JPH01139837A - Continuous widening of fiber bundle - Google Patents

Abstract

PURPOSE: To provide a method for continuously expanding fiber bundles, capable of uniformly and sufficiently expanding the fiber bundles, while preventing the generation of fuzzes and the breakage of single filaments, by impregnating a viscous substance into the fiber bundles continuously fed under a tension, press-expanding the impregnated fiber bundles and then removing the viscous substance. CONSTITUTION: This method for continuously expanding fiber bundles comprises imparting an unwinding tension to plural fiber bundles 2, 2... to pull out the fiber bundles, feeding the fiber bundles into a comb-type guide 4 to parallel the fiber bundles in a sheet-like shape, nipping the sheet-like bundles between mold release paper sheets 9, 10 coated with a viscous substance and pulled out from wound members 5, 7, reducing the viscosity of the viscous substance on a hot plate 11, passing the laminate through press rolls 12 to impregnate the fiber bundles 2, 2... with the viscous substance and simultaneously expand the fiber bundles 2, 2..., peeling the mold release paper sheets 9, 10 through guide rolls 13, 14, and then dissolving off the viscous substance in dissolution tanks 21, 21....

Description

[Detailed description of the invention] (Industrial application field) This invention continuously widens a fiber bundle (strand),
This invention relates to a method of making ultra-thin fiber bundles.

(Prior art) Fiber bundles are widened by subjecting the fibers to physical or chemical treatments such as vapor deposition, sputtering, ion blating, plating, and chemical vapor deposition, or by applying a superconducting thin film around the fibers. This is necessary when forming a This is because if the fiber bundle is not widened sufficiently, these treatments will be applied around the fiber bundle and not around each individual fiber, that is, a single fiber.

Most preferably, the width is widened so that there is almost no overlap of single fibers in the thickness direction.

As a method for widening a fiber bundle, a method such as that described in, for example, Japanese Unexamined Patent Publication No. 61-275438 is known. In this method, the fiber bundle is struck by a rotating guide or a reciprocating guide while traveling under tension, and the width of the fiber bundle is widened by utilizing the kneading action of these guides. However, in this conventional method, the so-called raw fiber bundle is struck under tension with a rotating guide or a reciprocating guide, so there are problems such as generation of fluff and breakage of single fibers. be. In particular, this disadvantage is significant in the case of carbon fibers, etc., which have very low bending strength. Further, there is also the problem that a difference in tension occurs between the single fibers, resulting in partial loosening, or that the single fibers overlap irregularly.

(Problems to be Solved by the Invention) It is an object of the present invention to solve the above-mentioned problems of the conventional method, and not only make it possible to widen the fiber bundle in a -like manner and sufficiently, but also to prevent fuzz and An object of the present invention is to provide a method for continuously widening a fiber bundle, which can prevent the occurrence of single yarn breakage.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a step of continuously supplying a fiber bundle under tension, a step of impregnating the fiber bundle with a viscous substance, A continuous method for widening a fiber bundle is provided, which includes the steps of pushing and widening the fiber bundle impregnated with a viscous substance, and removing the viscous substance from the widened fiber bundle.

To explain this invention in detail, the fiber bundle to be widened consists of 100 to 500 single fibers with a diameter of about 3 to 50 μm.
A bundle of about 00 fibers, such as carbon fiber,
Ceramic fibers such as glass fibers, boron nitride fibers, silicon nitride fibers, silicon carbide fibers, alumina fibers, zirconia fibers, metal fibers such as synthetic fibers, silver fibers, copper fibers, iron fibers, aluminum fibers, stainless steel fibers, etc. , polyimide fibers, polyamide-imide fibers, polyester fibers, polyacrylonitrile fibers, polyethylene fibers, polyaramid fibers, and other organic fibers. Such a fiber bundle is preferably a so-called non-twisted fiber bundle that does not have any twist.

Although the width of only one fiber bundle may be widened, usually, a plurality of fiber bundles are supplied parallel to each other in one direction in the form of a sheet, and the fiber bundles are widened at the same time. Further, a force of about 10 to 100 g is applied to each fiber bundle so that the tension is maintained during running.

Examples of the viscous substance to be impregnated into the fiber bundle include epoxy resin, unsaturated polyester resin, polyester resin,
Use resins such as polyvinyl acetate resin, cellulose acetate resin, silicone resin, polyvinyl butyral resin, polyvinyl alcohol resin, polyvinylpyrrolidone resin, methacrylic resin, and starch after diluting them with organic solvents, water, etc. as necessary. .

The viscosity of the viscous substance varies slightly depending on the type of fiber, the thickness of the fiber bundle, the feeding speed of the fiber bundle, etc., but is in the range of 0.1 to 1.
Approximately 0 poise is appropriate.

The fiber bundle can be impregnated with the above-mentioned viscous substance by various methods. For example, a method may be used in which a release paper coated with a viscous substance is pressed onto the fiber bundle, and the viscous substance is transferred from the release paper to the fiber bundle to impregnate it. Alternatively, a so-called dipping method, in which the fiber bundle is immersed in a viscous substance and pulled up, can be used.

Prior to or simultaneously with the width widening, the fiber bundle impregnated with a viscous substance may be heated to make the single fibers easier to move. The heating temperature varies somewhat depending on the type of viscous substance, but for example, when using epoxy resin, 1
The temperature is about 00 to 200°C.

Removal of viscous material from widened fiber bundles usually involves
Use a solvent. Examples of organic solvents include ketones such as acetone and methyl ethyl ketone, alcohols such as methyl alcohol and ethyl alcohol, esters such as ethyl acetate and methyl cellosolve, and ethers such as methyl ether and methyl isopropyl ether. Hydrocarbons such as toluene, xylene, hexane, etc. can be used. Also, if the viscous substance is water-soluble, it can be removed using water. Alternatively, viscous materials can be removed by burning off under an oxygen atmosphere. In addition, when removing a viscous substance using a solvent, water, or the like, for example, caustic soda or the like may be added thereto to improve wettability with the fiber bundle.

To remove the viscous substance using an organic solvent or water, a fiber bundle impregnated with the viscous substance may be immersed and run in a bath of the organic solvent or water. At this time, if the organic solvent or water in the bath is actively fluidized, removal becomes easier. Flow can be achieved by placing a spray nozzle in the bath and spraying the organic solvent or water in the bath onto the running fiber bundle, or by using a stirring blade or the like to flow in one direction, preferably in the opposite direction to the running direction of the fiber bundle. This can be done by creating a directional flow.

In addition, when removing a viscous substance using an organic solvent, it is preferable to wash the fiber bundle with distilled water or the like after removal.

To explain this invention in more detail based on the drawings, the first
In the figure, a plurality of packages 1.1,...
From there, a plurality of raw fiber bundles 2.2, . Arrange them.

Next, the aligned fiber bundles 2.2, . The material is sandwiched between a release paper 10 whose surface is coated with a viscous substance, which is pulled out via a guide roll 8, and further heated with a hot plate 11 to lower the viscosity of the viscous substance. 12, and from the release paper 9.10 the fiber bundle 2.
Transferring and impregnating the viscous substance to 2.2, . . . and pushing and expanding the fiber bundle 2.2, . However, the viscous substance may be applied only to one of the release papers, preferably only to the lower release paper 10.

Next, the upper release paper 9 is peeled off through the guide roll 13 and wound onto the core 15, and the lower release paper 10 is similarly peeled off through the guide roll 14 and wound onto the core 16, so that the viscous material is After obtaining the fiber bundle 17 which had been impregnated and expanded, the tension of the fiber bundle 17 was adjusted by the joint action of the nip roll 18, the dancer roll 19, and the guide roll 20, which were arranged roughly in series with each other. , fiber bundle: 17
Multiple dissolving tanks 2 for dissolving and removing viscous substances from
1.21, ...... is immersed and run.

As shown in FIG. 2, the dissolving tanks 21, 21, . ,
A plurality of pressure rolls 24 are arranged opposite to the perforated roll 23.
．． 24, . . . , between the perforated roll 23 and the pressure rolls 24, 24, . The fiber bundle 17 is run to dissolve and remove the viscous substance impregnated therein.

Next, the widened fiber bundle 25 thus obtained is washed with water if necessary, and then led to a dryer 27 via a nip roll 26, dried in the dryer 27, and then wound around a core 29 via a guide roll 28. take.

(Example 1) An untwisted fiber bundle of carbon fibers (single fiber diameter = 6 μm, number of single fibers: 1000) was prepared by the method shown in FIGS. 1 and 2.
The book) has been expanded.

That is, the above-mentioned fiber bundles were pulled out at a speed of 1.5 m/min, and while applying a tension of 50 Cl per fiber bundle, they were drawn parallel to each other in one direction into a sheet shape, and then separated using two sheets of release paper coated with polyvinyl alcohol. Supply and sandwich between
The fiber bundle was impregnated with polyvinyl alcohol, and the fiber bundle was pressed and expanded by passing it through a pressure roll to which a force of roughly 3 g was applied. The width of each fiber bundle in this state was about 1 Qmm, which was about 10 times the original width.

Next, the fiber bundle impregnated with polyvinyl alcohol and widened is passed through hot water at 90°C containing 1% by weight of caustic soda as a wetting agent to dissolve the polyvinyl alcohol.
Removed. At this time, hot water was forced to circulate at a rate of 5 liters/minute. In addition, the dissolution tank had five stages. The width of the fiber bundle in this state was about 9.4 mm, which was the same as before removing the polyvinyl alcohol.

Next, the fiber bundle from which the polyvinyl alcohol had been removed was passed through a washing tank containing distilled water, similar to the dissolving tank, and washed while forcedly circulating the distilled water at a rate of 5 liters/minute. Note that the cleaning tank had three stages.

Next, the washed fiber bundle was dried in an oven at 120'C, and then wound around a core. The width of the fiber bundle in the rolled state was 8.5 mm, and no fuzz or opening was observed.

(Example 2) Width was expanded in the same manner as in Example 1 except that the fiber bundle was replaced with a non-twisted carbon fiber bundle having 3000 single fibers. The width of the fiber bundle after widening was about 15 mm, which was about 6 times the width before widening. This width was approximately 14.2 mm after removing the polyvinyl alcohol, and approximately 13 mm when wound onto the core. Visual observation revealed that there was almost no fuzz and no opening of the eyes was observed.

(Effects of the Invention) In this invention, since the fiber bundle is pressed and expanded with respect to the fiber bundle impregnated with a viscous substance, it is possible not only to prevent the generation of fluff and single yarn breakage, but also to expand the width of the fiber bundle. Since the open state is once fixed by the viscous substance, even if the viscous substance is removed, the fiber bundle does not easily return to its original shape. Further, if the viscous substance is removed immediately before using the fiber bundle, it is possible to almost completely prevent the fiber bundle from returning to its original form from the expanded state during storage or the like. Roughly speaking, if a press roll or the like is used to press and widen the fiber bundle, the degree of width expansion can be easily changed by simply changing the pressing force.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing how the method of the present invention is carried out, and FIG. 2 is a schematic side sectional view showing a viscous substance dissolving tank. 1: Fiber bundle package 2: Raw fiber bundle 3 Two guide rolls 4: Tag shape guide 5: Release paper roll 6: Guide roll 7: Release paper roll 8 Two guide rolls 9: Release paper 10 Two release paper 11: Hot play-1 to 12: Suppression roll 13 Ni guide roll 14 Ni guide roll 15: Winding core 16 Double winding core 17: Fiber bundle 18 impregnated with viscous substance and widened Ni roll 19: Dancer roll 20 Ni Guide roll 21: viscous substance dissolving tank 22: tank body 23: porous roll 24: suppression roll 25: fiber bundle after removal of viscous substance 26 roll 27: dryer 28 guide roll 29: winding core

Claims (1)

[Claims] a step of continuously supplying a fiber bundle under tension; a step of impregnating the fiber bundle with a viscous substance; a step of pushing and widening the fiber bundle impregnated with the viscous substance; and a step of expanding the width of the fiber bundle. and removing the viscous substance from the fiber bundle.