is formed by being filled with a back forming resin and covers the back 17 of the base 16. A middle resin layer 22 coming in contact with the solids 20 is placed in the space between the back 17 of the base 16 and the layer 19. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a toothbrush having a flocked portion in which a plurality of bristles formed by bundling bristles are planted, and a method for manufacturing the toothbrush.

  The toothbrush generally includes a hair transplant part in which a plurality of hair bundles are implanted, a grip part, and a neck part that connects these parts. Further, the toothbrush flocked portion includes a plurality of flock holes provided in the flocked portion, each having a hair bundle planted using a metal piece called a flat wire, and a plurality of flocked flocked flocks. One in which each hair bundle is implanted in a flock hole is known.

  In fusion flocking, a hair bundle is inserted into each of a plurality of flock holes provided in a flocking base constituting a flocked portion, and one end of the hair bundle is melted at the back portion of the flocking base to form a molten lump. In the state where one end of each hair bundle is fixed and fixed to the flocking base, the flocking base is placed in the mold, and the back surface is filled with resin to form a back molding layer. The hair transplant part in which the hair bundle is planted is obtained.

  Further, in the flocked part formed by fusion flocking, when the flocked base with the hair bundle fixed is installed in the mold and the back molding layer is formed, the filling pressure of the resin injected and filled into the back part The injected resin oozes out from the gap between the flocked hole and the hair bundle to the surface side opposite to the back surface of the flocked base and impairs the aesthetics of the flocked part, and also reduces the bristle of the hair bundle. It may disturb the direction of the bristle of the hair bundle. Such a tendency is remarkable when the adhesiveness between the hair bundle resin and the flocking base resin and the adhesiveness between the hair bundle resin and the back molding layer resin are not good.

On the other hand, when the flocked part is formed by fusion flocking, the resin injected into the back part is prevented from seeping out from the gap between the flocked hole and the hair bundle to the surface side of the flocked base. Various techniques have been developed for improving the alignment of the bristles of the hair bundles and preventing the bristle of the hair bundles from falling out during use (see, for example, Patent Document 1 and Patent Document 2).
JP 2003-135154 A JP 2003-310353 A

  On the other hand, the fused flocking has a higher degree of freedom when designing and manufacturing the flocked portion than a hair bundle planted using a flat wire, and has a plurality of different bundle diameters or cross-sectional shapes. It is also easy to plant hair bundles inclined at different angles, hair bundles having different heights, and hair bundles having a plurality of tip shapes in the hair transplantation part. In recent years, it has been desired to further improve the degree of freedom in the design and manufacture of the flocked portion for the purpose of further improving the plaque removal effect and ease of brushing of the toothbrush.

  In the toothbrush by fusion flocking, as shown in FIG. 5, the back side opposite to the surface side formed by protruding the hair bundle as a toothbrush in the flocked hole 50 so that the hair bundle implanted after molding is difficult to come off. A funnel-shaped tapered surface 51 having a diameter increasing toward the surface is provided, and a melted mass for fixing the hair bundle 52 is formed on the funnel-shaped tapered surface 51. When the hole diameter on the surface side of the flocked hole 50 is Φ and the angle of expansion of the tapered surface 51 is θ, if the angle of expansion θ is increased, the hair bundle 52 is difficult to come out, but the melted hair bundle As a result, the bristle of the hair bundle 52 is easily cut and the interval between the hair bundles 52 is widened. In addition, if the diameter Φ on the surface side of the flocked hole 50 is too small, the bristle of the hair bundle 52 melted in the molten mass is easily cut or pulled out, so the surface-side diameter Φ needs to be larger than a certain value. It is.

  As described above, the shape, size, and spacing between the hair bundles of the flocked holes are restricted in order to make the bristles of the hair bundles difficult to pull out or cut off, and the degree of freedom in designing and manufacturing the flocked parts is limited. Therefore, without receiving these restrictions, the resin injected into the back surface during molding prevents the resin from seeping out from the gap between the flocked hole and the hair bundle, and the alignment of the hair bundles is improved. The development of a new technique in which bristle of hair bundles is difficult to come off during use is desired.

  In the present invention, the resin injected into the back surface at the time of molding of the flocked portion is placed on the surface side from the gap between the flocked hole and the hair bundle without being restricted by the shape and size of the flocked pores and the spacing between the hair bundles. It is an object of the present invention to provide a toothbrush that can effectively prevent protrusion and a method for manufacturing the toothbrush.

  The present invention is a toothbrush having a flocked portion in which a plurality of hair bundles formed by bundling bristles are planted, wherein the flocked portion is inserted and arranged in a flocked base having a plurality of flocked holes, It consists of a hair bundle in which one end portion is heated and melted so that a molten mass is formed on the back surface portion of the flocked base, and a back molding layer that is formed by filling a resin covering the back surface portion of the flocked base, and The object is achieved by providing a toothbrush in which the intermediate resin layer is interposed between the back surface portion of the flocked base and the back surface molding layer in contact with the molten mass.

  Further, the present invention is a method of manufacturing a toothbrush having a hair transplant portion in which a plurality of hair bundles formed by bundling bristles are planted, wherein one end portion of the hair bundle projects from the back surface of the hair transplant base. A hair bundle insertion step of inserting and arranging the hair bundles in the flock holes, a melt lump forming step of forming a molten lump by heating and melting one end portion of the hair bundle protruding from the back surface portion of the flocked base, and a molten lump A step of forming an intermediate resin layer by a hot melt resin application step or a resin sheet installation step on the back portion of the formed flocking base, and filling the back portion of the flocking base with a resin covering the intermediate resin layer Thus, the above object is achieved by providing a method for manufacturing a toothbrush including a back surface forming step for forming a back surface forming layer.

  Furthermore, the present invention is a method for manufacturing a toothbrush having a flocked portion in which a plurality of bristle bundles formed by bundling bristles are planted, and openings corresponding to the plurality of flocked holes formed in the flocked base are formed. The opening resin sheet is installed on the back surface of the flocking base with the opening aligned with the flocking hole, and one end protrudes from the back surface to the opening and flocking hole of the opening resin sheet. A hair bundle insertion step of inserting and arranging the hair bundle in a state of being made to melt, and a molten mass that forms a molten mass in a state where one end portion of the hair bundle protruded from the back surface portion is heated and melted and adhered to the open resin sheet By providing a manufacturing method of a toothbrush including a forming step and a back surface forming step of covering the opening resin sheet and the molten mass to fill a back surface portion of the flocked base with a resin to form a back surface forming layer, Achieved purpose

  According to the toothbrush of the present invention or the manufacturing method of the toothbrush, the resin injected into the back surface portion of the flocked base at the time of forming the flocked portion without being restricted with respect to the shape, size and spacing between the follicles of the flocked hole. Can effectively be prevented from exuding to the surface side of the flocked base from the gap between the flocked hole and the hair bundle.

  As shown in FIG. 1, the toothbrush 10 according to a preferred embodiment of the present invention includes a flocked portion 12 in which a plurality of hair bundles 11 are implanted, a gripping portion 13 (see FIG. 2B), and these. Each of the hair bundles 11 is planted in a plurality of flock holes 15 by so-called fusion flocking. Moreover, the toothbrush 10 of this embodiment WHEREIN: In the flocked base 16 which comprises the flocked part 12, the metal mold | die 18 (FIG. 18) is shown in the back surface part 17 on the opposite side to the surface side which protrudes and forms the hair | bristle bundle 11 of the toothbrush 10. 3 (g)) is disposed and the back molding layer 19 is formed by pouring and filling the back molding resin, the injected resin is implanted by the filling pressure of the resin filling the back surface portion 17. It has a structure that can effectively avoid the surface of the flocked base 16 from the gap between the pore 15 and the hair bundle 11.

  That is, the toothbrush 10 of the present embodiment is a toothbrush having a flocked portion 12 in which a plurality of bristle bundles 11 formed by bundling bristles are planted, and the flocked portion 12 includes a flocked base 16 having a plurality of flocked holes 15. The hair bundle 11 is inserted and arranged in the flocked hole 15, and the one end portion 21 (see FIG. 3B) of the hair bundle 11 is heated and melted to form the molten mass 20 on the back surface portion 17 of the flocked base 16. And a back molding layer 19 formed by covering the back surface portion 17 of the flocked base 16 and filling a resin for back molding, between the back surface portion 17 and the back molding layer 19 of the flocked base 16. The intermediate resin layer 22 is interposed in contact with the molten mass 20.

  In this embodiment, prior to planting the hair bundle 11 in the hair-planting portion 12 of the toothbrush 10, as shown in FIGS. 2 (a) and 2 (b), the gripping portion 13, the neck portion 14, and the hair-planting portion 12 are used. The toothbrush main body 23 with which the flocking base 16 is integrated is formed. In order to form the toothbrush main body 23, a main body mold 26 having a cavity 24 corresponding to the shape of the toothbrush main body 23 provided with the flocked base 16 and a resin injection path 25 communicating with the cavity 24 is used. Then, the main body mold 26 is set in an injection molding machine (not shown), and a thermoplastic resin (not shown) is injected into the cavity 24 from the resin injection path 25 with a predetermined injection molding pressure, Demold after cooling.

  Here, as resin for forming the toothbrush main body 23, the normal thermoplastic resin conventionally used for the toothbrush main body can be especially used without a restriction | limiting. Examples of the thermoplastic resin include polyolefins such as polypropylene, polyesters such as polycarbonate, polymethyl methacrylate, and polyethylene terephthalate, acrylonitrile-styrene copolymers, acrylonitrile-butadiene-styrene copolymers, and the like. A thermoplastic resin can be used alone or in a suitable manner.

  As shown in FIG. 1, a plurality of flock holes 15 are formed in the flocking base 16 of the toothbrush body 23 so as to correspond to the arrangement positions of the bristles 11. As the shape of the flocked hole 15, in addition to a substantially circular shape, a substantially oval shape, a substantially elliptical shape, various triangular shapes, various rectangular shapes, and the like can be appropriately selected. In the present embodiment, a plurality of flocked holes 15 having a plurality of types of opening shapes are distributed over substantially the entire flocked base 16 so as to correspond to the cross-sectional shape of the proximal end portion of the hair bundle 11 having a plurality of different shapes. It is arranged and an opening is formed.

  Each hair bundle 11 implanted in the flock hole 15 of the flocking base 16 has, for example, a dozen to a few tens of bristle that is a filament material having a thickness of, for example, 6 to 10 mil (0.15 to 0.25 mm). Formed by bundling. As the bristle that constitutes the hair bundle 11, those made of conventional materials conventionally used for toothbrush hair such as polyamide such as nylon and polyester such as polybutylene terephthalate can be used. Each bristle bundle 11 is in the flocked part 12 by the flocked base 16 from the surface from which the bristle bundle 11 protrudes as a brush on the formed toothbrush (from the side opposite to the back part 17 across the flocked hole 15), preferably 7 Each is implanted so as to have a hair length of about 12 mm.

  Each hair bundle 11 planted in the flock hole 15 of the flocking base 16 is heated and melted at one end portion 21 (see FIG. 3B) of the hair bundle 11 protruding from the back surface portion 17 of the flocking base 16. By forming a molten lump 20 having a larger lump diameter than the hole diameter of the flocked hole 15, it is fixed to the flocked base 16. The one end portion 21 of the hair bundle 11 can be easily heated and melted by using a non-contact heat source (not shown). As the non-contact heat source, a laser oscillator that emits a laser beam, a halogen lamp that collects and irradiates light from a light source, or the like can be used.

  The back molding layer 19 formed so as to cover the back surface portion 17 of the flocking base 16 is made of a polyolefin for back molding, such as polyolefin such as polypropylene, polyester such as polycarbonate, polymethyl methacrylate, and polyethylene terephthalate, and acrylonitrile-styrene copolymer. It can be formed using a thermoplastic resin such as acrylonitrile-butadiene-styrene copolymer, and preferably the same resin as the toothbrush body 23 is used. In order to form the back surface molding layer 19, for example, after the flocking base 16 is positioned with respect to the die 18 (see FIG. 3G) of the back surface forming device 27, the injection molding (gate) 28 of the die 18 is used. Resin is discharged, and the discharged resin is injected and filled into the space between the back surface portion 17 and the mold 18. Accordingly, even if the back surface portion 17 of the flocked base 16 has irregularities due to the molten mass 20, the back surface molding layer 19 is formed so that the back-molding resin that has been injected and filled follows the unevenness of the back surface portion 17. Here, the back surface portion 17 of the flocked base 16 is a back surface filling concave portion 30 by being provided with an outer peripheral wall portion 29 along the entire periphery thereof. This makes it possible to simplify the structure of the mold 18 of the back surface molding device 27 and increase the adhesive area between the back surface molding resin and the back surface portion 17, thereby increasing the adhesive strength of the back surface molding layer 19. In particular, it is possible to effectively prevent liquid or the like from entering between the back surface portion 17 and the back surface molding layer 19 from the outside.

  In the present embodiment, between the back surface portion 17 and the back surface molding layer 19 of the flocked base 16, at least part of the back surface portion 17 surrounded by the outer peripheral wall portion 29, preferably over substantially the entire region, Alternatively, the intermediate resin layer 22 is provided in a state where it is in contact with the molten mass 20 including the region where the flocked hole 16 is formed, and preferably the entire region where the flocked hole 16 is formed. The thickness of the intermediate resin layer 22 is provided thinner than the height of the outer peripheral wall portion 29. As the resin constituting the intermediate resin layer 22, various thermoplastic resins such as ethylene vinyl acetate copolymer, nylon elastomer, urethane elastomer, admer resin, and partially saponified ethylene vinyl acetate copolymer can be used. However, it is preferable to use a thermoplastic resin having adhesiveness with the molten mass 20 formed by melting one end portion 21 of the hair bundle 11. For example, when the hair bundle 11 is made of polyamide such as nylon, the resin constituting the intermediate resin 22 is admer resin, urethane elastomer, partially saponified ethylene vinyl acetate copolymer having adhesiveness with the hair bundle 11. It is preferable to use coalescence or the like.

  The intermediate resin layer 22 is provided in contact with the molten mass 20 in a state of covering at least the peripheral edge of the molten mass 20. Since the intermediate resin layer 22 is in contact with at least the peripheral edge of the molten mass 20, the resin injected into the back surface portion 17 when the back surface molding layer 19 is molded is interposed between the flock holes 15 and the hair bundle 11. It is possible to effectively prevent oozing from the gap to the surface side. In addition, when the entire molten mass 20 is covered, there is an intermediate resin layer between the molten mass even when the resin for back molding is filled, so the molten mass and the filled resin may come into contact with each other. Therefore, it is difficult to be affected by the heat of the back surface filling resin.

  By using a resin having adhesiveness with the molten mass 20 as the resin constituting the intermediate resin layer 22, the molten mass 20 and the intermediate resin layer 22 are bonded and integrated, and the bristle of the hair bundle 11 is formed by the intermediate resin layer 22. By being firmly supported, it is possible to further prevent the bristle of the hair bundle 11 from being pulled out, and it is possible to better maintain the alignment of the hairs of the hair bundle.

  Moreover, in this embodiment, since the intermediate resin layer 22 is provided in contact with the molten lump 20 in a state of covering the molten lump 20, when the intermediate resin layer 22 is a resin having adhesiveness, The intermediate resin layer 22 can be bonded and integrated in a more stable state. In addition, since the molten mass 20 is covered with the intermediate resin layer 22, the injection port 28 of the back surface molding device 27 (FIG. 3G) when the back surface molding resin is injected into the back surface portion 17 of the flocking base 16. Can be arranged at an arbitrary position toward the back surface portion 17, and the degree of freedom in setting the gate position can be improved.

  When the molten lump 20 formed by heating and melting one end portion 21 of the hair bundle 11 is directly subjected to the flow of the resin from the injection port 28, it is softened by the heat of the resin, The fixed state to the back surface part 17 becomes weak. For this reason, since the bristle of the hair bundle 11 becomes easy to come out or the alignment of the rising of the hair bundle 11 is impaired, the resin injection port 28 for back molding avoids the molten mass 20 in the conventional technique. It was necessary to provide in position. In the present embodiment, since the molten mass 20 is covered with the intermediate resin layer 22, it is possible to prevent the resin flow from the injection port 28 from directly hitting the molten mass 20. 17 can be provided at arbitrary positions, thereby increasing the degree of freedom in setting the gate position.

  Furthermore, in this embodiment, an intermediate resin layer is formed by laying hot melt resin in a thickness of about 10 to 600 μm in the back surface filling recess 30 surrounded by the outer peripheral wall portion 29 of the back surface portion 17 of the flocked base 16. 22 can be provided. Moreover, the intermediate resin layer 22 can also be provided by disposing the resin sheet 31 having a thickness of about 10 to 600 μm so as to be fitted into the back surface filling recess 30 surrounded by the outer peripheral wall portion 29. By forming the intermediate resin layer 22 using the resin sheet 31, it is possible to simplify the process of forming the intermediate resin layer 22 on the flocked portion 12.

  And in the toothbrush 10 of this embodiment provided with the above-mentioned structure, the flocked part 12 can be easily formed using the resin sheet 31 according to the manufacturing process shown to Fig.3 (a)-(i), for example. The manufacturing steps shown in FIGS. 3A to 3I are performed by inserting the hair bundles 11 into the flock holes 15 of the flocking base 16 in a state where the one end portion 21 of the hair bundle 11 protrudes from the back surface portion 17. A bundle insertion step (see FIGS. 3A and 3B) and a melt lump forming step in which one end portion 21 of the hair bundle 11 protruding from the back surface portion 17 of the flocked base 16 is heated and melted to form a melt lump 20. (Refer FIG.3 (c)) and the resin sheet installation process which covers the back surface part 17 of the flocked base 16 in which the molten lump 20 was formed, and installs the resin sheet 31 (refer FIG.3 (d), (e)). And a resin sheet melting step in which the installed resin sheet 31 is heated and melted, and a back surface forming the back surface molding layer 19 by covering the resin sheet 31 and filling the back surface portion 17 of the flocking base 16 with a back surface molding resin. A molding step (see FIGS. 3G to 3I). Here, when a resin having adhesiveness with the molten lump 20 is selected as the resin sheet 31, the resin sheet melting step for heating and melting the resin sheet 31 includes an adhesion step by bonding the molten lump 20 and the resin sheet 31. (See FIG. 3 (f)).

  Here, in the hair bundle insertion step, as shown in FIGS. 3A and 3B, for example, a hair bundle shaping hole having an inner peripheral shape similar to the outer peripheral shape of the hair bundle 11 implanted in the hair-planted portion 12. The hair transplant base 16 of the toothbrush main body 23 is set in the hair bundle holding jig 33 formed with 32 in a state where the hair transplant hole 15 is matched with the hair bundle shaping hole 32. Thereafter, using a known hair bundle planting device (not shown), each of the hair bundles 11 is inserted into the matched flock hole 15 and the hair bundle shaping hole 32 from above, and the upper end portion of the hair bundle 11 is inserted. Is disposed as one end portion 21 so as to protrude upward from the upper surface of the back surface portion 17.

  In the molten lump forming step, the one end portion 21 of the hair bundle 11 protruding on the back surface portion 17 of the flocked base 16 is preferably heated and melted using the above-described non-contact heat source, as shown in FIG. Then, a molten mass 20 is formed. The hair bundle 11 is brought into close contact with or fixed to the back surface portion 17 of the flocked base 16 by the molten mass 20.

  In the resin sheet installation step, as shown in FIGS. 3D and 3E, the above-described resin sheet 31 is surrounded by the outer peripheral wall portion 29 of the back surface portion 17 while covering the formed molten mass 20. It is installed so as to fit into the back surface filling recess 30.

  In the resin sheet melting step, preferably, the above-described non-contact heat source is used to melt the resin sheet 31 and the molten mass 20 by heating the installed resin sheet 31 from above, as shown in FIG. As the bonding step, the resin sheet 31 is bonded in a state in which the resin sheet 31 is conformed to the unevenness by the upper surface of the molten mass 20.

  It is not always necessary to perform the resin sheet melting step. Even when the resin sheet melting step is omitted and the resin for back molding is injected and filled above the resin sheet 31, the resin for back molding is formed by the resin sheet 31. Since the contact between the flocked hole 15 and the hair bundle 11 is blocked, the back surface 17 of the flocked part 12 from the gap between the flocked hole 15 and the hair bundle 11 (on the flocked base 16 with the flocked hole 15 interposed therebetween) It can be sufficiently prevented from oozing out on the opposite side.

  In the back surface forming step, as shown in FIGS. 3 (g) to 3 (i), the flock base 16 to which the hair bundle 11 is fixed and the resin sheet 31 is attached is set on the hair bundle holding jig 33. In the state, it is positioned at a predetermined position of the mold 18 (see FIG. 3G) of the back surface molding device 27. Thereafter, the resin for back molding is discharged from the injection port (gate) 28 of the mold 18 to fill and fill the space between the back surface portion 17 of the flocked base 16 and the mold 18. When a predetermined time has elapsed and the injected and filled resin is solidified to form the back surface molding layer 19, the mold 18 is removed, and the flocked portion 12 set from the hair bundle holding jig 33 is removed. Thereby, the toothbrush 10 of this embodiment which has the hair transplant part 12 in which the bristle bundle 11 which bundles a bristle was planted is manufactured.

  Moreover, as the 2nd manufacturing method of this invention, the flocked part 12 of the toothbrush 10 respond | corresponds with the some flock hole 15 of the flocked base 16 according to the manufacturing process shown, for example to Fig.4 (a)-(g). It can also be formed using an opening resin sheet 31 ′ having openings 34 formed at the respective positions. 4 (a) to 4 (g), the opening resin sheet 31 ′ in which (a plurality of) openings 34 are formed at positions corresponding to the plurality of the flocking holes 15 of the flocking base 16 is formed into flocked holes. 15 with the opening 34 covering the back surface portion 17 of the flocking base 16 with the opening 34 matched (see FIGS. 4A and 4B), and the one end portion 21 with the back surface portion 17 and A hair bundle insertion step (see FIGS. 4B and 4C) for inserting and arranging the hair bundles 11 in the flock holes 15 of the flocking base 16 so as to protrude from the opening resin sheet 31 ′; A melt lump forming step (see FIG. 4 (d)) in which one end portion 21 of the hair bundle 11 protruding from the back surface portion 17 of the base 16 is heated and melted to form a melt lump 20, an opening resin sheet 31 'and melting Back surface molding by covering the lump 20 and filling the back surface portion 17 of the flocking base 16 with resin. Back molding process to form a 19 and a (FIG. 3 (e) ~ (g) refer). In the melt lump forming step, if the opening resin sheet 31 ′ has adhesiveness with the resin constituting the hair bundle 11, the melt lump 20 and the opening peripheral edge of the opening resin sheet 31 ′ are bonded at the time of forming the melt lump. Can do.

  Here, in the opening resin sheet installation step, as shown in FIGS. 4A and 4B, a hair bundle shaping hole having an inner peripheral shape similar to the outer peripheral shape of the hair bundle 11 implanted in the flocked portion 12. The hair transplant base 16 of the toothbrush main body 23 is set in the hair bundle holding jig 33 formed with 32 in a state where the hair transplant hole 15 is matched with the hair bundle shaping hole 32. Thereafter, the opening resin sheet 31 ′ in which the plurality of openings 34 are formed is surrounded by the outer peripheral wall portion 29 of the back surface portion 17 in a state where the openings 34 are respectively matched with the plurality of flock holes 15 of the flocking base 16. It installs so that it may fit in the recessed part 30 for back filling.

  In the hair bundle insertion step, as shown in FIGS. 4B and 4C, each hair bundle 11 is made to correspond to the opened resin sheet 31 ′ using a known hair bundle planting device (not shown). Are inserted from above into the bristles 15 of the bristles 16, the bristles 15 of the bristles 16, and the bristles forming holes 32 of the bristles holding jig 33, respectively. It arrange | positions in the state protruded upwards from the upper surface of sheet | seat 31 '.

  In the molten lump forming step, preferably, the above-described non-contact heat source is used to heat and melt the one end portion 21 of the hair bundle 11 protruding upward from the back surface portion 17 of the flocked base 16 and the upper surface of the opening resin sheet 31 ′. As a result, as shown in FIG. 4 (d), the molten mass 20 is formed on the back surface portion 17. If the opening resin sheet 31 ′ is a resin having adhesiveness with the hair bundle 11, the molten mass 20 can be bonded to the opening peripheral edge of the opening 34. As a result, the opening resin sheet 31 ′ is bonded to the molten mass 20 as a unit without any gap.

  In the back surface forming step, as shown in FIGS. 4E to 4G, the flocked base in which the hair bundle 11 and the opening resin sheet 31 ′ are bonded together without any gap through the molten mass 20 in the back surface portion 17. 16 is positioned at a predetermined position of the mold 18 (see FIG. 3G) of the back surface forming device 27 while being set in the hair bundle holding jig 33. Thereafter, the resin for back molding is discharged from the injection port (gate) 28 of the mold 18 to fill and fill the space between the back surface portion 17 of the flocked base 16 and the mold 18. When the predetermined time has elapsed and the injected and filled resin is solidified to form the back molding layer 19, the mold 18 is removed and the flocked portion 12 set from the hair bundle holding jig 33 is removed. Thereby, the toothbrush 10 of this embodiment which has the hair transplant part 12 in which the bristle bundle 11 which bundles a bristle was planted is manufactured.

  And according to the manufacturing method of this invention, the toothbrush 10 in which the flocked part 12 was formed is shaping | molding of the flocked part 12 without receiving restrictions about the shape of the flocked hole 15, the magnitude | size, and the space | interval between the hair | bristle bundles 11, for example. It is possible to effectively prevent the resin for back molding that is sometimes injected into the back surface portion 17 from seeping out from the gap between the flock hole 15 and the hair bundle 11 to the surface side.

  That is, according to the present invention, the flocked portion 12 of the toothbrush 10 is interposed between the back surface portion 17 of the flocked base 16 and the back molding layer 19 with the intermediate resin layer 22 in contact with the molten mass 20. Therefore, the gap between the hair bundles 11 respectively installed on the back surface portion 17 of the flocked base 16 and the flock holes 15 via the molten mass 20 is covered by the intermediate resin layer 22 provided on the back surface portion 17. It will be. As a result, the resin for molding the back surface injected into the back surface portion 17 is blocked by the intermediate resin layer 22, so that it does not reach the gap between the flocked hole 15 and the hair bundle 11, and from these gaps to the surface side. It is possible to effectively prevent the resin from seeping out. Further, the seepage of the resin from the gap between the flocked hole 15 and the hair bundle 11 is blocked by the intermediate resin layer 22 interposed between the back surface portion 17 and the back surface molding layer 19 of the flocked base 16. Therefore, there is no restriction on the shape, size, and spacing between hair bundles for preventing exudation, for example, and it is possible to improve the degree of freedom of design and manufacture of the hair transplant part. In addition, since the influence of the heat of the back molding resin injected into the back surface portion 17 is alleviated by the intermediate resin layer 22, the molten mass 20 is deformed by the heat of the back molding resin or melted again. Therefore, it is possible to prevent the bristle of the hair bundle 11 from being cut or pulled out.

  Furthermore, in this invention, since the intermediate resin layer 22 and the molten lump 20 can be made into the adherence state by employ | adopting the resin with adhesiveness as the hair bundle 11 as the intermediate resin layer 22, the hair bundle 11 is Thus, the intermediate resin layer 22 is also effectively supported, whereby it is possible to maintain good alignment of the hairs of the hair bundle 11 and the bristle of the hair bundle 11 is removed during use. It is also possible to prevent it from being cut off. Furthermore, by forming the intermediate resin layer 22 so as to cover the molten mass 20, for example, when the back molding layer 19 is molded using a transparent resin, the molten mass 20 is covered with the colored intermediate resin layer 22. It is also possible to improve the beauty of the toothbrush 10.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the flocked portion is not necessarily formed by the above-described manufacturing process, and can be formed by other various manufacturing methods. In addition, the shape of the plurality of flock holes in the flocked portion and the shape of the plurality of hair bundles to be planted do not necessarily have different types of shapes, and all the flock holes and hair bundles have the same shape. You may have.

It is principal part sectional drawing explaining the structure of the toothbrush which concerns on preferable one Embodiment of this invention. (A) is sectional drawing of the main body shaping | molding die for forming a toothbrush main body, (b) is sectional drawing of a toothbrush main body. (A)-(i) is principal part schematic sectional drawing which illustrates the manufacturing process which forms the flocked part of a toothbrush. (A)-(g) is principal part schematic sectional drawing which illustrates the other manufacturing process which forms the flocked part of a toothbrush. It is sectional drawing which shows typically the flock hole provided in the flock base of a toothbrush.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Toothbrush 11 Hair bundle 12 Flocking part 13 Grasping part 14 Neck part 15 Flocking hole 16 Flocking base 17 Back part 18 of a flocking base Back mold 18 Back molding layer 20 Molten mass 21 One end 22 Intermediate resin layer 23 Toothbrush Main body 26 Main body molding die 29 Outer peripheral wall portion 30 Back surface filling recess 31 Resin sheet 31 ′ Opening resin sheet 32 Hair bundle shaping hole 33 Hair bundle holding jig 34 Opening of opening resin sheet

Claims (4)

A toothbrush having a flocked portion in which a plurality of bristle bundles of bristles are planted,
The flocked portion includes a flocked base having a plurality of flocked holes, the hair bundle that is inserted and arranged in each flocked hole, one end is heated and melted, and a molten lump is formed on the back surface of the flocked base, and A back molding layer formed by filling a resin covering the back surface of the flocked base,
Between the back portion of the flocked base and the back molding layer, an intermediate resin layer is interposed in contact with the molten mass,
The intermediate resin layer is a toothbrush made of a resin having adhesiveness with the molten mass.   The toothbrush according to claim 1, wherein the intermediate resin layer is in contact with the molten mass in a state of covering at least a peripheral portion of the molten mass. A method for producing a toothbrush having a flocked portion in which a plurality of bristles formed by bundling bristles are planted,
A hair bundle inserting step of inserting and arranging each of the hair bundles in the flock holes of the flocked base with one end of the bristles protruding to the back, and one end of the hair bundle protruding to the back of the flocked base A melt lump forming step of forming a molten lump by heating and melting, a step of forming an intermediate resin layer by a hot melt resin coating step or a resin sheet setting step on the back surface portion of the flocked base on which the molten lump is formed, and A back molding step of covering the intermediate resin layer and filling the back part of the flocked base with a resin to form a back molding layer,
The method for manufacturing a toothbrush, wherein the resin sheet installation step includes a resin sheet melting step in which the resin sheet is heated and melted. A method for producing a toothbrush having a flocked portion in which a plurality of bristles formed by bundling bristles are planted,
The flocking part includes a flocking base having a plurality of flocking holes,
Opening resin sheet installation in which an opening resin sheet in which openings corresponding to a plurality of flocking holes formed in the flocking base are formed is installed on the back surface portion of the flocking base in a state in which the opening matches the flocking hole A hair bundle inserting step of inserting and arranging the hair bundle in a state where one end portion is projected from the back surface into the opening and flocking hole of the opening resin sheet, and heating one end portion of the hair bundle projected to the back surface portion A molten lump forming step for forming a molten lump in a state where it is melted and bonded to the opening resin sheet, and a back molding layer is formed by filling the back portion of the flocked base with a resin covering the opening resin sheet and the molten lump. The manufacturing method of a toothbrush including the back surface formation process to form.

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