JP2014228573A - Method of manufacturing optical fiber and optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing optical fiber that can prevent printing omission even when the shift of a wire occurs and can easily identify an identification mark, and optical fiber.SOLUTION: With a method of manufacturing optical fiber, an identification mark 11 for identifying optical fiber is printed onto the surface of an optical fiber wire by spraying an ink drop onto the optical fiber wire 16 from an ink nozzle. The ink nozzle 23 scans in a direction inclined against the longitudinal direction of the optical fiber wire to print the identification mark. On the optical fiber 10, the identification mark is printed by this manufacturing method.

Description

  The present invention relates to an optical fiber manufacturing method and an optical fiber for printing an identification mark for identifying an optical fiber on the surface of an optical fiber by spraying ink droplets from an ink nozzle onto the optical fiber.

In general, an optical fiber has a structure in which two coating layers are provided outside a glass fiber forming an optical waveguide, and a colored layer is provided outside the coating layer. An optical fiber composed of a glass fiber and two coating layers is also called an optical fiber.
Previously, a colored layer was provided on the optical fiber strand as described above, and the optical fiber in the optical fiber cable was identified by color coding. There is a need to identify the fiber. For this reason, in addition to color coding, a method is used in which an identification mark for identifying an optical fiber is provided on the surface of an optical fiber, and the optical fiber is identified by an identification mark pattern or the like.

  In general, an ink jet printer or the like is used to provide an identification mark on the surface of an optical fiber. For example, Patent Document 1 discloses a technique in which an ink nozzle of a printer is scanned (moved) in the longitudinal direction of a traveling optical fiber, and ink droplets are sprayed onto the optical fiber. Patent Document 2 discloses a technique related to the adhesion of an identification mark.

JP 2005-123041 A JP 2004-157193 A

  However, as in the ink nozzle described in Patent Document 1, when scanning in the longitudinal direction (traveling direction) of the optical fiber strand, the optical fiber strand moves along a direction intersecting the longitudinal direction ( There is a problem that a phenomenon that the identification mark is not printed on the optical fiber (also referred to as missing printing) occurs. Further, since printing is performed only on one side of the optical fiber, there is a problem that it is difficult to recognize the identification mark when viewed from the side opposite to the printed side.

  The present invention has been made in view of the above-described circumstances, and provides an optical fiber manufacturing method and an optical fiber that can prevent a print omission even if line blurring occurs and easily recognize an identification mark. Objective.

  The present invention is an optical fiber manufacturing method for printing an identification mark for identifying an optical fiber on a surface of the optical fiber by spraying ink droplets from the ink nozzle onto the optical fiber, wherein the ink nozzle includes: The identification mark is printed by scanning in a direction inclined with respect to the longitudinal direction of the optical fiber.

  According to the method for manufacturing an optical fiber of the present invention, even if the optical fiber strands are broken, the probability that the optical fiber strands are present within the range scanned by the ink nozzles is high, and it is difficult for print omission to occur. . Also, the identification mark can be easily recognized.

It is a figure which shows the external appearance of the optical fiber by one form of this invention. It is arrow sectional drawing in the II-II line | wire of FIG. It is a figure which shows the manufacturing apparatus of the optical fiber by one form of this invention. It is a figure which shows the model for demonstrating the relationship between the inclination angle of an ink nozzle, and allowable amplitude. It is a figure which shows the relationship between the inclination angle of an ink nozzle, and the length of an identification mark when changing the speed of the longitudinal direction of an optical fiber. It is a figure which shows the relationship between the speed of the longitudinal direction of an optical fiber, and the length of an identification mark.

  An optical fiber manufacturing method and an optical fiber according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the optical fiber 10 has an identification mark 11 indicating the type of optical fiber. For example, seven identification marks 11 form one pattern in succession, and the seven identification marks 11 constitute a set of continuous identification marks 12. The continuous identification mark 12 is repeatedly formed with a predetermined interval.

  As will be described later, the identification mark 11 is printed in an inclined state with respect to the longitudinal direction (traveling direction) of the optical fiber 10 by spraying ink droplets by an ink jet method. For this reason, the seven identification marks 11 are printed in a spiral shape, for example, and when viewed in a plan view as shown in FIG. The lower outline of the mark 11 is visible, and the visible range of each identification mark 11 is different. In other words, the printing is performed by wrapping around the back side of the printed surface, and is easily visible from the opposite side of the printed side.

  FIG. 2 is a cross-sectional view of one of the seven identification marks 11. The optical fiber 10 includes a glass fiber 13, a primary resin layer 14, a secondary resin layer 15, an identification mark 11, and a colored layer 17. A glass fiber 13 whose outer periphery is covered with a primary resin layer 14 and whose outer periphery is covered with a secondary resin layer 15 is also called an optical fiber 16.

  The glass fiber 13 is an optical waveguide having a core part and a clad part and having a standard outer diameter of, for example, 125 μm. The glass fiber 13 is made of quartz glass. The primary resin layer 14 is a coating layer made of a soft resin having an outer diameter of about 190 to 200 μm and a relatively low Young's modulus. The secondary resin layer 15 is a coating layer made of a hard resin having an outer diameter of about 240 to 250 μm and a relatively high Young's modulus. The colored layer 17 is a transparent or translucent colored layer made of ultraviolet curable ink (for example, urethane acrylate) and having a thickness of about 5 to 10 μm.

  As shown in FIG. 2, the identification mark 11 covers a part of the outer periphery of the secondary resin layer 15 and wraps around in the circumferential direction of the optical fiber 16, and the range has a central angle larger than 180 °. However, it is difficult to recognize from the side opposite to the printed side. As described above, if the identification mark 11 is printed in a spiral shape, for example, the presence or absence of the identification mark 11 on the optical fiber 10 can be easily recognized from the side opposite to the printed side.

FIG. 3 shows an example of an optical fiber manufacturing apparatus. The manufacturing apparatus 20 includes a supply bobbin 21, a roller 22, an ink nozzle 23, a colored layer forming device 24, a capstan 25, and a take-up bobbin 26.
An optical fiber 16 before printing the identification mark 11 is wound around the supply bobbin 21. The optical fiber 16 is supplied from the supply bobbin 21 to the manufacturing apparatus 20 and is fed through a roller 22 toward an ink jet printer having an ink nozzle 23.

  As will be described later, the ink nozzle 23 scans with an inclination with respect to the longitudinal direction of the optical fiber 16 and ejects ink droplets onto the surface of the secondary resin layer of the optical fiber 16 to print the identification mark 11. To do. The optical fiber 16 on which the identification mark 11 is printed is fed out toward the colored layer forming device 24 at a location away from the ink nozzle 23 via another roller 22.

A colored layer 17 is applied from above the identification mark 11 to the optical fiber 16 on which the identification mark 11 is printed by the colored layer forming device 24. Thereafter, the colored layer 17 is formed by passing through an ultraviolet irradiation device for curing the colored layer 17.
The optical fiber 10 on which the colored layer 17 is formed is taken up by a capstan 25 via a further roller 22 and taken up on a take-up bobbin 26.

表１は、識別マークの最大長さと許容される振幅の大きさとの関係を示している。
インクノズルを光ファイバ素線の長手方向（走行方向）に対して傾斜してスキャンすれば、識別マークが印字される長さは短くなるものの、光ファイバ素線が線ぶれしてもインクノズルがスキャンした範囲内に光ファイバ素線が存在する確率が高くなるため、印字抜けが発生し難くなる。
この点について、光ファイバ素線の長手方向の速度を一定値（２５０００ｍｍ／ｓ＝１５００ｍ／ｍｉｎ）とし、インクノズルのスキャン速度を１７０００ｍｍ／ｓとし（したがって、光ファイバ素線に対するインクノズルの相対速度は８０００ｍｍ／ｓ）、インクノズルの傾斜角度θを０°，５°，７°，１０°，２０°の順に変更して、外径２５０μｍの光ファイバ素線に印字できる識別マークの最大長さ（最大マーク長）を後述の理論式を用いて求め、この最大マーク長を印字するのに対して許容される振幅（許容振幅）の大きさを求めてみた。なお、印字するドットの大きさは１５０μｍとし、印字されたドットの端から端までの長さを最大マーク長としている。また、光ファイバ素線の長手方向の速度が０ｍｍ／ｓの場合の最大マーク長は、４.５ｍｍであった（インクノズルのスキャン方向は光ファイバ素線の走行方向と同じであるため、光ファイバ素線が走行している場合の、角度が０°の時の最大マーク長は、４.５ｍｍよりも短くなる）。

Table 1 shows the relationship between the maximum length of the identification mark and the allowable amplitude.
If the ink nozzle is scanned while being inclined with respect to the longitudinal direction (running direction) of the optical fiber, the length of the identification mark printed is shortened. Since there is a high probability that an optical fiber is present within the scanned range, it is difficult for print omission to occur.
In this regard, the speed in the longitudinal direction of the optical fiber is a constant value (25000 mm / s = 1500 m / min), and the scanning speed of the ink nozzle is 17000 mm / s (therefore, the relative speed of the ink nozzle with respect to the optical fiber). Is the maximum length of the identification mark that can be printed on an optical fiber having an outer diameter of 250 μm by changing the inclination angle θ of the ink nozzle in the order of 0 °, 5 °, 7 °, 10 °, and 20 °. (Maximum mark length) was determined using a theoretical formula described later, and the amplitude (allowable amplitude) allowed for printing the maximum mark length was determined. The size of dots to be printed is 150 μm, and the length from the end of the printed dots to the end is the maximum mark length. In addition, the maximum mark length when the speed in the longitudinal direction of the optical fiber was 0 mm / s was 4.5 mm (Because the scanning direction of the ink nozzle is the same as the traveling direction of the optical fiber, (When the fiber is running, the maximum mark length when the angle is 0 ° is shorter than 4.5 mm).

As a result, as shown in Table 1, when the inclination angle θ of the ink nozzle was 0 °, the maximum mark length was 3.7 mm, and the allowable amplitude for printing this maximum mark length was ± 0.2 mm.
If the angle is set, a part of the printing part also protrudes from the optical fiber, so that the maximum mark length is shorter than that at 0 °. However, since the maximum mark length can be printed even if the line fluctuates to some extent, the allowable amplitude increases. When the inclination angle θ is 5 °, the maximum mark length is 2.9 mm and the allowable amplitude is ± 0.28 mm. When the inclination angle θ is 7 °, the maximum mark length is 2.5 mm and the allowable amplitude is ± 0.36 mm. When the inclination angle θ is 10 °, the maximum mark length is 2.2 mm and the allowable amplitude is ± 0.48 mm. As the inclination angle θ increases, the maximum mark length decreases, but the allowable amplitude increases. I understand that.

  Here, the length of the identification mark is predetermined according to standard specifications (standard length: for example, 2 mm), and must be longer than this standard length. When the inclination angle θ is 20 °, the maximum mark length is 1.9 mm, and a standard mark length cannot be printed. Therefore, in Table 1, the allowable amplitude is not obtained. In other words, in this case, an allowable angle at which the maximum mark length can be printed is further expanded when the inclination angle is 20 ° or more, but it is not suitable because an identification mark having a standard length cannot be printed.

FIG. 4 shows a model for explaining the relationship between the inclination angle of the ink nozzle and the allowable amplitude.
It is assumed that the longitudinal speed V _{F of} the optical fiber 16 and the scanning speed V _{I of the} ink nozzle are positive, and the moving direction of the optical fiber 16 and the scanning direction of the ink nozzle are positive in the direction of the arrow.
Further, the length L of the identification mark in the longitudinal direction of the optical fiber 16 is set, and the angle formed by the longitudinal direction of the optical fiber 16 and the scanning direction of the ink nozzle is the inclination angle θ of the ink nozzle, and the optical fiber 16. Of the outer diameter D.

In the right triangle ABC of FIG. 4, when time is t and the speed V _F and the speed V _I are both constant, in the longitudinal direction of the optical fiber 16,

を満たす。
一方、光ファイバ素線１６の長手方向に対して直交する方向では、

Meet.
On the other hand, in the direction orthogonal to the longitudinal direction of the optical fiber 16,

を満たす。
式１，２を用いてｔを消去すれば、

Meet.
If t is deleted using Equations 1 and 2,

となる。
ここで、式３において、Ｖ_Ｉｃｏｓθ＝Ｖ_Ｆの場合、識別マークの長さは、例えばインク滴の大きさに相当する長さは印字されることになり、実際には０にはならない。このため、インク滴の大きさや印字位置の精度などで決まる定数ａとすると、識別マークの長さＬは、

It becomes.
Here, in Formula 3, in the case of V _I cosθ = V _F, the length of the identification mark, for example, the size length corresponding to of the ink droplets would be printed, not in fact zero. For this reason, if the constant a is determined by the size of the ink droplet and the accuracy of the printing position, the length L of the identification mark is

となる。
この式４において、光ファイバ素線１６の外径Ｄは一定値（例えば０.２５ｍｍ）であり、また、使用するインクジェットプリンタが同じであれば、インクノズルのスキャン速度Ｖ_Ｉも一定値（例えば１７０００ｍｍ／ｓ＝１０２０ｍ／ｍｉｎ）となる。上記のように、識別マークの長さＬは規格長さ（例えば２ｍｍ）が決められているため、この所定長以上の長さになるように、傾斜角度θ、光ファイバの線速Ｖ_Ｆを決定する必要がある。

It becomes.
In this equation 4, the outer diameter D of the optical fiber 16 is a fixed value (e.g. 0.25 mm), also, if the ink jet printer that uses the same scanning speed V _I also fixed value of ink nozzles (e.g. 17000 mm / s = 1020 m / min). As described above, since the length L of the identification mark are standard length (e.g., 2 mm) is determined, so that in this predetermined length or longer, the inclination angle theta, the linear velocity V _F of the optical fiber It is necessary to decide.

FIG. 5 is a diagram showing the relationship between the inclination angle of the ink nozzle and the length of the identification mark when the longitudinal speed of the optical fiber is changed.
The scanning speed _{V I} of the ink nozzles constant at 17000mm / s, by changing the longitudinal direction of the velocity _{V F} of the optical fiber 1667mm / s, 5000mm / s, 16667mm / s, 20000mm / s, in the order of 25000 mm / s Then, the relationship between the inclination angle θ of the ink nozzle and the length L of the identification mark was obtained using Equation 4.

As a result, as shown in FIG. 5, the length L of the identification mark increases as the inclination angle θ decreases, as in the result of Table 1, but the size of the identification mark increases in the longitudinal direction of the optical fiber. It depends on the speed _{V F.} When the speed V _{F in} the longitudinal direction of the optical fiber is 16667 mm / s (= 1000 m / min), the speed V _F and the scanning speed V _I are almost equal. The constant a shown is substantially constant regardless of the inclination angle θ.

FIG. 6 is a diagram showing the relationship between the speed in the longitudinal direction of the optical fiber and the length of the identification mark.
Specifically, the inclination angle θ of the ink nozzles constant at 5 °, the longitudinal velocity _{V F} of the optical fiber is changed within a range from 1667mm / s up to 25000 mm / s, the length of the identification mark L Was measured. As a result, it can be seen that the value of L is the lowest at the same speed as the scanning speed of the ink nozzle, and the L increases as the distance from the ink nozzle increases.

As described with reference to FIG. 3, the optical fiber 16 is wound around a long section between the rollers 22 and is in an environment in which wire shake is likely to occur. However, if the ink nozzle is scanned while being inclined with respect to the longitudinal direction of the optical fiber, even if the optical fiber is shaken, there is a probability that the optical fiber is present within the scanned range of the ink nozzle. It can be seen that it becomes difficult to cause missing printing due to the increase. Further, since the printing is performed in a spiral shape, the identification mark can be easily recognized from the side opposite to the printed side.
According to the experiment in which the ink nozzles are tilted as described above, the state where the continuous print omission has occurred once every 50 km and the occurrence frequency was 2 × 10 ⁻³ %. The state of continuous omission of 1 m or more occurred only once every 300 km, and the frequency of occurrence was greatly reduced to 3.3 × 10 ⁻⁴ %.

DESCRIPTION OF SYMBOLS 10 ... Optical fiber, 11 ... Identification mark, 12 ... Continuous identification mark, 13 ... Glass fiber, 14 ... Primary resin layer, 15 ... Secondary resin layer, 16 ... Optical fiber strand, 17 ... Colored layer, 20 ... Manufacturing apparatus, DESCRIPTION OF SYMBOLS 21 ... Supply bobbin, 22 ... Roller, 23 ... Ink nozzle, 24 ... Colored layer formation apparatus, 25 ... Capstan, 26 ... Winding bobbin

Claims (3)

An optical fiber manufacturing method for printing an identification mark for identifying an optical fiber on a surface of the optical fiber by spraying an ink droplet from an ink nozzle onto the optical fiber,
An optical fiber manufacturing method in which the ink nozzle scans in a direction inclined with respect to the longitudinal direction of the optical fiber and prints the identification mark. The length of the identification mark in the longitudinal direction of the optical fiber strand is L, the velocity in the longitudinal direction of the optical fiber strand is V _F , the scanning speed of the ink nozzle is V _I , and the longitudinal direction of the optical fiber strand Where the inclination angle of the ink nozzle, which is the angle formed by the scanning direction of the ink nozzle, is θ, the outer diameter of the optical fiber is D, and a is a constant, L

The method for manufacturing an optical fiber according to claim 1, wherein the length becomes equal to or longer than a predetermined length.   An optical fiber on which the identification mark is printed by the optical fiber manufacturing method according to claim 1.

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