JP4943945B2 - Method for producing split yarn fabric and split yarn fabric - Google Patents

Description

  The present invention relates to a method for producing a split yarn fabric using a split yarn impregnated with a resin and a split yarn fabric.

  Fabrics using carbon fibers are attracting attention as functional materials that are laminated and have high strength and high elastic modulus.

  The spread yarn fabric manufactured by the manufacturing method described in Patent Document 1 is characterized in that it is thin, has a low basis weight and is excellent in resin impregnation properties, and a laminated molded composite material is difficult to delaminate. There is a drawback in that the range of application is narrow because processing and handling in prepreg processing are liable to cause misalignment and gaps and followability to a three-dimensional shape is poor.

Fabrics using 0.5K carbon fiber yarns and 1K carbon fiber yarns are commercially available, and have a low basis weight and relatively good resin impregnation. Laminated molded composites can be opened compared to fabrics using 3K carbon fiber yarns. It has the characteristics that it is difficult to delaminate next to the textile fabric, and since the mesh is small, misalignment and gaps are unlikely to occur, and the followability to the three-dimensional shape is excellent. However, since 0.5K carbon fiber yarn and 1K carbon fiber yarn have only general-purpose yarn (tensile strength is 4000 MPa, tensile elastic modulus is 235 GPa), physical properties with high strength and high elastic modulus cannot be obtained. There is a disadvantage that it is limited. There is a limit of 125 g / m ² in producing a low weight fabric.

  Furthermore, 0.5K carbon fiber yarns and 1K carbon fiber yarns are expensive, and naturally the fabric itself is also expensive.

  The split yarn described in Patent Document 2 is a split yarn for low-weight, low-mesh fabrics, but is produced in a process of separating after fiber opening and impregnating with a resin, so that a lot of fluff occurs and practical use is difficult. It is.

Japanese Patent No. 2983531 Japanese Patent Laid-Open No. 11-32369

  An object of the present invention is to provide a method for producing a spread yarn fabric and a split yarn fabric having excellent followability to a three-dimensional shape, and having a high strength and a high elastic modulus.

The present invention includes a fiber opening step of opening carbon fibers having a fineness of 300 tex or more,
An impregnation step of impregnating the spread carbon fiber with a resin;
A splitting step of splitting the carbon fiber impregnated with resin into a width of 7 mm or less;
And a weaving step of weaving the split yarns obtained by splitting into warps and wefts.

  In the opening process, the present invention is characterized in that carbon fibers having 6,000 or more filaments are opened.

  In the present invention, the resin impregnated in the carbon fiber in the impregnation step is a thermosetting resin or a thermoplastic resin.

  Further, the present invention is a split yarn fabric manufactured by the above-described method for manufacturing a split yarn fabric.

  According to the present invention, carbon fibers having a fineness of 300 tex or more are opened in the opening step, and in the impregnation step, the opened carbon fibers are impregnated with a resin. In the splitting process, the carbon fibers impregnated with the resin are split into a width of 7 mm or less, and in the weaving process, the split fibers obtained by splitting are woven as warps and wefts.

  By using carbon fibers having a fineness of 300 tex or more, high strength, high elastic modulus and low price can be realized, and fluffing can be prevented by impregnating the resin before splitting. Furthermore, by using a split yarn having a width of 7 mm or less, it is possible to realize a split yarn fabric excellent in low fabric weight, low mesh, that is, excellent followability to a three-dimensional shape.

  Further, according to the present invention, in the opening step, a split fiber fabric with higher strength and higher elastic modulus can be realized by opening carbon fibers having 6,000 or more filaments.

  According to the invention, a thermosetting resin or a thermoplastic resin can be used as the resin impregnated into the carbon fiber in the impregnation step.

  In addition, the present invention is manufactured by the above-described method for manufacturing a split fiber fabric, thereby realizing splitting that achieves high strength, high elastic modulus, low cost, and is excellent in preventing fluff and following a three-dimensional shape. A yarn fabric can be realized.

Hereinafter, the present invention will be described more specifically with reference to embodiments.
The method for producing a split yarn fabric of the present invention includes the following steps.
(1) Fiber opening process (2) Impregnation process (3) Splitting process (4) Weaving process Each process is demonstrated.

(1) Opening step In the opening step, first, carbon fibers having a high fineness are opened to a predetermined width.
The fineness of the carbon fiber opened in the opening process is preferably 300 tex or more, particularly preferably 400 tex or more.

  Here, tex is a unit representing the thickness (fineness) of the yarn. A yarn having a length of 1000 m and a weight of 1 g is called 1 tex.

  When the fineness is smaller than 300 tex, not only the strength is insufficient and a sufficient elastic modulus cannot be obtained, but also the carbon fiber itself is expensive.

  A conventionally known method can be used for the opening method. For example, fiber bundles are squeezed with a round bar or the like, opened by applying a water stream or high-pressure air, or opened by ultrasonic irradiation.

  In this embodiment, two rolls are arranged in parallel at a predetermined interval, and a vacuum is drawn from below in the area between the two rolls, so that the fiber bundle is downward in the area between the two rolls. Adopts a negative-pressure air type that is bent and opened.

  Negative-pressure air-type opening devices are commercially available, and examples include opening devices manufactured by Harmoni Sangyo Co., Ltd.

  By using such a fiber opening method, the fiber can be opened uniformly without cutting or meandering the fibers.

  In the opening process, for example, a raw yarn having a width of about 3 to 5 mm is opened until the width becomes 20 to 35 mm. The fiber opening feed rate can be opened at a relatively high speed of 1 m / min to 30 m / min.

(2) Impregnation step In the impregnation step, a predetermined matrix resin is impregnated with the opened carbon fiber.
Since the number of fibers in the thickness direction is reduced by the fiber opening, the matrix resin can be impregnated into the fiber bundle uniformly in a short time.

  As the matrix resin to be impregnated, for example, a thermosetting resin such as an epoxy resin or a phenol resin, or a thermoplastic resin such as a polyurethane resin is preferably used.

  As the epoxy resin, an aqueous epoxy resin in an emulsion state in which an epoxy resin is dispersed in water is preferable. For example, Epiretz manufactured by Japan Epoxy Resin Co., Ltd. can be used. The molecular weight of the epoxy resin is preferably about 3000 to 4500 and relatively low molecular weight.

  As the phenol resin, a type using water as a main solvent is preferable. For example, Phenolite HP series manufactured by Dainippon Ink & Chemicals, Inc. can be used. The resol type phenolic resin is characterized by high flame retardancy and long pot life.

  The polyurethane resin is preferably a water-based urethane resin in which a urethane elastomer is dispersed in water. For example, Takelac W series manufactured by Mitsui Chemicals Polyurethane Co., Ltd. can be used. The molecular weight of the polyurethane resin is about 80,000 to 150,000, which is higher than that of the epoxy resin.

  The opened carbon fiber is pulled up after being immersed in an aqueous solvent in which a matrix resin is dispersed while being continuously fed for a predetermined time.

  In order to remove the aqueous solvent pulled up and adhering to the carbon fiber, it is dried by a drying roll or the like.

  Drying by a drying roll evaporates moisture by continuously feeding the pulled up carbon fibers along the outer circumferential surface of the drying roll in the circumferential direction in a state where they are in contact with each other from about a half to two-thirds. The drying roll preferably has a heat capacity capable of evaporating the contained water even at the maximum speed in the opening process. For example, an aluminum alloy having a diameter of 220 mm, a width of 180 mm, and a temperature of 100 to 120 ° C. can be used. .

  The dipping time is adjusted so that the amount of the matrix resin attached is about 1% to 40%, preferably 10% to 20% of the entire spread fiber.

(3) Separation process At the stage where drying is finished, a wide spread resin-impregnated sheet-like spread fiber is obtained, and this is divided into a split fiber having a predetermined width.

  The sheet-like spread yarn is continuously fed and separated by a separating device. The yarn width of the split yarn is desirably 7 mm or less. If it is larger than 7 mm, the three-dimensional shape followability becomes remarkably inferior.

  FIG. 1 is an external view showing an outline of the fiber separation device 1. The upper side of the drawing is the top direction of the splitting device, and the lower side of the drawing is the ground direction of the splitting device 1. FIG. 2 is a side view of the fiber separation device 1 as viewed from the direction of the arrow in FIG.

  The sheet-like spread yarn is continuously fed in a direction perpendicular to the paper surface from the front side to the back side. The plurality of round blades 2 are provided at predetermined intervals in the thickness direction, and rotate in the circumferential direction at a constant rotation speed by a rotation shaft that penetrates the center of each round blade.

  Below the round blade 2, the support member 3 is disposed between the blades so as to partially overlap in the radial direction. The support member 3 is composed of a plurality of disks having a thickness smaller than the distance between the blades, and rotates in the circumferential direction at a constant rotation speed by a rotation shaft that passes through the center of each disk.

  The interval between the round blades 2 is the width of the split yarn to be split, and the split split yarn is supported by the support member 3 from below vertically and is continuously wound up without being bent. Sent to the device.

  The carbon fiber handled in the present invention is composed of filaments having a diameter of 5 to 7 μm, and is subjected to subsequent processing in a state where the filaments are intricately entangled even after opening. If a filament running obliquely with respect to the feeding direction is cut, the filament is split along the filament, so that it is difficult to obtain a split yarn having a desired width after splitting.

  In the present invention, after being impregnated with the resin, it is split by the splitting device 1 as described above, so that split yarns having no variation in yarn width can be obtained.

  The rotary shaft of the round blade 2 is rotationally driven by, for example, a servo motor. The servo motor used has an output of 200 W, a rated rotational speed of 30 to 2700 rpm, and a rated torque of 0.4 Nm.

The rotation speed of the round blade 2 is set to 10 to 900 rpm, and the torque is set to 1.2 Nm.
When an epoxy resin is used as the matrix resin, the rotational speed is preferably 420 to 550 rpm, and the feed rate is preferably 2 to 8 m / min.
When a polyurethane resin is used as the matrix resin, the rotational speed is preferably 380 to 480 rpm, and the feed rate is preferably 2 to 18 m / min.

(4) Weaving process Weaving is performed by using the split yarn divided into a predetermined width in the splitting process as a diameter yarn and a weft yarn. The weaving method is not particularly limited and can be performed by a conventionally known method. For example, a needle loom, a shuttle loom, a rapier loom, a gripper loom, and the like can be used. A rapier loom is preferable, and a single rapier loom is particularly preferable among them.

The split yarn fabric thus obtained has a light weight of 40 to 90 g / m ² , a tensile strength of 1600 to 2900 MPa, a tensile elastic modulus of 150 to 330 GPa, a sufficiently high strength, and a high elastic modulus. It is a woven fabric.

In the weaving process, it is particularly important to supply the weft so that twisting does not occur and to apply an optimum tension.
In order to prevent twisting, it is brought into contact with the rotating roll every 300 mm (preferably every 200 mm or less). If the weft is in a free state of 300 mm or more, twisting is likely to occur. As the tension to the weft, an optimum tension is applied by using a weight having a variable weight.

  As described above, according to the production method of the present invention, it is possible to provide a low-weight fabric with a low cost compared to a fabric using 0.5K carbon fiber yarn or 1K carbon fiber yarn. The followability of the three-dimensional shape is not much different from the conventional one, but the selection range of usable carbon fibers is widened to meet a wide range of needs such as strength and price.

1 is an external view showing an outline of a fiber separation device 1. FIG. It is a side view of the fiber separation apparatus 1 seen from the arrow direction of FIG.

Explanation of symbols

1 Separating device 2 Round blade 3 Support member

Claims (4)

An opening process for opening carbon fibers having a fineness of 300 tex or more;
An impregnation step of impregnating the spread carbon fiber with a resin;
A splitting step of splitting the carbon fiber impregnated with resin into a width of 7 mm or less;
And a weaving step of weaving the split yarns obtained by splitting into warps and wefts.   The method for producing a split yarn fabric according to claim 1, wherein in the opening step, carbon fibers having 6,000 or more filaments are opened.   The method for producing a split yarn fabric according to claim 1 or 2, wherein the resin impregnated in the carbon fiber in the impregnation step is a thermosetting resin or a thermoplastic resin.   A split yarn fabric manufactured by the method for manufacturing a split yarn fabric according to any one of claims 1 to 3.

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