JPH0148861B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention combines a sheet winding method and a compression flow molding method to create a spinning pot made of fiber reinforced resin (FRP) in which the side wall portion and the bottom/tail portion have different fiber shapes. This invention relates to a molding method that allows easy simultaneous production.

The spinning pot used in the production of man-made fibers is
With the artificial fiber cake inside, it is about
Since it rotates at a high speed of 8000 rpm, it is required to have sufficient strength from a safety standpoint.In addition, from the standpoint of energy conservation, it must be lightweight to reduce power and reduce air resistance during rotation. Therefore, it is required that the wall thickness be thin and the surface be smooth.

In response to these demands, products made of Bakelite with steel wires and products made of fiber reinforced resin (FRP) using carbon fiber have been proposed (Japanese Patent Application Laid-open Nos. 56-15406 and 56-15407). , 56−
(See Publication No. 18004).

As shown in Fig. 1, a spinning pot consists of a side wall 1, a bottom 2, and a tail 3. Generally, in order to save energy, the thickness of the side wall is made thinner to reduce weight. The most effective method is to smooth the surface and reduce air resistance during driving. The above-mentioned FRP spinning pot is suitable for reducing the weight of the side wall because the fibers can be oriented in a specific direction to increase strength and reduce the wall thickness accordingly, making it a promising energy-saving measure. However, in reality, when attempting to manufacture a spinning pot made of FRP with long fibers oriented in the circumferential direction of the pot, the following problems occurred.

For example, when trying to wind fibers circumferentially using the filament winding method, it is technically difficult to wind the bottom part perpendicular to the rotation axis of the pot, and it is inevitable to wind the fiber at an angle of about 30 degrees to the circumferential direction. I have no choice but to wind it at an angle. In this case, the tensile strength of FRP decreases significantly. Furthermore, spinning pots formed by the filament winding method require reprocessing such as machining or painting the surface. Further, even by sheet winding or tape winding, it is difficult to conveniently form the spinning pot simultaneously and integrally with the side wall and bottom of the spinning pot.

As a result of our study to develop a molding method that does not have the drawbacks of conventional methods, the present inventors found that the objective could be achieved by adopting an unprecedented technique that combines the sheet winding method and compression flow molding method. I found it.

That is, the present invention has the following gist. This method uses a male mold and a female mold to simultaneously manufacture a spinning pot whose side wall portion, bottom portion, and tail portion are made of fiber-reinforced resin with different fiber forms. A fiber sheet impregnated with a thermosetting resin is wound around the female mold, and the lower part of the female mold is filled with a molding material made of short fibers impregnated with a thermosetting resin.The male mold is incorporated into the female mold, and then heated. The material is compressed at the bottom to flow from the lower part of the female mold to the part corresponding to the side wall of the spinning pot, and the flow pressure at this time pressurizes the resin-impregnated fiber sheet on the side of the male mold.
This is a method of forming a spinning pot in which the entire body is hardened under pressure.

According to the molding method of the present invention, the bottom of the pot can be easily molded, and a spinning pot with almost no thickness unevenness and a smooth surface can be obtained without requiring machining or painting after molding. In the spinning pot obtained here, the fiber morphology of the FRP differs between the side wall part and the bottom/tail part, and in particular, the side wall part is made of unidirectional fibers oriented at ±20 degrees with respect to the pot rotation direction. Products made of FRP reinforced with sheets have the required strength but are thin, making them superior in terms of safety and energy savings.

Next, the molding method of the present invention will be explained.

This molding method is carried out using a male die 4 and a female die 5 as shown in FIG. As shown in FIG. 3, a fiber sheet 6 impregnated with a thermosetting resin is wound around the side surface of the male mold a, and a molding material 7 made of short fibers impregnated with a thermosetting resin is placed under the female mold 5b. Fill.

The fibers of the fiber sheet and the short fibers of the molding material are both inorganic fibers and organic fibers that are normally used in the production of FRP, such as carbon fibers, glass fibers, and aromatic polyamide fibers. One or more types of these can be used. Examples of thermosetting resins include epoxy fibers, unsaturated polyester resins, furan resins, phenolic resins, and polyimide resins.

The mixing ratio of reinforcing fibers and resin is preferably 30 to 70% by volume; if it is less than 30% by volume, the strength will decrease, and if it exceeds 70% by volume, moldability will decrease and the fiber content will increase. There is no commensurate further increase in strength.

As the fiber sheet to be wound around the side surface of the male mold, a fiber sheet aligned in one direction, a fabric sheet, or the like is used. When using unidirectional fiber sheets,
The orientation of the fibers is preferably within a range of ±20 degrees with respect to the circumferential direction which is subject to the greatest stress during operation of the spinning pot, ie, the direction of rotation of the pot. If the orientation angle is outside this range, the strength and elastic modulus of the spinning pot in the circumferential direction will decrease. It is best to arrange the fibers symmetrically. When using a fabric sheet, it is also possible to strengthen the sheet by changing the direction as appropriate with respect to the direction of rotation of the pot.

When winding a fiber sheet around the side of a male mold, the thickness after winding will inevitably be thicker than the cavity of the mold (the gap between the male and female molds, equivalent to the thickness after molding), but it will not fit into the female mold. In order to more smoothly assemble the male die, it is convenient to wind the side of the male die thicker at the bottom and thinner at the top. It is convenient to wind the fiber sheet around the tapered part of the side surface of the male mold by dividing the fiber sheet into several tape-like pieces. The length of the fiber sheet or fiber tape is the circumference of the side wall of the pot.
If it is 1.5 times or less, the fluidity of the material in the mold cavity during molding will be good, and a spinning pot with a smooth surface can be obtained.

The fiber material constituting the molding material filled in the lower part of the female mold is short fiber, and the fiber length is usually 1 to 100.
mm. If it is less than 1 mm, the strength of the molded product will decrease,
If it exceeds 100mm, the fluidity of the molding material will deteriorate,
Neither is preferable.

After preparing as above, insert the male mold into the female mold and compress while heating. At this time,
As shown in Figure 4, the resin impregnated into the fiber sheet wound around the side of the male mold flows into the cavity of the mold due to the fluid pressure of the molding material accompanying the movement of the mold, hardens under pressure, and spins. pots are manufactured.

The obtained spinning pot has no voids, and as shown in FIG. 5, the boundary 12 between the winding portion 10 and the short fiber reinforced portion 11 is firmly integrated, and the entire pot has sufficient strength.

In addition, its surface is smooth like the mold surface, and there is no need for reprocessing. In particular, a spinning pot manufactured by winding a unidirectional long fiber sheet with the fiber orientation angle within a range of ±20 degrees with respect to the pot rotation direction using the molding method of the present invention is most advantageous in terms of strength. Even if the wall thickness of the side wall portion is thin, it has sufficient strength and is extremely useful from the standpoint of safety and energy saving.

The present invention will be explained by examples, and comparative examples will be shown.

Example A unidirectionally aligned prepreg sheet (fiber content: 54 volume %) of carbon fiber impregnated with epoxy resin (Beshuite, manufactured by Toho Beslon Co., Ltd.) was prepared.
Its length (fiber direction) is 1.1 of the circumference of the spinning pot.
I doubled the size and cut the width to about 30mm. The obtained prepreg sheet (400 g) was wound around the side surface of the male mold a shown in FIG. 3 so that the angle between the pot rotation direction and the fiber direction was 0 degrees (parallel). At this time, the untapered upper part of the male mold side surface was wound less than the thickness after molding, and the tapered lower part was wound accordingly, so that the number of layers was increased at the lower part of the side surface.

Separately, a strand of carbon fiber (same as above) impregnated with epoxy resin was cut into a length of 15 mm, and 800 g of the obtained short fibers were filled into the lower part of the female mold b shown in FIG.

Insert the male mold into this female mold and adjust the mold temperature.
It was gradually press-fitted while heating to 80°C. The mold temperature was then raised to 130°C in about 30 minutes. By the time the temperature reached approximately 90°C during this temperature rise, the male mold was completely press-fitted into the female mold. Subsequently, the molding was completed by keeping the temperature at 130°C for about 90 minutes.

The obtained carbon fiber reinforced resin spinning pot was
The surface was extremely smooth and the dimensional accuracy was good.
The side wall thickness is approximately 2mm and the entire pot weighs approximately 1200.
It was hot at g.

By the way, the side wall thickness of Bakelite spinning pots with steel wire, which are currently widely used, is 8 mm.
The total weight of the pot is approximately 2600g.

Comparative example: Approximately 1,500 g of strands of carbon fiber impregnated with epoxy resin (same as above) cut into 15 mm pieces were filled into the lower part of a female mold, and into the female mold was a male mold (no prepreg sheet was wound). was press-fitted and the fibers and resin were flowed to every corner of the sides to form the mold. In this case, the molding conditions were the same as in the examples.

The resulting spinning pot had a smooth surface, but in order to provide the required strength, the side wall thickness was approximately 3.5 mm, and the entire pot weighed approximately 1500 g.

[Brief explanation of drawings]

Figure 1 is a schematic cross-sectional view of the spinning pot, Figure 2 is a schematic cross-sectional view of the male mold incorporated into the female mold, and Figure 3 is a schematic cross-sectional view of the spinning pot.
The figure is a schematic cross-sectional view of a male mold a wound with a prepreg sheet and a female mold b filled with a molding material, and FIG. 4 is a cross-sectional diagram of a male mold a wrapped with a pre-preg sheet and a female mold b filled with a molding material. FIG. FIG. 5 is a partially enlarged cross-sectional diagram showing the fiber orientation in the side wall, bottom, and tail of the spinning pot obtained in the example. Explanation of symbols, 1: Side wall part, 2: Bottom part, 3: Tail part, 4: Male mold, 5: Female mold, 6: Prepreg sheet, 7: Molding material, 8: Part corresponding to the side wall part of the spinning pot, 9: Spinning pot bottom/tail portion, 1
0: Winding part, 11: Short fiber reinforced part, 1
2: Boundary.

Claims (1)

[Scope of Claims] 1. A method for simultaneously and integrally manufacturing a spinning pot whose side wall portion and bottom/tail portion are made of fiber-reinforced resin with different fiber forms, using a male mold and a female mold, the method comprising: A fiber sheet impregnated with a thermosetting resin is wound around the side of the mold, a molding material made of short fibers impregnated with a thermosetting resin is filled in the lower part of the female mold, and the above-mentioned material is poured into the female mold. After incorporating the male mold, it is compressed under heat to flow the molding material from the lower part of the female mold to a portion corresponding to the side wall of the spinning pot, and while the flow pressure at this time pressurizes the resin-impregnated fiber sheet on the side of the male mold, A method for forming spinning pots that hardens the entire body under pressure. 2. The molding method according to claim 1, wherein a unidirectional fiber sheet impregnated with a thermosetting resin is wound around the side surface of the male die so that the orientation angle of the fibers is within a range of ±20 degrees with respect to the spinning pot rotation direction. 3. The molding method according to claim 1, wherein a fabric sheet impregnated with a thermosetting resin is wound around the side surface of the male mold.