JPS60165211A - Manufacture of prepreg - Google Patents

Abstract

PURPOSE:To prevent resin impregnation unevenness, suppressing the occurrence of fluff due to the breakage of a single strand by providing a resin pool-control plate at the position being at least adjacent to or in contact with the under surface of a laminate, causing said plate to be adjacent to the nip point of heating rolls at the front of said nip point. CONSTITUTION:A resin pool-control plate 20 is provided at least at the under side of a laminate 18. While said plate is causes to be adjacent to or in contact with the laminate 18, it is also caused to be adjacent to the nip point 21 of heating rolls 19, 19 and placed at the front of the nip point 21. Consequently, the occurrence of resin pool under the nipping pressure by the heating rolls at least under the laminate may be prevented. Accordingly, the occurrence of fluff caused by the breakage of the single strand of the reinforcing fiber due to the resin pool is suppressed, whereby the fluff may be at least prevented from being included in between the prepreg and the lower sheet, and also the unevenness of the resin impregnation due to the fluff accumulation may be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a prepreg manufacturing apparatus, and particularly to an improvement for preventing the occurrence of fuzz and resin unevenness in prepreg.

[Prior art]

Conventionally, prepreg is produced by stacking resin carrier sheets coated with B-stage (semi-cured) resin on both sides of reinforcing fiber strands arranged in a sheet shape, and sandwiching the resulting stack between heated rolls. It was manufactured by pressing the resin carrier sheet to transfer and impregnate the reinforcing fibers with the resin.

However, in such conventional manufacturing equipment, as shown in FIG. 1, the stacked body 1 is compressed and squeezed by heating rolls 2.2, so that the sheet swells in front of the heating rolls.
Resin pools 3 are formed on the upper and lower sides of the stacked body 1.

In this resin reservoir, as the stacked body moves due to the rotation of the heating roll 2.2, the accumulated resin rotates, and as a result, the resin is particularly weak against bending force like carbon fiber. In ili strong fibers, the single yarns are cut and fluff is generated, which then falls off.

This fallen fuzz is accumulated in the resin reservoir 3 (1゛i),
Not only does it damage the resin moldings against the reinforcing fibers, but it also causes residual unevenness on the prepreg.

[Purpose of the invention]

An object of the present invention is to suppress the generation of fuzz due to cutting of single filaments, and to prevent unevenness of resin in prepreg.

[Structure of the invention]

The present invention achieves the above object by superimposing sheets on both sides of a sheet-like reinforcing fiber, each of which has a resin-supporting sheet, and by pressing the superimposed body with heated rolls to transfer the resin to the reinforcing fiber. In the impregnated prepreg manufacturing apparatus, a resin pool control plate is provided in front of the nip point of the heating roll, in proximity to the nip point, and in proximity to or in contact with at least the lower surface of the stacked body. It is characterized by:

〔Example〕

Hereinafter, the present invention will be explained based on the details shown in the drawings.

In FIG. 2, the reinforcing fibers 11 are fed out from the package 12 parallel to each other and in sheet form, while the lower resin carrier sheet 13 is fed in strip form from a roll 14, and the reinforcing fibers 11 are fed from a roll 14 in each case via guide rolls 15,15. The resin surface side of the lower resin carrying sheet 13 is first superimposed on the lower surface of the resin carrier sheet 13 .

Further, the upper resin carrying sheet 17 is fed out from the roll 16, and the resin side of the upper resin carrying sheet 17 is superimposed on the upper surface of the reinforcing fibers 11 to form a stacked body 18.

In the present invention, either one of the upper and lower resin-carrying sheets may be a sheet that does not carry resin. That is, the resin support sheet may be superimposed on either side of the above-mentioned stacked body.

Here, the reinforcing fibers used in the present invention are carbon fibers, glass fibers, organic high modulus fibers such as polyaramid fibers, high strength and high modulus fibers such as silicon carbide fibers, alumina fibers, and boron fibers. It is used in the form of strands.

Such reinforcing fibers may be of one type, or two or more types of fibers may be used, alternating in the width direction, such as carbon fiber and glass fiber, or carbon fiber and organic high-modulus fiber. They may be used by arranging them regularly or irregularly.

The base sheets for the upper and lower resin-carrying sheets are kraft paper with a thickness of about 0.05 to 0.2 mm;
A coating layer of a filler such as clay, starch, polyethylene, polyvinyl alcohol, etc. is provided on one or both sides of roll paper, glassine paper, etc., and a silicone-based sealant, etc. is further applied on each coating layer.
Alternatively, a non-silicone mold release agent, preferably a mold release agent made of a condensation reaction type silicone of polydimethylsiloxane and polydimethylhydrodiene siloxane, or an addition reaction type silicone, is applied.

The resin supported on the sheet is a thermosetting resin such as epoxy resin, unsaturated polyester resin, phenol resin, or polyimide resin. These resins are in a B-stage (semi-cured) state.

The amount of resin supported is such that the resin content of the final prepreg is 20 to 70% by weight, preferably 30 to 50% by weight.
It will be refined to become Note that it is preferable that the resin be supported on the sheet by coating.

The sheet also functions as a so-called release paper, preventing the reinforcing fibers in the prepreg from becoming disordered and protecting the prepreg from absorbing moisture.

In the present invention, the stacked body 18 is then heated by the heating roll 1.
9.19 is supplied, compressed, and heated to transfer and impregnate the reinforcing fibers with the resin, thereby obtaining a unidirectional prepreg.

What is important in the present invention is that the resin pool control plate 2
0 is provided.

This resin pool control plate 20 is provided at least on the lower side of the stacked body 18, is located close to or in contact with the stacked body 18, and is located at the nip point 2 of the heating rolls 19, 19.
1 and located in front of the nip point 21.

FIG. 2 shows the vicinity of the heating roll 19, 19 in more detail, and by providing the resin pool control plate 20, the resin pool 3
is formed only on the upper side of the stacked body 18.

The position of the resin pool control plate 20 is preferably that of the heating roll 1.
The position is about 1 mm below the height of the nip point of 9.19, and the resin pool control plate 20 can also be used on the upper side of the stacked body 18 in the same way.

The heating roll is used to spread the reinforcing fiber strands and impregnate them with the resin,
℃, preferably 90-150°C.

Further, the pressing force is several kilograms per 1 cm as a linear pressure.

Next, in the present invention, the sheet 17' constituting the upper resin carrying sheet 17 is peeled off from the obtained prepreg via a guide roll 22, and a roll 23 for winding it up is used.
A roll 25 for supplying the scrim cloth 24 and a scrim cloth bonding roll 26, 26 are further provided as needed, and the obtained prepreg 27 is wound up on a winding roll 28.

Note that scrim cloth is a plain weave or satin weave of the above-mentioned reinforcing fibers, and if it is made of carbon fiber or organic high elastic fiber, it has a thickness of 0.02 to 0.15 mm,
Preferably 0.02-0.05mm, basis weight 10-90g
/ rl, preferably 20 to 60 g/r+ (and
If it is made of glass fiber, the thickness is 0.01
~0.1n+m, preferably 0.02-0.05mm
, weight 10~80g/n? It is.

Such scrim cloth has the function of imparting strength in the width direction to the unidirectional prepreg and preventing the arrangement of reinforcing fibers from becoming disordered.

Further, the scrim cloth bonding roll 26 is heated at a heating temperature of 5
The temperature is 0 to 130°C, preferably 70 to 120°C, and the pressing force is about several kg/cm as a linear pressure.

The unidirectional prepreg obtained in the above example was 0.02
It has a thickness of ~1 mm, preferably 0.03-0.5 mm, and contains 30-80% by weight, preferably 50-70% by weight of reinforcing fibers.

In the above embodiment, a case has been described in which the strands of reinforcing fibers are drawn parallel to each other in a sheet shape and then paid out, but it is also possible to pay out a material that has been processed into a sheet shape in advance, such as a mat or woven fabric.

〔Effect of the invention〕

As described above, according to the present invention, the resin pool control plate is provided in front of the nip point of the heating rolls, in the vicinity of the nip point, and in a position close to or in contact with at least the lower surface of the stacked body. It is possible to prevent a resin pool from being formed at least on the lower side of the stacked body due to the pressure applied by the heating roll. Therefore, it is possible to suppress the generation of fluff due to the single fibers of the reinforcing fibers being cut by the resin pool, and it is possible to prevent fluff from being mixed between the prepreg and the lower sheet at least, and to prevent the accumulation of fluff. It is possible to prevent uneven resin impregnation due to

Note that if a resin pool control plate is provided only on the bottom side of the stacked body, a resin pool will be formed on the top side of the stacked body and fluff will similarly occur, but this fluff is easy to observe because it is on the top side. It can be removed after peeling off the sheet constituting the upper resin-carrying sheet.

Furthermore, by appropriately adjusting the distance between the resin pool control plate provided on the lower side of the stacked body and the distance between the stacked body and the nip point of the heating rolls, the amount of resin pool generated on the upper side of the stacked body can be controlled. This makes it possible to prevent the occurrence of fuzz and uneven resin impregnation due to an excessive amount of resin accumulation.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the occurrence of resin pools near the heating roll of a conventional prepreg manufacturing device, Fig. 2 is a schematic side view showing an embodiment of the present invention, and Fig. 3 is an illustration of the vicinity of the heating roll in the present invention. FIG. 11--Reinforcing fiber, 13.17-Resin support sheet, 1
9-heating roll, 20-resin pool control plate, 21-nip point.

Claims (1)

[Claims] In a prepreg manufacturing apparatus, in which sheets, each of which has at least one resin-supporting sheet, are superimposed on both sides of a sheet-shaped reinforcing fiber, and the superimposed body is compressed with heated rolls to transfer and impregnate the reinforcing fiber with resin, A prepreg manufacturing apparatus characterized in that a resin pool control plate is provided in front of a nip point of the heating rolls, in proximity to the nip point, and in a position close to or in contact with at least a lower surface of the stacked body.