JPH0489210A - Manufacture of prepreg - Google Patents

Abstract

PURPOSE:To enable grooves to be made in the form of stripes in the arranging direction of reinforced fibers on the surface by removing one release paper of prepreg in which reinforced fibers are inserted between a pair of matrix resin-applied release papers, and attaching a heat shrinkable film thereon, and then allowing the film to be shrunk by heating. CONSTITUTION:In upper and lower paired release papers 12a, 12b of prepreg 4 comprising matrix resin 2 and reinforced fibers 3, one release paper 12a is removed, and on the surface removed, a heat shrinkable film 15 is attached, and further a shrinkable film 15 is contracted by heating from the outside thereof. In this way, prepreg 1 is obtained wherein grooves are formed in the form of stripes in the arranging direction of the reinforced fibers 3 on the surface of the prepreg 4. In this fashion, when the prepreg laminate is subjected to vacuum drawing, air in the laminate interfaces can be removed perfectly, as a result, a composite material molding can be obtained that has no residual voids in the laminate interfaces and also has an excellent adhering property.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. The present invention relates to a method for producing a prepreg made of a matrix resin and reinforcing fibers, and more specifically, when producing a composite material molded product by laminating prepregs and curing them by heating, The present invention relates to a method for producing a prepreg with stripes that makes it possible to obtain a composite material molded product with no residual voids at the interface.

A composite material molded product is manufactured by laminating prepregs made of matrix resin and reinforcing fibers and heating and curing the prepreg laminate.

In this method of manufacturing composite material molded products using prepregs, air sandwiched between the interfaces between the laminated prepregs, that is, the interfaces of the prepreg laminates, remains as voids.
To prevent this, air is removed from the prepreg laminate interface by, for example, vacuuming the prepreg laminate in an autoclave, and then external pressure is applied in the autoclave to remove air at the interface between the prepregs. The laminate is heated and cured while the cavities are crushed and brought into close contact.

However, even if a prepreg laminate, which is a laminate of flat, smooth-surfaced sheets called prepreg, is vacuumed, it is difficult to remove air from the interface of the laminate. A considerable amount of air remains as voids at the interface. For this reason, even if the prepreg laminate is heat-cured while applying external pressure, the resulting composite material molded product cannot always obtain sufficient desired properties such as strength due to the influence of the remaining voids.

Therefore, the inventors of the present invention aimed to obtain a composite material molded product with no residual voids at the interface of the laminate. If it is formed into a striped shape, when the prepreg laminate is vacuumed, the air at the interface of the laminate can be almost completely removed through the grooves to the outside of the laminate. The external pressure applied can crush the grooves and air-free cavities at the interface of the prepreg laminate to bring them into close contact, and as a result, it is possible to obtain a composite material molded product with good adhesion without any voids remaining at the interface of the laminate. It turns out it can be done.

Therefore, an object of the present invention is to provide a manufacturing method that can easily produce a striped prepreg in which grooves in the direction of the reinforcing fibers of the prepreg are formed in a striped manner on the entire surface of at least one side of the prepreg.

The above-mentioned objects are achieved by the prepreg manufacturing method according to the present invention. In summary, the present invention involves inserting reinforcing fibers between a pair of release papers that have few facing surfaces (one of which is coated with a matrix resin, and applying heat and pressure from the outside of the pair of release papers). to form a prepreg made of the matrix resin and reinforcing fibers, and then peel off one of the pair of release papers from the prepreg,
At the same time, the other release paper is peeled off and attached again, and then a heat-shrinkable film is attached to the surface of the prepreg on the side from which the release paper has been removed, and the heat-shrinkable film is heated from the outside. By shrinking the
The method for producing a prepreg is characterized in that grooves are formed in stripes on the surface of the prepreg in the direction in which the reinforcing fibers are arranged.

1 hill Examples of the present invention will be described in detail below.

FIG. 1 is a perspective view showing an example of a striped prepreg manufactured by the manufacturing method of the present invention, FIG. 2 is a cross-sectional view of the same (cross-sectional view), and FIG. FIG.

As shown in FIGS. 1 and 2, the striped burblegue made by the method of the present invention has a small surface area of the prepreg 4 made of matrix resin 2 and reinforcing fibers 3 (on one side, in the direction in which the reinforcing fibers 3 are arranged). A striped groove 5 is formed on the entire surface thereof.

In the method of the present invention, after manufacturing the prepreg 4, one of the pair of upper and lower release papers 12a, 12b is peeled off and removed, and a heat-shrinkable film (hereinafter referred to as By attaching a shrink film (simply referred to as a shrink film) 15 and shrinking the shrink film 15 by heating from the outside, grooves 5 are formed in stripes on the surface of the prepreg 4 in the direction in which the reinforcing fibers 3 are arranged.
A striped prepreg 1 is obtained.

This will be explained below.

As shown in FIG. 3, upper and lower release papers 12a and 12 coated with matrix resin 2 are supplied from supply rollers 9a and 9b.
b is supplied to the hot press section 6 with the surfaces coated with the matrix resin 2 facing each other, and the upper and lower release papers 12a, 12b are
The reinforcing fibers 3 are inserted between the matrix resin 2 by supplying the reinforcing fibers 3 using the reinforcing fiber supply roller 13.

In this example, the matrix resin 2 was an epoxy resin mixed with a curing agent, and the reinforcing fibers 3 were carbon fibers. Incidentally, the application of the matrix resin 2 to one of the release papers 12a and 12b can be omitted.

The pressure heating unit 6 includes upper and lower pressure rollers 7a, 7b placed on both the outsides of the pair of release papers 12a, 12b, and heating means (not shown) such as a heating plate placed on one or both of the outsides. It consists of

The matrix resin 2 of the upper and lower release papers 12a, 12b and the reinforcing fibers 3 inserted therebetween are the release papers 12a, 12b.
Pressure is applied from the outside by upper and lower pressure rollers 7a and 7b to impregnate the reinforcing fibers 3 with the matrix resin 2, and the matrix resin 2 is semi-cured by being heated by a heating means (not shown). A prepreg 4 consisting of the reinforcing fibers 3 and the reinforcing fibers 3 is obtained.

Next, the release paper 12a on one of the pair of release papers 12a, 12b is wound up by the winding roller 13, peeled off from the prepreg 4, and removed.

At the same time, the release paper 12b under the other one is moved by the roller 16a,
By rotating the roller 16b between 16c, it is peeled off from the prepreg 4 and attached to the prepreg 4 again.
An air phase is interposed between the prepreg 4 and the release paper 12b under it to weaken the adhesion between them.

Next, a shrink film 15 such as a polyethylene film is supplied and attached to the surface of the prepreg 4 from which the release paper 12a has been removed using the film supply roller 14, and heated from the outside by a heating means 18 such as a heating lamp to form a shrink film. Shrink 15. At this time, since the prepreg 4 has weak adhesion to the release paper 12b, it is pulled in the width direction by the contraction of the shrink film 15.
Mainly on the upper surface in the elongated direction (the direction in which the reinforcing fibers 3 are arranged)
Grooves 5 are formed in the prepreg 4. Grooves 5 are formed in stripes in the direction in which the reinforcing fibers 3 are arranged on the entire upper surface.The matrix resin 2 is made of epoxy resin, and the reinforcing fibers 3 are made of carbon fiber. The striped prepreg 1 can be easily obtained.

Once the striped prepreg 1 is obtained in the above manner, the shrink film 15 is wound up and removed from the striped prepreg 1 by the winding roller 19, and a cover film (not shown) is replaced with the striped prepreg 1. 1 and cover it.

According to the thus obtained striped prepreg 1, -5 is laminated with the striped prepreg 17 facing upward as shown in FIG. The air caught between the interfaces between the striped prepregs 1 can be almost completely removed to the outside of the laminate 17 through the tube 5, and the interface between the prepreg laminates 17 can be removed by the external pressure applied during subsequent heating and curing. The groove 5 and the cavity from which the air has been removed can be crushed and brought into close contact. Therefore, it is possible to obtain a carbon fiber composite material molded product with good adhesion and no residual voids at the interface of the laminate.

In the above embodiments, the shrink film 15 is pasted on the upper surface of the prepreg 4 and heated to shrink, thereby forming the grooves 5 mainly on the upper surface of the prepreg 4. 5 can also be formed using the same method.

Further, in the above description, a case has been described in which matrix resin 2 is applied to both of the upper and lower release papers 12a and 12b, but it is sufficient that matrix resin 2 is applied to at least one of them.

In addition, although the explanation has been given using an example in which epoxy resin is used as the matrix resin 2 and carbon fiber is used as the reinforcing fiber 3, it is also possible to use a thermosetting resin such as an unsaturated polyester resin, polyimide resin, or bismaleimide resin as the matrix resin 2. As the reinforcing fiber 3, organic fibers such as glass fibers, aramid fibers, and polyester fibers, inorganic fibers such as boron, metal fibers such as titanium, or hybrid fibers using these fibers simultaneously can be used. . Further, as the Schunk film 15, a polypropylene film or the like can also be used in addition to the polyethylene film.

1 Plate Danko 1 As explained above, in the method of the present invention, reinforcing fibers are inserted between a pair of release papers coated with a matrix resin on at least one of the opposing surfaces, and By heating and pressurizing from the outside, a prepreg made of matrix resin and reinforcing fibers is formed, and then one release paper is peeled off and removed from the repreg, and the other release paper is peeled off and added again. Then, a shrink film is attached to the surface of the prepreg from which the release paper has been removed, and the shrink film is shrunk by heating from the outside, so grooves are formed in stripes on the surface of the prepreg in the direction in which the reinforcing fibers are arranged. striped prepreg can be easily obtained.

FIG. 2 is a perspective view showing an example of a striped prepreg.

FIG. 2 is also a cross-sectional view.

FIG. 3 is an explanatory diagram showing an embodiment of the manufacturing method of the present invention.

FIG. 4 is a front view showing a striped prepreg laminate according to the present invention.

Prepreg with lco stripe 2-coat matrix resin 3: Reinforced fiber 4 nib reg 5: Lecture 15.Shrink film 17: Prepreg laminate 18: Heating means

[Brief explanation of the drawing]

FIG. Figure 2

Claims (1)

[Claims] 1) A reinforcing fiber is inserted between a pair of release papers coated with matrix resin on at least one of the opposing surfaces, and
By applying heat and pressure from the outside of the pair of release papers, a prepreg made of the matrix resin and reinforcing fibers is formed, and then one of the release papers of the pair of release papers is peeled off and removed from the prepreg. At the same time, the other release paper is peeled off and attached again, and then a heat-shrinkable film is pasted on the surface of the prepreg on the side from which the one release paper has been removed, and the heat-shrinkable film is heated from the outside. A method for producing a prepreg, characterized in that by shrinking the prepreg, grooves are formed in a stripe pattern on the surface of the prepreg in the direction in which the reinforcing fibers are arranged.