JP2016061001A - Composite yarn and method for producing composite yarn - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite yarn capable of improving a coverage and a degree of adhesion of a synthetic fiber yarn to a core yarn and capable of suppressing a damage of a core yarn.SOLUTION: The composite yarn 1 comprises: a core yarn 10; and a first cover 20 that covers the periphery of the core yarn 10 by being weft knitted by using a synthetic fiber yarn to protect the core yarn 10. The composite yarn 1 can improve a coverage and a degree of adhesion of the synthetic fiber yarn of the first cover 20 to the core yarn 10 since the synthetic fiber yarn of the first cover 20 for covering the core yarn 10 is weft knitted. However, in the case of weft knitting, a fastening force to directly wind the synthetic fiber yarn around the core yarn 10 cannot be provided. Therefore, it is possible to suppress a damage of the core yarn 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a composite yarn obtained by covering a core yarn such as a carbon fiber yarn, a metal yarn, or an optical fiber with a synthetic fiber yarn, and a method for producing the composite yarn.

  Patent Documents 1 to 3 disclose composite yarns in which a fiber bundle (core yarn) obtained by bundling a large number of carbon fiber yarns is covered with a thermoplastic synthetic fiber yarn. Specifically, Patent Document 1 discloses that a composite yarn is formed by winding a loop of a synthetic fiber yarn of a thermoplastic synthetic fiber around a carbon fiber bundle in a loop shape using a sewing machine. Patent Document 2 discloses a composite yarn in which a carbon fiber bundle is covered by warp knitting (knitting) a synthetic fiber yarn. Patent Document 3 discloses a composite yarn that covers a carbon fiber bundle by winding (twisting or twisting) a synthetic fiber yarn in a spiral shape.

Japanese Patent No. 5279121 Japanese Patent No. 5372538 JP 2012-207340 A

  In the composite yarn described in Patent Document 1, the synthetic fiber yarn (hanging yarn) that covers the core yarn (carbon fiber bundle) is sewn in an over-loop shape at regular intervals using a lock sewing machine. Therefore, the covering ratio of the synthetic fiber yarn to the core yarn is low, and the core yarn may jump out from the gap of the synthetic fiber yarn.

  In the composite yarn described in Patent Document 2, since the synthetic fiber yarn covering the core yarn (carbon fiber bundle) is warp knitted, the coverage of the synthetic fiber yarn to the core yarn is higher than that of Patent Document 1, but still not enough. In addition, in the case of warp knitting, a large number of core yarns are arranged in the vertical direction, whereas synthetic fiber yarns are also arranged in the vertical direction, so the core yarns cannot be strongly tightened by the synthetic fiber yarns, The degree of adhesion of the synthetic fiber yarn to the core yarn is low. When the synthetic fiber yarn has low adhesion to the core yarn, a hot press (heating and pressurizing) is used to produce a prepreg with a composite yarn using a carbon fiber bundle for the core yarn and a thermoplastic synthetic fiber yarn. ), The permeability of the synthetic fiber yarn into the carbon fiber bundle is low, and the degree of adhesion between the carbon fiber bundle and the synthetic resin is low.

  In the composite yarn described in Patent Document 3, since the core yarn (carbon fiber bundle) is directly wound with the synthetic fiber yarn, the coverage and adhesion of the synthetic fiber yarn to the core yarn can be increased, but the core yarn is damaged. May end up.

  Accordingly, the present invention provides a composite yarn that can increase the coverage and adhesion of the synthetic fiber yarn to the core yarn, and can suppress damage to the core yarn, and a method for producing the composite yarn. For the purpose.

  The composite yarn of the present invention includes a core yarn and a first cover that covers the periphery of the core yarn by weft knitting using a synthetic fiber yarn and protects the core yarn.

  The composite yarn manufacturing method of the present invention includes a first covering step of covering the periphery of the core yarn with a first cover knitted using synthetic fiber yarn to protect the core yarn.

  According to the composite yarn and the composite yarn manufacturing method, since the synthetic fiber yarn of the first cover that covers the core yarn is a weft knitting, the core fiber is covered with the synthetic fiber yarn of the first cover. The rate can be increased. As a result, the core yarn can be prevented from jumping out from the gap between the synthetic fiber yarns.

  Further, in the case of weft knitting, the core yarn is knitted so that the core yarn in the longitudinal direction is wound with the synthetic fiber yarn, so that the core yarn can be relatively strongly tightened by the synthetic fiber yarn of the first cover. The adhesion degree (tightening force) of the synthetic fiber yarn of the first cover can be increased. By adjusting the tension of the synthetic fiber yarn during knitting, the synthetic fiber yarn can be knitted so that the synthetic fiber yarn is properly adhered to the core yarn. As a result, when producing prepregs of knitted fabrics, woven fabrics, and braided fabrics that are knitted, woven and composed of composite yarns using carbon fiber bundles for core yarns and thermoplastics for synthetic fiber yarns, The permeability (penetration degree) of the synthetic fiber yarn into the carbon fiber bundle by (heating and pressurization) can be increased, and the adhesion degree between the carbon fiber bundle and the synthetic resin can be increased.

  However, in the case of weft knitting, there is no tightening force to wind the synthetic fiber yarn directly around the core yarn, so that the core yarn can be prevented from being damaged.

  The thickness of the synthetic fiber yarn in the first cover described above may be not less than 33 dtex and not more than 250 dtex. According to this, if the thickness of the synthetic fiber yarn in the first cover is 33 dtex or more, the coverage of the synthetic fiber yarn of the first cover with respect to the core yarn can be increased, and the core from the gap of the synthetic fiber yarn can be increased. The yarn can be prevented from jumping outward. Further, if the thickness of the synthetic fiber yarn in the first cover is 250 dtex or less, knitting using a knitting machine is possible.

  The number of stitches of the same course in the first cover described above may be 2 or more and 6 or less. According to this, the diameter of the cylindrical knitting of the first cover can be reduced, and the adhesion degree (tightening force) of the synthetic fiber yarn of the first cover to the core yarn can be increased.

  Further, the number of stitches per 1 cm natural length of the same wale in the first cover described above may be 6 or more and 14 or less. The natural length means a length in a state where no tension or the like is applied, that is, a state where the natural length is naturally placed on the table. If the number of stitches per 1 cm natural length of the same wale in the first cover is 6 or more, the coverage of the synthetic fiber yarn of the first cover with respect to the core yarn can be increased, and the gap between the synthetic fiber yarns The core yarn can be prevented from jumping outward. Further, if the number of stitches per 1 cm of natural length of the same wale in the first cover is 14 or less, the stitching defect of the covering stitches is caused due to the stitches becoming too fine. In addition, it is possible to prevent the composite yarn from becoming soft and difficult to knit, weave and compose with the composite yarn.

  The above-described composite yarn may further include a second cover that covers the periphery of the first cover using a synthetic fiber yarn, and causes the first cover to adhere to the core yarn. In addition, the above-described composite yarn manufacturing method further includes a second covering step of covering the periphery of the first cover with a second cover using synthetic fiber yarns, and bringing the first cover into close contact with the core yarn. You may go out. According to this, since the second cover is applied from above the first cover, the degree of adhesion of the synthetic fiber yarn of the first cover to the core yarn can be further increased. As a result, a prepreg of a knitted fabric, a woven fabric, and a braid is formed by knitting, weaving, and composing a composite yarn using a carbon fiber bundle as the core yarn and a thermoplastic material as the synthetic fiber yarn of the first cover. In this case, the permeability (penetration) of the synthetic fiber yarn into the carbon fiber bundle by hot pressing (heating and pressurization) can be further increased, and the adhesion between the carbon fiber bundle and the synthetic resin can be further increased. it can.

  Moreover, the coverage with the synthetic fiber yarn in the first cover described above may be higher than the coverage with the synthetic fiber yarn in the second cover.

  Further, the above-described composite yarn may further include a third cover that covers the periphery of the second cover using a synthetic fiber yarn and makes the first cover adhere to the core yarn. In addition, the above-described composite yarn manufacturing method further includes a third covering step of covering the periphery of the second cover with a third cover using synthetic fiber yarn, and bringing the first cover into close contact with the core yarn. But you can. According to this, the adhesion degree of the synthetic fiber yarn of the first cover to the core yarn can be further increased.

  Further, the synthetic fiber yarn in the second cover described above may be spirally wound around the first cover. According to this, since the synthetic fiber yarn of the second cover is indirectly wound from above the first cover, the synthetic fiber yarn of the first cover adheres to the core yarn while suppressing damage to the core yarn. The degree can be increased.

  Further, the synthetic fiber yarn in the second cover described above is spirally wound around the first cover in the first direction, and the synthetic fiber yarn in the third cover is the first direction. The periphery of the second cover may be spirally wound in the opposite second direction. According to this, since the synthetic fiber yarn of the third cover is further indirectly wound on the first and second covers, the synthesis of the first cover with respect to the core yarn is suppressed while preventing the core yarn from being damaged. The degree of adhesion of the fiber yarn can be further increased.

  Further, the above-described core yarn may include a carbon fiber yarn, and the synthetic fiber yarn of the first cover may include a thermoplastic resin. The core yarn described above may include carbon fiber yarns, and the synthetic fiber yarns of the first and second covers may include a thermoplastic resin. Moreover, the above-described core yarn may include carbon fibers, and the knitting yarns of the first, second, and third covers may include a thermoplastic resin. According to this, as described above, when producing a prepreg of a knitted fabric, a woven fabric, or a braided material by knitting, weaving, and composing a composite yarn in which a core yarn is covered with a synthetic fiber yarn, The permeability (penetration degree) of the synthetic fiber yarn into the carbon fiber bundle by pressurization) can be increased, and the adhesion degree between the carbon fiber bundle and the synthetic resin can be increased.

  According to the present invention, in the composite yarn in which the core yarn is covered with the synthetic fiber yarn, the coverage and adhesion of the synthetic fiber yarn to the core yarn can be increased, and the core yarn can be prevented from being damaged. it can.

It is a figure which fractures | ruptures and shows the composite yarn which concerns on the 1st Embodiment of this invention. It is a figure which shows the end surface of the composite yarn which concerns on the 1st Embodiment of this invention. FIG. 3 is a development view of the first cover shown in FIGS. 1 and 2. It is a figure which shows the manufacturing method of the composite yarn which concerns on the 1st Embodiment of this invention. It is a figure which shows the Example of the composite yarn of 1st Embodiment. It is a figure which fractures | ruptures and shows the composite yarn which concerns on the 2nd Embodiment of this invention. It is a figure which shows the end surface of the composite yarn which concerns on the 2nd Embodiment of this invention. It is a figure which shows the manufacturing method of the composite yarn which concerns on the 2nd Embodiment of this invention. It is a figure which shows the Example of the composite yarn of 2nd Embodiment. It is a figure which fractures | ruptures and shows the composite yarn which concerns on the 3rd Embodiment of this invention. It is a figure which shows the end surface of the composite yarn which concerns on the 3rd Embodiment of this invention. It is a figure which shows the manufacturing method of the composite yarn which concerns on the 3rd Embodiment of this invention.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.
[First Embodiment]

  FIG. 1 is a partially broken view showing a composite yarn according to the first embodiment of the present invention, and FIG. 2 is a view showing an end face of the composite yarn according to the first embodiment of the present invention. . The composite yarn 1 of the first embodiment shown in FIGS. 1 and 2 includes a core yarn 10 and a first cover 20.

  The core yarn 10 is a carbon fiber bundle obtained by bundling a large number of carbon fiber yarns. As a carbon fiber bundle, 1K (1000 filaments), 3K (3000 filaments), etc. can be used, for example. The periphery of the core yarn 10 is covered with a first cover 20.

  A developed view of the first cover 20 is shown in FIG. As shown in FIG. 3, the first cover 20 covers the periphery of the core yarn 10 by weft knitting (knitting) using the knitting yarn. The first cover 20 is intended to protect the core yarn 10. In this regard, weft knitting can make the stitches finer than warp knitting.

  The number of wales in the first cover 20, that is, the number of stitches in the same course is 2 or more and 6 or less. The number of courses per 1 cm of natural length in the first cover, that is, the number of stitches per 1 cm of natural length of the same wale is 6 or more and 14 or less.

  As the knitting yarn of the first cover 20, a thermoplastic synthetic fiber yarn having a thickness of 33 dtex (decitex) to 250 dtex (decitex) that can be easily covered is used. Examples of the thermoplastic synthetic fiber yarn material (synthetic resin) include polyethylene resin, polyester resin, nylon (polyamide) resin, and polypropylene resin.

  FIG. 4 is a flowchart showing a composite yarn manufacturing method according to the first embodiment of the present invention. A first cover 20 is applied to the core yarn 10. Specifically, the periphery of the core yarn 10 is covered with the first cover 20 by weft knitting (knitting) using the knitting yarn. In this way, the core yarn 10 can be protected by the first cover 20 (first covering step) (step S1).

  According to the composite yarn 1 and the composite yarn manufacturing method of the first embodiment, the synthetic fiber yarn of the first cover 20 that covers the core yarn 10 is a weft knitting (knitting). The coverage of the synthetic fiber yarn of the first cover 20 can be increased. As a result, the core yarn 10 can be prevented from jumping outward from the gap between the synthetic fiber yarns.

  In the case of weft knitting, the core yarn 10 is knitted so that the longitudinal core yarn 10 is wound with the synthetic fiber yarn, so that the core yarn 10 can be relatively strongly tightened by the synthetic fiber yarn of the first cover 20. The adhesion degree (tightening force) of the synthetic fiber yarn of the first cover 20 to the core yarn 10 can be increased. By adjusting the tension of the synthetic fiber yarn at the time of knitting, the synthetic fiber yarn can be knitted so as to be in close contact with the core yarn 10 appropriately. As a result, a prepreg of a knitted fabric, a woven fabric, or a braid was formed by knitting, weaving, and composing a composite yarn using a carbon fiber bundle for the core yarn 10 and a thermoplastic fiber for the synthetic fiber yarn of the first cover 20. When produced, the permeability (penetration) of the synthetic fiber yarn into the carbon fiber bundle can be increased by hot pressing (heating and pressurization), and the adhesion between the carbon fiber bundle and the synthetic resin can be increased. it can.

  However, in the case of weft knitting, there is no tightening force to wind the synthetic fiber yarn directly around the core yarn, so that the core yarn 10 can be prevented from being damaged.

  Moreover, since the thickness of the synthetic fiber yarn in the 1st cover is 33 dtex or more and 250 dtex or less, it has the following advantages. That is, if the thickness of the synthetic fiber yarn in the first cover 20 is 33 dtex or more, the coverage of the synthetic fiber yarn of the first cover 20 with respect to the core yarn 10 can be increased, and the synthesis in the first cover 20 is achieved. It is possible to suppress the core yarn 10 from jumping outward from the gap between the fiber yarns. Further, if the thickness of the synthetic fiber yarn in the first cover 20 is 250 dtex or less, knitting using a knitting machine is possible.

  If the thickness of the synthetic fiber yarn in the first cover 20 is less than 33 dtex, the synthetic fiber yarn is too thin and a gap is formed in the weft knitting structure, and the synthetic fiber yarn of the first cover 20 with respect to the core yarn 10 The coverage cannot be increased sufficiently. On the other hand, if the thickness of the synthetic fiber yarn in the first cover 20 exceeds 250 dtex, the synthetic fiber yarn is too thick, and the synthetic fiber yarn does not pass through the needle of the knitting machine, so that knitting using the knitting machine becomes difficult.

  Further, since the number of stitches of the same course in the first cover 20 is 2 or more and 6 or less, the diameter of the cylindrical knitting of the first cover 20 can be reduced, and the first cover for the core yarn 10 can be reduced. The adhesion degree (tightening force) of 20 synthetic fiber yarns can be increased. A weft knitting structure with 7 or more stitches may be used, but since the diameter of the tubular knitting increases, the degree of adhesion of the synthetic fiber yarn of the first cover 20 to the core yarn 10 decreases. End up.

  Further, since the number of stitches per 1 cm natural length of the same wale in the first cover 20 is 6 or more and 14 or less, the following advantages are obtained. That is, if the number of stitches per 1 cm natural length of the same wale in the first cover 20 is 6 or more, the coverage of the synthetic fiber yarn of the first cover 20 to the core yarn 10 can be increased, It is possible to sufficiently suppress the core yarn 10 from jumping outward from the gap between the synthetic fiber yarns of the one cover 20. When the number of stitches per 1 cm natural length of the same wale is less than 6, the coverage of the synthetic fiber yarn of the first cover 20 with respect to the core yarn 10 is low, and the synthetic fiber yarn of the first cover 20 It is not possible to sufficiently suppress the core yarn 10 from jumping out of the gap.

  On the other hand, when the number of stitches per 1 cm natural length of the same wale is 15 or more, the core yarn 10 can be prevented from jumping out from the gap between the synthetic fiber yarns of the first cover 20. Since it becomes too fine, a cover-knitting stitch with a flaw is generated. In addition, the composite yarn becomes inflexible and it becomes difficult to knit, weave and compose the composite yarn. In other words, if the number of stitches per 1 cm natural length of the same wale in the first cover 20 is 14 or less, the stitches of the covering stitches are caused by the stitches of the first cover 20 being too fine. Occurrence of fogging defects (tack flaws) can be suppressed, and the composite yarn can be prevented from becoming soft and difficult to be knitted, woven and composed with the composite yarn.

  According to the composite yarn 1 of the first embodiment, an application for performing curved surface molding of carbon fiber reinforced thermoplastic (CFRPP) as a material of carbon fiber reinforced plastic (CFRP), It is suitable for use as a pellet material for forming a carbon fiber reinforced thermoplastic into a fine powder.

  In an application for performing curved surface molding of a carbon fiber reinforced thermoplastic, according to the composite yarn 1 of the first embodiment, the carbon fiber yarn (core yarn) can be knitted without causing filament breakage. Moreover, since the ratio of both can be set by changing the thickness and density of a thermoplastic synthetic fiber yarn with respect to a carbon fiber yarn, the carbon fiber reinforced plastic with the mixing ratio according to the objective can be made.

Here, FIG. 5 shows an example of the composite yarn 1 of the first embodiment. Thus, it was confirmed that the idea of the present invention can be implemented.
[Second Embodiment]

  FIG. 6 is a partially broken view showing the composite yarn according to the second embodiment of the present invention, and FIG. 7 is a view showing the end face of the composite yarn according to the second embodiment of the present invention. . The composite yarn 2 of the second embodiment shown in FIGS. 6 and 7 is different from the first embodiment in that the composite yarn 1 further includes a second cover 30. The other structure of the composite yarn 2 of the second embodiment is the same as that of the composite yarn 1 of the first embodiment.

  The 2nd cover 30 covers the circumference | surroundings of the 1st cover 20 by winding spirally using the knitting yarn (twisting and twisting). The purpose of the second cover 30 is to bring the first cover 20 into close contact with the core yarn 10. Therefore, the second cover 30 may have a relatively rough winding method. That is, the coverage with the knitting yarn in the first cover 20 is higher than the coverage with the knitting yarn in the second cover 30.

  As the knitting yarn of the second cover 30, the same thermoplastic synthetic fiber yarn as that of the first cover 20 is used.

  FIG. 8 is a flowchart showing a composite yarn manufacturing method according to the second embodiment of the present invention. As shown in FIG. 8, the first covering step (step S1) described above is performed.

  Next, the second cover 30 is applied to the first cover 20. Specifically, the periphery of the first cover 20 is covered with the second cover 30 by spirally winding (twisting or twisting) the knitting yarn. In this way, the second cover 30 can bring the first cover 20 into close contact with the core yarn 10 (second covering step) (step S2).

  According to the composite yarn 2 and the composite yarn manufacturing method of the second embodiment, the same advantages as the composite yarn 1 and the composite yarn manufacturing method of the first embodiment can be obtained.

  Furthermore, according to the composite yarn 2 and the composite yarn manufacturing method of the second embodiment, since the second cover 30 is applied from above the first cover 20, the synthetic fiber of the first cover 20 with respect to the core yarn 10. The degree of adhesion of the yarn can be further increased. As a result, a prepreg of a knitted fabric, a woven fabric, and a braid was formed by knitting, weaving, and composing a composite yarn using a carbon fiber bundle for the core yarn 10 and a thermoplastic yarn for the synthetic fiber yarn of the second cover 30. When produced, the permeability (penetration) of the synthetic fiber yarn into the carbon fiber bundle by hot pressing (heating and pressing) can be further increased, and the adhesion between the carbon fiber bundle and the synthetic resin is further increased. be able to.

  Further, since the synthetic fiber yarn of the second cover 30 is indirectly wound from above the first cover 20, the synthetic fiber yarn of the first cover 20 with respect to the core yarn 10 is suppressed while preventing the core yarn 10 from being damaged. The degree of adhesion can be further increased.

Here, FIG. 9 shows an example of the composite yarn 2 of the second embodiment. Thus, it was confirmed that the idea of the present invention can be implemented.
[Third Embodiment]

  FIG. 10 is a partially broken view showing the composite yarn according to the second embodiment of the present invention, and FIG. 11 is a view showing an end face of the composite yarn according to the third embodiment of the present invention. . The composite yarn 3 of the third embodiment shown in FIGS. 10 and 11 is different from the second embodiment in that the composite yarn 2 further includes a third cover 40. The other structure of the composite yarn 3 of the third embodiment is the same as that of the composite yarn 2 of the second embodiment.

  The 3rd cover 40 covers the circumference | surroundings of the 2nd cover 30 by winding (twisting and twisting) spirally using a knitting yarn. Similar to the second cover 30, the third cover 40 is intended to bring the first cover 20 into close contact with the core yarn 10. Therefore, the third cover 40 may have the same rough winding method as the second cover 30. That is, the coverage with the knitting yarn in the first cover 20 is higher than the coverage with the knitting yarn in the third cover 40.

  In the present embodiment, the winding direction (second direction) of the third cover 40 is opposite to the winding direction (first direction) of the second cover 30. Further, as the knitting yarn of the third cover 40, the same thermoplastic synthetic fiber yarn as that of the first and second covers 20 and 30 is used.

  FIG. 12 is a flowchart showing a composite yarn manufacturing method according to the third embodiment of the present invention. As shown in FIG. 12, the first and second covering steps (steps S1 and S2) described above are performed.

  Next, the third cover 40 is applied to the second cover 30. Specifically, the periphery of the second cover 30 is covered with the third cover 40 by spirally winding (twisting or twisting) the knitting yarn. The winding direction (second direction) of the third cover 40 is opposite to the winding direction (first direction) of the second cover 30. In this way, the second cover 30 can bring the first cover 20 into close contact with the core yarn 10 (third covering step) (step S3).

  According to the composite yarn 3 and the composite yarn manufacturing method of the third embodiment, the same advantages as the composite yarn 2 and the composite yarn manufacturing method of the second embodiment can be obtained.

  Furthermore, according to the composite yarn 3 and the composite yarn manufacturing method of the third embodiment, the third cover 40 is further applied on the first and second covers 20, 30. The degree of adhesion of the synthetic fiber yarn of the cover 20 can be further increased.

  Further, since the synthetic fiber yarn of the third cover 40 is further indirectly wound on the first and second covers 20 and 30, the first yarn to the core yarn 10 is suppressed while preventing the core yarn 10 from being damaged. The adhesion degree of the synthetic fiber yarn of the cover 20 can be further increased.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, in the present embodiment, an example in which the knitting yarn is spirally wound as the second and third covers 30 and 40 is shown, but the second and third covers 30 and 40 are not limited to the present embodiment. For example, the second and third covers 30 and 40 only need to be able to bring the first cover 20 into close contact with the core yarn 10, and weft knitting, knit, sewing, You may form using techniques, such as a braid.

  Moreover, although the core yarn which consists only of carbon fiber yarn was illustrated in this embodiment, another material may be contained in a core yarn. For example, the core yarn may include a thermoplastic synthetic fiber yarn that is aligned with the carbon fiber yarn. According to this, since the aligned synthetic fiber yarn is closer to the carbon fiber yarn, the degree of adhesion of the synthetic fiber yarn to the carbon fiber yarn can be further increased. In addition, the ratio of thermoplastic synthetic fiber yarn to carbon fiber yarn is increased.

  For example, the core yarn may include a metal yarn that is aligned with the carbon fiber yarn. According to this, it is possible to energize the aligned metal yarns to generate heat, and to increase the permeability (penetration degree) of the thermoplastic synthetic fiber yarn in the first cover into the carbon fiber bundle. Can do.

  Moreover, although the form which uses a carbon fiber bundle for the core yarn 10 was illustrated in this embodiment, the thought of this invention is not limited to this. The idea of the present invention can be applied to a form in which a metal thread, an optical fiber, or the like is used for the core thread 10, for example. In this embodiment, synthetic fiber yarns that are not thermoplastic are used as the synthetic fiber yarns of the first, second, and third covers 20, 30, and 40.

  A composite yarn obtained by covering a metal yarn with a synthetic fiber yarn can energize the metal yarn, and is applied to uses such as heat insulation gloves and heat socks. Further, a composite yarn obtained by covering an optical fiber with a synthetic fiber yarn is applied to uses such as a material with a self-diagnosis function capable of detecting damage. When the optical fiber is damaged, light leaks from the damaged portion, so that damage can be detected.

  1, 2, 3 ... composite yarn, 10 ... core yarn, 20 ... first cover, 30 ... second cover, 40 ... third cover.

Claims (15)

Core yarn,
A first cover that covers the periphery of the core yarn by weft knitting using synthetic fiber yarn and protects the core yarn;
A composite yarn comprising   The composite yarn according to claim 1, wherein the thickness of the synthetic fiber yarn in the first cover is 33 dtex or more and 250 dtex or less.   The composite yarn according to claim 1 or 2, wherein the number of stitches of the same course in the first cover is 2 or more and 6 or less.   The composite yarn according to any one of claims 1 to 3, wherein the number of stitches per 1 cm natural length of the same wale in the first cover is 6 or more and 14 or less.   The composite according to any one of claims 1 to 4, further comprising a second cover that covers the periphery of the first cover using a synthetic fiber yarn, and that closely contacts the first cover to the core yarn. yarn.   The composite yarn according to claim 5, wherein a coverage by the synthetic fiber yarn in the first cover is higher than a coverage by the synthetic fiber yarn in the second cover.   The composite yarn according to claim 5 or 6, further comprising a third cover that covers the periphery of the second cover with a synthetic fiber yarn and that causes the first cover to adhere to the core yarn.   The composite yarn according to claim 5 or 6, wherein the synthetic fiber yarn in the second cover is spirally wound around the first cover. The synthetic fiber yarn in the second cover is spirally wound around the first cover in the first direction,
The synthetic fiber yarn in the third cover is spirally wound around the second cover in a second direction opposite to the first direction.
The composite yarn according to claim 7. The core yarn includes carbon fiber yarn,
The synthetic fiber yarn of the first cover includes a thermoplastic resin.
The composite yarn according to any one of claims 1 to 4. The core yarn includes carbon fiber yarn,
The synthetic fiber yarns of the first and second covers include a thermoplastic resin.
The composite yarn according to any one of claims 5, 6, and 8. The core yarn includes carbon fiber,
The knitting yarns of the first, second and third covers include a thermoplastic resin;
The composite yarn according to claim 7 or 9.   A method for producing a composite yarn, comprising a first covering step of covering the periphery of a core yarn with a first cover knitted using synthetic fiber yarn to protect the core yarn.   14. The composite according to claim 13, further comprising a second covering step of covering the periphery of the first cover with a second cover using a synthetic fiber yarn and closely attaching the first cover to the core yarn. Yarn manufacturing method.   The composite according to claim 14, further comprising a third covering step of covering the periphery of the second cover with a third cover using synthetic fiber yarns and closely attaching the first cover to the core yarns. Yarn manufacturing method.