JPH0255221B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fiber-reinforced plastic tube (hereinafter referred to as
Regarding molding equipment for FRP pipes.

Conventional methods for forming FRP pipes include the FW method, centrifugal molding, hand lay-up method, and spray-up molding method. The FW method is a method in which a glass roving is pre-impregnated with resin, then wrapped around a rotating mandrel under tension and cured. Therefore, a difference in strength occurs between the axial direction and the circumferential direction of the molded product. In addition, because the molding method wraps around the outside of the mold, the finished appearance (outer surface) of the molded product may be poor.
When performing secondary bonding on the inner surface of FRP pipes, there are drawbacks depending on the purpose of the molded product, such as the need to grind the inner surface with a sander to increase the bonding strength.
The centrifugal molding method supplies glass fibers and a resin composition inside a hollow mandrel that is rotating at high speed.
This method uses centrifugal force to impregnate glass fibers with resin, defoaming them, and curing them. This method requires high-speed rotation of the mandrel in order to obtain a large centrifugal force. As the diameter of the mandrel increases, the weight also increases, and excessive external force is applied to the bearing due to deformation due to heat or eccentric load during molding, which can cause failure. In addition, with the centrifugal molding method, it is impossible to change the wall thickness in the axial direction, and if the glass content (ratio of glass fiber to resin) is increased,
Centrifugal force alone has drawbacks such as insufficient impregnation and defoaming, making it difficult to increase the glass content. In addition, the hand lay-up method and spray-up method require a lot of time for molding, so it is necessary to streamline and
Development of a machine is desired.

The present invention eliminates the drawbacks of these conventional manufacturing methods and molded products, has a small difference in strength in the axial and circumferential directions, and reduces the need for internally wound FRP pipes that require no sanding when secondary bonding to the internal surface. Molding by speed rotation,
The wall thickness of the FRP pipe in the axial direction can be freely changed, and the glass content can be made relatively high.
It provides a molding device for FRP pipes.

The present invention uses a hollow circular horizontal formwork that moves while rotating, cuts the glass roving before reaching the inner surface of the formwork and mixes it with a resin composition, and mixes the cut glass roving and the resin composition. The resin composition is supplied to the inner surface of the mold in a state in which the resin composition is The present invention relates to an FRP pipe forming apparatus in which a resin composition and cut glass roving are supplied in a mixed state, and the glass roving is impregnated with a resin composition and defoamed using the above-mentioned impregnating and defoaming apparatus.

In the present invention, the resin composition used is a room temperature curable resin, for example, a composition containing an unsaturated polyester resin. The resin composition may contain a curing agent, a curing accelerator, a filler, etc. as necessary.

Filling materials include calcium carbonate, talc,
Organic and inorganic fillers such as aluminum hydroxide, clay, glass balloons, and milled fibers can be used depending on the required performance of the product.

A known hollow circular formwork is used. The glass roving is fed into the mold while being cut to a predetermined length. The glass roving supplied into the mold and cut is impregnated with the resin composition supplied into the mold and defoamed. The formwork is reciprocated as many times as necessary depending on the thickness of the FRP pipe. Since the formwork is moved while rotating, if the supply amount of the resin composition and cut glass roving is constant and the moving speed of the formwork is constant, a homogeneous FRP with a constant wall thickness can be produced.
A pipe is obtained, and by changing the moving speed arbitrarily, the wall thickness of the FRP pipe can be freely changed in the axial direction.

In the molding apparatus according to the present invention, an impregnating and defoaming device that rotates as the mold frame rotates is disposed near a point where the resin composition and cut glass rovings are fed into the mold frame. A resin composition and cut glass rovings are supplied to the inner surface of the mold and pressed against the inner surface of the mold by an impregnating and defoaming device. The resin composition and the cut glass roving are supplied to the inner surface of the mold in a mixed state. Due to the action of the impregnating and defoaming device and the adhesion of the resin composition to the inner surface of the mold, sufficient impregnation and defoaming can be achieved even within the critical speed (the speed at which the centrifugal force generated by the rotation of the mold balances the gravity of the resin and glass). will be done.

Next, embodiments of the present invention will be described with reference to the drawings.

In FIGS. 1 and 2, reference numeral 1 denotes a circular formwork that moves while rotating, and is rotatably supported around a horizontal axis 3 via a plurality of rollers 2, and its rotation is controlled by a drive device 4. This is done using the roller 2. These are placed on a traverse frame 5 that moves in the axial direction of the formwork, and are moved together with the traverse frame 5 by a drive device 6. 7 is a supply device for the resin composition and the cut glass roving; 8 is an impregnation and defoaming device for impregnating and defoaming the cut glass roving with the resin composition; It is attached to the tip of the arm 9 that fixes the device. 11 is a glass roving, 12 is a resin composition, and 13 is a resin composition supply pump.

FIGS. 3a and 3b show an example of a feeding device that feeds the glass roving while cutting it into the inner surface of the mold while mixing it with the resin composition. This feeding device is configured to be able to produce cut glass rovings of different sizes. That is, it consists of a receiving roller 10A, a roller with a cutting blade 10B, and a pinch roller 10C. Glass roving 11, which is a continuous long fiber, is 1
It is supplied between 0A and 10C, and by driving 10A, glass roving 11 is cut into 11a by 10B. The length of the glass roving to be cut can be changed by changing the pitch between the blades of 10B. On the other hand, the resin composition 12 is supplied to the resin composition supply nozzle 1 by the resin composition supply pump 13.
4 and cut glass roving 11
It is distributed and supplied to the inner surface of the mold together with a.

Figure 4 shows an impregnating and degassing device, which consists of cut glass rovings 1 distributed and supplied to the inner surface of the formwork.
It impregnates and defoames the resin 1a and the resin 12, and comes into contact with the inner surface of the mold and rotates as the mold rotates. To explain the impregnating and defoaming device, in FIG. 4, 8A indicates a defoaming roll, which preferably has a cylindrical shape and has grooves in the circumferential direction on its surface to facilitate impregnation and defoaming. Various methods can be considered, such as wrapping a brush around the area, but there are no particular limitations. Reference numeral 8B denotes a support arm for the defoaming roll 8A, which is attached to the tip of the fixed arm 9 so as to be rotatable about X as a fulcrum. The defoaming roll 8A is fitted into the tip of the support arm 8B so as to contact the inner surface of the formwork 1 and rotate as the formwork rotates. The pressing pressure of the defoaming roll 8A against the formwork 1 is:
This is performed by a pressure regulator 8C that connects the support arm 8B and the fixed arm 9. The pressure of the pressure regulator 8C can be adjusted using an air cylinder, oil pressure, spring, etc. The connection between the support arm 8B, the fixed arm 9, and the pressure regulator 8C is supported by a fulcrum that can rotate so that the length of the pressure regulator 8C can be changed by adjusting the pressure. The spray gun 8D sprays a solvent or the like toward the defoaming roll surface to prevent the resin composition and cut glass roving from adhering to and wrapping around the defoaming roll, and is provided as necessary. . This can be done with a paint spray gun, etc.

The optimum mounting position of the impregnating and defoaming device will be explained with reference to FIG.

The formwork 1 is rotated counterclockwise in the direction of the arrow shown in the figure. The contact point between the formwork and the defoaming roll 8A is marked ○A. The angle α formed by the line ○B from the contact point ○A toward the center of the formwork 1 and the support arm 8B is preferably in the range of 30 to 90 degrees.

According to the present invention, the rotational speed of the formwork is set within the so-called critical speed, which is the speed at which the centrifugal force generated by the rotation and the gravity of the resin composition and the cut glass roving are almost equal. Can be done.

According to the present invention, although it depends on the molding thickness of the FRP pipe and the viscosity of the resin composition used, approximately 1/1/2 of the critical speed is achieved.
Even at a speed as low as 5, sufficient impregnation and defoaming can be achieved and an excellent molded product can be obtained.

An example will be explained.

Example 1 An FRP pipe was formed using the apparatus shown in FIG.

1 Dimensions of FRP pipe: Outer diameter 2500 mm Thickness 10 mm Length 10 m 3 Materials used Unsaturated polyester resin Polyset 595PT (manufactured by Hitachi Chemical) Hardening agent: Permec N (manufactured by NOF) 1.0% by weight of resin Glass fiber: Glass Roving R2310-06-54 (manufactured by Fuji Fiber) 3 Molding conditions Rotating speed of the mold: 12 rpm Moving speed of the mold in the axial direction: 0.16 to 0.64 m/min Setting angle α of the defoaming roll (Fig. 4 a) : 75゜ Diameter of defoaming roll: 300mm Grooved polyethylene material supply amount Unsaturated polyester resin composition 10Kg/min Glass roving 5Kg/min Number of times the formwork is moved: After applying once, return the formwork to the initial position and repeat again. (molded thickness 5 mm at the time of one-time application).

Thickness accuracy of FRP pipe: 10±0.7mm Physical properties of FRP pipe Passed grade 5 of Defense Agency FRP standard with glass content of 32% Molding time: 1 hour Molding temperature: Room temperature Length of cut glass roving: 25mm As shown in the examples, the effects of the invention are that internally wound FRP pipes can be formed at low speeds below the critical speed;
Compared to centrifugal molding which is carried out at above critical speeds, the manufacturing costs of the formwork and drive equipment are lower.

In the centrifugal molding method, the glass content is generally up to 35%, but according to the present invention, it is possible to mold the glass content up to about 50%, which has the effect of increasing the physical strength of the FRP pipe. There is.

In addition, internally wound FRP pipes can be formed by manual labor such as hand lay-up, but the present invention has the effect of reducing the number of man-hours by about 1/10 compared to manual labor.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional front view showing one embodiment of the molding apparatus of the present invention, FIG. 2 is a cross-sectional side view thereof, and FIGS. 3 a and b are schematic diagrams of a feeding device for resin composition and cut glass roving. 4a and 4b are schematic diagrams of the impregnating and defoaming apparatus. Explanation of symbols, 1...Circular formwork, 2...Roller, 3
...Horizontal axis, 4...Drive device, 5...Traverse frame, 6...Drive device, 7...Supply device, 8...Impregnation and defoaming device, 8A...Defoaming roll, 8B...Support arm, 8
C...Pressure regulator, 8D...Spray gun, 9...Arm, 10A...Receiving roller, 10B...Roller with cutting blade, 10C...Pinch roller, 11...Glass roving, 12...Resin composition, 13...Resin composition supply pump , 14...Resin composition supply nozzle.

Claims (1)

[Claims] 1 Hollow circular horizontal formwork that moves while rotating.
A supply device that cuts the glass roving and mixes it with a resin composition before reaching the inner surface of the mold, and supplies the cut glass roving and the resin composition to the inner surface of the mold in a mixed state, and the mold. An impregnating and defoaming device is installed on the inner surface and rotates as the mold rotates, and the resin composition and the cut glass roving are supplied in a mixed state to the inner surface of the mold by the supply device, A molding device for a fiber-reinforced plastic tube, in which the glass roving is impregnated with a resin composition and defoamed using the impregnating and defoaming device described above.