JP2832682B2 - Molding method for molded articles containing brittle material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a molded article containing a brittle material suitable for forming a lure or the like in which pulverized shells are mixed.

[0002]

2. Description of the Related Art FIG. 7 shows an example of a lure 50 used for lure fishing. This type of lure 50 includes a lure main body 51 imitating a fish shape.
Is integrally formed of a synthetic resin. In addition, 52 is a fishing hook.

When the lure body 51 is formed, for example, a decorative material (brittle material) 53 using crushed shells is used.
Is mixed in the synthetic resin, a large number of decorative materials 53 appear on the surface of the lure main body 51, so that the light reflection of the decorative materials 53 allows the lures to function as more effective lures. Is also enhanced.

Conventionally, when such a lure main body 51 (molded article containing a brittle material) is formed, a resin material (pellet) is used.
A fixed proportion of the decorative material 53 is blended, and the resin material and the decorative material 5 are mixed.
Injection molding was performed by supplying the mixed raw material of No. 3 to the heating cylinder of the injection molding machine.

[0005]

However, the conventional molding method described above has the following problems since the resin material and the decorative materials 53 are supplied together inside the heating cylinder.

First, the decorative materials 53, such as crushed shells, are brittle, so that when the resin is plasticized and melted by the screw, cutting or chipping occurs due to the shearing force of the screw.
The original decorativeness and light reflectivity of the decorative materials 53 are impaired.

Second, since the size and weight of the pellets used for the resin material and the decorative materials 53 are different, even if they are mixed at the raw material stage, they cannot be mixed uniformly.
As a result, a uniform and high-quality molded product cannot be obtained, for example, the distribution of the decorative materials 53 is uneven.

[0008] The present invention has been made to solve the problems existing in such prior art, making the brittle material less likely to break, preventing the original properties such as decorativeness and light reflectivity from being impaired. It is an object of the present invention to provide a method of molding a brittle material-containing molded product that can obtain a homogeneous and high-quality molded product by uniformly mixing and distributing it in a resin.

[0009]

According to the present invention, there is provided a method for molding a brittle material-containing molded article according to the present invention, wherein a heating cylinder 3 having a screw 2 incorporated in an injection molding machine 1 is provided inside a heating cylinder 3 and a rear portion of the heating cylinder 3 is provided. The resin material Ma is supplied from one material supply unit 4, the resin material Ma is plasticized and melted and transferred to the front of the heating cylinder 3, and the vent hole 6 located forward of the first material supply unit 4. The brittle material Mb, such as a crushed shell, is released from the second material supply unit 5 using the resin M released by the vent hole 6.
The brittle material Mb and the plasticized and melted resin Mm are added without changing the shear force of the screw 2 to the brittle material Mb without adding the shearing force of the screw 2 to the brittle material Mb.
Is mixed and transferred to the front of the heating cylinder 3.

[0010]

According to the method for molding a brittle material-containing molded article according to the present invention, first, the first material supply section 4 disposed at the rear of the heating cylinder 3 is provided.
, The resin material Ma is supplied into the heating cylinder 3. Thereby, the resin material Ma is plasticized and melted inside the heating cylinder 3 by the rotation of the screw 2 and the heating of the heating cylinder 3, and is transferred to the front of the heating cylinder 3.

On the other hand, the plasticized molten resin Mm is
Is reached, a brittle material Mb, such as a crushed shell, is removed from the inside of the heating cylinder 3 from the second material supply unit 5 using the vent hole 6 located forward of the first material supply unit 4. Supplied to As a result, the brittle material Mb enters the plasticized and melted resin Mm, and the resin Mm and the brittle material Mb are mixed by the rotation of the screw 2 and transferred to the front of the heating cylinder 3. Then, a resin Mm mixed with the brittle material Mb is injection-filled into a mold, and the molded product containing the brittle material (the lure body 5) is formed.
1) is molded.

Therefore, the shearing force of the screw 2 during the plasticization and melting of the resin Mm is not applied to the brittle material Mb, and the compressed resin Mm is released in the vent hole 6,
Since the brittle material Mb is supplied to the released resin Mm, cutting or breakage of the brittle material Mb is eliminated or reduced.
Further, although the size and weight of the pellets used for the resin material Ma and the brittle material Mb are different from each other, they are separately supplied at the stage of the raw material, and in particular, the brittle material Mb is sequentially added to the plasticized molten resin Mm to be transferred. Therefore, they can be uniformly mixed.

[0013]

Next, preferred embodiments according to the present invention will be described in detail with reference to the drawings.

First, the configuration of an injection molding machine 1 that can carry out the molding method according to the present invention will be described with reference to FIGS.

As shown in FIG. 3, the injection molding machine 1 comprises an injection device 10 and a mold clamping device (not shown) having a mold 11. The injection device 10 includes a heating cylinder 3 having a screw 2 therein. The heating cylinder 3 has an injection nozzle 12 at a front end thereof, and a screw driving device 13 for rotating and moving the screw 2 forward and backward at a rear end of the heating cylinder 3. Is provided.

A first material supply section 4 for supplying a resin material (pellet) is provided at the rear of the heating cylinder 3. The first material supply unit 4 includes a device block 14, a hopper 15 for housing a resin material is provided at an upper end of the device block 14, and a horizontal material supply passage 16 is provided inside the device block 14. The material intake side of the material supply passage 16 communicates with a drop port 15 s of the hopper 15, and the material discharge side of the material supply passage 16 communicates with a vertical fall passage 17 provided inside the apparatus block 14. Further, a feed screw 18 is built in the material supply passage 16, and a feed screw 18 is provided on a side surface of the device block 14.
And a drive motor unit 19 for driving the feed screw 18 to rotate is provided.

Therefore, the material supply passage 16 from the hopper 15
Is fed by a feed screw 18 rotated by a drive motor unit 19, and falls through a vertical drop passage 17 to be supplied into the heating cylinder 3. In this case, the supply amount of the resin material is variably controlled by the rotation speed of the drive motor unit 19 and the like.

On the other hand, a second material supply unit 5 for supplying a brittle material is provided in the heating cylinder 3 located in front of the first material supply unit 4. By the way, in the case of a vent type injection molding machine, since a vent hole 6 for discharging steam and gas components generated from the molten resin to the outside is provided in an intermediate portion of the heating cylinder 3, the vent hole 6 is directly A second material supply unit 5 is provided. As shown in FIG. 4, the second material supply unit 5 includes a device block 21, a hopper 22 for containing a brittle material is provided at an upper end of the device block 21, and a horizontal material is provided inside the device block 21. A supply passage 23 is provided.
The material intake side 23i of the material supply passage 23 is
The material discharge side 23o of the material supply passage 23 communicates with a vertical drop passage 24 provided inside the apparatus block 21. Note that the upper end of the vertical drop passage 24 communicates with the atmosphere so that it also functions as a vent hole. Further, a feed screw 26 is built in the material supply passage 23, and a drive motor unit 27 that is connected to an end of the feed screw 26 and drives the feed screw 26 to rotate is arranged on one side surface of the device block 21. Set up.

On the other hand, a support mechanism 28 is mounted on the other side of the device block 21. In this case, the support mechanism 28
Is attached to and detached from a mounting hole 29 provided in the device block 21. The support mechanism 28 has a cylindrical bearing 30,
The supported shaft 26 a provided at the tip of the feed screw 26 is rotatably supported by the bearing 30.
The supported shaft 26a is formed to have a smaller diameter than the intermediate shaft portion 26b of the feed screw 26, and the intermediate shaft portion 26b and the bearing 30 have the same outer diameter. The rotation detecting rod 31 is inserted into the support mechanism 28 and engages with the tip of the supported shaft 26a when the support mechanism 28 is mounted on the device block 21. In the figure, reference numerals 25...
2 shows a fixing bolt for mounting on a vehicle.

Further, a regulating member 32 is provided on the outer peripheral surface of the distal end of the bearing portion 30. As shown in FIGS. 4 and 6, the regulating member 32 includes a disc-shaped regulating plate 33 provided integrally with the tip of the bearing 30. A plurality of notches are provided at regular intervals in the circumferential direction of the regulating plate 33 along the circumferential direction, and are formed so as to be entirely gear-shaped. Then, a regulating ring 34 is attached to the periphery of the regulating plate 33. Thereby, a large number of holes (notches) 35... Are provided in the regulating member 32 along the circumferential direction.

A fixed gap S is provided between the material supply passage 23 and the feed screw 26. Then, a sleeve-like (cylindrical) closing member 36 for closing the gap S is prepared and attached to the gap S. This closing member 36 is detachable from the material supply passage 23. In the drawing, reference numeral 37 denotes a fixing bolt for fixing the closing member 36.

On the other hand, in addition to the support mechanism 28,
FIG. 5 in which the regulating member 32 is removed from the supporting mechanism 28.
Is separately prepared, and the support mechanism 28p and the support mechanism 28 can be arbitrarily exchanged.

Therefore, the configuration of the second material supply unit 5 can be selected according to the type of the brittle material used. That is,
When the brittle material is a relatively small sphere such as a glass balloon (or glass bead), as shown in FIG.
Support mechanism 2 having regulating member 32 in device block 21
8 and the closing member 36 may be attached. Note that the glass balloon is an internally hollow granular sphere having a diameter of about 0.03 to 0.06 mm. Thereby, the brittle material M
a is a plurality of holes (notches) 35 provided in the regulating member 32.
, The amount of the brittle material Ma passing through the regulating member 35 is regulated (restricted) by the size, the number, and the like of the holes (notches) 35. Further, since the gap S is closed by the closing member 36, the problem that the brittle material Mb flows directly to the heating cylinder 3 through the gap S is eliminated.

On the other hand, when the brittle material Mb is relatively large, such as a crushed shell, as shown in FIG. 5, a support mechanism 28p without the restricting member 6 is mounted on the device block 23 and closed. The member 9 may be removed. Thereby, the second material supply unit 5 has the same structure as the first material supply unit 4. Therefore, a gap S is formed between the material supply passage 23 and the feed screw 26, and the adverse effect that the brittle material Mb is caught between the material supply passage 23 and the feed screw 26 does not occur. The supply amount of the brittle material Mb is variably controlled by the rotation speed of the drive motor unit 27 and the like.

Next, a molding method according to the present invention using such an injection molding machine 1 will be described with reference to FIGS.

First, as shown in FIG. 1, a resin material Ma is supplied to the inside of the heating cylinder 3 from a first hopper section 4 disposed at the rear of the heating cylinder 3. Thus, the resin material Ma is heated by the rotation of the screw 2 and the heating of the heating cylinder 3.
And is transferred to the front of the heating cylinder 3.

On the other hand, the plasticized molten resin Mm is
2, the brittle material Mb is supplied from the second hopper 5 into the heating cylinder 3 as shown in FIG. As a result, the brittle material Mb enters and mixes with the plasticized and melted resin Mm.
Is rotated, the resin Mm and the brittle material Mb are mixed and transferred to the front of the heating cylinder 3. Then, the resin Mm in which the brittle material Mb is mixed is injected and filled into the mold 11 through the injection nozzle 12, and a brittle material-containing molded product such as the lure main body 51 shown in FIG. 7 is formed.

Therefore, the cutting or chipping of the brittle material Mb due to the shearing force of the screw during kneading of the resin Mm is reduced or eliminated, and the disadvantage of losing the original decorativeness and light reflectivity of the decorative material Mb is eliminated. .

Although the size and weight of the pellets used for the resin material and the decorative material 53 are different, they are separately compounded at the material stage, and are sequentially added to the plasticized molten resin Mm during transfer. Since it is added, it can be uniformly mixed, the uneven distribution of the brittle material Mb is eliminated, and a uniform and high quality molded product can be obtained.

The embodiment has been described in detail above.
The present invention is not limited to such an embodiment.
For example, as the brittle material Mb, white sand having brittle properties,
It can be applied to any other brittle materials such as ceramics, glass fiber, and the like. In addition, details, configurations, shapes, and quantities can be arbitrarily changed without departing from the spirit of the present invention.

[0031]

As described above, according to the method for molding a brittle material-containing molded product according to the present invention, the first material supply arranged at the rear of the heating cylinder is provided inside the heating cylinder having a screw built in the injection molding machine. The resin material is supplied from the portion, and the resin material is plasticized and melted and transferred to the front of the heating cylinder, and from the second material supply portion using the vent hole located in front of the first material supply portion. Variably control the supply amount so that brittle materials such as ground shells are uniformly mixed with the resin released through the vent holes, and apply a screw shear force to the brittle materials. Instead, since the brittle material and the plasticized and melted resin are mixed and transferred to the front of the heating cylinder, the following remarkable effects can be obtained.

The brittle material is less likely to break, and the original properties such as decorativeness and light reflectivity are not impaired.

By uniformly mixing and distributing in the resin, a homogeneous and high-quality molded product can be obtained.

[Brief description of the drawings]

FIG. 1 is a principle configuration diagram of an injection molding machine for explaining a molding method according to the present invention,

FIG. 2 is an operation explanatory view showing a supply state of a brittle material by the molding method,

FIG. 3 is a partial cross-sectional side view of an injection molding machine capable of performing the molding method.

FIG. 4 is a cross-sectional side view of a second hopper in the injection molding machine.

FIG. 5 is a cross-sectional side view of a second hopper unit in which another mode is selected in the injection molding machine.

FIG. 6 is a front view of a regulating member in the second hopper,

FIG. 7 is a front view of a lure (molded product containing brittle material),

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 injection molding machine 2 screw 3 heating cylinder 4 first material supply unit 5 second material supply unit 6 vent hole Ma resin material Mb brittle material Mm plasticized and melted resin

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-76614 (JP, A) JP-A-48-18351 (JP, A) JP-A-52-66569 (JP, A) JP-A-2- 153714 (JP, A) JP-A-8-91164 (JP, A) JP-A-8-72659 (JP, A) JP-A-2-265722 (JP, A) JP-A-5-57750 (JP, A) JP-A-1-127308 (JP, A) JP-A-3-251420 (JP, A) JP-A-7-304035 (JP, A) JP-A-61-95906 (JP, A) JP-A-63-33917 (JP, U) Japanese Utility Model 63-53715 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B29C 45/00-45/84 B29C 31/10

Claims (1)

(57) [Claims] 1. A resin material is supplied from a first material supply unit disposed at a rear portion of a heating cylinder into a heating cylinder including a screw provided in an injection molding machine, and the resin material is plasticized and melted to be heated. The resin released from the second material supply unit using the vent hole located in front of the first material supply unit and the brittle material such as pulverized shells is released by the vent hole while being transferred to the front of the cylinder. The feed rate is variably controlled so as to be uniformly mixed so that the brittle material and the plasticized molten resin are mixed without adding a shearing force of the screw to the brittle material, and mixed in front of the heating cylinder. A method for forming a molded article containing a brittle material, comprising transferring the molded article to a brittle material.