JPH0353089B2 - - Google Patents

Description

Detailed Description of the Invention The present invention uses a molding resin composition obtained by cutting carbon fiber bundles pre-impregnated with a thermosetting resin into lengths of 10 to 50 mm, and compressing and fluidizing them in a mold to form a spinning pot. The present invention relates to a method for manufacturing.

More specifically, a carbon fiber bundle pre-impregnated with a thermosetting resin is cut into lengths of 10 to 50 mm, and a molding resin composition with a carbon fiber content of 35 to 60% by volume is used to fill the lower part of a female mold. , compressing with male and female molds while heating to compress and fluidize the molding resin composition,
The present invention relates to a method for producing a spinning pot that is sufficiently strong and lightweight by being molded throughout the inside of a mold.

In the method of the present invention, the fiber content is reduced without going through a pre-shaping process in which the resin composition for molding is wound around a mold in advance or pasted into a shape that is the same as or similar to that of a spinning pot, which is a molded product. By compressing and fluidizing a molding resin composition with a high carbon content in a mold, a spinning pot can be efficiently produced.

The spinning pot used in the production of man-made fibers is
Since it rotates at high speed, it is required to have sufficient strength for safe operation, and in recent years, it is required to be lightweight in order to save energy.

Conventionally, spinning pots are known to be made of Bakelite with steel wire or fiber reinforced resin (FRP) (Japanese Patent Application Laid-open Nos. 56-15407 and 56-15406).
No. 56-58004, No. 56-20605, No. 53-
(Refer to each publication No. 31810). FRP spinning pots are manufactured by winding the core material over the core material.

However, according to the winding method, it is difficult to wind the yarn at the bottom of the spinning pot (the bottom 2 perpendicular to the axis between the side surface 1 and the tail 3 in FIG. 1), so special measures are required and the operation is difficult. becomes a nuisance.

In addition, when conventional molding methods use resin materials for sheet-like molding, such as resin-impregnated fabrics and resin-impregnated paper, which have a high content of reinforcing materials, drapability is required, and pre-shaping This requires a great deal of manpower and time for lamination. Moreover, the boundaries (seams) of the sheet-like materials often cause defects in the quality of the product pot.

The present inventors conducted studies to solve the above-mentioned difficulties, and as a result, succeeded in producing a spinning pot that has sufficient strength and is lightweight using a simple method.

The present invention is as follows.

10~ carbon fiber bundles pre-impregnated with thermosetting resin
Carbon fiber content cut to 50mm length is 35-60% by volume
The molding resin composition is filled into the lower part of the female mold of the spinning pot, and when the viscosity of the thermosetting resin is between 10 and 1000 poise while heating, the molding is performed using the same male and female molds. 1. A method for producing a spinning pot having a carbon fiber content of 35 to 60% by volume, the method comprising compressing and fluidizing a resin composition for use in spinning and distributing it throughout the inside of a mold.

The spinning pot obtained by the present invention has a carbon fiber content of 35 to 60% by volume and has high strength. Further, according to the present invention, unlike the resin-impregnated fabric or resin-impregnated paper, there is no need for lamination, and there is no defect in the product due to the seam of the sheets, and the fiber content is high and the strength is excellent. In addition, there is no need for the complicated operation seen in winding methods.

The molding resin composition used in the present invention consists of a thermosetting resin and carbon fiber (reinforced fiber) with a fiber length of 10 to 50 mm.
In manufacturing the pot, carbon fiber is included in the molding resin composition in an amount of 35 to 60% by volume. The resin composition for molding may optionally contain a curing agent such as dicyandiamide and a curing accelerator such as 3-(3,
4-dichlorophenyl)-1,1-dimethylurea or the like, to which a flame retardant such as boron trifluoride/monoethylamine ( _BF3 /MEA) is added may also be used. The amount added is usually 5% by weight or less based on the resin. There is no particular restriction on the type of thermosetting resin, and examples thereof include epoxy resins, unsaturated polyester resins, furan resins, phenolic resins, and polyimide resins.

In the present invention, the reinforcing fiber is a carbon fiber having high specific strength and high specific modulus, and is most suitable for reducing the weight of the spinning pot and reducing the thickness of the side wall.
The fiber length of the carbon fiber needs to be 10 to 50 mm; if it is less than 10 mm, it will have little effect on the mechanical properties of the molded product, and if it exceeds 50 mm, the fluidity of the resin composition will deteriorate. Preferably it is around 15 mm.

The molding resin composition used is a carbon fiber bundle impregnated with a thermosetting resin in advance and cut into lengths of 10 to 50 mm. The carbon fiber bundle is a normal carbon fiber bundle composed of 1000 to 24000 filaments.

It is preferable to add a tack regulator, such as talc, to the resin composition, which improves the workability of cutting fiber bundles.

The method of the present invention will be explained with reference to the drawings.

The resin composition for molding is poured into the lower part of the female mold (Fig. 2b).
4) (The lower part here refers to the part corresponding to the tail part of the product pot. Therefore, when molding is performed with the mold shown in Figure 2 upside down, the part of the product pot The viscosity of the thermosetting resin increases while heating.
At a pressure of 10 to 1000 poise, the male mold (Fig. 2a) is press-fitted into the female mold (Fig. 2b), and the resin composition is flowed into the gap between the molds and molded. The state immediately before completion of mold compression is as shown in FIG. 3, and at this time the resin composition consisting of resin and carbon fibers is flowing into the gap between the side walls of the mold. After the compression is completed, the molded product is cured by applying sufficient heat and then removed from the mold to produce a spinning pot.

In the present invention, the male mold must be press-fitted while heating while the thermosetting resin has a viscosity of 10 to 1000 poise. This viscosity refers to the viscosity of a resin composition that contains a thermosetting resin, a curing agent, etc., and does not contain carbon fibers. If the viscosity is less than 10 poise, there will be an imbalance in the flow of the resin and carbon fiber, and in extreme cases, only the resin will flow.
Moreover, when it exceeds 1000 poise, the fluidity of the composition containing resin and fibers becomes poor.

Generally, when the temperature of a thermosetting resin containing a curing agent is increased, the viscosity initially decreases, but when a certain temperature is reached, the viscosity begins to increase due to a curing reaction. The viscosity at this specific temperature is the minimum viscosity.
-7700) when heated from room temperature at 4°C/min, the viscosity changes in three patterns as shown in Figures 4 to 6, centered around 10 to 1000 poise.
Needless to say, this temperature-viscosity curve changes depending on the rate of temperature increase of the resin composition.

As shown in the resins shown in Figure 4, the minimum viscosity is
When the temperature is higher than 1000 poise, it becomes difficult for the carbon fiber and resin to flow. When the resin shown in Figure 5 is heated under pressure, the resin viscosity becomes a value in the resin viscosity range of 10 to 1000 poise, which enables good flow between the carbon fiber and the resin, which is the ideal value. Flow is obtained and molding can be carried out conveniently. As shown in the resin shown in Figure 6, the resin viscosity is 10.
If you try to pressurize the flow in a region where the pressure is less than poise, the flow between the carbon fiber and the resin will become unbalanced, and only the resin will flow.
Attempts to pressurize flow in such areas should be avoided.

If the flow is completed when the resin viscosity is between 10 and 1000 poise before it reaches its minimum, or when the resin viscosity starts to rise after reaching its minimum and reaches a value of 10 to 1000 poise, pressurized flow is performed. , although the latter is generally preferred.

If the temperature is raised suddenly, the curing reaction will rapidly proceed10.
The time between 1000 poise and 1000 poise becomes very short, which is not desirable. It is preferable to pressurize while raising the temperature so that the curing reaction proceeds slowly and the pressure remains in the range of 10 to 1000 poise for as long as necessary for fluidization.

In addition, during heating, the resin viscosity is maintained at an appropriate temperature to allow part of the reaction to proceed and increase the viscosity.
When it reaches 1000 poise, it may be pressurized and fluidized to perform molding.

The optimal resin for the molding resin composition as described above is one that exhibits a temperature-viscosity curve as shown in FIG. 5 when the temperature is raised from room temperature at a rate of 4 DEG C./min.
The following resins can be exemplified as such resins.

[Resin A]

EPN1138 (manufactured by Ciba Kaigy Co., Ltd.) 100 parts by weight Epicote OL-53-B-40 (manufactured by Ciel Chemical Co., Ltd.)
35 〃 Dicyandiamide 3 〃 3-(3,4-dichlorophenyl)-1,1-dimethylurea 5 〃 Minimum viscosity approximately 600 poise [Resin B] EPN1138 (manufactured by Ciba Kaigy) 100 parts by weight DER684-EK-40 (Dow Chemical Company) made)
35 〃 BF ₃・MEA 3 〃 Minimum viscosity approximately 500 poise [Resin C] Epicote 1002) manufactured by Ciel Chemical Co., Ltd.) 80 parts by weight Epicote 828 (same as above) 20 〃 BF ₃・MEA 3 〃 Minimum viscosity approximately 20 poise Method of the present invention When molding is carried out, the volume content of carbon fiber can be increased to 35 to 60% by volume, and the resulting spinning pot has high strength, which makes it possible to reduce the wall thickness and achieve weight reduction. This is advantageous in terms of energy saving measures. Since the present invention uses compression flow molding using a mold, the resulting spinning pot has high precision, the labor of post-processing can be omitted, and the surface of the spinning pot can be finished smoothly.

According to the present invention, the above-mentioned excellent effects can be obtained by a simple method, so the present invention is extremely advantageous industrially.

The present invention will be explained below with reference to Examples.

Example 1 Carbon fiber (Beshuite manufactured by Toho Beslon Co., Ltd.)
100 parts by weight of EPN1138 (manufactured by Ciba Geigy) and Epicoat OL- as an epoxy resin were added to the strands.
35 parts by weight of 53-B-40 (manufactured by Ciel Kagaku Co., Ltd.), 3 parts by weight of dicyandiamide as a curing agent, and 3-(3,4-dichlorophenyl)-1,1- as a curing accelerator.
The material was impregnated with a mixture of 5 parts by weight of dimethyl urea, and 1 part by weight of talc was added to adjust the tack, and then cut into a length of 15 mm. The above material is filled into the lower part of the female mold as shown in Figure 2b, and the male mold shown in Figure 2a is placed on top of it, and the mold temperature is raised to approximately 80°C over 1 hour. Press-fitting of the mold [Fig. 2b] and the male mold [Fig. 2a] was completed, and then the mold temperature was raised to 130°C, and molding was completed in 90 minutes. The viscosity of the resin composition during molding and flow was 900 poise.

The spinning pot obtained by the above method had a very smooth surface and good dimensional accuracy. In addition, the side wall thickness is approximately 3.5 mm, and the weight of the pot is approximately
It was lightweight at 1500g. The carbon fiber content of the pot was 46% by volume.

By the way, the thickness of the side wall of Bakelite spinning pots containing steel wire, which are currently widely used, is 8 mm, and the weight of the pot is about 2600 g.

[Brief explanation of drawings]

Fig. 1 shows an example of a spinning pot, Fig. 2 a shows an example of a spinning pot male mold, and Fig. 2 b shows an example of a spinning pot female mold.
FIG. 3 shows an embodiment of the method of the present invention using a mold. Figure 4 shows the viscosity-temperature relationship when the minimum viscosity is higher than 1000 poise, Figure 5 shows the minimum viscosity between 10 poise and 1000 poise, and Figure 6 shows the viscosity-temperature relationship when the minimum viscosity is lower than 10 poise. shows. Explanation of symbols, 1: Side view of spinning pot, 2:
Bottom part of the spinning pot, 3: Tail part of the spinning pot, 4: Lower part of the spinning pot female mold.

Claims (1)

[Claims] 1 10 carbon fiber bundles pre-impregnated with thermosetting resin
A molding resin composition with a carbon fiber content of 35 to 60% by volume cut into ~50 mm length is filled into the lower part of the female mold of the spinning pot, and heated until the viscosity of the thermosetting resin reaches 10 to 1000. When the carbon fiber content is between 35 and 60% by volume, the molding resin composition is compressed and flowed in the same male and female molds to spread it throughout the mold. A method of manufacturing a spinning pot.