JPS61154812A - Manufacture of prepreg - Google Patents

Abstract

PURPOSE:To obtain an elongate prepreg with high productivity and good yield, by rolling a unidirectional prepreg together with a double-side releasable polyester film, and cutting the obtained roll along a special direction in connection with the axis of the roll. CONSTITUTION:A unidirectional prepreg is rolled together with a double-side releasable polyester film, and the obtained roll is cut along the direction perpendicular to the axis of the roll. As reinforcing fiber can be mentioned carbon fiber, glass fiber, aramid fiber, etc., which are generally used as 300-12,000 strands. The strands are spread such that the weight per unit is 15-300g/m<2>, and are arranged in one direction to form a sheet 300-1,500mm in width. Although the large the width, the better the productivity, if the width is greater than 1,500mm, the sheet tends to have uneven thickness, and therefore a prepreg with a width of 500-1,000mm is most preferable when both the productivity and the physical properties are taken into consideration. As a matrix resin for the prepreg is preferable a thermosetting resin in a view of the handleability and working and molding property.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for efficiently manufacturing a narrow unidirectional prepreg.

(Prior art) Composite materials of fiber-reinforced resins using carbon fibers as reinforcing materials have been widely used in sporting goods, automobile parts, and aerospace materials, and when used for these purposes, strands, It is often manufactured by molding a prepreg made by impregnating a strand array, a woven fabric, or the like with a resin.

This prepreg includes woven prepreg, unidirectional prepreg, etc. depending on the fiber arrangement form, and usually has a
The prepreg with a width of 500 mm is cut as appropriate during molding, and is used by laminating it.

When manufacturing pipe-shaped articles such as golf club shafts and fishing rods, cut sheets of unidirectional prepreg are mainly used, and this sheet is wrapped around a metal core and hardened and molded. Alternatively, a pipe-shaped article is made by winding strand brief legs using a filament winding method and then hardening and molding them.

(Problems with conventional methods) In the method of using one-sided prepreg, the cut ends of the cut prepreg often exist continuously in the axial direction of the molded article, so that the circumferential cross section of the molded article is isotropic. I hated missing something. In the method of using strand prepreg for forming into a pipe-like object, the strand prepreg has a substantially circular cross section, and therefore the formed object tends to be thick and the surface is likely to have irregularities. Furthermore, strand prepregs have problems such as talc and the like being added to adjust tack, resulting in poor physical properties and limited resin compositions.

In order to eliminate these problems, it is conceivable to use a narrow sheet prepreg having a width of 3 to 200 mm and a thickness of 0.101 to 0.31 mm. The production of such narrow prepreg requires 1 to 10 strands of 300 to 12,000 strands.
This is done by rolling out the textbook into a sheet and impregnating it with resin.

However, according to this method, in the manufacturing process,
After resin impregnation, it is necessary to cut and straighten the yarn disorder on both sides of the prepreg and shape it to a specified width, which results in a large amount of cutting waste, waste of fiber and resin, and poor production yield. There is. For example, when obtaining a prepreg with a width of 31111, 1/2 to 1/3 of the amount of II miscellaneous material becomes waste due to the adjustment of yarn disorder on both sides, and even more of the resin material is wasted.

Furthermore, since the resin impregnation is carried out while running a strand of a certain length, there is a problem that the production efficiency decreases as the width becomes narrower.

The present inventors have arrived at the present invention as a result of studies on methods for solving such problems.

(Structure of the Invention) The present invention is characterized in that a unidirectional prepreg is wound into a roll through a double-sided peeled ↑1 poly 1 stell film, and then the obtained roll is cut in a direction of 90 degrees with respect to the roll axis. This is a method for manufacturing narrow unidirectional prepreg.

When a narrow prepreg is manufactured using this method,
Narrow prepreg can be obtained with high productivity and good yield.

The reinforcing fibers used in the present invention include:

Examples include carbon S fibers, glass fibers, and 1M aramid strands, and strands of 300 to 12,000 strands are usually used.

These strands have a fiber weight of 15-300g,'m
' and aligned in one direction, width 30
It is made into a sheet of 0 to 1500+u+.

The wider the width, the higher the productivity, but if the width exceeds 1500mm, unevenness in sheet thickness tends to occur.
Considering both productivity and physical properties, it is 500 to 100.
01Ilr# width is preferred.

The use of carbon l1lI male as the reinforcing fiber provides the optimum in terms of the physical properties of the composite material and the thickness of the prepreg.

As the matrix resin for the prepreg, a thermosetting resin is preferable from the viewpoint of handleability and processability.

The resin can be impregnated into the fiber sheet by either a hot melt method or a solvent method.

The resin content of the prepreg is usually 28 to 60% (by weight). A double-sided releasable polyester film is used as the release film. In the case of other materials, such as paper, paper dust is generated during cutting and adheres to the narrow tape surface.

Polyethylene film and polypropylene film have no stiffness, and the narrower the film, the more difficult it is to handle. Particularly during molding, when the tape is unwound, the film breaks and pieces remain in the molded product, causing a significant deterioration in physical properties.

In addition to polyester film, films with elasticity can also be used.

Polyester film has a tear strength of 15kO/
It is best to use one with a diameter of 11m or more. A thickness of about 20 to 50 μm is usually used. A polyester film coated with a release material such as silicone or polyolefin on both sides is used.

The prepreg, which is made by impregnating IJI miscellaneous sheet with matrix resin, is rolled with a roll diameter of 50 mm through this double-sided peelable film.
It is wound up into a ~200mm paper tube. If the diameter of the paper tube is small, there is a risk of undulations occurring in the prepreg.

The amount of winding is preferably 1001 mm or less. thickness 10
If it exceeds 0 mm, de-centering tends to occur when cutting into narrow widths. The preferred thickness is up to about 5 times the cutting width.

The prepreg wound up into a Q-roll via a double-sided peelable polyester film is cut to a predetermined width in a direction of 90 degrees to the roll axis, that is, in the circumferential direction. If you do I & D before rolling it up, f! It is easy to produce defective products such as fiber disorder at both ends and poor winding appearance.

The cutting width is usually 3 to 2001Il111, and the narrower the cutting width, the greater the effect of the present invention.

In particular, in the present invention, the prepreg with a fiber basis weight of 50Q/IR' or less is preferably made into a tape-like prepreg with a width of 10m+a or less, and as a result, even if it is wound during molding of a thin vibrator, the reinforcing fibers will not be strained in the thickness direction. A good molded product can be obtained without leaving any residue.

(Effect of the invention) According to the present invention, the following effects can be obtained.

(1) Narrow prepreg can be obtained with good productivity.

(2) Prepreg of a desired width can be made by simply cutting using a prepreg manufacturing equipment for wide width products.

■ Since no peeling material based on paper is used, there is no generation or adhesion of paper dust during cutting, and molded products with high physical properties can be produced.

■ Since a double-sided releasable polyester film is used as the release material, the strength of the release material is high and continuous wrapping is possible at high molding speeds.

■ Since the prepreg is in the form of a tape, the reinforcing fibers are continuous, and it can be used like a conventional filament wind, but it can be used without the uneven surface of a filament wind molded product.

Example: Phenol novolak type epoxy resin, Araldite E
PN1138 (manufactured by Nippon Ciba Geigy) 70 parts by weight,
Bisphenol A epoxy resin, Epicote 1002
(manufactured by Yuka Shell Epoxy Co., Ltd.) 20 parts by weight, Epicoat 83810 parts by weight, dicyandiamide 3 parts by weight (based on 100 parts of resin), 3 (3,4-dichlorophenyl) -
A resin composition consisting of 5 parts by weight of 1,1-dimethylurea (based on 100 parts of resin) was impregnated with 150 carbon fiber bundles of 3000 carbon fibers having a width of 1000 nm.
+m sheet prepreg. This prepreg had a resin content of 45% by weight and a fiber basis weight of 30 g/ra'.

A 30 μm thick polyester film coated with a silicon release material on both sides was used as a carrier sheet, and the sheet prepreg was rolled up into a roll to have a thickness of 30 mff+ on a paper tube with an outer diameter of 90 mm+.

Next, the obtained roll was cut into a width of 7 mm using a disc-shaped cutter at 90 degrees to the roll axis (circumferential direction) to obtain 130 tape-shaped prepregs each having a width of 7 mm.

This tape-like prepreg has a thickness of 0.21 g/m2 and a thickness of 0.
．． 03 mrrl, there is no melting of the film when cutting, there is no mixing of film pieces, the film has good peelability and smooth unwinding property even during use, and the tip diameter is 51IIW.
Original diameter 10mm, length 1000an taper core 5m
The operability is also good when winding at 1 minute.

For comparison, the above 1000mm wide sheet prepreg was cut directly (rolled and scraped) into 7mm width.
When 140 rolls were wound up, defective cutting and winding of the 1M were found, and only 67 good products were obtained.

Claims (1)

[Claims] A method for producing a narrow unidirectional prepreg, which comprises winding up the unidirectional prepreg onto a roll via a double-sided peelable polyester film, and then cutting the obtained roll at 90 degrees to the roll axis.