JPH0489208A - Manufacture of prepreg - Google Patents

Abstract

PURPOSE:To enable grooves in the direction of reinforced fibers to be formed into stripe form in one entire surface by the use of pressurizing rollers disposed at least on one outside of a pair of release papers in the form of providing a plurality of steps along the axial direction thereof. CONSTITUTION:Upper and lower release papers 12a, 12b coated with matrix resin 2 are supplied to a thermal compression part 6, and reinforced fibers 3 are inserted therebetween from a reinforced fiber supplying roller 13, and at the thermal compression part, at least one of the upper and lower pressurizing rollers 7a, 7b are used for compression in the form of providing steps thereon. In this manner, prepreg having grooves 5 at least on one surface is formed, thereby obtaining stripe-contained prepreg 1. When a prepreg laminated matter 17 laminated therewith is vacuum drawn, air in the laminate interfaces can be removed out of the laminate nearly perfectly through the grooves 5, as a result, an excellent adhesive composite material molding can be obtained wherein voids never reside in the laminate interfaces.

Description

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

Composite material molded products are 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 prepregs, is vacuumed, it is difficult to remove air from the interface of the laminate; remains as a void. 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 present inventors conducted extensive research in order to obtain a composite material molded product with no residual voids at the interface of the laminate, and found that grooves along the alignment direction of the reinforcing fibers of the prepreg were formed on the entire surface of at least one side of the prepreg. If it is formed into a stripe shape, when the prepreg laminate in which these are laminated is vacuumed, the air at the interface of the laminate can be almost completely removed through the grooves and out of the laminate, and at the same time it can be used during subsequent heat curing. External pressure can be used to crush the grooves and cavities from which air has been removed at the interface of the prepreg laminate, resulting in a composite material molded product with good adhesion and no residual voids at the interface of the laminate. It turns out.

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 stripes on the entire surface of at least one side of the prepreg.

The above 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 coated with a matrix resin on at least one of their opposing surfaces, and simultaneously heating the pair of release papers from the outside with a heating means. When forming a prepreg made of the matrix resin and reinforcing fibers by applying pressure with a pressure roller, a small amount of the release paper of the pair of the pressure rollers (both of which are placed on the outside of one A plurality of steps are provided along the axial direction of the roller and used for pressure, thereby obtaining the prepreg having grooves formed in stripes on its surface in the direction in which the reinforcing fibers are arranged. This is a method for manufacturing prepreg.

Forecast 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, and FIG. 3 is a diagram showing an example of the manufacturing method of the present invention. It is an explanatory diagram.

As shown in FIGS. 1 and 2, the striped blob regue according to the method of the present invention is produced by forming a striped blob regue on at least one surface of a prepreg 4 made of a matrix resin 2 and reinforcing fibers 3 along the direction in which the reinforcing fibers 3 are arranged. A5 is formed in stripes on the entire surface.

In the method of the present invention, the prepreg 4 is produced in a hot pressing section 6.
As shown in FIG. 4, at least one of the upper and lower pressure rollers 7a and 7b is provided with a step 8 and used for pressure, thereby forming a prepreg 4 having grooves 5 on one surface. Then, a striped prepreg L is obtained.This will be explained below.

As shown in FIG. 3, upper and lower release papers 12a and 12b coated with matrix resin 2 from supply rollers 9a and 9b are
The reinforcing fibers 3 are supplied from the reinforcing fiber supply roller 13 between the matrix resin 2 of the upper and lower release papers 12a and 12b, and reinforced. Fiber 3 is inserted.

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 section 6 is the same as the upper and lower pressure rollers 7a and 7b arranged on both the outer sides of the pair of release papers 12a and 12b (heating means (not shown) such as a heating plate arranged on one or both of the outer sides). 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.

At this time, in the present invention, in order to form grooves 5 in stripes in the direction in which the reinforcing fibers 3 are arranged on the entire surface of at least one of the prepregs 4, at least one of the pressure rollers 7a and 7b is applied. The roller is provided with a plurality of stages along its axial direction.

In this embodiment, as shown in FIG.
A is provided with a plurality of steps 8 in the axial direction. The convex portion 8a of the stage 8 of the upper pressure roller 7a presses the matrix resin 2 and the reinforcing fibers 3 from above the upper release paper 12a, and the convex portion 8a applies the reinforcing fibers 3 to the upper surface of the prepreg 4. This is for forming grooves 5 complementary to each other in the arrangement direction.

In this embodiment, the width of the convex portion 8a is 2 to 3 mm, and the concave portion 8a has a width of 2 to 3 mm.
Although the width of b is set to 0.3 to 1 mm, the width of the convex portions 8a, the width of the concave portions 8b between the convex portions 8a, etc. are determined by the width of the grooves 5 formed in the prepreg 4, the arrangement pitch of the grooves 5, etc. It may be determined as appropriate depending on the type of matrix resin 2, the arrangement density of reinforcing fibers 3, etc.

According to this embodiment, the grooves 5 are formed on the surface of the prepreg 4 in a complementary manner by the convex portions 8a of the steps 8 of the upper pressure roller 7a, so that the grooves 5 are formed on the entire surface of the prepreg 4 in the direction in which the reinforcing fibers 3 are arranged. A striped prepreg 1 in which grooves 5 are formed in striped shapes, matrix resin 2 is made of epoxy resin, and reinforcing fibers 3 are made of carbon fiber can be easily obtained.

Once the striped prepreg 1 has been obtained in the above manner, the release paper 12a above the striped prepreg 1 is taken up and removed by the winding roller 13, and the cover film 12a is removed from the supply roller 14 instead. 15
It is sufficient to supply the striped prepreg 1 and cover it with the striped prepreg 1, and then wind it up with the winding roller 16.

According to the striped brimbregue thus obtained, by stacking them with the grooves 5 facing upward as shown in FIG. 5, when the prepreg laminate 17 is evacuated, the striped The air caught between the interfaces between the prepregs 1 can be almost completely removed from the laminate 17 through the grooves 5, and the grooves at the interfaces of the prepreg laminate 17 can be removed by the external pressure applied during subsequent heat curing. 5 and the cavity from which 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 embodiment, the step 8 is provided on the upper pressure roller 7a, but the step 8 may be provided on the lower pressure roller 7a or both of the upper and lower pressure rollers 7a and 7b. In addition, it is sufficient to install not only all of these pressure rollers 7a and 7b, but also a small number of them on the most downstream one.When a stage 8 is provided on the lower pressure roller 7a, the prepreg 4 is A striped prepreg with grooves 5 formed on the lower surface is obtained, and when steps 8 are provided on both the upper and lower pressure rollers 7a and 7b, a striped prepreg with grooves 5 formed on the upper and lower surfaces of the prepreg 4 is obtained. It will be done.

Further, in the above description, the case where the matrix resin 2 is applied to both the upper and lower release papers 12a and 12b is shown, but the matrix resin 2 may be 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 poron, metal fibers such as titanium, or hybrid fibers using these fibers simultaneously can be used. .

As explained above, in the method of the present invention, reinforcing fibers are inserted between a pair of release papers coated with matrix resin on at least one of their opposing surfaces, and When forming a prepreg made of matrix resin and reinforcing fibers by heating the release paper from the outside with a heating means and at the same time applying pressure with a pressure roller, at least one of the release papers of a pair of the pressure rollers is heated. Since the pressure roller placed on the outside is used for pressure by providing multiple steps along its axial direction, the striped surface has grooves formed in stripes along the direction in which the reinforcing fibers are arranged. Prepreg can be easily obtained.

[Brief explanation of the drawing]

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 the same cross-sectional view. FIG. 3 is an explanatory view showing one embodiment of the manufacturing method of the present invention. FIG. FIG. 5 is a plan view showing a pressure roller. FIG. 5 is a front view showing a laminate of striped prepreg according to the present invention. Upper pressure roller: Step: Convex part nibble leg laminate agent

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
When forming a prepreg made of the matrix resin and reinforcing fibers by heating the pair of release paper from the outside with a heating means and simultaneously applying pressure with a pressure roller, the release paper of the pair of the pressure rollers is heated. By using a pressure roller disposed on the outside of at least one of the surfaces in a plurality of stages along the axial direction of the pressure roller, stripes are formed on the surface of the prepreg in the direction in which the reinforcing fibers are arranged. A prepreg manufacturing method characterized by obtaining a prepreg having grooves formed therein.