JPS62132637A - Process for drawing of fiber-reinforced plastic cylinder and apparatus therefor - Google Patents

Abstract

PURPOSE:To suppress the occurrence of the crack or residual stress of shapes, by providing the spraying mechanism of an abrasive material between the exit of a die and a driving mechanism, and by controlling a fluid containing the abrasive material to preset temperature. CONSTITUTION:There are provided a heated hot die 14 for executing the removing of excessive resin from a fibrous assembly, the shaping of outer shape and the hardening of resin, and a spraying mechanism 16 of an abrasive material for spraying fluid containing the abrasive material controlled to a preset temperature to the surface of a shapes 15 which is set up between the exit of this hot die 14 and a driving mechanism 17. The temperature of the hot die 14 is controlled as having a temperature gradient of 100 deg.C near the inlet and 170 deg.C at the latter half section. Therefore the temperature of the shapes 15 becomes about 160 deg.C just after passing through the hot die 14. This high-temperature shapes 15 passes through the spraying mechanism 16 of the abrasive material, and is sprayed by high-pressure air with a particulate abrasive material, for example an alumina. Thereby it is possible to prevent the internal crack or residual stress, and to simultaneously execute the removal of flash and the abrasive finishing of the surface of the shapes 15.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method and apparatus for continuous molding of fiber-reinforced plastic (hereinafter abbreviated as FRP) cylinders, which are used, for example, as members for large space structures [conventional Technology] 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, which are impregnated with thermosetting resin to form a matrix. Thick-walled insulated pipes and corrosion-resistant pipes are actually manufactured using this method.

FIG. 3 is an example of molding a solid rod, and is a configuration diagram explaining the basic concept of the conventional pultrusion method and its device.
This is quoted from JP-A-50-75263. In the figure, 1 indicates reinforcing fibers that are drawn out from a bin;
2 is a bath for impregnating a thermosetting resin; 3 is a resin-impregnated fiber aggregate; 4a and 4b are hot dies for removing excess resin from the aggregate 3 and adjusting the overall external shape; 5 is a hot die for curing and molding the molded product; It is a belt-type drive mechanism that grips and pulls out to the right in the drawing.

Next, the operation will be explained. First, the reinforcing fibers 1 drawn out from the bobbin are collected, and then passed through a resin bath 2 to be impregnated with a thermosetting resin to obtain a predetermined molded product. In this case, the drive mechanism 5 grips the molded product and obtains a pulling force to the right, but this mechanism is capable of continuous pulling operation by means of a belt type means.

The above example is for obtaining a solid rondo, 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 Japanese Unexamined Patent Publication No. 51-58467, configurations as shown in FIGS. 4 and 5 are exemplified as drive mechanisms in this case, respectively. In Fig. 4, 6 is a core bar around which a fiber aggregate is wound.This fiber aggregate is passed through a hot die 8 to remove excess resin, shape the outer shape, and harden the molded material. It becomes 7. 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. In addition, in FIG. 5, lO is a hot die, 11 is a molded product, and 12a and 12b are two drive mechanisms each having a gripping part. The mechanism by which it is pulled out is shown.

[Problem that the invention seeks to solve]

In the pultrusion molding method using thermosetting resin as described above, the hot dies 4a, 4b, 8, 10 are usually 1
It is heated to about 50°C. 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 will have a temperature of 150°C or higher, and in the molding method involving the core metal shown in Figures 4 and 5, the core metal will also have a temperature close to this. . On the other hand, the temperature of the gripping portion of the drive mechanism is approximately at room temperature, and therefore, the molded product passing through the hot die is subjected to a large thermal shock due to a rapid temperature drop during the first gripping operation at the gripping portion. This will cause delamination or leave residual stress in the molded product, and in any case, the product will not have the desired physical properties and will lack dimensional stability. Moreover, this effect becomes more pronounced when the heat capacity of the product part is small (the core metal part has a relatively large heat capacity), such as a cylinder with a thin wall (for example, a thickness of 2 μ or less). Therefore, by using carbon fibers as reinforcing fibers, such as those used in large space structure components, by taking advantage of their specific strength and specific modulus, there is a need to achieve extremely light weight, or thin wall thickness, for the required strength. Conventional molding methods cannot adequately handle the molding of such products. To solve this problem, it may be possible to increase the distance from the hot die outlet to the gripping part so that the molded product can be gripped after it has cooled down sufficiently, but this would increase the length of the manufacturing equipment and is not practical.

In addition, hot dies are usually split-type from the viewpoint of maintenance such as recycling, and in such cases, cracks occur in the molded product due to the mating surfaces of the hot die, and in addition, hardened resin powder is present on the surface of the molded product. These surface finishes are also necessary because of the appearance of these surfaces. However, this finishing treatment has traditionally been carried out in batches as a separate process.
This was a factor that reduced production efficiency.

This invention was made 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.

[Failure to solve the problem]

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

[Effect]

In this invention, in order to spray an abrasive material at a predetermined temperature before gripping the fiber-reinforced plastic cylindrical molding,
The temperature of the molded product in a high temperature state gradually decreases, preventing rapid cooling at the gripping portion of the drive mechanism, and preventing internal cracks and residual stress caused by thermal shock. In addition, the surface of the molded product can be polished and polished 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 a thermosetting resin is wound;
15 is a heated hot die for removing excess resin from the fiber aggregate, shaping the outer shape, and curing the resin;
is an FRP cylindrical molded product which is led out from the hot die 14 and is in a high temperature state immediately after curing, and 16 is provided on the downstream side of the hot die 14 and contains an abrasive material controlled at a predetermined temperature on the surface of the molded product 15, as will be described later. An abrasive spraying mechanism for spraying fluid is used, and 17 is a drive mechanism for pulling out the core metal 13 and molded product 15 together in the direction of the arrow (to the right in the drawing).

Next, I will explain the molding method and the equipment used for it.
For example, trading card P405 (trade name, manufactured by Toshi Co., Ltd.) is first wound around the core metal 13. Due to the power generated at this time, it moves to the right in the drawing, passes through a 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 drawing taper section near the hot die 14, it is heated to a certain level and returned to a fluid state, and excess resin is removed by the drawing action, and the overall external shape is adjusted in the next flat section. The resin is then hardened to form a cylinder. In this case, the temperature of the hot die 14 is adjusted to have a temperature gradient of 100° C. near the inlet and 170° C. in the rear half, so that 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) to smoothly pull out the molded product 15.

The hot molded product 15 led out from the hot die 14 passes through an abrasive spraying mechanism 16. This mechanism 1
6 is installed so that the molded article 15 passes through the housing 16a, and the temperature of the molded article 15 gradually decreases as the molded article 15 is subjected to treatment, for example, when it is exposed to the edge.

In this case, the annealing curve of the molded product 15 can be arbitrarily set by varying the pressure and amount of the fluid, the form of the spray, and the temperature of the abrasive. A specific method is to attach a heater to the abrasive storage container and control the temperature of the abrasive or the temperature of the fluid containing the abrasive.
It is possible to better control the influence of thermal shock on 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 mm, the temperature of the molded product immediately before the holding part of the drive mechanism 17 was 75°C.
descended to. Furthermore, 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. This situation is shown in FIG. 2, where a solid line 18 indicates this embodiment. A broken line 19 indicates the temperature of the molded product when the spraying mechanism 16 is not provided as a comparative example. As is clear from the broken line 19, this was not observed in the comparative example when gripping, but in the example.

〔Effect of the invention〕

As described above, according to the present invention, a mechanism for spraying the abrasive is provided between the outlet of the hot die and the inlet of the gripping part of the drive mechanism, and the abrasive to be sprayed or the spray containing the abrasive is to spray the fluid in a predetermined direction. Since the temperature of the molded product in the high temperature state can be gradually lowered, rapid cooling at the drive mechanism gripping part can be prevented, and this thermal shock can prevent cracks, delamination, and delamination of the molded product. The generation of residual stress 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 a fiber-reinforced plastic cylinder according to an embodiment of the present invention, and a block diagram showing a drive mechanism of a second fixed molding apparatus. 13... Core metal, 14... Hot die, 15... Molded product, 16... Abrasive material spraying mechanism, 17... Drive mechanism.

Claims (2)

[Claims] (1) Reinforced fibers impregnated with thermosetting resin are wound around a core metal, and this wrapped integral object is hardened through a hot die to form a fiber-reinforced plastic cylinder, and this molded object is held in the grip of the drive mechanism. In a pultrusion molding method for a fiber-reinforced plastic cylinder in which the cylinder is molded while being gripped and continuously pulled out, the fiber-reinforced plastic cylinder passes through the hot die and before being gripped by the gripping part of the drive mechanism,
A method for pultrusion molding a fiber-reinforced plastic cylinder, which comprises spraying an abrasive or a fluid containing an abrasive at a predetermined temperature. (2) A mechanism for wrapping reinforcing fibers impregnated with a thermosetting resin around a core metal, a hot die for pulling out and curing the reinforcing fibers and core metal together to form a fiber-reinforced plastic cylinder, and reinforcing the fibers after passing through the hot die. an abrasive spraying mechanism that sprays an abrasive or a fluid containing an abrasive onto a plastic cylinder; a temperature control mechanism that controls the temperature of the abrasive or fluid containing an abrasive to a predetermined value; and a temperature control mechanism provided at a downstream side of the abrasive spraying mechanism. 1. A pultrusion molding apparatus for a fiber-reinforced plastic cylinder, characterized in that the apparatus comprises a drive mechanism having a gripping part that grips and pulls out the fiber-reinforced plastic cylinder and the core bar together from the hot die.