JPH0664054A - Method of molding composite material - Google Patents

Abstract

PURPOSE:To provide a molded object with no breakage of a surface resin by interposing a buffer layer formed of a thin film of an elastomer material between a main body of a mold and a composite material thereby to absorb the partial contact with the mold or the irregularity of the thickness of a laminate sheet by means of the elasticity of the layer. CONSTITUTION:A buffer layer 3 of a thin film is coated on the surfaces of main bodies 1A, 1B of a web mold to be in touch with a composite material. Similarly, a buffer layer 4 of a thin film is coated on the surfaces of main bodies 2A, 2B of a flange mold to be in touch with the composite material. These buffer layers 3, 4 are formed of thin films of an elastomer material of a predetermined thickness and held in tight contact with the respective main bodies of the molds. Therefore, buffer layers 3, 4 are interposed between the composite material and the main bodies of the molds.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for molding a composite material.

[0002]

2. Description of the Related Art A composite material made of fibrous reinforced plastic is lightweight and has high strength, and is therefore widely used as a structural member for aircraft and the like. As the molding technology for this composite material, an autoclave method of heating and curing by bag molding in an autoclave and a matched die molding method using two male and female mating molds have been implemented.

The former molding technique is disclosed in, for example, Japanese Patent Publication No. 58-2.
Known from No. 7090, this is an uncured composite material loaded on an elastomeric material tool formed according to the shape of the composite material, vacuum bag molded, and heat cured in an autoclave. It is what makes me.

Further, the matched die molding technique is known, for example, from Japanese Patent Publication No. 61-53939, in which a resin melt is pressure-molded by using a mold whose male and female end faces slide and close. is there.

[0005]

However, among these prior arts, among those known from Japanese Patent Publication No. 58-27090, an elastomer-based material tool is characterized in that the preforms are laminated and formed due to their material characteristics. However, a dedicated preforming die is separately required for forming the preformed body, and the proportion of the die cost increases. In addition, it is necessary to transfer the molded preform from the preforming mold to the autoclave or the final curing mold. There is a problem that the whole processing time becomes long due to the replacement.

Further, in the one disclosed in Japanese Patent Publication No. 61-53939, there is no problem when the molten resin is simply injected into the mold under pressure, but the ratio of the fiber and the resin is accurately controlled. In the case of molding a required resin-impregnated fiber laminate, voids are likely to occur in the mold due to local mold contact or variations in the plate thickness of the laminated product. Even in such a case, since additional resin cannot be replenished to the mold, sufficient pressure is not applied to the void portion, and defects such as surface resin defect occur in this portion.

In order to prevent this, it is necessary to perform temporary alignment before heating and pressure curing to replenish the resin impregnated fiber to the part where the mold is not well contacted, which is troublesome. It takes a long time and affects the cost.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, to eliminate the need for a preforming die, and to absorb a local die contact, variations in laminated plate thickness and the like. The present invention is to provide a molding method.

[0009]

In order to achieve the above object, the present invention provides a mold body made of a hard material molded according to the shape of a composite material product to be molded, and the mold body A resin-impregnated fibrous body was laminated on the molding surface and preformed into a predetermined shape, and then a buffer layer made of a thin film elastomer was interposed between the mold body and the preformed composite material product. After that, it is characterized by being heated and pressurized in an autoclave to be cured.

[0010]

According to the present invention, since the buffer layer made of a thin film elastomer is interposed between the mold body and the composite material, the buffer layer is well adapted to the molding surface of the mold body, and due to its elastic deformation. It is possible to absorb local mold contact and variations in laminated plate thickness.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a method for molding a composite material according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a mold used in the molding method according to the present invention. This molding mold is for molding an I-beam widely used as a structural member of an aircraft. This molding die comprises a pair of left and right web molding die bodies 1A and 1B for molding the I-beam web portion.
And a pair of upper and lower flange forming die bodies 2A and 2B for forming the flange portion of the I-beam. Second
The figure shows a composite material as a product molded by this molding die, and includes a pair of U-shaped webs 5A, 5B and flanges 6A joined to the upper and lower end surfaces of the flanges of the web.
It consists of 6B.

The web forming mold bodies 1A and 1B are formed in a shape and size corresponding to the I-beam webs 5A and 5B, and the flange forming mold bodies 2A and 2B correspond to the I-beam flanges 6A and 6B. It is molded into a shape and size that Each of the mold bodies 1 and 2 is made of a hard material such as metal, has a strength sufficient to withstand the molding pressure of the composite material product, and can be repeatedly used. Further, a thin film-shaped buffer layer 3 is lined on the contact surface of the web forming die bodies 1A and 1B with the composite material, and similarly, the flange forming die bodies 2A and 2B.
A thin film-shaped buffer layer 4 is lined on the contact surface of the composite material in B. These buffer layers 3 and 4 are made of a thin film-shaped elastomer material having a predetermined thickness and are in close contact with the respective mold bodies 1 and 2. Thereby, the buffer layers 3 and 4 are interposed between the composite material and the mold bodies 1 and 2. The buffer layers 3 and 4 are made of an elastomer material resin and have remarkable elasticity at around room temperature. In this case, the buffer layers 3, 4
It is preferable that, in addition to moderate elasticity, the mold bodies 1 and 2 have compatibility with, heat resistance, releasability, and durability. For example, a Teflon-based film having a thickness of about 0.1 mm or a thick film. A 0.5 mm thick nylon film can be selected. In the case of a Teflon type film, it is preferable to apply a pressure sensitive adhesive to one surface and to stick the pressure sensitive adhesive to the mold bodies 1 and 2 via this pressure sensitive adhesive.

Next, the case of molding the I-beam shown in FIG. 2 with such a mold will be described. The I-beam webs 5A and 5B are formed by laminating resin-impregnated fibrous bodies on the surface of the web mold body 1 and preforming them into a predetermined shape. On the other hand, the flanges 6A and 6B are formed by laminating a resin-impregnated fibrous body on the mold surface of the flange molding die body 2 for preforming. Next, the main bodies 1A, 1B, 2A,
2B is applied and assembled into the I-beam shape inside the mold body. After that, after the filler is properly inserted,
An I-beam composite material in which the web 5 and the flange 6 are integrated is obtained by being heated and pressurized and cured in the autoclave.

As described above, according to the molding method of the present invention, both the pre-molding and the final curing can be performed by the same mold, so that the number of molds can be reduced to half and the pre-molding can be performed. It eliminates the need to transfer the body and speeds up molding. Also, in both pre-molding and final curing, a buffer layer made of a thin film elastomer is interposed between the composite material and the mold body, so that the buffer layer fits well on the molding surface of the mold body. Thus, it is possible to mold a high-quality composite material with less surface resin defects and the like, which can absorb local variations in plate thickness and variations in plate thickness in the case of lamination due to the elasticity of the buffer layer.

FIG. 3 shows another embodiment of the present invention, in which the same elements as those in the above embodiment are designated by the same reference numerals. In this embodiment, the web forming mold bodies 1A and 1B are used.
And a flange forming die body 2A, 2B form a die. These mold bodies 1A, 1B, 2A and 2B are made of a hard material alone and are not provided with a buffer layer.
FIG. 4 shows I molded by such mold bodies 1 and 2.
Beam, which is a pair of left and right webs 5A, 5B
And flanges 6A and 6B joined to the upper and lower end surfaces of the web
It consists of and. A thin film-shaped buffer layer 3 is provided on the outer surface of the web 5 that contacts the web mold body 1 during molding, and a buffer layer 4 is provided on the outer surface of the flange 6 that contacts the flange mold body 2. Has been.
That is, in this embodiment, the buffer layers 3 and 4 are attached to the composite body side, which is a molded product, so as to be interposed between the composite body and the mold body. In this case, the buffer layers 3 and 4 are made of an elastomer-based material resin as in the above-described embodiment, and have appropriate elasticity to contact the mold bodies 1 and 2. As the resin to be selected, since the buffer layers 3 and 4 are provided on the composite side, it is preferable that the resin has good releasability from the mold bodies 1 and 2, for example, a nylon-based release film having a thickness of about 0.05 mm. A nylon fiber cloth for release having a thickness of about 0.1 mm is suitable.

In order to mold the composite according to this embodiment, a laminate of resin-impregnated fibrous bodies and a buffer layer 3 are laminated on the web mold main body 1 to obtain a preform for the web portion and the resin. The impregnated fiber body laminate and the buffer layer 4 are laminated on the cap mold body 2 to obtain a preform for the cap portion. Next, the preform and the mold bodies 1 and 2 are assembled into an I-beam shape so that the buffer layers 3 and 4 come into contact with the mold bodies 1 and 2, respectively, and the web 5 and the cap 6 are hardened and cured by heating and pressing. Simultaneous joining is performed. Even in such an embodiment, the mold body can be used for both preforming and final curing, and since a buffer layer is interposed between the composite body and the mold body, as in the above-mentioned embodiment, a local It is possible to absorb variations in die contact and plate thickness.

Although the above embodiment is applied to an I-beam shaped composite body, the present invention can be similarly applied to the molding of other shaped composite bodies.

[0019]

As is apparent from the above description, according to the present invention, since the buffer layer made of the thin film elastomer material is interposed between the mold body and the composite material, the elasticity thereof locally causes It is possible to absorb variations in the plate thickness of the mold and the lamination, to obtain a molded product without surface resin defects, and to perform preforming and final curing with the same mold, so that molding can be performed easily and quickly. .

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a molding die according to the present invention.

FIG. 2 is a perspective view showing a composite material product to be molded.

FIG. 3 is a perspective view showing another embodiment of the present invention.

FIG. 4 is a perspective view showing a composite material product to be molded.

[Explanation of symbols]

 1 type main body 2 type main body 3 buffer layer 4 buffer layer

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Claims (3)

[Claims] 1. A mold body made of a hard material molded according to the shape of a composite material product to be molded is prepared, and a resin-impregnated fiber band is laminated on the molding surface of the mold body to obtain a predetermined shape. After preforming, and then interposing a buffer layer made of a thin film elastomer between the mold body and the preformed composite material product, it was heated and pressurized in an autoclave to be cured. A method for forming a characteristic composite material. 2. The method of molding a composite material according to claim 1, wherein the buffer layer is attached to a contact surface of the mold body with the composite material. 3. The method for molding a composite material according to claim 1, wherein the buffer layer is attached to a contact surface of the composite material with a mold body.