JPH0965932A - Brush manufacturing method - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To provide a brush of integral molding type, which has high bristle implantation strength, less burr, and good bristling. With A mold having a conical protrusion 10 ₁ into the through-hole opening end outer peripheral portion of the cavity of the handle mold 10, the tufts 1 of the fused mass 2 the conical projection 10 ₁
The material flow a which is further projected and is injected into the cavity 13 and flows along the conical protrusion 10 ₁ and is reversed toward the fusion mass 2 is the material flow that is about to flow out from the through hole. the fused mass 2 was filled in offsetting b is held in the molding material fused mass 2 and tufts root portion 1 ₁ is embedded in the molding material within the cavity and little quality good brush also high flocked strength burrs generated .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a brush, such as a toothbrush or a hair brush, in which a plastic brush portion is integrated when molding a handle portion.

[0002]

2. Description of the Related Art Recently, instead of a brush in which a bunch of hair is fixed to a hair-implanting hole in a handle using a metal piece or a metal wire,
It has been proposed to integrate a plastic brush part during molding of the handle part. Conventionally, in this type of brush, one end of a bristled brush is melted to form a fused mass, and the enlarged part of the bristled brush is introduced into a mold for forming a handle, and It is known that after the material is injected and filled, the respective hair bundles are integrally fixed in the handle portion by curing the plastic (Japanese Patent Publication No. 6-16725, Japanese Patent Publication No. 2-503150). .

[0003]

In the conventional method of forming a fused mass at the end of a hair bundle and then injecting a molding material into a mold to mold a bristle member or a brush, the bristle strength (molding strength) In order to improve the difficulty of pulling out the hair bundle from the body), it is preferable to inject the molding material into the mold with the hair bundle fusion mass inserted deeply into the mold, but the pressure during injection molding There is a drawback that the molding material flows out from the through hole to cause burrs. This burr is a part of the molding material that exudes from the gap between the hair bundle and the through hole.
Although it is possible to reduce the occurrence rate and size of burrs to some extent by increasing the density of hair bundles in the through holes and adjusting molding conditions such as injection pressure and injection speed,
Burrs protruding from the flocked surface impair the product appearance and
The large burr had a problem that it might damage the oral cavity. Therefore, the fused mass at the protruding end of the hair bundle is made into a fused mass having a cross section larger than the cross section of the through hole, and the through hole is closed by this fused mass when the molding material is injected (Japanese Patent Publication No.
No. 16725) has also been proposed, but since the fused mass of the hair bundle is near the head surface, it is not sufficiently satisfactory for the hair transplant strength, and also has the drawback that it easily spreads outward from the root of the hair tuft of the hair tuft there were. In addition, a method of inserting the fused mass of hair bundle deeply into the mold of the head part and molding (Japanese Patent Laid-Open No. 2-503
No. 150) had a drawback that the mold system was complicated.
The present invention is intended to easily eliminate these drawbacks of the related art, and with a simple mold structure, a high hair transplant strength and a good hair transplant condition can be obtained without requiring a special mold system. In addition, it is to obtain a safe molding method in which burrs do not easily come out above the flocked surface.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a hair bundle is introduced into a hair bundle insertion through hole provided in a handle molding die to project one end of the hair bundle, and heat the protruding end portion. A brush in which the bristles are integrally transplanted to the handle by forming a fused mass by means, positioning the fused mass in the mold cavity for the handle molding, and then introducing the molding material, and curing the molding material to mold the handle. In the method for manufacturing the above, using a mold having a conical projection on the outer peripheral portion of the through-hole opening end of the mold cavity for handle molding, the fused mass of the hair bundle is projected from the conical projection, The molding material is injected into the cavity in the mold and flows along the conical projection to reverse the flow toward the fusion mass. Embedded in the molding material in the cavity, It is an excellent brush high flocked strength hair standing by holding Gokatamari and tufts root portion in the molding material.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In this brush manufacturing method, a fused mass at one end of a bristle bundle is projected into an inner space of a mold for molding a handle,
By injecting the molding material into the mold, when the flocking member or the brush is molded, the flow of the material that is reversed toward the fusion mass cancels the flow of the material that is about to flow out from the through hole, and thus the fusion mass. And the root part of the hair bundle is held by the molding material, and without the need for a special mold system, the hair transplant strength is high, and a hair transplant condition with good hair raising is obtained,
In addition, it is possible to obtain a good quality brush with less burr.

[0006]

EXAMPLE An example of the present invention will be described with reference to the examples of FIGS. 1 to 3. A hair bundle pin is introduced by introducing the hair bundle 1 into a hair bundle insertion through hole 11 provided in a handle molding die 10. At 15, one end of the hair bundle is aligned and projected, and the protruding end portion is heated by a heating plate 12 by a heat source 12 ₁ or heating means 12 such as hot air or infrared rays.
A fused mass 2 having a cross section larger than that of the through hole 11 is formed, and the fused mass 2 is positioned in the cavity 13 of the handle molding die 10 to close the handle molding die 10 or After the fused mass 2 is positioned in the cavity 13 after closing, the molding material is introduced, and when the handle 4 is formed by hardening the molding material to form the brush 4 in which the hair bundles 1 are integrally planted on the handle 3, the handle Mold 10 for molding
By using a mold having a conical projection 10 ₁ on the outer peripheral portion of the opening of the through hole of the cavity, the fused mass 2 of the hair bundle 1 is positioned so as to project from the conical projection 10 ₁ , and the cavity 1 in the mold
3, the molding material is injected, and the material flow a that flows along the conical protrusion 10 ₁ and is reversed toward the fusion mass 2 and the material flow b that is about to flow out from the through hole are offset and filled. And the fused mass 2 is embedded in the molding material in the cavity.
There tresses root portion 1 ₁ a is small quality good brush burr high flock strength is held by the molding material.

In this case, the hair bundle insertion pin 15 is slidably inserted into each of the hair bundle through holes 11 provided in the handle forming die 10 and the hair bundles 1 are stopped at a predetermined position and fused. The mass 2 is fixed in the cavity 13, and it is preferable that the hair bundle insertion pins 15 are simultaneously moved at once. The conical protrusion 10 ₁ has a height of 0.
1-2 mm, preferably 0.2-1.0 mm, difference between top surface diameter and bottom surface diameter 0.2-4.0 mm, preferably 0.4-
It is good to set it to about 1.2 mm. Further, the insertion distance of the hair bundle in the cavity 13 can be arbitrarily selected according to the thickness of the base of the flocking member or the thickness of the brush head portion, and the hair bundle is spread outward from the root of the root. Care is taken to keep the hair straight without standing up.

Further, when the molding material filled in the cavity 13 is soft enough to allow the fused mass 2 of the hair bundle 1 to move before solidifying, the molding material surrounds the hair bundle root portion 1 ₁ and can be filled. By pressing the hair bundle 1 into the through hole 11 with the hair bundle insertion pin 15 and inserting the hair bundle fused mass up to near the center of the molded body, the hair bundle fused mass 2 and the hair bundle root ₁₁ are Since it can be held securely with the molding material,
Sufficient flocking strength may be obtained, and flocking with good hair may be made possible. During this injection molding,
By closing the through hole 11 for inserting the hair bundle with the hair bundle fusion mass 2, it is possible to prevent the molding material from flowing out of the through hole and becoming a burr, which is convenient.

In the specific example of FIG. 4, the handle forming die 1 is used.
The conical protrusion 10 ₁ of 0 has a groove 10 ₂ radially provided around the through hole 11 on the inclined surface of the conical protrusion 10 _{1 to} form a material flow for guiding and flowing the molding material in one direction and molding is performed. It is possible to prevent the molding material from exuding into the hair bundle and to suppress the occurrence of burrs. Even if the fused mass 2 is deeply embedded in the handle 3, the conical projection 10 ₁ still exists, so that the hair bundle through hole opening end 11
The gap between ₁ and the fused mass 2 is also narrowed, which reduces burr formation and is effective.

The present invention also includes the following characteristic structure. A brush manufacturing method for filling a molding material by supporting the hair bundle at a predetermined position by a hair bundle insertion pin in each of the plurality of hair bundle through holes. A method for manufacturing a brush, in which a material flow is generated by concave grooves radially provided around a through hole on a slope of the conical protrusion to form the material.

[0011]

According to the present invention, the fused mass of the hair bundle is projected from the conical protrusion by using the mold having the conical protrusion on the outer peripheral portion of the opening of the through hole of the cavity in the handle molding die. When positioned, the molding material is injected into the cavity in the mold and flows along the conical protrusions and is reversed toward the fusion mass, so that the material flow that is about to flow out from the through-hole cancels out. By filling and filling the fused mass into the molding material in the cavity and holding the fused mass and the root of the hair bundle with the molding material, it is possible to reduce the occurrence of burrs,
The hair bundle fusion mass can be inserted up to near the center of the molded body, and
By holding the root of the hair bundle with a molding material, it is possible to obtain sufficient flocking strength, and it is possible to achieve flocking with good napping, and further, it is possible to achieve good quality and high appearance quality and reliability. In addition to that, because the molding material can be injected with the gap between the fused mass and the tip of the conical projection open,
There is also an advantage that the step of pulling up the hair bundle and closing the hair bundle through hole with the fused mass is not necessary, and there is an effect that productivity can be significantly improved.

[Brief description of drawings]

FIG. 1 is a process explanatory view of a manufacturing method according to an embodiment of the present invention, in which (a) is a hair bundle inserting step, (b) is a fused mass forming step, (c) is a step immediately before injection molding, and (d) is a hair bundle pushing step. , (E) shows a mold release process.

2A and 2B are enlarged vertical cross-sectional views of a part of the molding process of the example of FIG. 1, in which FIG.

FIG. 3 is a perspective view of a portion of the product.

FIG. 4 is an enlarged vertical cross-sectional view of a part of the manufacturing process of another embodiment of the present invention, in which (a) shows the injection and (b) shows the inner surface of the mold.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Hair bundle 2 Fusion mass 3 Handle 4 Brush 10 Handle forming mold 10 ₁ Conical protrusion 11 Through hole 11 ₁ Opening end 12 Heating means 12 ₁ Heat source 13 Cavity 15 Hair bundle insertion pin

Claims (1)

[Claims] 1. A hair bundle is introduced into a through hole for hair bundle insertion provided in a handle molding die to project one end of the hair bundle,
The protruding end is formed into a fused mass by heating means, the fused mass is positioned in the cavity of the mold for molding the handle, the molding material is introduced, and the hair is formed on the handle by molding the handle by curing the molding material. In a method for manufacturing a brush in which a bundle is integrally transplanted, a mold having a conical protrusion on an outer peripheral portion of an opening end of a through hole of a cavity in a handle forming mold is used to form a fused mass of the hair bundle into the cone. A method for manufacturing a brush, characterized in that the fused mass and the root of the hair bundle are held by the molding material by injecting the molding material into the cavity in the mold so as to project from the protrusions.