JPH0692126B2 - Method for manufacturing fiber-reinforced plastic pipe material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a pipe material made of fiber reinforced plastic which is used as a mast or other structural material of a ship.

(Prior Art) Conventionally, the fiber-reinforced plastic pipe material is manufactured by the pultrusion method,
It is molded by a method such as a filament winding molding method.

(Problems to be Solved by the Invention) Among the conventional molding methods described above, in the pultrusion molding method, an expensive mold is required for each shape related to molding, and the equipment of the molding machine is expensive. In the filament winding molding method, an expensive mandrel is also required for each shape related to molding, the equipment of the molding machine is expensive, and the productivity is poor. Further, in any of the molding methods, it is necessary to arrange the fibers at an angle with respect to the axial direction of the pipe material, so that the fibers cannot be arranged in parallel with the axial direction of the pipe material, and therefore the fiber reinforced There is a drawback in that the effect of 1 cannot be maximized in the longitudinal direction.

On the other hand, there is a method of manufacturing a tubular body by winding a woven fabric of reinforcing fibers impregnated with synthetic resin around the core material and curing the synthetic resin. This causes problems such as variation in dimensions and easy occurrence of delamination, which may weaken the finished product.

Therefore, the present invention does not require expensive equipment machines, molds, mandrels, etc., can be produced at low cost, is suitable for the production of a small amount of other types of tubing, and fibers in the axial direction of the tubing. It is an object of the present invention to provide a molding method which can be arranged, and which can further improve strength and size.

(Means for Solving the Problems) In the present invention, in order to solve the above problems, a paper tube such as a cylinder or a square tube is used as a core material, and a woven or non-woven fabric prepreg of reinforcing fibers is wound around the core material. Or, wrapping a woven or non-woven fabric of reinforcing fibers not impregnated with synthetic resin, impregnating with synthetic resin, curing the synthetic resin, and then destroying the paper cylinder to produce fiber reinforced plastic tubing Adopted the method of doing. In addition, in order to maximize the effect of fiber reinforcement in the longitudinal direction, we adopted a method to match the extension direction of the fiber with the extension direction of the core material when winding woven or non-woven fabric of reinforcing fibers or their prepregs. did. In addition, in order to prevent the deformation of the paper cylinder as the core material during molding, a method is adopted to dry the paper cylinder and stabilize its dimensions before winding the woven or non-woven fabric of reinforcing fibers or their prepregs. did. Further, when the paper cylinder as the core material is destroyed and removed after the synthetic resin is hardened, a method is adopted in which the paper cylinder is soaked in hot water and the paste is dissolved to destroy it.

(Working) In the manufacturing method of the present invention, a paper tube widely used for concrete formwork is used as the core material. In this type of paper cylinder, not only cylindrical shape but also square shape,
An arbitrary rectangular tube such as a hexagon can be obtained at low cost. Further, the paper cylinder is lightweight, easy to handle, and excellent in workability. According to this method, large-scale and expensive equipment, mold, and mandrel are unnecessary. This method is particularly suitable for high-mix low-volume production. Upon molding, the extending direction of the fibers in the woven or non-woven fabric of the reinforcing fibers can be arranged parallel to the axis of the paper cylinder as the core material. In this case, the mechanical properties in the longitudinal direction of the pipe material are large. Be improved.

(Embodiment) "Embodiment 1" A first embodiment of the present invention will be described with reference to FIGS. 1 to 6 show the steps of the manufacturing method according to the first embodiment of the present invention, and FIG. 1 is a perspective view of a paper tube,
2 is a cross-sectional view of the paper cylinder in a sealed state, FIG. 3 is a perspective view showing the winding process of the material, FIG. 4 is a cross-sectional view of the paper cylinder wound with the material, and FIG. 5 is a restraining tape. Fig. 6 is a perspective view showing the winding process of Fig. 6, Fig. 6 is a sectional view of the constraining tape in a wound state, Fig. 7 is a perspective view showing a resin curing process, and Fig. 8 is a sectional view of a completed fiber-reinforced plastic pipe material.

In this example, a circular paper tube 1 (commercially available concrete formwork paper tube) having an outer diameter of 100 mm, a length of 5,000 mm and a thickness of 7 mm was used as a core material, and CFRP (carbon fiber reinforced plastic) was used as the core material.
The CFRP pipe material 10 is molded by winding the non-woven fabric prepreg 2 (which is obtained by impregnating fibers with a synthetic resin in advance).

In this method, first, as shown in FIG.
After heating at 0 ° C for 30 minutes and drying, as shown in Fig. 2,
Immediately after inserting the desiccant 3 into the inside, a moistureproof seal 4 made of a water-impervious synthetic resin film is attached to both ends for sealing. This drying process reduces the diameter of the paper tube 1 by 0.2 to 0.3 mm.

Then, as shown in FIGS. 3 and 4, CFR is attached to the outer circumference of the paper cylinder 1.
Ten layers of the non-woven fabric prepreg 2 of P were wound. The nonwoven fabric has fibers arranged in one direction, and in this example, the fibers were wound in six layers in parallel with the axis of the paper tube 1 and four layers in the circumferential direction.

Then, as shown in FIGS. 5 and 6, a polyester restraining tape 5 is wrapped around the outer periphery of the prepreg 2, and as shown in FIG. 7, heated at 160 ° C. for 1 hour to squeeze out excess resin, The layers of prepreg 2 were adhered to each other to cure the resin.

Next, this was dipped in boiling water to elute the glue in the paper tube 1 to weaken it, and then destroyed and removed.

As a result, as shown in FIG.
We were able to manufacture a healthy CFRP pipe material 10 with a length of 2 mm and a length of 4,000 mm. The bending elastic modulus (Kgf /
mm ² ) and bending strength (Kgf / mm ² ) are compared with those of CFRP pipe material of the same shape produced by the filament winding method.

As shown in the above table, the product of the present invention exhibits superior properties to those obtained by the filament winding method, in the filament winding method, the direction of the reinforcing fibers is inclined with respect to the axis of the pipe material. In the present invention, it is based on the fact that it is completely parallel to the axis.

When the paper tube 1 is used without being dried by preliminary heating, shrinkage occurs at the time of heating for hardening the resin,
The effect of restraint by the restraint tape 5 was diminished, and eventually, 30% of the surface area of the finished product had a delaminated portion.

"Example 2" In another example, 250 mm x 250 mm square, length 6,000 mm, thickness 8
mm square tubular paper cylinder is used as the core material, and a hybrid CFRP woven fabric is wrapped around this core, which is impregnated with synthetic resin to form CF.
RP pipe material was molded. In this example, instead of the prepreg, a woven fabric not previously impregnated with a resin is wound,
The method is almost the same as the method of the previous embodiment except that it is impregnated with resin later, and thus the illustration is omitted.

That is, in this example, the paper cylinder was previously dried at 140 ° C. for 1 hour, and then the vinyl ester-based paint was applied to the inner peripheral surface and both end surfaces to prevent moisture. Then, the operation of spraying and impregnating the synthetic resin by spraying on each roll of the hybrid CFRP woven fabric was repeated to form eight hybrid CFRP woven fabric layers. Then, this was heated at 140 ° C. for 1 hour to cure the synthetic resin, and then the paper cylinder was removed in the same manner as in the previous example to manufacture a tubular material.

As a result, there is no resin accumulation on the corners as seen in the conventional drawing method, and it is a very good 253 mm × 253 mm.
× 5,500mm square tube material was completed.

(Effects of the Invention) As described above, in the present invention, the paper cylinder 1 such as a cylinder or a square cylinder which is heated and dried, and in which the desiccant 3 is inserted and sealed with the moisture-proof seal 4 is used as the core material. Wrap woven or non-woven fabric prepreg 2 around the outer periphery,
Alternatively, a woven or non-woven fabric of reinforcing fibers not impregnated with synthetic resin may be wrapped around to impregnate the synthetic resin, and then a binding tape may be wrapped around the outer periphery of the prepreg 2 to cure the synthetic resin, and then the paper tube 1 By adopting the method of manufacturing the fiber-reinforced plastic pipe material 10 by destroying, the core material of arbitrary shape can be obtained at extremely low cost, expensive molding machine equipment is not required, and therefore the fiber-reinforced plastic pipe material can be supplied at low cost. be able to. Further, by appropriately drying the inside and outside of the paper tube 1, it is possible to prevent the paper tube 1 from shrinking during heating for hardening the resin, so that the dimensions can be stabilized and the binding tape can be bound. By the action, the layers adhere to each other, and strength that does not weaken by peeling can be obtained. Further, when the woven or non-woven fabric of reinforcing fibers or the prepreg thereof is wound and the extension direction of the fibers is aligned with the extension direction of the core material, the fiber reinforcement effect is maximized in the longitudinal direction. It is possible to provide a fiber-reinforced plastic pipe material having higher strength than that obtained by the conventional method.

[Brief description of drawings]

The drawings show the manufacturing process of one embodiment of the present invention.
FIG. 2 is a perspective view of the paper cylinder, FIG. 2 is a sectional view of the paper cylinder in a sealed state,
FIG. 3 is a perspective view showing a winding process of the material, FIG. 4 is a sectional view showing a state in which the material is wound around a paper tube, FIG. 5 is a perspective view showing a winding process of a restraining tape, and FIG. 6 is a restraining tape. FIG. 7 is a cross-sectional view of a tape wound state, FIG. 7 is a perspective view showing a resin curing process, and FIG. 8 is a cross-sectional view of a completed fiber-reinforced plastic pipe material. 1 ... paper cylinder, 2 ... prepreg, 3 ... desiccant, 4 ...
Moisture-proof seal, 5 ... Restraint tape, 10 ... Fiber reinforced plastic pipe material.

Claims (4)

[Claims] 1. A paper cylinder, such as a cylinder or a square cylinder, which is heated and dried, and a desiccant is inserted into the inside to seal the openings at both ends with moisture-proof seals, is used as a core material, and the outer periphery thereof is impregnated with a synthetic resin in advance. A method for producing a fiber-reinforced plastic pipe material, which comprises wrapping a woven or non-woven fabric of reinforcing fibers, further winding a restraining tape around the outer periphery thereof, curing the synthetic resin, and then breaking the paper cylinder. 2. A core material is a paper cylinder, such as a cylinder or a square cylinder, which is heated and dried, and a desiccant is inserted thereinto, and openings at both ends are sealed with moisture-proof seals. Alternatively, a method for producing a fiber-reinforced plastic pipe material, which comprises winding a non-woven fabric, impregnating the fiber with a synthetic resin, winding a binding tape around the fiber, curing the synthetic resin, and then breaking the paper cylinder. . 3. The woven or non-woven fabric of the reinforcing fiber is wound around a core material such that the extension direction of the fiber is the same as the extension direction of the core material. For manufacturing fiber reinforced plastic pipe material. 4. The method for producing a fiber-reinforced plastic pipe material according to claim 1, wherein the paper cylinder as the core material is destroyed by dissolving the paste in hot water.