JPH0232132B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to fiber-reinforced plastics (hereinafter referred to as
Regarding continuous pultrusion molding of cylinders (abbreviated as FRP) and its equipment, for example, continuous pultrusion molding of lightweight, long and thin cylinders using high elasticity carbon fiber as a reinforcing material, such as those used as members for large space structures. The present invention relates to applicable methods and devices used therein.

[Conventional technology]

Impregnated with thermosetting resin to form a matrix
The pultrusion method is well known as a continuous molding method for long molded products with a constant cross-sectional shape, such as FRP cylinders. Manufacturing is actually taking place.

FIG. 3 shows an example of molding a solid rod, and is taken from Japanese Patent Laid-Open No. 75263/1983 as a block diagram for explaining the basic concept of a conventional pultrusion method and its apparatus. In the figure, 1 is a reinforcing fiber fed out from a bobbin, 2 is a bath for impregnating thermosetting resin, 3 is a resin-impregnated fiber aggregate, 4a, 4
b is a hot die that removes excess resin from the assembly 3, adjusts the overall external shape, and hardens and molds it; 5 is a belt-type drive mechanism that grips the molded product and pulls it out to the right in the drawing.

Next, the operation will be explained. First, the reinforcing fibers 1 fed out from the bobbin are collected, and then transferred to the resin tank 2.
A fiber aggregate 3 impregnated with a thermosetting resin is obtained by passing through the fibers. Next, this assembly 3 is passed through hot dies 4a and 4b to remove excess resin, adjust the overall external shape, and further harden to obtain a predetermined molded product. In this case, the drive mechanism 5
This mechanism grasps the molded product and obtains a pulling force to the right, and this mechanism is capable of continuous pulling operation by means of a belt type means.

The above example is for obtaining a solid rod, but as a method for obtaining a hollow cylinder, a method of winding a fiber aggregate impregnated with a thermosetting resin around a core metal and then performing pultrusion molding is proposed in JP-A-51. −20281 and JP-A-Sho
It is described in Japanese Patent No. 51-58467, and configurations as shown in FIGS. 4 and 5 are illustrated as drive mechanisms in this case, respectively. In FIG. 4, reference numeral 6 denotes a core metal around which a fiber aggregate is wound. By passing this fiber aggregate through a hot die 8, excess resin is removed, the outer shape is formed, and the molded article 7 is formed. Become. At this time, the molded product 7 is gripped and driven by a pair of rollers 9a and 9b and pulled out in the direction of the arrow. Also, in Figure 5, 10
11 is a hot die, 11 is a molded product, 12a and 12b are two drive mechanisms each having a grip part, and the molded product 11 that has passed through the hot die 10 is transferred to the drive mechanism 12.
The mechanism that is pulled out to the right in the drawing is shown at a and 12b.

[Problem that the invention seeks to solve]

In the pultrusion molding method using a thermosetting resin as described above, the hot dies 4a, 4b, 8, and 10 are usually heated to about 150°C for curing. This temperature needs to be further increased if, for example, the drawing speed is to be increased in order to increase production efficiency. For this reason, the molded product immediately after passing through the hot die has a temperature of 150° C. or more, and in the molding method using the core shown in FIGS. 4 and 5, the core also has a temperature close to this temperature. On the other hand, the temperature of the gripping portion of the drive mechanism is approximately at room temperature, and therefore, the molded product that has passed through the hot die is subjected to a large thermal shock due to a rapid temperature drop during the first gripping operation in the gripping portion. This results in delamination or residual stress in the molded product, and in any case, the product does not have the desired physical properties and lacks dimensional stability. Moreover, this effect becomes more significant in cases where the heat capacity of the product part is small, such as a cylinder with a thin wall (for example, a thickness of 2 mm or less), and the heat capacity of the metal core part is relatively large. Therefore, it is necessary to use carbon fiber as a reinforcing fiber, such as those used as members for large space structures, to take advantage of its superior specific strength and specific modulus, and to achieve extremely light weight, or thin wall thickness, for the required strength. Conventional molding methods are not suitable for molding such products. In order to solve this problem, it may be possible to increase the distance from the hot die exit to the gripping part so that the molded product can be gripped after it has sufficiently cooled, but this would increase the length of the manufacturing equipment and is not practical.

In addition, many hot dies are of a split type for maintenance purposes such as recycling, and in such cases, burrs occur on the molded product due to the mating surfaces of the hot die, and the surface layer of the molded product is covered with hardened resin. These surfaces are also required to be finished because powder will come out. However, this finishing treatment has conventionally been often carried out in batches as a separate process, which has been a factor in reducing production efficiency.

This invention was made in order to solve the above-mentioned problems, and provides a pultrusion molding method and apparatus for fiber-reinforced plastic cylinders that can continuously mold fiber-reinforced plastic cylinders with excellent physical properties with high efficiency. The purpose is to obtain.

[Means for solving problems]

The pultrusion molding method and apparatus for a fiber-reinforced plastic cylinder according to the present invention include an abrasive spraying mechanism provided between the outlet of the hot die and the inlet of the gripping part of the drive mechanism, and the abrasive or a fluid containing the abrasive. The temperature is controlled to a predetermined temperature.

[Effect]

In this invention, since the abrasive material at a predetermined temperature is sprayed before the gripping operation of the fiber-reinforced plastic cylindrical molding, the temperature of the high-temperature molding gradually decreases and rapid cooling at the gripping part of the drive mechanism is prevented. This can prevent internal cracks and residual stress caused by thermal shock. Additionally, the surface of the molded product can be polished and deburred at the same time.

〔Example〕

FIG. 1 is a diagram showing the configuration of an apparatus for pultrusion forming a fiber-reinforced plastic cylinder according to an embodiment of the present invention. In FIG. 1, 13 is a core metal around which a fiber aggregate made of reinforcing fibers impregnated with thermosetting resin is wound, and 14 is used to remove excess resin from the fiber aggregate, shape the outer shape, and harden the resin. A heated hot die 15 is drawn out from the hot die 14 and is heated in a high temperature state immediately after curing.
An FRP cylindrical molded product, 16 is provided on the downstream side of the hot die 14, and as will be described later, an abrasive spraying mechanism that sprays a fluid containing an abrasive controlled at a predetermined temperature onto the surface of the molded product 15, 17 is a core metal 13 This is a drive mechanism for pulling out the molded product 15 and the molded product 15 together in the direction of the arrow (to the right in the drawing).

Next, the molding method and the apparatus used therein will be explained. In this embodiment, tape-shaped CF prepreg is used as the resin-impregnated fiber aggregate as the constituent material of the FRP. And this CF prepreg tape, for example, product name Torayka P405 (Toray Industries, Inc.)
is first wound around the core metal 13. The temperature of the prepreg tape at this time is approximately around room temperature. Next, this prepreg tape is moved to the right in the drawing by the drawing driving force of the drive mechanism 17, passes through the hot die 14 together with the core metal 13, and is pultruded. here,
In order to facilitate disassembly and cleaning, the hot die 14 has a structure in which it is split into two parts, for example, in a cross-sectional direction parallel to the axis. When the prepreg passes through the narrowing taper section near the entrance of the hot die 14, it is once returned to a fluid state by a predetermined heating process, excess resin is removed by the squeezing action, and the overall external shape is adjusted in the next flat section. It hardens to form a cylinder.
In this case, the hot die 14 has a temperature of 100°C near the entrance.
The temperature is controlled so that the latter half has a temperature gradient of 170°C, and therefore the temperature of the molded product 15 immediately after passing through the hot die 14 is approximately 160°C. The drive mechanism 17 has two gripping portions (not shown), so that the molded product 15 can be pulled out smoothly.

The hot molded product 15 led out from the hot die 14 passes through an abrasive spraying mechanism 16. This mechanism 16 includes a molded article 15 in a housing 16a.
By blowing a granular abrasive material such as alumina onto the molded product 15 with high-pressure air, the resin residue on the surface of the molded product and burrs generated by the joints of the hot die 14 are polished. It is something. The temperature of the molded article 15 is gradually lowered by this spraying treatment. In this case, the annealing curve of the molded product 15 can be arbitrarily set by varying the pressure, amount and spraying form of the sprayed fluid, and the temperature of the abrasive material. A specific method is to attach a heater to the abrasive storage container and control the temperature of the abrasive material or the temperature of the sprayed fluid containing the abrasive material. can be controlled with. In this example, when air containing 20 to 30 μm of alumina powder was adjusted to 60°C and blown at a pressure of 5 kg/cm ² , the temperature of the molded product immediately before the gripping portion of the drive mechanism 17 dropped to 75°C. Further, the molded article 15 was cooled down to 30°C at the time of being gripped by the gripping portion, and the quenching temperature difference at this time was about 45°C. FIG. 2 shows this state, and the solid line 18 indicates this embodiment. The broken line 19 indicates the spraying mechanism 16 as a comparative example.
The temperature of the molded product is shown in the absence of . As is clear from this broken line 19, in the comparative example, at the time of gripping, approximately
Thermal shock occurs due to rapid cooling to 75℃. Also,
Comparative observation of the condition of the molded product revealed cracks, twisting when cut into 10 mm width rings, and delamination in the comparative example, but no such problems were observed in the example. .

〔Effect of the invention〕

As described above, according to the present invention, an abrasive spraying mechanism is provided between the outlet of the hot die and the inlet of the grip portion of the drive mechanism, and the abrasive material to be sprayed or the spray fluid containing the abrasive material is controlled to a predetermined temperature. As a result, the temperature of the hot molded product can be gradually lowered, preventing rapid cooling of the gripping part of the drive mechanism, and preventing cracks, delamination, and residual stress in the molded product due to thermal shock. can be suppressed. At the same time, surface polishing such as deburring of molded products can be performed continuously, making it possible to increase production efficiency. Therefore, from these points, it is possible to provide a continuous pultrusion method and an apparatus therefor which can provide both excellent physical properties and high productivity.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a pultrusion molding apparatus for fiber-reinforced plastic cylinders according to an embodiment of the present invention, and Fig. 2 shows a comparison of molded product temperatures between the same apparatus and an apparatus without an abrasive spraying mechanism. Figure, 3rd
The figure is a configuration diagram of an apparatus for explaining a conventional pultrusion method, and FIGS. 4 and 5 are configuration diagrams showing a drive mechanism of the conventional pultrusion apparatus, respectively. 13... Core metal, 14... Hot die, 15...
Molded article, 16... Abrasive spraying mechanism, 17...
Drive mechanism.

Claims (1)

[Scope of Claims] 1. Reinforcing fibers impregnated with thermosetting resin are wound around a core metal, and this wound integral body is hardened through a hot die to form a fiber-reinforced plastic cylinder, and this molded object is connected to a drive mechanism. In a pultrusion molding method for a fiber-reinforced plastic cylinder in which the cylinder is gripped by a gripper and continuously pulled out, the fiber-reinforced plastic cylinder passes through the hot die and before being gripped by the gripper of the drive mechanism, a predetermined A method for pultrusion molding of fiber-reinforced plastic cylinders, characterized by spraying a temperature-controlled abrasive or a fluid containing an abrasive. 2. A mechanism for wrapping reinforcing fibers impregnated with a thermosetting resin around a core metal, a hot die for forming a fiber-reinforced plastic cylinder by pulling out and curing the reinforcing fibers and the core metal together, and the fiber-reinforced plastic cylinder after passing through the hot die. an abrasive spraying mechanism that sprays an abrasive or a fluid containing an abrasive to the abrasive; a temperature control mechanism that controls the temperature of the abrasive or the fluid containing the abrasive to a predetermined value; A pultrusion molding apparatus for a fiber-reinforced plastic cylinder, characterized in that it is equipped with a drive mechanism having a gripping part that grips and pulls out the fiber-reinforced plastic cylinder and core bar together from the hot die.