JP2003011155A - Fabric decorative molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fabric decorative molding method using a hot nozzle. SOLUTION: This fabric decorative molding method uses the hot nozzle and especially performs a fabric decorative molding process by directly injecting a molten resin onto the back of a fabric 4. The injection angle of the molten resin to be supplied to the fabric 4 from the hot nozzle 10 is changed at a tip of the hot nozzle 10 from a perpendicular direction 11 with the fabric 4 to a parallel direction 12. Consequently, the fabric 4 arranged right before a gate hole 3 is not impaired by the high pressure and high temperature molten resin. In positive terms, the hot nozzle 10 is a bifurcated hot nozzle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fabric decoration molding method using a hot nozzle.

[0002]

2. Description of the Related Art The hot runner technology has the advantage that it can contribute to cost reduction by productivity improvement in mass continuous production because it does not generate sprue or runner and can shorten the molding cycle. . However, it has been pointed out that the mold cost is generally high and the handling is difficult. Hot runners were also generally considered to have high pressure losses. The reason for this is that in the case of a mechanical seal (valve gate), flow resistance occurs because the valve slides in the resin passage, while on the other hand, a thermal seal that incorporates a heater called a torpedo in the passage, so-called This was because in the case of the internal heating type, the torpedo also became a flow resistance. This hot runner system
Various types can be distinguished by the hot nozzle, the gate, and the opening / closing mechanism of the gate. Among these, "Samocongate (registered trademark)" of S-IPI Co., Ltd. can be mentioned as one that technically overcomes the above disadvantages.

The hot nozzles can be roughly classified into thermal seals and mechanical seals according to the gate seal system.
“Samocongate®” is a thermal seal.
The thermal sealing is to close the gate by lowering the temperature of the gate tip to solidify the resin, and heating and cooling means for melting and solidifying the resin in synchronization with the molding cycle are required. Since "Samocongate (registered trademark)" does not have a separate heater, it is a mechanism that causes an electric current to flow through the tube itself that forms the resin passage to generate heat, so the inside of the passage is hollow and the tip of the gate is sharp. The greatest feature is that it can be heated. Therefore, the pressure loss is minimized because the passage is hollow and there is no resistance. In addition, the gate tip is heated by a method that uses an external heating means such as a band heater.
Although the heater cannot be inserted to the position where it is inserted into the mold, "Samocongate (registered trademark)" heats the nozzle itself, so it is possible to heat up to just before the cavity and introduce the molten resin at a high temperature. Becomes Due to this feature, the resin fluidity is good, (1) products that are not filled by other methods can be filled, (2) the number of nozzles can be reduced, (3) injection / compensation pressure is reduced, and cycle is shortened. The advantages are (4) the surface burr of the product and the transferability of grain, etc. are improved, and (5) the product with the opening has a problem that the weld is hard to see when the resin collides with each other at high temperature. Have. Based on these characteristics, daily commodities, home appliances, and large automobile parts are molded using this hot runner system. Hereinafter, a method for forming and decorating a fabric for a vehicle door trim will be described.

Usually, in the decorative molding of fabric for automobile door trim, a bubble gate or the like is used in the fabric portion, and the resin is injected by the gate method. Generally, there are two types of gate systems, an open type that uses heat balance and a valve gate that opens and closes mechanically.
In the case of a valve gate, since the resin flow rate per point is relatively small, it is necessary to use a multi-point method (see reference numeral 3 in FIG. 4) or to increase the injection pressure and injection speed in order to fill the fabric part. is there. However, in the case of the multi-point type, the injection timing is set to a plurality of valve gate holes 3 (see FIG.
If it is not adjusted for each time, there may be a drawback that the fabric to be decorated is wrinkled. Further, when the injection pressure and the injection speed are increased, the pressure gradient in the cavity becomes large, which may be one of the causes of defective molding. Therefore, it is usually desired to mold at a pressure as low as possible. As described above, in the case of the multi-point gate method, the occurrence of weld on the product surface becomes a problem.
Therefore, there is a case where a method of minimizing the weld is performed by utilizing CAE to study the gate pitch and adopting the optimum gate position. Therefore, in the case of the multi-point gate method as compared with the one-point gate method, the normal handling becomes more complicated.

Further, when the resin is directly injected onto the back surface of the fabric to integrally form the fabric, in the conventional method, as shown in FIG. High-pressure and high-temperature resin is directly injected into the part at an angle almost vertical (reference numeral 11
In some cases, the fabric 4 after molding may have a design problem such as hair fall (see reference numeral 13). As one method of avoiding this problem, measures have been taken to protect the design surface of the fabric by laminating urethane, a decorative fabric or the like on the back side of the fabric. However, performing these processes prolongs the molding time, and the unit price of the fabric becomes expensive due to the combination of new members, and finally the unit price of the product is increased.

Another prior art relating to a method of molding a door trim using a hot runner is Japanese Patent Laid-Open No. 7-2904.
85 publication. In this disclosure example, 1
The purpose of the present invention is to reduce the mold clamping force when molding a plurality of resin molded products using one mold device. Specifically, a main hot runner that communicates with the injection molding machine to introduce the resin material into the cavity, a branch hot runner that is branched from the main hot runner in four directions, and two branch hot runners. A direct gate that is divided and a valve that shuts off or injects the molten resin from these gates are provided. Compared with the conventional technique in which all the cavities are injected and filled by a single injection, a time lag is provided in the injection operation to reduce the total internal cavity pressure to about half. By lowering the internal pressure, the mold clamping force is reduced, thus reducing the cost of the entire mold device. However, since the hot runner is branched into a plurality of parts, a valve for controlling the injection of the molten resin is required, and the operation is not easy. In addition, there is no specific description of gate configurations other than the direct gate method. That is, it is not assumed that the resin is directly injected onto the back surface of the fabric to integrally form the fabric. For this reason,
There is a possibility that the above-mentioned problem that the hair of the fabric is partially collapsed may occur.

In addition, various plastic injection molding techniques have been developed and applied, for example, stamping molding, injection compression molding and the like. Among these applied and developed products, there is a product in which a skin material can be laminated and composited simultaneously at the time of melt compression molding, and a large interior product such as an automobile door trim can be manufactured by one molding. However, these molding methods still have problems such as dedicated equipment and molding time. For example, when it is difficult to introduce new equipment, these methods are not used in the field. In addition, a method of forming a fabric portion into a product shape in advance and setting the molded product in a mold and injecting it is also performed, but the number of processing steps increases and the unit price increases.

[0008] Therefore, as a method for forming a decorative fabric for a door trim for an automobile, a low-cost and simple forming method which utilizes existing equipment and does not leave problems such as hair fall on the formed fabric by a one-point gate method. Being sought.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object thereof is to provide a high-quality fabric decoration molding method at low cost.

[0010]

As a means for solving the above-mentioned problems, the present invention is the invention as set forth in claim 1, in which a cavity formed between a pair of movable mold and fixed mold is used. In a fabric decoration molding method of arranging a fabric of a predetermined shape and supplying a molten resin into the cavity to integrally mold the fabric and the molten resin, one of the pair of movable mold and fixed mold On the other hand, at least one hot nozzle is arranged, the fabric is arranged at a predetermined position in the cavity facing the hot nozzle, and a molten resin is supplied into the cavity to integrally integrate the fabric and the molten resin. It is characterized by being molded. In this configuration, the hot nozzle is used to integrally mold the fabric and the molten resin,
It is possible to provide a simple and relatively low-cost method for decorating a fabric.

Next, in the invention described in claim 2, in the invention described in claim 1, the hot nozzle is a branch type hot nozzle.
In this configuration, by arranging the direction of the outlet hole of the hot nozzle in a direction parallel to the fabric, in order to avoid the molten resin from directly hitting the fabric in a direction perpendicular to the fabric, It is possible to avoid problems such as hair fall.

The fabric decoration molding method according to the present invention is basically constructed as described above, but the branch type hot nozzle can be applied to an overlap gate, a disc gate or a submarine gate. However, in any of the gate configurations, it is possible to prevent the fabric arranged immediately before from falling down. The gate of the hot nozzle may have a circular shape or a trapezoidal cross section. Furthermore, although a single hot nozzle is preferably used in the molding method according to the present invention, a plurality of hot nozzles may be used. However, in this case, the injection timing is adjusted for each hot nozzle.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. In a preferred embodiment according to the present invention, a hot nozzle according to the above "Samocongate (registered trademark)" is used as a hot runner system.

FIG. 1 is a conceptual diagram showing a method for forming and decorating a fabric for automobile door trim, FIG. 2 is an enlarged sectional view taken along the line AA of FIG. 1, and FIG. 3 is a further enlarged view of FIG. Is shown. 1 corresponds to FIG. 4 according to the conventional embodiment, and FIG. 3 corresponds to FIG. 5 according to the conventional embodiment. Referring to FIG. 1, reference numeral 1 indicates a door trim body, and reference numeral 3 indicates a gate hole of a hot nozzle 10 (see FIG. 2). Usually, high-temperature, high-pressure molten resin is injected from these one or more gate holes 3
Fabrics and the like are decorated at the locations shown in. The decorative area 2 changes into various shapes and sizes depending on the design of the door trim 1. For example, a speaker (not shown) or the like may be formed integrally with the door trim 1.

In the embodiment according to the present invention, the above-mentioned "Samocongate (registered trademark)" is used to increase the flow rate of the molten resin per one-point gate. (See FIG. 2), the molten resin is injected and filling is performed. Therefore, preferably the gate hole 3
Is one (see FIG. 1). Therefore, the operation method of injecting the molten resin is relatively simple, and the cost required for the fabric decoration molding can be reduced.

FIG. 2 is a side view of a mold used in a method for forming and decorating a fabric in which a molten resin is directly injected onto the back surface of the fabric 4 by using the hot nozzle 10 to integrally form the fabric. Here, reference numeral 8 indicates a movable mold, and reference numeral 9 indicates a fixed mold that acts in pairs. In FIG. 2, the movable mold 8 and the fixed mold 9 are arranged with a space therebetween, but in operation, these molds are clamped and a cavity 5 is formed between them, and the inside of the cavity 5 is formed. The fabric 4 is arranged at a predetermined position. Reference numeral 10 represents a hot nozzle, and reference numeral 10a represents a hot nozzle or another type of nozzle. The molten resin is injected from the hot nozzle 10 to fill the cavity 5, and the fabric 4 placed immediately before the hot nozzle 10 is integrally decorated with the molten resin. Further, the hot nozzles 10 are usually arranged at the locations shown in these gate holes 3 perpendicularly to the fixed mold 9.

Further, as is well known in the prior art, the gate hole 3 (see FIG. 1) is an inlet for supplying the molten resin to the cavity 5 and is greatly related to the quality of the molded product.
Gate design usually occupies an important part of mold design.
There are various types of the gate hole 3, and the gate hole 3 is determined in consideration of the shape of the molded product, required performance, moldability and the like. In a preferred embodiment according to the present invention, a branch type hot nozzle 10 is used when performing the decorative molding of a fabric by directly injecting a molten resin onto the back surface of the fabric 4 arranged in the cavity 5 of the molds 8 and 9. To do. That is, as shown in FIG. 3, the injection angle of the molten resin flowing from the hot nozzle 10 toward the fabric 4 is changed from the vertical direction 11 to the parallel direction 12 with respect to the fabric 4. Specifically, the gate hole 3 of the hot nozzle 10 is configured to be displaced from the vertical direction 11 to the parallel direction 12 with respect to the fabric 4,
The molten resin flowing out from the gate hole 3 is prevented from damaging the fabric 4 arranged immediately before the gate hole 3. In other words, the gate hole 3 and the fabric 4
The molten resin flowing from the hot nozzle 10 arranged perpendicularly to the fabric 4 is opened in the direction parallel to the fabric 4 in the direction parallel to the fabric 4.
Flow to 2. However, other than that, for example, an overlap gate that changes the flow direction by 90 degrees, a disc gate used for a molded product having a hole in the center, or a submarine gate that injects molten resin from the side wall of the cavity is used immediately before the gate hole 3. It is possible to apply to the branch type hot nozzle according to the embodiment of the present invention so as to avoid damaging the fabric 4 arranged in the above.

Therefore, in the case of performing the decorative molding of the fabric 4 by arranging the gate hole 3 of the nozzle 10 'vertically to the fabric 4 as in the conventional fabric decorative molding shown in FIG. It is possible to avoid the problem that the high-temperature and high-pressure molten resin injected from the gate hole 3 of the'flows in the direction 11 perpendicular to the fabric 4 and damages the fabric 4 (see reference numeral 13). that's all,
Although the fabric decorative molding of the present invention has been described with respect to a specific embodiment, the optimum branching conforming to the above purpose depending on the product shape, the size or shape of the fabric, the decorative position of the fabric, the type of the fabric, etc. Mold hot nozzles can be used.

Further, in the embodiment according to the present invention, as shown in FIG. 3, the gate hole 3 is arranged so as to project into the cavity 5 by a predetermined length d, but when the hot runner is taken out immediately after molding, This gap is filled with the same molten resin so that design problems do not occur in the quality of the molded product.

The case of molding the vehicle door trim 1 has been described above as the embodiment of the present invention.
In addition to the above, the above-described fabric decoration molding method may be applied to automobile instrument panels, side garnishes, or products in different fields such as daily necessities and home appliances.

[0021]

Since the present invention is a method for forming and decorating a fabric configured as described above, according to the invention described in claim 1, the hot nozzle is used to integrate the fabric and the molten resin. It is possible to provide a simple and relatively low-cost fabric decoration molding method for molding into a fabric.

According to the invention described in claim 2, in addition to the effect described in claim 1, by arranging the outlet hole of the hot nozzle in a direction parallel to the fabric, the molten resin is directly applied to the fabric. Therefore, it is possible to avoid the occurrence of problems such as hair collapse on the fabric after molding, especially immediately before the hot nozzle, in order to avoid hitting in the vertical direction.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a method for forming and decorating a fabric for a vehicle door trim according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view taken along the line AA.

FIG. 3 is a conceptual diagram showing a molten resin injection method of a hot nozzle used in the fabric decoration molding method according to the embodiment of the present invention.

FIG. 4 is a conceptual diagram showing a conventional method for decorating and forming a fabric for automobile door trim.

FIG. 5 is a conceptual diagram showing a molten resin injection method in a fabric decoration molding method according to a conventional technique.

[Explanation of symbols]

1 door trim 2 decoration range 3 gate holes 4 fabric 5 cavities 8 movable molds 9 Fixed mold 10 hot nozzles

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tetsuo Shimizu             Co., Ltd., 5158 Hiraguchi, Hamakita City, Shizuoka Prefecture             Ota seat (72) Inventor Junji Okano             Co., Ltd., 5158 Hiraguchi, Hamakita City, Shizuoka Prefecture             Ota seat (72) Inventor Tatsuo Jimbo             Co., Ltd., 5158 Hiraguchi, Hamakita City, Shizuoka Prefecture             Ota seat (72) Inventor Fujio Yamada             3-48 Toei, Chiryu City, Aichi Prefecture Esuipi             Within the corporation (72) Inventor Katsuaki Oshima             3-48 Toei, Chiryu City, Aichi Prefecture Esuipi             Within the corporation (72) Inventor Mineo Funamizu             3-48 Toei, Chiryu City, Aichi Prefecture Esuipi             Within the corporation (72) Inventor Daisaku Yamaguchi             1-1 Fukutomi Nagata Gifu City Gifu Prefecture Yamaguchi Seiki Co., Ltd.             Business F term (reference) 4F202 AD16 AH25 CA11 CB01 CB12                       CB13 CK02                 4F206 AD16 AH25 JA07 JB12 JB13                       JQ81

Claims (2)

[Claims] 1. A fabric having a predetermined shape is placed in a cavity formed between a pair of movable molds and a fixed mold,
In a fabric decoration molding method of supplying a molten resin into the cavity to integrally mold the fabric and the molten resin, at least one hot nozzle in at least one of the pair of movable molds and fixed molds. And arranging the fabric at a predetermined position in a cavity facing the hot nozzle, and supplying molten resin into the cavity to integrally mold the fabric and the molten resin. Decorative molding method. 2. The method for decorating fabric decoration according to claim 1, wherein the hot nozzle is a branched hot nozzle.