JPH091569A - Manufacture of fiber-reinforced resin product - Google Patents

Abstract

PURPOSE: To provide a simple method for manufacturing a fiber-reinforced resin product capable of rapidly impregnating a reinforcing fiber with a thermosetting resin liquid cured by increasing its viscosity in a short time and molding a predetermined product. CONSTITUTION: An outer mold form 1 is mounted on a bottom plate 2, a predetermined quantity of a resin is cast in the form 1, and then a core 3 previously installed with a reinforcing fiber 7 is inserted into the form 1. Thus, the liquid level of the resin is raised to a specified position, the fiber 7 is impregnated with the resin and then cured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a hollow object reinforced with fibers from a resin, which is used, for example, in the manufacture of resin pipes made from a thermosetting resin.

[0002]

2. Description of the Related Art Conventionally, as a method of manufacturing a hollow resin product reinforced with fibers, a method of continuously molding a pipe material made of a thermosetting resin has been most frequently used. Here, the continuous resin pipe is used. The molding method will be described as a typical example of the conventional technique.

Conventionally, at first, long fibers such as glass impregnated with a thermosetting resin in advance are manually wound around a rotatable mandrel called a mandrel in a vertical and horizontal direction to obtain a predetermined resin. When the layer thickness is reached, a batch method has been adopted in which the whole is heated to cure the resin and then the mandrel is extracted.

However, although the batch method can be manufactured with simple equipment, not only is the resin capable of maintaining the viscosity capable of being impregnated limited during the winding operation that requires a long time, but the required resin layer is made of resin impregnated fibers only. If the necessary thickness is increased for forming, there is an uneconomical aspect in that the amount of fibers used is increased, and it was decided to shift to the continuous molding method described below.

FIG. 4 is a flow chart showing the outline steps of the conventional continuous molding method.

In FIG. 4, first, in step S10,
A long strip of paper prepared in advance is spirally wound around the outer circumference of the mandrel on the mount to form a primary paper tube, and then the mandrel is moved to extend the primary paper tube in the axial direction. After forming, and after reaching a predetermined length, the mandrel is removed (step S11), and then a strip of paper is wound around the extended primary paper tube for several layers to form a thick paper tube (step S12).

On the other hand, reinforcing fibers such as long glass fibers are continuously passed through a resin liquid tank containing a thermosetting resin to produce impregnated fibers in which the reinforcing fibers are impregnated with a resin liquid ( Step S13), winding on the surface of the aforementioned paper tube alternately in the circumferential direction and the axial direction (Step S1).
4).

A belt-shaped resin mortar made by kneading a thermosetting resin and an aggregate is spirally wound around it without any gaps, and if necessary, several layers are stacked to form a primary resin having a required thickness. A tube is formed (step S15).

Then, the primary resin pipe is put in a heating furnace to be heated and cured (step S16), and then step S13.
An impregnated fiber was produced in the same manner as in (step S17), and the impregnated fiber was wound around the surface of the cured primary resin tube for further reinforcement.
The next resin tube is formed (step S18), and is heated and cured again in the heating furnace to form the target fiber-reinforced resin tube material (step S19).

Thereafter, the pipe material is cut into a predetermined length and the paper tube of the inner layer is pulled out (step S20) to manufacture a desired product.

Thereafter, the cutting of the pipe material in step S20,
The work of pulling out the paper tube is repeated (step S21).

[0012]

However, in the case of the manufacturing method of the above technique, the resin is impregnated into the fiber by continuously passing the reinforcing fiber through the resin liquid tank, and the impregnated fiber is impregnated with paper. Since it is a method of winding on a pipe, it is necessary to keep the viscosity low enough to allow the resin liquid to be impregnated into the reinforcing fiber during the winding process which requires several tens of minutes.

As the resin liquid used in this method, an unsaturated polyester is generally used because it is hard to cure at room temperature and maintains a low viscosity for a long time, but it rapidly cures when heated. However, when mixed with a curing agent, a phenol resin liquid that is lightweight and has high temperature durability has a white turbidity phenomenon even after about 10 minutes even at room temperature, resulting in a rapid increase in viscosity, which results in Since impregnation cannot be performed, this method cannot be used in this method, which requires a long time for winding work.

Further, the hand spray-up method in which the unsaturated polyester solution is sprayed with a spray gun immediately before winding the reinforcing fiber tends to scatter to the surroundings, and liquid particles come into contact with the outside air to accelerate curing.

That is, in the case of this method, there is a problem that usable resins are limited.

Further, in this method, although the complicated process is almost automated, there is a contradiction that the process becomes more advantageous as the equipment such as the paper tube and the mounting base becomes longer, and the longitudinal section is the same. Applicable only to products that are
When changing the diameter of the resin pipe, it is necessary to make adjustments over all equipment, and furthermore, when the product is completed, a paper tube that must be discarded is produced, which is a waste of materials.

[0017]

The method for producing a fiber-reinforced resin product of the present invention is a method of manufacturing a fiber-reinforced resin product, which comprises: The core in which the reinforcing fibers are stretched is inserted into the resin liquid to raise the liquid level of the resin to a predetermined position, and the entire reinforcing fibers are impregnated with the resin liquid and then cured.

[0018]

First, the reinforcing fiber is stretched around the core in the axial direction and / or the circumferential direction. Next, a pre-measured curable resin liquid is poured into the outer mold to which the bottom plate is attached, and then the core is gently inserted into the outer mold from above. At this time, the liquid level of the previously injected resin rises by an amount corresponding to the volumes of the core and the reinforcing fiber and reaches the specified position. If this state is maintained, the resin completely penetrates into the reinforcing fibers, and balance between the liquid level increase due to the capillary phenomenon and the liquid level decrease due to bubble discharge, and the liquid level is stabilized. When the liquid level is stabilized in this way, a desired product is manufactured by heating and curing and then extruding a resin from the outer mold and cutting both ends.

[0019]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a partially cutaway side view showing a schematic structure of a mold of a product manufactured based on the method for manufacturing a fiber-reinforced resin product according to the present invention, and FIG. 2 is a state without a stop plate. FIG. 3 is a plan view showing the schematic structure of the upper part of the mold.

In FIGS. 1 and 2, reference numeral 1 denotes an outer form having an upper flange 11 and a lower flange 12, which is formed in a hollow truncated cone shape having a thick upper portion and a thin lower portion. A circular bottom plate 2 is attached below the outer mold 1 by a plurality of attachment bolts 21.

Reference numeral 3 denotes a core metal (hereinafter referred to as a core) which is a middle frame loosely fitted and arranged in the outer mold frame 1, and like the outer mold frame 1 described above, has a hollow upper part and a lower part which is thin. It is formed in a truncated cone shape, and a filling space 4 is formed between the outer mold 1 and the core 3. A suspending metal fitting 32 is provided on the upper end of the core body 31 occupying the main body of the core 3, a crown-shaped upper claw 5 is attached to the outer peripheral surface of the upper end, and the outer peripheral surface of the lower end has the same shape. A fitting portion 33 into which the crown-shaped lower claw 6 is fitted is formed.

As shown in FIGS. 1 and 2, the upper claw 5 has an upper claw ring 51 mounted on the upper end of the peripheral surface of the core body 31.
And a plurality of upper claws 52 radially mounted on the peripheral surface of the upper claw ring 51 at appropriate intervals.

The lower claw metal 6 is mounted radially on the lower claw ring 61 fitted in the fitting part 33 and on the peripheral surface of the lower claw ring 61 at an appropriate interval so as to correspond to the lower inner diameter of the outer mold frame 1. It is composed of a plurality of lower claws 62 planted with substantially the same outer diameter.

Between the plurality of upper claws 52 and the lower claws 62, a plurality of reinforcing fibers 7 for reinforcing the resin product, for example, long glass fibers, are reciprocated and stretched.

On the upper surface of the upper flange 11, a circular stopper plate 8 having a support hole 81 in the center is detachably arranged, and the inner diameter of the support hole 81 is the outer circumference formed by a plurality of upper claws 52. The diameter is the same as that of the outer mold 1 and is slightly smaller than the inner diameter of the upper part of the outer mold 1, and is attached to the upper flange 11 by a plurality of mounting bolts 82.

Next, a method of manufacturing a fiber reinforced resin product by using the mold configured as described above will be described with reference to FIG.

First, the core 3 is mounted on the core body 31 installed on a mounting base (not shown), and the core 3 is attached.
Are assembled (step S1), and the reinforcing fiber 7 is multiply stretched between the upper claw 52 and the lower claw 62 in the axial direction and / or the circumferential direction (step S2).

Next, the outer formwork 1 is mounted on the bottom plate 2 with the mounting bolts 21.
After fixing by (step S3), a resin solution (hereinafter simply referred to as resin) in which an appropriate amount of a curing agent is mixed with a pre-measured thermosetting resin such as phenol resin is injected into the outer mold 1 (step). S4), subsequently, the core 3 on which the reinforcing fiber 7 is stretched is gently inserted from above the outer mold 1. At this time, since the outer diameter of the lower claw formed by the plurality of lower claws 62 and the inner diameter of the lower end of the outer mold 1 are almost the same, the core 3 is placed at the center of the outer mold 1, and The liquid level of the previously injected resin rises by an amount corresponding to the volumes of the core 3 and the reinforcing fiber 7 and reaches the specified position near the upper flange 11 in the formed filling space 4. Core 3 in this state
If the stopper plate 8 is covered from above the support hole 8 as described above,
Since the inner diameter of 1 and the outer diameter of the upper claw 52 are the same, the stopper plate 8 is attached to the upper flange 11 by the mounting bolt 82.
The core 3 is fixed to the center of the outer mold 1 by fixing the core 3 (step S5).

If this state is maintained, the resin completely permeates the reinforcing fiber 7, balances the liquid level increase due to the capillary phenomenon and the liquid level decrease due to bubble discharge, and the liquid level is stabilized (step S6). .

When the liquid level is stabilized in this way, the whole is brought into a heating furnace and heated and cured (step S7).
When the core body 31 is carried out to the outside and the core body 31 is pulled up by the take-out device (not shown) via the hanging metal fitting 32, the resin reinforced by the reinforcing fibers 7 is held by the stopper plate 8 and cannot be lifted up. , The upper claw 52, the lower claw ring 61, and the lower claw 62 remain in the outer mold 1. Then, after removing the stopper plate 8 and the bottom plate 2, resin is extruded from the outer mold 1 (step S8),
If the upper claw 52 and the lower claw 62 are cut (step S
9) The desired product is manufactured. [Test results] Pipe length 55
The results of the production of a prototype having a diameter of 00 mm, an outer diameter of 190 mm, a wall thickness of 12 to 20 mm and an amount of reinforcing fibers of 13 kg by the above-mentioned method are shown below.

First, in step S2, which is the preparation period, 2
Although it took 0 minutes, (1) the time for blending the resin and the curing agent was 1 minute (2) the time for injecting it into the outer mold 1, that is, 1.5 minutes in step S4 (3) the core Until the insertion is completed (the first step of step S5)
Was 2 minutes.

As a result, (1) + (2) + (3) becomes 4.
It only takes 5 minutes, and the time from the start of blending until the occurrence of cloudiness is 10
I was able to completely fall below a minute.

In the present embodiment, the outer mold 1 and the core 3 have been described as hollow and frustoconical, which is suitable for the production of electric poles. Any of the above can be applied.

Although the thermosetting resin has been described as a phenolic resin, according to the present application, not only unsaturated polyester but also epoxy resin can be used since the time required from resin mixing adjustment to core fixing is short. And reinforcing fiber 7
Although the long glass fiber is exemplified, other organic fiber, cloth glass fiber, or metal net may be used.

Further, the outer mold frame may be formed by assembling appropriately divided dividing members.

[0037]

EFFECTS OF THE INVENTION The present invention is a system in which a core in which a reinforcing fiber is stretched is inserted into a predetermined amount of resin to raise the resin liquid level and the entire reinforcing fiber is impregnated with the resin. Since the resin is exposed to the outside air for a short period of time and a low viscosity can be maintained, the restriction on the resin used can be relaxed and a method with excellent versatility can be provided.

Further, unlike the conventional continuous molding method, since the molding can be easily carried out in a desired mold, not only the shape and size of the product are not limited, but also a long apparatus is not required.
Further, since the resin is made to flow in from above, it is not necessary to use a sturdy facility such as a pressure injection method from below.

Further, since there is no resin liquid tank or hand spray device, safe and clean work can be performed, and no extra material such as a paper tube is required.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view showing a schematic structure of a mold of a product manufactured based on a method for manufacturing a fiber-reinforced resin product according to the present invention.

FIG. 2 is a plan view showing a schematic structure of an upper portion of a mold.

FIG. 3 is a flowchart illustrating a manufacturing method of the present invention.

FIG. 4 is a flowchart showing a schematic process of a conventional continuous molding system.

[Explanation of symbols]

 1 Outer formwork 2 Bottom plate 3 Core 7 Fiber for reinforcement

Claims (1)

[Claims] 1. A constant amount of a curable resin liquid is injected into an outer mold which is mounted on a bottom plate and has an open upper end, and a core in which reinforcing fibers are stretched in advance is inserted into the resin liquid. Then, the liquid level of the resin is raised to a predetermined position, the entire reinforcing fiber is impregnated with the resin liquid, and then the resin is cured.