JPH07117141A - Production of fiber reinforced thermosetting resin molding - Google Patents

Abstract

PURPOSE:To continuously and inexpensively produce a thick-walled fiber reinforced thermosetting resin molding having no air bubbles remaining therein by pultrusion. CONSTITUTION:In the production of a molding, a hard mold 6 equipped with a plurality of branch passages 11 having required passage cross sections on the inlet side thereof and the main passage 10 communicating with all of the branch passages 11 and having the cross section almost corresponding to the total cross section of all of the branch passages is prepared. Uncured resin compd. impregnated fibers 5 are divided on the inlet side of the curing mold to be drawn into a plurality of the branch passages 11 and guided to the main passage 10 during period when the resin compd. infiltrated into the reinforcing fibers 5 is uncured in the hard mold to be made to integrally meet with each other. Continuously, during a period when the reinforcing fibers 5 are passed through the main passage, the resin compd. is cured under heating and a molding 9 composed of a fiber reinforced thermosetting resin having a predetermined cross section is drawn out of the main passage 10 of the hard mold 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fiber-reinforced thermosetting resin molded product, and more particularly to a molded product having a thick wall with a thickness of more than 15 mm, for example, by a pultrusion molding method. The present invention relates to a method for producing a molded body that is suitable for production.

[0002]

2. Description of the Related Art Conventionally, in the pultrusion molding method, as a method of impregnating a reinforcing fiber mainly composed of linear continuous fibers with a resin mixture, for example, the reinforcing fiber is continuously stored in a resin liquid tank containing a resin liquid. Method of passing through and impregnating, or press-fit from a resin liquid injection hole provided near the inlet of the curing mold,
A method of impregnation in a curing mold is used. Here, in the former method, the reinforcing fibers after being impregnated with the resin liquid are always opened by the elasticity of the fibers themselves and contain bubbles, and most of these bubbles are impregnated with the resin. The fibers were removed to the outside together with the excess resin squeezed out when the fibers were drawn into the curing mold.

As a method of more positively removing bubbles, for example, as disclosed in Japanese Patent Laid-Open No. 4-305439, the resin-impregnated reinforced fiber is passed through a vacuum deaeration step before being drawn into a curing mold. Has taken a method of forcibly removing bubbles.

[0004]

By the way, when the molded product has a thickness of, for example, about 3 to 5 mm, it is possible to remove air bubbles in the reinforcing fiber without any problem by any of the above methods. However, in the case of manufacturing a molded product having a particularly large wall thickness, for example, a thickness of more than 15 mm, according to the conventional method of squeezing with the resin liquid at the mold inlet, the molded product shape is formed at the mold inlet portion. There has been a problem that air bubbles are entrained in the reinforced fibers that are focused, and all the air bubbles cannot be squeezed out, and the air bubbles remain inside the molded body.

Further, in the conventional method of injecting the resin liquid from the vicinity of the inlet of the curing mold, there is a problem that the resin liquid cannot be completely impregnated into the inside of the reinforcing fiber, and bubbles are removed by vacuum deaeration. In the method, the bubbles existing inside the reinforcing fiber cannot be expected to have a great effect because the fiber itself becomes an obstacle, and the low-boiling point component contained in the resin liquid volatilizes to increase the viscosity of the resin compound and further remove the bubbles. There was a problem that bubbles became difficult.

The object of the present invention is to solve the above-mentioned problems of the prior art and to continuously provide a fiber-reinforced thermosetting resin molded body having a thickness of, for example, more than 15 mm and having no air bubbles inside. Moreover, there is a need to provide a method that can be manufactured at low cost.

[0007]

In order to achieve the above-mentioned object, the present invention is a method for producing a fiber-reinforced thermosetting resin molded product by pultrusion, wherein a required passage cross-sectional area is provided on the inlet side. Curing including a plurality of molding material passage branch passages and a molding material passage main passage that communicates with all of the molding material passage branch passages and has a cross-sectional area substantially equivalent to the total cross-sectional area of all branch passages Prepare a mold, impregnate the reinforced resin mainly composed of linear continuous fibers with an uncured thermosetting resin compound, and divide the uncured resin compound-impregnated reinforcing fiber at the inlet side of the curing mold. After the resin compound impregnated into the reinforcing fibers is uncured inside the curing mold after being drawn into the plurality of branch passages for molding material passage, all the uncured resin compound-impregnated reinforcing fibers are formed into the molding material. Introduces to the main passage for passage While continuing to pass through the main passage, the resin composition is heat-cured, and a molded body made of a fiber-reinforced thermosetting resin having a predetermined cross-sectional area is drawn out from the main passage of the curing die. The gist is a method for producing a fiber-reinforced thermosetting resin molded body.

The curing mold used in the method of the present invention is
A plurality of molding material passage branch passages having a required passage cross-sectional area are provided on the inlet side.

Then, all the reinforcing fibers forming the molded body are
It is distributed from the entrance of each branch passage according to the cross-sectional area of the branch passage, and is drawn into the curing mold.

The passage on the inlet side of the curing mold may be divided into any shape, for example, either in the vertical direction or in the left / right direction, but when a sheet-like reinforcing fiber such as a mat is used, the sheet is divided into sheets. It is preferable to have a shape that does not hinder the insertion of the reinforced fiber.

The uncured resin composition-impregnated reinforcing fibers that have been divided and drawn into the curing mold are:
The resin composition is introduced into a main passage for passage of molding material in the mold so as to be merged and integrated, and subsequently, while passing through the main passage, the resin compound is cured by heating.

The term "uncured resin liquid" as used herein means that the resin liquid is kept in a liquid state before hardening and gelation.

In the present invention, the number of divisions of the inlet side passage of the curing mold can be appropriately changed according to the thickness of the molded body, but if it is divided into a large number, the molding becomes complicated and a problem occurs. Need to be small. Here, preferably, the thickness (height) of the entrance of the divided branch passage
Is preferably 10 mm or less in order to completely squeeze out the bubbles.

Examples of the curable resin used in the present invention include thermosetting resins such as unsaturated polyester resin, epoxy resin, vinyl ester resin and phenol resin.

In the present invention, the filler to be optionally added to the resin liquid is, for example, calcium carbonate, aluminum hydroxide, glass powder, glass beads, glass balloons, whiskers, etc., and the thermosetting used in the present invention. What is dispersed in a solid state without being dissolved in the organic resin can be used, and it may be an inorganic substance or an organic substance. Further, the shape thereof may be spherical particles, fibrous powder, flaky powder or the like.

The reinforcing fibers used in the present invention include
Examples include rovings (straight continuous fibers) such as glass fibers, carbon fibers, and organic fibers, continuous strand mats, chopped strand mats, cross mats, lami mats, etc. When roving is used alone or both rovings and mats are used. It may be used together. The volume content of the reinforcing fibers is preferably in the range of 30% or more and 50% or less.

In the method of the present invention, the reinforcing fibers are impregnated with the curable resin composition in the process of passing through the impregnation tank containing the curable resin composition, and the cross-sectional shape of the molded body is divided into a plurality of shapes by the guide. After being shaped, it is distributed to the inlets of a plurality of branch passages of the curing mold and drawn into the mold.

The reinforced fibers divided into a plurality of parts pass through the respective molding material passage branch passages in the heating die, and then merge in the forming material passage main passage inside the curing die to form a formed body. Be integrated. Before and after joining, the curable resin compound-impregnated reinforcing fiber passing through the molding material passage will bend and advance, and the smaller the angle formed by each branch passage for forming material passage before joining, the stronger the reinforcing fiber. Can proceed smoothly.

The resin compound-impregnated reinforcing fibers that have been introduced into the main passage and integrated together are heat-cured while they continue to pass through the main passage, and a molded body having a predetermined cross-sectional area is formed in the main passage of the mold. Pull out from the end. After that, the molded body,
Cut to a desired length with a cutting machine.

[0020]

The hardening die used in the above method is provided with a plurality of molding material passage branch passages having a required passage cross-sectional area on the inlet side thereof, and communicating with all the molding material passage branch passages inside. A molding material passage main passage having a cross-sectional area substantially corresponding to the total cross-sectional area of the branch passage is provided.

Since the uncured resin compound-impregnated reinforcing fiber is divided on the inlet side of the curing mold and drawn into a plurality of molding material passage branch passages, the bubbles existing in the reinforcing fibers are generated in the curing die branch passage. The squeeze is easily squeezed together with the surplus resin at the inlet portion of, and the amount of the reinforcing fibers that converge in the sectional shape of the branch passage in each branch passage is small, so that entrainment of bubbles is eliminated. Therefore, a molded product having a very small void ratio can be obtained even though it is thick, and has a thickness of, for example, more than 15 mm, and is a high-strength fiber-reinforced thermosetting resin molded product in which no bubbles remain inside. Can be stably and continuously manufactured.

[0022]

Embodiments of the present invention will now be described in detail with reference to the drawings.

In FIGS. 1 and 2 showing a concrete example of an apparatus used for carrying out the method for producing a molded article of the present invention, the reinforcing fibers (1) made of continuous fibers are continuously drawn out from a plurality of bobbins. The reinforcing fiber (1) continuously passes through the impregnation tank (2) containing the uncured liquid (3) of the thermosetting resin compound for forming the molded body, and the fiber (1) Is impregnated with the uncured resin formulation.

According to the method of the present invention, the uncured resin compound-impregnated reinforcing fiber (5) is shaped by the guide (4) into a shape in which the cross-section of the molded body is divided into upper and lower parts. , On the inlet side of the curing mold (6), it is drawn into the inlets (7) and (7) of the upper and lower two molding material passage branch passages (11) (11).

Then, while the resin composition impregnated into the reinforcing fibers is uncured inside the curing mold (6), all the uncured resin composition-impregnated reinforcing fibers (5) are passed through the molding material. It is led to the main passage (10) and merged and integrated.

A heater (12) is arranged on the outer peripheral wall of the main passage (10) of the mold (6), and then the uncured resin compound-impregnated reinforcing fiber (5) passes through the inside of the main passage (10). In the meantime, the resin composition is heat-cured to form a molded body (9) made of a fiber-reinforced thermosetting resin having a predetermined cross-sectional area, and this molded body (9) is molded into a curing mold (6). The main body (10) is pulled out by a take-up machine (8), and the molded body (9) is cut by a cutter (not shown).

As shown in FIG. 3, the cross section of the molded product (9) molded in this manner is such that two molded product parts (9a) and (9b) made of fiber-reinforced thermosetting resin are integrated in the upper and lower parts. In addition, the molded body (9) has the upper and lower molded body parts (9a) (9
It has a combined cross-sectional area of b).

Example 1 A molded body (9) of Example 1 was manufactured according to the following molding material and molding conditions according to the above molding process.

(1) Molding material Reinforcing fiber glass roving (4450, manufactured by Asahi Fiber Glass Co., Ltd.)
No.) Continuous mat (made by Asahi Fiber Glass, 45
No. 0) Roving: Continuous mat = 95: 5 (weight ratio) Resin blend Resin: Isophthalic acid unsaturated polyester 100 parts by weight Curing agent: t-Butylperoxybenzoate 1.5 parts by weight Release agent: Positive Phosphoric acid internal mold release agent 0.7 parts by weight Filler: calcium carbonate 30 parts by weight (2) Molding conditions Mold temperature distribution 100 ° C to 150 ° C Mold size Total length = 1000 mm Molding speed 50 cm / min Curing mold (6 ) The upper and lower two branch passages (11) entrance (7),
Each of the pieces was divided into a shape having a width of 100 mm and a thickness of 10 mm, arranged vertically, and molded by the above molding material and molding conditions to obtain a molded body (9) having a width of 100 mm and a thickness of 20 mm.
The fiber content in the molded body (9) was about 40% by volume.

Embodiment 2 FIG. 4 shows an apparatus used in the second embodiment of the present invention. Here, the difference from the case of the first embodiment is that
The point is that the branch passages (11) on the inlet side of the curing mold (6) are in three stages of upper, middle, and lower. Then, the inlets (7) of the upper, middle, and lower three-stage branch passages (11) of the curing mold (6) are also 100 mm wide and 10 mm thick.
As mm, a molded body (9) was manufactured in the same manner as in Example 1 above.

As described above, the cross section of the molded product (9) thus obtained is, as shown in FIG. 5, molded product parts (9a) (9b) (comprising three upper, middle and lower fiber reinforced thermosetting resins). 9c) is integrated, and the molded body (9) is the upper, middle and lower molded body parts.
(9a) (9b) (9c) combined cross-sectional area, ie width 1
It had a thickness of 00 mm and a thickness of 30 mm.

Comparative Example 1 A molding having a width of 100 mm and a thickness of 20 mm was molded by the same molding material and molding conditions as in Example 1 above without dividing the inlet side of the mold passage (that is, only the main passage was used for branching passage). Was formed).

Comparative Example 2 Similarly, a molded body having a width of 100 mm and a thickness of 30 mm was molded without dividing the inlet side of the mold passage.

Next, the above Examples 1 and 2 and Comparative Example 1
The performance of the molded products produced in Nos. 2 and 2 was evaluated, and the obtained results are shown in Table 1.

In Table 1, the flexural strength and flexural modulus were measured in the drawing direction of the molded body according to JIS K7055, and the void ratio was measured according to JIS K7053.

[0036]

[Table 1] As is clear from Table 1 above, the molded bodies of Examples 1 and 2 obtained by the method of the present invention had a small void ratio and high strength.

On the other hand, the molded products according to Comparative Examples 1 and 2 had a higher void ratio and thus a lower strength than the molded products according to the method of the present invention.

FIG. 6 shows a molded product (9) manufactured according to a modification of the present invention. The difference from the case of the first embodiment is that the branch passage (1
1) is provided in two steps, one above the other and two from the left and right (not shown).

The cross section of the molded body (9) of this modified example is, as shown in the figure, molded body portions (9a) (9b) (9c) composed of two upper and lower and two left and right fiber reinforced thermosetting resins. (9d) has an integrated structure, and the molded body (9) has a cross-sectional area obtained by combining the cross-sectional areas of the four molded body parts (9a) (9b) (9c) (9d). .

[0040]

As described above, the present invention is a method for producing a fiber-reinforced thermosetting resin molded product by pultrusion, which comprises a plurality of molding material passing branches having a required passage cross-sectional area on the inlet side. Prepare a curing mold that has a passage and a main passage for molding material passage that communicates with all the branch passages for passage of molding material inside and that has a cross-sectional area approximately equivalent to the total cross-sectional area of all branch passages. Reinforcement fibers mainly composed of continuous fibers are impregnated with an uncured thermosetting resin mixture, and the uncured resin mixture-impregnated reinforcement fibers are divided at the inlet side of the curing mold to divide into a plurality of molding material passage branch passages. Then, while the resin mixture impregnated in the reinforcing fibers is uncured inside the curing mold, all the uncured resin mixture-impregnated reinforcing fibers are guided to the molding material passage main passage and joined. Integrated, and this continues in the main passage During over to, allowed heat curing the resin formulation, is characterized in that the draw than the main passage of the curing mold a molded body made of a fiber reinforced thermosetting resin having a predetermined cross-sectional area.

Therefore, according to the method of the present invention, since the reinforcing fiber impregnated with the resin mixture is divided and drawn into the curing mold, the bubbles contained in the reinforcing fiber are excessive at the entrance of the branch passage of the curing mold. Since it is easy to be squeezed out together with the resin, and the amount of the reinforcing fibers that converge in the sectional shape of the branch passage in each branch passage is small, entrainment of air bubbles is eliminated.

Therefore, although it is thick, a molded product having a very small void ratio can be obtained, and the thickness is, for example, 15 mm.
It is possible to stably and continuously produce a high-strength fiber-reinforced thermosetting resin molded product having a thickness of more than 100 mm and no bubbles remaining inside. Moreover, since the apparatus used in the method of the present invention has a simple structure, the manufacturing process does not become complicated, and it can be carried out with a very small capital investment. Therefore, the production of a high-strength fiber-reinforced thermosetting resin molded article is possible. This has the effect of significantly reducing the cost.

[Brief description of drawings]

FIG. 1 is a schematic view showing a first example of an apparatus for carrying out the method for producing a fiber-reinforced thermosetting resin molded product of the present invention.

FIG. 2 is an enlarged cross-sectional view of a hardening die portion of the apparatus.

3 is a cross-sectional view of a molded body produced by the method of the present invention using the apparatus of FIG.

FIG. 4 shows a second example of an apparatus for carrying out the method for producing a molded article of the present invention, and is an enlarged cross-sectional view of a curing mold part of the apparatus.

5 is a cross-sectional view of a molded body manufactured by the method of the present invention using the apparatus of FIG.

FIG. 6 is a cross-sectional view showing a third example of a molded body manufactured by the method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reinforcement fiber 2 Impregnation tank 3 Unhardened thermosetting resin compound 4 Guide 5 Unhardened resin compound Impregnated reinforcing fiber 6 Curing mold 7 Branch passage inlet 8 Pulling machine 9 Fiber reinforced thermosetting resin molded product 10 Molding Main passage for material passage 11 Branch passage for passage of molding material

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Claims (1)

[Claims] 1. A method for producing a fiber-reinforced thermosetting resin molded article by pultrusion molding, comprising a plurality of molding material passage branch passages having a required passage cross-sectional area on the inlet side, and all the molding material inside. Prepare a curing mold that has a main passage for molding material passage that has a cross-sectional area that is in communication with the passage branch passages and that substantially corresponds to the total cross-sectional area of all the branch passages. The uncured thermosetting resin composition is impregnated, and the uncured resin composition-impregnated reinforcing fiber is divided on the inlet side of the curing mold and drawn into a plurality of molding material passing branch passages. Internally, while the resin compound impregnated in the reinforcing fibers is uncured, all the uncured resin compound impregnated reinforcing fibers are guided to the molding material passage main passage to be merged and integrated. While passing the A method for producing a fiber-reinforced thermosetting resin molded product, which comprises heat-curing and drawing out a molded product of a fiber-reinforced thermosetting resin having a predetermined cross-sectional area from a main passage of a curing mold.