WO2007148420A1

WO2007148420A1 - Toothbrush, process for producing the same and production apparatus

Info

Publication number: WO2007148420A1
Application number: PCT/JP2006/322378
Authority: WO
Inventors: Toshifumi Takeuchi; Hiroshi Umado
Original assignee: Narutoya Co., Ltd.
Priority date: 2006-06-19
Filing date: 2006-11-09
Publication date: 2007-12-27

Abstract

A toothbrush that realizes not only high implanted bristle tensile strength but also high recyclability, and that is enhanced in sanitary and safety performances, enabling reduction of production cost. There is provided a toothbrush comprising resinous handle (21) and, fixed to head part (22) thereof, brush part (27) formed by gathering of a multiplicity of resin yarns, wherein an adhesive of moldable thermoplastic resin, exhibiting an adherence to the resin yarn forming the brush part (27) and, in a hardened state, becoming a rigid body exhibiting a mechanical strength required for at least the head part (22) of the handle (21), is molded into at least the head part (22) of the handle (21), and wherein by insert molding by the adhesive, the brush part (27) is bonded and fixed to the head part (22) of the handle (21). The adhesive is typically a dimer acid based thermoplastic polyamide resin.

Description

Specification

Toothbrush, manufacturing method and manufacturing apparatus

Technical field

The present invention relates to a popular toothbrush used in general households, a manufacturing method thereof, and a manufacturing apparatus.

Background art

[0002] A conventional toothbrush has a plurality of small yarn bundles configured by bundling greave yarns and is implanted in parallel at predetermined intervals in the same direction on the head portion of the handle made of greaves. It is a so-called flat toothbrush. This flat toothbrush is provided with a plurality of planting holes in which the thread bundle is implanted in the head part of the handle. Each thread bundle is folded in half at the center and inserted into the flock hole, and then bent. The individual yarn bundles are fixed to the head portion by driving a piece of metal such as brass or aluminum slightly larger than the flock hole from above the insertion portion.

[0003] As another method of fixing a yarn bundle, when molding a flat toothbrush handle, a plurality of yarn bundles are inserted into a molding die, and mold grease is injected into the molding die in this state. For example, Patent Documents 1 to 3 describe a method of implanting a plurality of yarn bundles at the head portion at the same time as forming the handle. This method by insert molding is called in-mold method. The root portions of the plurality of yarn bundles are integrated by welding and formed to have a larger diameter than the other portions.

[0004] Patent Document 1: Japanese Patent Laid-Open No. 60-116303

Patent Document 2: Japanese Patent Laid-Open No. 61-268208

Patent Document 3: Japanese Patent Laid-Open No. 2-111305

[0005] In addition, a cylindrical toothbrush with a 360-degree shape and no directionality, a roller-shaped toothbrush, and an angle of 1 to 1.3 degrees inward when planting a thread bundle, There are a wide variety of products on the market that reflect the current health orientation, such as flat toothbrushes with a higher density of grease yarn and flat toothbrushes with the tip of the greave yarn in the yarn bundle tapered by a chemical.

[0006] Among these popular type toothbrushes, flat toothbrushes, in particular, a structure for fixing a head portion of a handle and a yarn bundle Let's examine the problem.

[0007] In the flat toothbrush, both the yarn bundle and the handle, which are the main constituent parts, are made of grease. Therefore, recycling the resin is an important issue. A flat toothbrush that uses a metal piece such as brass or aluminum to fix the thread bundle in the flock hole of the head part, it is necessary to separate the metal piece that secures the thread bundle when collecting the grease. It is necessary to pull out all the yarn bundles from the head part. For this reason, the present situation is that the recovery of the grease of the flat toothbrush of this structure does not proceed slowly.

[0008] In Japan, tap water used for brushing teeth is soft water (acidic water) with low lime content. The metal piece used to hold the bundle of popular flat toothbrushes, especially brass, is very sensitive to acid and very corrosive. Use of such a metal in the oral cavity is not preferable in terms of health and safety, and it is necessary to overcome this. In addition to this, it is necessary to consider the accident of swallowing infants.

[0009] There are flat toothbrushes that change the color of the front, middle, rear, and thread bundles to practice tooth brushing for infants. When manufacturing this flat toothbrush, there exists a problem which the number of processes increases by the number of colors. For example, when planting 10 white yarn bundles, 10 yellow yarn bundles, and 10 blue yarn bundles into 30 flocking holes, complete the implantation of the white yarn bundle for all batches of products, and then replace the yarn bundle. Then, work with yellow and blue yarn bundles. Due to such an increase in the number of processes, flat toothbrushes with different colors of yarn bundles are expensive and have a problem in their spread.

[0010] For flocking holes, a diameter of 1.7 mm is the mainstream, and for the depth, 3.5 mm is the mainstream to ensure JIS standard 8NZcm ² (also the ISO standard), which is the flocking tensile strength. Yes. As a result, the thickness of the head of the handle is required to be at least 5 mm, and there are many accidents that damage the oral cavity due to poor operability in the oral cavity.

[0011] In this way, the flat toothbrushes that are commonly used in the general public are not recyclable and are not completely sanitary and safe when focusing on the thread bundle fixing structure. It is difficult to reduce the cost further. The cause of these problems is the use of metal pieces to secure the yarn bundle.

[0012] On the other hand, a flat toothbrush in which the yarn bundle is fixed to the head portion of the handle by the in-mold method does not cause the yarn bundle italic problem and the hygiene problem. On the other hand, the thread bundle There is a fatal problem as a flat toothbrush that the constant strength is low.

[0013] That is, the greave yarn forming the bundle of flat toothbrushes has a nylon force. On the other hand, the pattern has PP (polypropylene) or PET (polyethylene terephthalate) force. Since the two are not attached, the yarn bundle fixed to the head portion of the pattern by molding is only mechanically fixed to the head portion. Specifically, the yarn bundle is fixed to the head portion of the handle by an anchor effect in which the base end portion of the yarn bundle is united by welding and the welded portion is formed to have a larger diameter than other portions. It ’s just that. For this reason, the flocking bow I tension strength is extremely low compared to the case of fixing with a metal piece, and it is difficult to satisfy the standard value of flocking tensile strength specified by JIS and ISO.

[0014] For this reason, most flat toothbrushes manufactured by the in-mold method are on the market!

Disclosure of the invention

Problems to be solved by the invention

[0015] The present invention is intended to solve such problems of conventional toothbrushes, and has high flocking tensile strength, good recyclability, and high hygiene and safety performance. Means for solving the problems of providing a toothbrush that can be reduced in cost, and a method and apparatus for manufacturing the toothbrush

[0016] In order to achieve the above object, the present inventor changed the way of thinking, uses an adhesive as a mold resin used in the in-mold method, and the brush part at the same time as the mold formation on the head part of the handle. It was planned to fix by gluing. Then, the brush part is firmly fixed to the head part of the handle by adhesion. The properties required for the resin are first to show adhesion to the greave yarns constituting the brush part, and secondly to the mechanical strength (hardness required for the handle in the cured state. And third, it is safe to use in the oral cavity.

[0017] The present inventors diligently searched for an adhesive-based resin having these characteristics. As a result, we found a dimer acid-based thermoplastic polyamide resin as one of the resins. In addition to satisfying the above three requirements, this resin is in a fluid state at a relatively low temperature due to its low soft spot, and the force is low in viscosity in the fluid state and has good fluidity. It has the feature that the toothbrush handle can be molded even without it. Such adhesives If the toothbrush handle is molded by using a resin, and the brush part is fixed to the head part of the handle by insert molding, the thread bundle is firmly fixed to the head part without driving metal pieces. .

[0018] The toothbrush of the present invention has been completed on the basis of the knowledge that is earned, and a brush portion formed by collecting a large number of resin yarns is fixed to a head portion of a handle made of resin. The toothbrush is made of a thermoplastic resin that can be molded, exhibits adhesiveness to the resin thread that forms the brush part, and is required for at least the head part of the handle in the cured state. A configuration is adopted in which at least the head portion of the handle is molded by an adhesive that becomes a rigid body satisfying the strength, and the brush portion is bonded and fixed to the head portion of the handle by insert molding using the adhesive.

[0019] Further, according to the toothbrush manufacturing method of the present invention, a plurality of small yarn bundles configured by bundling greave yarns are planted at predetermined intervals on the head portion of the handle made of greaves in the same direction. A method for manufacturing a flat tooth brush, which has a recess corresponding to the shape of a handle of a flat tooth brush to be manufactured, and is provided with a through hole into which a plurality of yarn bundles are inserted in a portion corresponding to the head portion of the handle. The thread bundle inserting step of inserting the thread bundle into the through hole of the formed mold and the adhesive thread forming the thread bundle of the flat toothbrush are adhesive, and in a cured state, at least on the head portion of the handle An adhesive, which is a rigid body that satisfies the required mechanical strength, was injected into the recess with the yarn bundle inserted into the through hole of the mold, and injected into the recess of the mold. Toothbrush removal that takes out the molded product from the concave part together with the yarn bundle after the resin is cured And a to process.

[0020] Further, in the toothbrush manufacturing apparatus of the present invention, a plurality of small yarn bundles configured by bundling greave yarns are planted at predetermined intervals on the head portion of the handle made of greaves in the same direction. A flat tooth brush manufacturing apparatus having a recess corresponding to the shape of a handle of a flat tooth brush to be manufactured and provided with a through hole into which a plurality of yarn bundles are inserted in a portion corresponding to the head portion of the handle. A plurality of forming dies in order to convey the plurality of forming dies to the yarn bundle supply position, the resin injection position, and the toothbrush take-out position, and the forming dies provided at the yarn bundle supply position and conveyed to the supply position. A yarn bundle supply mechanism that inserts the yarn bundle into the through-hole of the wire and cuts it to a predetermined length; and a molding provided in the concave portion of the mold that is provided at the grease injection position and conveyed to the supply position. A resin injection device for injecting the resin, and a product extraction device for removing the resin molded product from the recess of the molding die provided at the toothbrush extraction position and transported to the extraction position.

In the toothbrush of the present invention, at least the head portion of the handle is molded, and at the same time as the forming, the brush portion is fixed to the head portion. The mold resin used here is an adhesive that exhibits adhesiveness to the resin thread forming the brush part and hardens to a rigid body having the mechanical strength required for at least the head part of the handle. . For this reason, the brush part must be adhered and fixed to the head part. Therefore, while maintaining the advantages of the flat tooth brush produced by the conventional in-mold method, the low fixing strength of the brush portion, which is the drawback thereof, is solved.

In the toothbrush of the present invention, an adhesive that bonds and fixes the brush part to the head part of the handle is important. The adhesive is a so-called hot-mel adhesive, and examples of the type of resin include polyolefin, EVA, polyester, polyurethane, and polyamide. From the viewpoint of physical properties, it is preferable that the point of moldability is a molding temperature of 100 to 240 ° C., a molding pressure at the molding temperature of 400 kgfZcm ² or less, and low temperature and low pressure molding is possible.

[0023] A particularly preferred adhesive is the aforementioned dimer acid-based thermoplastic polyamide resin. Its molding temperature (softening point range) is as low as 100 to 220 ° C, and its viscosity is very low at 50 OOOmPa.s or less at 230 ° C, and it has excellent fluidity during molding. This adhesive also conforms to the “Standards for Food Sanitation Law, Foods, Additives, etc. (Ministry of Health and Welfare Notification No. 370 of 1959)” and there is no safety problem. The typical chemical structure of dimer acid-based thermoplastic polyamide resin is shown in Formula 1.

[0024] [Chemical 1] Dimer acid Diamiso

n HOOC— D— COOH + n H ₂ N— R— NH,

-H

n

[0025] The present invention is particularly effective for a conventional flat toothbrush that can obtain sufficient flocking tensile strength only by fixing with a metal piece. 360 degree toothbrush (for example, Japanese Patent Application No. 20 This is also effective for spiral toothbrushes (patented by No. 05-355385).

[0026] In the flat toothbrush of the present invention, a plurality of small yarn bundles configured by bundling greave yarns are planted at predetermined intervals in the same direction on the head portion of the handle made of greaves. A plurality of yarn bundles are bonded and fixed to the head portion of the handle by insert molding using the adhesive. This ensures high fixing strength equivalent to that without using metal pieces.

[0027] In the flat toothbrush of the present invention, it is preferable that the roots of the plurality of yarn bundles are integrated by welding and formed thicker than the other portions. As a result, the plurality of yarn bundles are firmly fixed to the head portion by adhesion and mechanical fixing by the anchor effect. Further, the yarn bundle inserted into the through hole of the mold is held by the mold by the large diameter welded portion.

[0028] The handle in the toothbrush of the present invention can be molded entirely with the adhesive. In that case, the mechanical strength (hardness, rigidity, etc.) required for the handle is sufficient. There is a risk of shortage. For this reason, a hybrid structure in which only the head portion of the handle is molded with the above-mentioned adhesive and the other portion is made of other resin suitable for forming the handle (for example, PP, PET or AS) is desirable. It is.

[0029] If the head part of the handle is insert-molded with the above-mentioned adhesive and the other part is made of other resin such as PP, PET or AS, both must be manufactured separately and mechanically joined later. However, the other part can be integrated with the head part together with the brush part by insert molding with the adhesive. According to the latter configuration, the work for integrating the two is simplified, and the cost can be further reduced.

[0030] In the case of the latter configuration, the head portion and other portions are not necessarily good in adhesion, and may be hardly adhered depending on the combination of the types of grease. For this reason, it is preferable to provide a mechanical coupling part that exhibits an anchor effect with respect to the head part at the tip part of the other part of the handle. According to this configuration, even when the head portion and other portions are not bonded, both are securely coupled and fixed.

[0031] In the toothbrush manufacturing method of the present invention, the threadbrush insertion process, the grease injection process, and the toothbrush extraction process are sequentially performed. In the toothbrush manufacturing apparatus of the present invention, , Mold in order of yarn bundle supply position, grease injection position and toothbrush removal position The toothbrush is continuously manufactured by moving to.

[0032] The yarn bundle supply mechanism provided at the yarn bundle supply position of the manufacturing apparatus includes a heater that welds the end portion of the yarn bundle inserted into the through-hole of the forming die to have a larger diameter than the other portions by welding the recess side force. The configuration to equip is preferred. The advantages of forming a large-diameter weld with a heater are as described above.

[0033] This yarn bundle supply mechanism performs an approaching and separating operation with respect to the forming die in a state where the yarn bundle is inserted into the through hole corresponding to the through hole of the forming die on the upstream side of the forming die in the yarn bundle inserting direction. It is preferable to provide a movable yarn bundle guide that contacts the mold so that the corresponding through-holes are continuous in the approaching state and moves away from the yarn bundle cutting position in the separated state. With this yarn bundle guide, it is possible to automatically and reliably insert the yarn bundle into the through hole of the mold.

[0034] It is also reasonable for the yarn bundle supply mechanism to insert the yarn bundle from below into a through hole provided in a portion corresponding to the head portion of the handle of the mold. In that case, the yarn bundle guide is moved up and down below the forming die in a state where the yarn bundle is passed through the through hole corresponding to the opening hole of the forming die, so that the corresponding through holes are continuous at the rising limit. It is configured to come down below the yarn bundle cutting position at the lower limit.

[0035] The mold resin used in the resin injection device is made of a thermoplastic resin that can be molded, and exhibits adhesiveness to the resin thread that forms the thread bundle of the flat toothbrush. It is an adhesive that becomes a rigid body that satisfies the mechanical strength required for at least the head part of the handle in this state, and a dimer acid-based thermoplastic polyamide resin is preferred as the adhesive.

The invention's effect

[0036] Since the toothbrush of the present invention does not require the use of a metal piece having a brass equivalent force to fix the yarn bundle, it does not cause swallowing accidents due to falling off or corrosion, and no hygiene problems. . By not using a metal piece, the entire toothbrush becomes a grease and can be easily reused.

[0037] In the conventional flat toothbrush, the depth of the flock hole in the head portion must be 3.5 mm or more because it is in the industry standard of bow I tension strength, so the thickness of the head portion must be 5 mm or more. When Is done. For this reason, the brush part including the head part cannot be made compact in structure, and there are problems such as poor operability in the oral cavity, accidents, and difficulty in brushing the back face of the last molar. With respect to this problem, in the case of the toothbrush of the present invention, particularly the flat toothbrush, the thickness of the head portion can be suppressed while ensuring the brush length, and the above-mentioned problem can be solved.

[0038] Since the flat toothbrush of the present invention is not restricted by the metal piece, the angle can be easily given to the greave yarn in the yarn bundle, and the maximum angle is from about 1.3 degrees to about 5 degrees. Can be bigger. It is possible to mix two or more types of grease threads with different diameters and tip shapes into the yarn bundle, and the plaque removal effect can be enhanced compared to conventional popular flat toothbrushes. In other words, the thick greaves in the bundle are effective for removing plaque between teeth, the dense greaves are effective for gingival massage, and the sharp tapered hairs are used for periodontal pockets, etc. It is effective for removing plaque in a very small space.

[0039] With a conventional flat toothbrush, it is possible to easily give a color change for each bundle, which was impossible from the viewpoint of flocking cost, and it is easier for children to instruct tooth brushing. This makes it easier to learn about brushing teeth. In addition, since the number of the grease threads in a bundle can be freely adjusted, unlike the conventional flat toothbrush, the shape and size of the bundle can be easily changed. For this reason, a brush part with a very high density and a brush part with a low density can be easily provided.

[0040] As described above, the toothbrush of the present invention can increase the plaque removal ability while reducing the manufacturing cost, and has excellent characteristics in terms of resource reuse, and can be easily recycled. it can

[0041] Further, the toothbrush manufacturing method and manufacturing apparatus of the present invention can continuously and efficiently manufacture the above-described high-quality and economical flat toothbrush, and exhibit a great effect in reducing the manufacturing cost. To do.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a toothbrush showing a first embodiment of the present invention, and FIGS. 2 to 10 are explanatory views of a manufacturing apparatus for the toothbrush.

The toothbrush of the first embodiment is a flat toothbrush 20 as shown in FIG. Flat toothbrush 20 Consists of a handle 21 made of greaves and a brush portion 27 provided at the tip of the handle 21. The handle 21 includes a flat plate-like head portion 22 provided with the brush portion 21 and a square bar-like grip portion 24 extending rearward from the head portion 22.

[0044] The head portion 22 is made of a dimer acid-based thermoplastic polyamide resin, and integrally has a rectangular bar-like connecting portion 23 behind the flat plate portion. The grip portion 24 is different from the fat constituting the head portion 22, specifically, PP or PET, which is usually used as a handle of a toothbrush, and has a round bar-like connecting portion 25 with a thin tip. Thus, it is embedded and connected to a rectangular bar-like connecting portion 23 of the head portion 22. The connecting portion 25 of the grip portion 24 is provided with a plurality of diametrical through-holes 26 into which dimer acid-based thermoplastic polyamide resin flows for mechanical connection with the head portion 22. .

[0045] The brush portion 27 of the flat tooth brush 20 is an aggregate of a large number of yarn bundles 28 facing in the same direction, and the large number of yarn bundles 28 are implanted on the surface of the square plate portion of the head portion 22 at predetermined intervals. Yes. Each yarn bundle 28 is formed by bundling a predetermined number of nylon yarns, and a base end portion 29 embedded in the head portion 22 is integrally formed by welding and is formed to have a larger diameter than other portions. Yes.

[0046] The embedded portion of the yarn bundle 28 is firmly bonded to the dimer acid-based thermoplastic polyamide resin forming the head portion 22 of the handle 21, and the large-diameter weld portion 29 of the yarn bundle 28. Due to the anchor effect, the head portion 22 of the handle 21 is mechanically coupled and fixed.

FIG. 2 is a plan view (a) and an elevation view (b) showing the overall structure of the toothbrush manufacturing apparatus of the first embodiment, and FIGS. 3 to 8 show the detailed structure of each part of the manufacturing apparatus. It is a perspective view shown in order.

[0048] As shown in FIG. 2, the toothbrush manufacturing apparatus includes a forming mold conveying mechanism 9 composed of a horizontal turntable. A plurality of molding lower molds 6 are radially attached to the upper surface of the transport mechanism 9. The conveyance mechanism 9 intermittently rotates the turntable to convey the molding lower mold 6 in order to the yarn bundle supply position A, the resin injection position B, and the toothbrush take-out position C.

[0049] A concave portion 6a having a shape corresponding to the portion of the handle 21 of the flat toothbrush 20 to be manufactured is provided on the upper surface of the lower mold 6 for molding. Of the recess 6a, the part corresponding to the head part 22 of the lower mold 6 is exposed under the turntable, and the bottom of that part is shown in detail in FIG. As shown, a plurality of through holes 6b into which the yarn bundle la is inserted are provided corresponding to the respective positions of the plurality of yarn bundles 28 constituting the brush portion 27.

[0050] Below the yarn bundle supply position A of the turntable transport mechanism 9, a supply mechanism for the yarn bundle la is arranged. The supply mechanism of the yarn bundle la includes a plurality of bobbins 1 around which the yarn bundle la is wound. As shown in Fig. 3, each bobbin 1 is wound with a bundle of yarns la at a plurality of axial positions, and is aligned with the yarn bundle supply position A via the sensor 2 in the aligned state. Supply to comb 4. A movable thread bundle guide 5 is provided on the alignment comb 4.

[0051] As shown in FIG. 4, the alignment comb 4 is a chuck for fixing a predetermined number of yarn bundles la used for manufacturing the toothbrush while being aligned from both sides, and is driven up and down by the vertical robot 3. The 4a in FIG. 1 (b) represents the ascent limit of the comb 4 for alignment.

As shown in FIG. 5, the yarn bundle guide 5 aligns a predetermined number of yarn bundles la used for manufacturing the toothbrush at positions corresponding to the plurality of yarn bundles 28 constituting the brush portion 27. For this reason, the yarn bundle guide 5 is provided with a plurality of through holes through which a predetermined number of yarn bundles la penetrate at the same time so as to correspond to the plurality of yarn bundles 28 constituting the brush portion 27. This yarn bundle guide 5 is a lifting type, and in the ascending limit shown by 5a in FIG. Located below the cutter 8 that cuts the bundle la. Then, in the ascending limit that is in close contact with the lower surface of the molding lower mold 6, the through-hole forces are formed in the plurality of through-holes 6 b provided on the bottom surface of the portion corresponding to the head portion 22 of the recess 6 a of the molding lower mold 6. It will be in the state where the corresponding thing continues.

A heater 7 is provided above the yarn bundle supply position A of the turntable transport mechanism 9. As shown in FIG. 7, the heater 7 is positioned directly above the portion corresponding to the head portion 22 of the recess 9a of the lower mold 9 for molding. This heater 7 is also a liftable type, and is lowered from the upper retracted position to the lower limit indicated by 7a in FIG. 1 (b), and hot air is blown onto the portion corresponding to the head portion 22 of the lower mold recess 9a. Then, the upper end portion of the yarn bundle la pierced downwardly into the plurality of through holes 6b on the bottom surface is welded to form a large-diameter weld portion 29.

A resin injection device 11 is provided above the resin injection position B of the turntable transport mechanism 9. The resin injection device 11 is composed of an upper molding die 10 stacked on a lower molding die 6. Inlet 10b force Dimer acid-based heat softened in the recess 6a of the lower mold 6 and particularly in the portion corresponding to the head portion 22 of the handle 21 of the flat toothbrush 20 to be manufactured (including the connecting portion 23) Inject plastic polyamide resin. For this purpose, the molding upper die 10 closes the portion corresponding to the head portion 22 of the handle 21 of the flat toothbrush 20 to be manufactured in the recess 6a of the lower die 6 (including the connecting portion 23). ing.

[0055] Above the toothbrush take-out position C of the turntable type transport mechanism 9, a take-out device 12 for taking out the flat toothbrush 20 that has been molded and produced in the recess 6a of the lower mold 6 from the recess 6a is provided.

[0056] Next, a method for manufacturing the flat toothbrush 20 using the above-described toothbrush manufacturing apparatus will be described.

[0057] Before operating the toothbrush production apparatus, the yarn bundle la is pulled out from the reel 1 in the supply mechanism of the yarn bundle la, passed through the lifting and lowering alignment comb 4, and further through each of the through holes of the lifting and lowering yarn bundle guide 5. Pass through 5b (see Figure 4 and Figure 5). The upper end of the yarn bundle la is above the yarn bundle guide 5 and more specifically at the level of the cutting position by the cutter 7 below the lower mold 6. The alignment comb 4 grips the yarn bundle la from both sides so that the yarn bundle la is not lowered.

[0058] When the yarn bundle la is thus set, the toothbrush manufacturing apparatus is operated. Then, the yarn bundle guide 5 first rises to the upper limit and comes into close contact with the lower surface of the lower mold 6. Even in this state, the tip of the yarn bundle la is in each through-hole 5b of the yarn bundle guide 5. When the yarn bundle guide 5 is in close contact with the lower surface of the lower die 6, the corresponding through holes 5b, 6b are continuous with each other. Next, the alignment comb 4 rises while holding the yarn bundle la. As a result, the predetermined number of yarn bundles la rise simultaneously and are pierced through the continuous through holes 5b and 6b and into the plurality of through holes 6b of the lower mold recess 6a. This state is shown in FIG. The feed amount of the yarn bundle la is detected by the sensor 2, and the feed amount of the yarn bundle la is managed by using the output.

[0059] Fig. 7 (a) shows a case where the yarn bundle la is fed out to such an extent that each tip portion of the predetermined number of yarn bundles la slightly protrudes from the plurality of through holes 6b of the lower mold recess 6a into the recess 6a. As described above, the heater 7 provided immediately above the portion corresponding to the head portion 22 of the lower mold recess 6a is lowered, and hot air is blown to the portion corresponding to the head portion 22 of the lower mold recess 6a. As a result, as shown in FIG. 7 (b), the tip protruding portion of the yarn bundle la pierced through the plurality of through holes 6b of the lower mold recess 6a is melted. A plurality of cocoon yarns are fused and integrated by welding. At the same time, a welded portion 29 having a larger diameter than the other portions is formed at the tip protruding portion.

When the predetermined number of yarn bundles la has been welded, the yarn bundle la is cut by the cutter 8 below the lower mold 6. The predetermined number of yarn bundles la remaining on the lower die 6 are prevented from falling off the lower die 6 by the large-diameter welded portion 29 and are continuously held by the lower die 6. The cutting position by the cutter 8 is determined based on the bristle length of the brush portion 27 of the flat toothbrush 20 to be manufactured. Thus, the yarn bundle la remaining in the lower mold 6 becomes the yarn bundle 28 in the brush portion 27 of the flat toothbrush 20 to be manufactured.

[0061] When the yarn bundle 28 is set on the lower die 6, the lower die 6 moves from the yarn bundle supply position A to the resin injection position B. As shown in FIG. 8, the grip portion 24 of the handle 21 is inserted into the recess 6 a of the lower mold 6, particularly, the portion corresponding to the handle 21 of the flat toothbrush 20 to be manufactured, at the sallow injection position B. Thereafter, the upper mold 10 is stacked on the front part of the lower mold 6 to close the lower mold recess 6a. Specifically, in particular, the portion corresponding to the head portion 22 (including the connecting portion 23) of the handle 21 of the flat toothbrush 20 to be manufactured is completely closed in the lower mold recess 6a. Then, the dimer acid-based thermoplastic polyamide resin calorically heated in the soft state of the nozzle of the resin injection device 11 is injected into the resin injection hole 10a of the upper mold 10 and into the lower mold recess 6a. .

[0062] The dimer acid-based thermoplastic polyamide resin spreads completely to a predetermined region in the lower mold recess 6a by low pressure injection with high fluidity. The insertion of the grip portion 24 into the lower mold recess 6a and the setting of the upper mold 10 for molding may be performed between the yarn bundle supply position A and the resin injection position B. I like the saddles that have no obstacles in terms of schedule. In sachet injection, a certain amount is injected accurately by gram control.

[0063] When the injection of the grease into the lower mold recess 6a is completed, the lower mold 6 moves to the grease injection position B force and the toothbrush extraction position C. When the lower die 6 moves to the toothbrush take-out position C, the injected resin is hardened and forms the head portion 22 (including the connecting portion 23) of the flat toothbrush 20 to be manufactured. Thus, the flat toothbrush 20 to be manufactured is completed.

[0064] The completed flat toothbrush 20 is taken out from the recess 6a of the lower mold 6 by the take-out device 12. The take-out device 12 has a structure in which the handle 21 of the completed flat toothbrush 20 is taken out from the recess 6a by pushing it with a pin at two or three places. For this removal, the upper mold 10 is removed in advance. This removal is performed between the grease injection position B and the toothbrush removal position. It may be performed in between or at the toothbrush take-out position C. Force to be applied between the grease injection position B and the toothbrush extraction position C From the viewpoint of time schedule, there is no obstacle.

[0065] The features of the flat toothbrush 20 thus completed are as follows. The flat toothbrush 20 does not use a metal piece to fix a predetermined number of yarn bundles 28 to the head portion 22 of the handle 21. For this reason, there are no sanitary and safety problems caused by corrosion or dropping of metal pieces. Instead of using a metal piece, it uses molding instead and does not require high-pressure injection due to the good fluidity of the resin. For this reason, the manufacturing equipment and the manufacturing method are simple, and the manufacturing cost can be reduced. In addition, it is easy to recycle because it is all-resin.

[0066] Furthermore, by not using a metal piece driving, the thickness of the head 22 can be reduced, the operability in the oral cavity is good, and accidents such as damaging the oral cavity are greatly reduced. Further, brushing on the back surface of the last molar is facilitated.

[0067] A dimer acid-based thermoplastic polyamide resin is used to fix the yarn bundle 28 to the head portion 22 of the handle 21. This resin exhibits adhesiveness to the nylon-based resin thread constituting the yarn bundle 28, and adheres and fixes the yarn bundle 28. In addition, a large-diameter welded portion 29 is formed in the embedded portion of the yarn bundle 28, and mechanical fixing is also performed by an anchor effect. For this reason, the yarn bundle 28 is firmly fixed to the head portion 22 even though no metal piece is used, and the industrial standard regarding the fixing strength can be easily satisfied.

[0068] The handle 21 of the flat toothbrush 20 includes a head portion 22 and a grip portion 24, and only the head portion 22 is molded by a dimer monoacid-based thermoplastic polyamide resin. For this reason, the amount of sallow is small and the injection time is shortened. In addition, since the injection space is narrow, the molded part having a low risk of bubbles and the like is of high quality.

[0069] The dimer acid-based thermoplastic polyamide resin constituting the head portion 22 is slightly inferior in rigidity or the like to PP or PET, which are general constituent materials of the handle 21. The handle 21 is separated into the head part 22 and the grip part 24, and the grip part 24 is made of PP, PET, etc. It is.

[0070] The dimer acid-based thermoplastic polyamide resin constituting the head portion 22 and PP or PET constituting the grip portion 24 do not necessarily have good adhesion. However, the head part 22 A rod-like connecting part 23 is formed, and a narrow rod-like connecting part 25 is also formed in the grip part 24, and insert molding is performed by inserting the connecting part 25 when the connecting part 23 is molded. The grip 24 is connected and fixed. In addition, the connecting portion 25 of the grip portion 24 is provided with a through-hole 26 in the diameter direction through which mold resin penetrates. Since mold resin penetrates into the mold during molding, both are mechanically connected. Fixed. Therefore, the joint fixing strength between the two is sufficiently high.

[0071] When the yarn bundle 28 is fixed to the head 22 of the handle 21 by insert molding, if the yarn bundle 28 is fixed in a tapered shape, the grease thread constituting the yarn bundle 20 is, for example, 5 degrees. A large inward tilt angle can be easily set.

[0072] A predetermined number of yarn bundles 28 constituting the brush unit 27 are supplied in units of yarn bundles at the time of manufacture. Therefore, it is possible to freely color these yarn bundles 28.

FIG. 9 is a perspective view showing another example of the handle portion of the handle. In the above-described embodiment, the grip portion 24 of the handle 21 has a square bar shape. As shown in FIG. 8, the handle portion 24 can be a round bar shape or can be thickened in the middle of the longitudinal direction. Various shapes can be selected and the shape is not limited.

FIG. 10 is a perspective view of a toothbrush showing a second embodiment of the present invention, and FIG. 11 is a plan view (a) and an elevation view (b) showing the overall configuration of the toothbrush manufacturing apparatus.

[0075] The toothbrush of the second embodiment is a flat toothbrush 20 similar to the toothbrush of the first embodiment. The flat toothbrush 20 is different from the toothbrush of the first embodiment in that the entire handle 21 is molded by a dimer acid-based thermoplastic polyamide resin. Other configurations are practically the same as the toothbrush of the first embodiment.

As shown in FIG. 10, the toothbrush manufacturing apparatus for manufacturing the flat toothbrush 20 of the second embodiment is different from the above-described toothbrush manufacturing apparatus in the transport mechanism 9 for transporting the lower mold 6. . The conveyance mechanism 9 here is a conveyor system that conveys a plurality of lower molding dies 6 linearly in order to the yarn bundle supply position A, the resin injection position B, and the toothbrush take-out position C.

[0077] In order to inject the dimer acid-based thermoplastic polyamide resin into the entire recess 6a formed on the upper surface of the lower mold 6 corresponding to the shape of the handle 21 of the flat toothbrush 20, The upper mold 10 is overlaid on the lower mold 6 so as to cover the entire recess. Thread bundle supply position A The supply mechanism for the yarn bundle la is provided below the heater 7, the heater 7 is provided above, the grease injection device 11 above the grease injection position B, and the toothbrush extraction device above the toothbrush extraction position C. Other configurations such as 12 are substantially the same as the above-described toothbrush manufacturing apparatus shown in FIGS. In FIG. 11 (b), 4a represents the lower limit of the liftable forming comb 4, and 5a represents the lower limit of the liftable yarn bundle guide 5.

FIG. 12 is a perspective view of a toothbrush showing a third embodiment of the present invention, and a perspective view showing main manufacturing steps of the toothbrush of FIG.

The toothbrush of the third embodiment is a 360-degree toothbrush having a spiral cylindrical brush portion 27 at the tip head portion of the handle 21 (for example, a spiral tooth brush patented by Japanese Patent Application No. 2005-355385). Handle 21 can be made of PP or PET, while brush 27 can be made of nylon. As stated repeatedly, the adhesion between them is not always good. For this reason, a dimer acid-based thermoplastic polyamide resin can be used for this bonding, which is the third embodiment.

Specifically, a thin rod-like connecting portion having an outer diameter that is sufficiently smaller than the inner diameter of the central hole of the cylindrical brush portion 27 is provided at the tip portion of the handle 21. The connecting portion is provided with a plurality of through holes in the diameter direction for mechanical coupling. With this connecting portion inserted into the central hole of the cylindrical brush portion 27, a dimer acid-based thermoplastic polyamide resin is injected into the central hole of the cylindrical brush portion 27. The injected dimer acid-based thermoplastic polyamide resin is filled between the cylindrical brush portion 27 and the connecting rod of the handle 21, and is also filled into a plurality of through holes provided in the connecting rod. The hardened resin becomes the head portion of the handle 21, and is mechanically strongly bonded and fixed to the connecting portion of the handle 21, and is firmly bonded and fixed to the cylindrical brush 2 by adhesion.

[0081] By force, a 360-degree toothbrush in which the tip head portion of the handle 21 and the spiral cylindrical brush portion 27 are firmly coupled and fixed is manufactured.

FIG. 14 is a perspective view of a toothbrush showing a fourth embodiment of the present invention.

The toothbrush of the fourth embodiment is a replacement brush head in an electric toothbrush or the like. In this brush head, the handle 21 is composed of a head portion 22 and a connecting portion 23 extending rearward thereof, and the brush portion 27 is bonded and fixed to the head portion 22. The handle 21 is molded from dimer acid-based thermoplastic polyamide resin, and the brush 27 is As in the embodiment, the head portion 22 is fixed by adhesion and mechanical bonding by insert molding.

[0084] In the case of a replaceable brush head in an electric toothbrush, the connecting portion 23 of the handle 21 is connected to the driving portion of the electric toothbrush. If a portion corresponding to the grip portion 24 of the handle 21 is inserted into the connecting portion 23 of the handle 21 and mechanically fixed, a head replacement type flat toothbrush is formed.

FIGS. 15A to 15D are front views of a brush portion of a flat toothbrush showing still another embodiment of the present invention.

[0086] In the above-described embodiment, the toothbrush is the flat toothbrush 20, and the brush part 27 has a plurality of thread bundles 28 formed by bundling greave threads in the shape of a thin cylinder, the same as the head part 22 of the handle 21. It is constructed by planting in the direction. On the other hand, in the embodiment shown in FIG. 15 (a), the brush portion 27 is an integral type in which the grease yarns are densely packed. In the embodiment shown in FIGS. 15 (b) and 15 (c), the brush portion 27 is formed by bending or straightening a horizontally long yarn bundle 28 ′ in which the resin threads are arranged side by side like a fence and fixed on one end side. It is constructed by planting the head part 22 of the handle 21 as it is. Further, in the embodiment shown in FIG. 15 (d), the brush portion 27 has a configuration in which a horizontally long yarn bundle 28 and a thin and cylindrical yarn bundle 28 are mixed.

[0087] Also in these embodiments, at least the head portion 22 of the handle 21 is molded by a dimer acid-based thermoplastic polyamide resin, and the brush portion 27 is insert-molded as in the other embodiments. It is fixed to the head portion 22 by adhesion by means of mechanical bonding and mechanical bonding by the welded portion. In the present invention in which the yarn bundle is not fixed by driving a metal piece, it is easy to manufacture a toothbrush having such a deformed brush portion 27. That is, it is possible to form these irregular-shaped brush portions only by changing the supply mode of the yarn bundle and the resin yarn to the forming die.

Brief Description of Drawings

FIG. 1 is a perspective view of a toothbrush showing a first embodiment of the present invention.

[FIG. 2] (a) and (b) are a plan view and an elevation view showing the overall structure of the toothbrush manufacturing apparatus of the first embodiment.

FIG. 3 is a perspective view showing the detailed structure of each part of the manufacturing apparatus in the order of steps, showing a reel.

FIG. 4 is a perspective view showing the detailed structure of each part of the manufacturing apparatus in the order of steps, showing an alignment comb. 圆 5] A perspective view showing the detailed structure of each part of the manufacturing apparatus in the order of the process, showing a yarn bundle guide.

圆 6] A perspective view showing the detailed structure of each part of the manufacturing apparatus in the order of processes, showing the lower mold for molding. 圆 7] (a) and (b) are perspective views showing the detailed structure of each part of the manufacturing apparatus in the order of the process. Yes, shows lower mold and heater for molding.

[8] FIG. 8 is a perspective view showing the detailed structure of each part of the manufacturing apparatus in the order of steps, showing a lower mold for molding, an upper mold, and a grease injection device.

FIG. 9 is a perspective view showing another example of a grip portion of a handle.

圆 10] A perspective view of a toothbrush showing a second embodiment of the present invention.

[FIG. 11] (a) and (b) are a plan view and an elevation view showing the entire configuration of the toothbrush manufacturing apparatus.

[12] FIG. 12 is a perspective view of a toothbrush showing a third embodiment of the present invention.

[13] FIG. 13 is a perspective view showing the main manufacturing process of the toothbrush.

圆 14] A perspective view of a toothbrush showing a fourth embodiment of the present invention.

[FIG. 15] (a) to (d) are front views of a brush portion of a flat toothbrush showing still another embodiment of the present invention.

Explanation of symbols

1 Bobbin

la yarn bundle

2 Sensor

3 Vertical robot

4 Alignment comb

5 Yarn bundle guide

5b Negative hole

6 Lower mold for molding

6a recess

6b Negative hole 7 Heater

8 Cutter

9 Mold transfer mechanism

10 Upper mold for molding

10a Oil injection hole

11 Resin injection equipment

12 Ejector

20 flat toothbrush

21 patterns

22 Head

23, 25 Connection

24 Grip

26 Through-hole

27 Brush part

28, 28 'Yarn bundle

29 Large diameter weld

A Yarn bundle supply position

B

C Toothbrush removal position

Claims

The scope of the claims

[1] A toothbrush in which a brush portion formed by gathering a large number of grease yarns is fixed to a head portion of a handle made of greaves is made of thermoplastic greaves that can be molded and brushed. At least the head part of the handle is molded by an adhesive that exhibits adhesion to the grease yarn forming the part and becomes a rigid body that satisfies the mechanical strength required for at least the head part of the handle in the cured state. A flat toothbrush in which the brush portion is bonded and fixed to the head portion of the handle by insert molding with the adhesive.

[2] A flat toothbrush in which a plurality of small yarn bundles configured by bundling greave yarns are planted at a predetermined interval in the same direction on the head portion of the handle made of greaves, and are inserted by the adhesive. The toothbrush according to claim 1, wherein the plurality of yarn bundles are bonded and fixed to the head portion of the handle by molding.

[3] The toothbrush according to claim 2, wherein each root portion of the plurality of yarn bundles is integrated by welding and formed thicker than the other portions.

[4] The toothbrush according to claim 1, wherein the handle has a hybrid structure in which only the head portion is formed of the adhesive and the other portion is formed of another resin suitable for forming the handle.

5. The toothbrush according to claim 4, wherein the head part is integrated with other parts by insert molding with the adhesive.

6. The toothbrush according to claim 5, wherein the other part of the handle has a mechanical coupling part that exhibits an anchor effect with respect to the head part at a tip part thereof.

7. The toothbrush according to claim 1, wherein at least the adhesive constituting the head portion is a dimer acid-based thermoplastic polyamide resin.

[8] The toothbrush according to claim 4, wherein the other grease constituting the other part of the handle is PP, PET or AS.

[9] A method for producing a flat toothbrush in which a plurality of small yarn bundles configured by bundling greave yarns are planted at predetermined intervals in the same direction on the head portion of the handle made of greaves,

In the through hole of the forming die having a recess corresponding to the shape of the handle of the flat toothbrush to be manufactured and provided with a through hole into which a plurality of yarn bundles are inserted in the portion corresponding to the head portion of the handle A yarn bundle inserting step of inserting the yarn bundle and cutting it into a predetermined length; It is made of a thermoplastic resin that can be molded, and exhibits adhesiveness to the resin thread that forms the thread bundle of the flat toothbrush, and has the mechanical strength required for at least the head of the handle in the cured state. A grease injection step of injecting an adhesive that becomes a rigid body to be filled into the recess in a state where a thread bundle is inserted into the through hole of the mold;

The toothbrush manufacturing method including the toothbrush taking-out process which takes out a molded product with a thread bundle from the recessed part after the resin inject | poured into the recessed part of the shaping | molding die hardens | cured.

10. The toothbrush manufacturing method according to claim 9, wherein, in the yarn bundle insertion step, the end portion of the yarn bundle inserted into the through hole of the forming die is welded from the concave portion side to have a larger diameter than the other portion.

[11] A part other than the head part of the handle is manufactured in advance, and a part other than the head part of the handle is inserted into the recess of the mold in the step of injecting the resin before injecting the resin. The toothbrush manufacturing method according to claim 9, wherein the adhesive is limitedly injected into a portion corresponding to a handle head portion.

12. The method for producing a toothbrush according to claim 9, wherein the adhesive injected into the recess of the mold is a dimer acid-based thermoplastic polyamide resin.

[13] The method for producing a toothbrush according to claim 11, wherein the wax constituting the other part of the handle is PP, PET or AS.

[14] A flat toothbrush manufacturing apparatus in which a plurality of small yarn bundles configured by bundling greave yarns are planted at predetermined intervals in the same direction on the head portion of the handle made of greaves,

A plurality of forming dies having a recess corresponding to the shape of the handle of the flat toothbrush to be manufactured and provided with through holes into which a plurality of yarn bundles are inserted in the portion corresponding to the head portion of the handle A mold conveying mechanism that sequentially conveys to the position, the grease injection position, and the toothbrush removal position;

A yarn bundle supply mechanism that is provided at the yarn bundle supply position and inserts the yarn bundle into a through-hole of a forming die conveyed to the supply position and cuts it to a predetermined length;

A resin injection device which is provided with the resin injection position and injects the mold resin into the concave portion of the mold transferred to the supply position;

A toothbrush manufacturing apparatus comprising: a product take-out device for taking out the concave force of the molding die provided at the toothbrush take-out position and transported to the take-out position.

15. The yarn bundle supply mechanism according to claim 14, wherein the yarn bundle supply mechanism is equipped with a heater that forms an end portion of the yarn bundle inserted into the through hole of the forming die with a concave side force to form a larger diameter than other portions. Toothbrush manufacturing equipment.

[16] The yarn bundle supply mechanism performs an approach / separation operation with respect to the forming die in a state where the yarn bundle is inserted into the through hole corresponding to the through hole of the forming die on the upstream side of the forming die in the yarn bundle inserting direction. 15. The toothbrush manufacturing apparatus according to claim 14, further comprising a movable yarn bundle guide that contacts the forming die so that corresponding through holes are continuous in the approaching state and moves away from the yarn bundle cutting position in the separated state.

17. The toothbrush manufacturing apparatus according to claim 14, wherein the yarn bundle supply mechanism inserts the yarn bundle with a lower force into the through hole of the mold.

[18] The mold resin is made of a thermoplastic resin that can be molded and exhibits adhesiveness to the resin thread forming the thread bundle of the flat toothbrush, and at least the head of the handle in the cured state. 15. The toothbrush manufacturing apparatus according to claim 14, which is an adhesive that becomes a rigid body satisfying the mechanical strength required for the part.

19. The toothbrush manufacturing apparatus according to claim 18, wherein the adhesive is a dimer acid-based thermoplastic polyamide resin.