Air-blowing optical cable and production process thereof

Abstract

The invention discloses an air-blowing optical cable and a production process thereof, the air-blowing optical cable comprises a cable core and an outer protective layer wrapping the cable core, the cable core comprises a plurality of optical fibers and a bonding part for intermittently bonding the plurality of optical fibers in the axial direction, the outer wall of the outer protective layer is provided with a convex strip, and the convex strip is arranged on the outer wall of the outer protective layer. The height direction of the raised line extends towards the outer side along the radial direction of the optical cable, the length direction of the raised line extends along the length direction of the air-blowing optical cable, and the height of the raised line is set to be 0.1-0.4 mm. The outer side of the outer sheath is provided with the protruding strips, thereby reducing the friction force between the optical cable and an outer pipeline during laying, enabling the cable laying to be more efficient during air-blowing laying, reducing the damage, achieving the long-distance cable laying, and reducing the labor intensity. And meanwhile, the height of the raised line is set to be 0.1-0.4 mm, so that the raised line can pass through a sizing die and cannot be scratched with the sizing die, and the raised line is changed into a groove after subsequent vacuum negative-pressure vacuumizing, so that the original optical cable structure is changed.

Description

Technical Field

[0001] The invention relates to optical cable products, in particular to an air-blown optical cable and a production process thereof. Background Art

[0002] Air-blown optical cable is a technology that uses compressed gas (usually air) to pass optical cables or electrical cables through the inside of a pipe. This technology is mainly used for optical fiber wiring or cable wiring, especially in places where manual laying is difficult, such as long-distance underground pipes. Air-blown optical cable has the advantages of efficient cable laying, reduced damage, long-distance cable laying, reduced labor intensity, and strong scalability. Therefore, it is widely used in the telecommunications industry and other fields that require long-distance cable laying, especially in the construction of optical fiber networks.

[0003] However, in the prior art, when the optical cable is blown into the external pipe as a whole, the contact area between the outer sheath of the optical cable and the access pipe is large, which greatly increases the friction force, thereby increasing the difficulty of the air-blown optical cable construction and deployment.

[0004] However, after the sheath is extruded outside the cable core, the cable needs to enter a sizing die for sizing. Therefore, while reducing the difficulty of air-blown cable construction and laying, it is necessary to ensure that the production process of the cable meets the requirements. Summary of the invention

[0005] The present invention overcomes the shortcomings of the prior art and provides an air-blown optical cable and a production process thereof.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: an air-blown optical cable, comprising a cable core and an outer sheath wrapped around the cable core, a convex strip is arranged on the outer wall of the outer sheath, the height direction of the convex strip extends outward along the radial direction of the optical cable, the length direction of the convex strip extends along the length direction of the air-blown optical cable, the convex strip is spirally wrapped around the surface of the outer sheath, and the height of the convex strip is set to 0.1-0.4mm.

[0007] More specifically, on any radial surface of the air-blown optical cable, the cross-section of the convex strip is arc-shaped or trapezoidal.

[0008] More specifically, the pitch of the spiral convex strips is set to be less than or equal to 0.5 m.

[0009] To be more specific, α=a:b; 2.4≤α≤1; Wherein, a is the height of the convex stripe and b is the width of the convex stripe.

[0010] More specifically, the cable core includes a plurality of optical fibers and a bonding portion for bonding the plurality of optical fibers discontinuously in the axial direction.

[0011] More specifically, any bonding portion on any optical fiber is a first reference bonding portion, the adjacent bonding portion on the optical fiber adjacent to the first reference bonding portion is a second reference bonding portion, and the adjacent bonding portion on the optical fiber adjacent to the second reference bonding portion is a third reference bonding portion, and the first reference bonding portion, the second reference bonding portion and the third reference bonding portion are on the same straight line.

[0012] More specifically, two color wires are arranged outside the plurality of optical fibers, and the two color wires are wound forwards and reversely to bundle the plurality of optical fibers into an optical fiber bundle.

[0013] More specifically, a water-blocking yarn is arranged in the optical fiber bundle.

[0014] A production process for air-blown optical cables, comprising the steps of: S1, an optical fiber ribbon and a water-blocking yarn are provided, and two colored wires are wound forwardly and reversely on the outside of the optical fiber ribbon and the water-blocking yarn to form an optical fiber bundle; S2, a plurality of optical fiber bundles are twisted to form a cable core, and the cable enters a mold after being cabled; S3, the mold rotates, the cable core is extruded into the outer sheath in the mold, and the convex strips formed on the outer sheath are spirally wound on the outer sheath; S4, after the outer sheath is solidified, it enters a sizing die for vacuum sizing.

[0015] More specifically, the inner diameter of the sizing die is 0.6-0.8 mm larger than the outer diameter of the air-blown optical cable, and the length of the sizing die is set to 200-400 mm.

[0016] More specifically, a plurality of pressure-extraction holes are provided on the sizing die, and the coverage rate of the pressure-extraction holes is greater than 50% of the sizing die.

[0017] An air-blown optical cable and its production process solve the defects existing in the background technology. The present invention has the following beneficial effects: a convex strip is arranged on the outer side of the outer sheath to reduce the friction between the optical cable and the outer pipeline when laying, so that the air-blowing laying can be more efficient, reduce damage, long-distance cable laying, and reduce labor intensity; at the same time, the height of the convex strip is set to 0.1-0.4mm to ensure that when the optical cable is laid to the external pipeline, the friction is reduced, the air-blowing effect is ensured, and the laying difficulty is reduced, while the sizing die can be passed through, and no scratches are caused on the sizing die. After subsequent vacuum negative pressure vacuuming, the convex strip becomes a groove, changing the original convex strip structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention is further described below in conjunction with the accompanying drawings and embodiments; Figure 1 It is a cross-sectional view of the optical cable cut along the radial direction in which the convex strip of the present invention is arranged in an arc shape; Figure 2It is a cross-sectional view of the optical cable cut along the radial direction in which the convex strips of the present invention are arranged in a trapezoidal shape; Figure 3 It is a schematic diagram of the structure of a plurality of optical fibers and a bonding portion forming an optical fiber ribbon according to the present invention; Figure 4 It is a schematic diagram of the structure of an optical fiber bundle formed by bundling an optical fiber ribbon and a water-blocking yarn through a color line of the present invention; Figure 5 It is a schematic cross-sectional structure diagram of the sizing die of the present invention along the axial direction; Figure 6 It is a schematic diagram of the cross-sectional structure of the sizing die of the present invention along the radial direction; Figure 7 It is a process flow chart of the optical cable production process of the present invention; In the figure: 1, cable core; 11, optical fiber; 12, bonding part; 13, water-blocking yarn; 14, color line; 15, optical fiber ribbon; 16, optical fiber bundle; 2, water-blocking tape; 3, outer sheath; 4, reinforcement; 5, convex strip; 6, sizing die; 61, pressure-drawing hole. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the implementation of the present invention clearer, the technical scheme in the embodiment of the present invention will be described in more detail below in conjunction with the drawings in the embodiment of the present invention. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of the present invention, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limitations on the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0020] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present invention. The embodiments of the present invention are described in detail below in conjunction with the drawings.

[0021] It should be understood that the drawings are only used to illustrate the present application.

[0022] The present invention will now be further described in detail with reference to the accompanying drawings and embodiments. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0023] An air-blown optical cable, such as Figure 1-Figure 4 As shown, it includes a cable core 1 and an outer sheath 3 covering the cable core 1 .

[0024] like Figure 3 As shown, the cable core 1 includes a plurality of optical fibers 11 and a bonding portion 12 for axially discontinuously bonding the plurality of optical fibers 11, any bonding portion 12 on any optical fiber 11 is a first reference bonding portion, an adjacent bonding portion 12 on the optical fiber 11 adjacent to the first reference bonding portion is a second reference bonding portion, an adjacent bonding portion 12 on the optical fiber 11 adjacent to the second reference bonding portion is a third reference bonding portion, and the first reference bonding portion, the second reference bonding portion and the third reference bonding portion are on the same straight line. For example, three optical fibers 11 are provided, which are respectively the first optical fiber, the second optical fiber and the third optical fiber in sequence. Three bonding portions 12 are provided on each optical fiber 11, which are respectively the first bonding portion, the second bonding portion and the third bonding portion in sequence. The first bonding portion on the second optical fiber is defined as a first reference bonding portion. The optical fibers adjacent to the first reference bonding portion are the first optical fiber and the third optical fiber. The bonding portions adjacent to the first reference bonding portion are the first bonding portion of the first optical fiber and the first bonding portion of the third optical fiber. The two first bonding portions are the second reference bonding portion. If there is a fourth optical fiber, the optical fiber adjacent to the second reference bonding portion is the fourth optical fiber. The first bonding portion adjacent to the second reference bonding portion is the first bonding portion of the fourth optical fiber. This first bonding portion is the third reference bonding portion. The first reference bonding portion, the second reference bonding portion and the third reference bonding portion are on the same straight line. That is, the first bonding portions of the first optical fiber, the second optical fiber, the third optical fiber and the fourth optical fiber are on the same straight line.

[0025] The optical fiber 11 ribbon adopts high-precision glue dispensing technology, so that the adjacent bonding parts 12 of any adjacent optical fibers 11 are connected on the same straight line. In this solution, the bonding parts 12 are set as glue points, and the deviation between them is less than 0.1mm. High precision is conducive to ensuring that the difference between the cross-sections of several optical fibers 11 after cutting is extremely small during the overall welding process of the optical fiber 11 ribbon, which guarantees the stability of the welding performance to the maximum extent and helps to reduce the welding loss.

[0026] In this solution, the size of the bare optical fiber is set between 230μm and 240μm. After the optical fiber 11 is colored, the size of the optical fiber 11 is between 235μm and 245μm. Then, a layer of resin is coated on the surface of the optical fiber 11. After coating with resin, the size of the optical fiber 11 is between 240μm and 250μm.

[0027] The glue length of optical fiber 11 is D2 = 20 ± 5mm, the glue distance of optical fiber 11 is D3 = 40 ± 5mm, and the size of D4 under inclination is just D4 = D2 * (number of optical fibers 11 - 1), and the overall width of optical fiber bundle 16 is D1 = the size of optical fiber 11 after resin coating * N + (40 ~ 60μm), where 40 ~ 60μm is the correction factor, that is, the tiny gap directly existing in optical fiber 11, providing optical fiber 11 with higher mobility and external force resistance. Compared with the optical fiber ribbon 15 bonded with traditional glue dots, the same strength can be achieved with smaller glue dots, and if the same glue dot size is used, greater strength can be obtained.

[0028] The optical fiber ribbon 15 with a glue-point structure can ensure tight bonding between the optical fibers 11 with a very small amount of glue. The traditional optical fiber ribbon 15 is fully coated with resin, which will cause the overall structure of the optical fiber ribbon 15 to solidify. Once the optical fiber ribbon 15 is wound, it will be damaged, so it occupies a fixed space in the optical cable; the optical fiber ribbon 15 disclosed in this solution can roll the entire optical fiber 11 into a strand, and can also be twisted less than one circle, which greatly enhances its flexibility, greatly reduces the space required by the optical fiber ribbon 15, and provides a smaller bending radius.

[0029] like Figure 4 As shown, two color wires 14 are arranged outside the plurality of optical fibers 11, and the two color wires 14 are wound forward and backward to bundle the plurality of optical fibers 11 into a bundle, and the plurality of optical fibers 11 are bonded to form an optical fiber ribbon 15, and the two color wires 14 can bundle only one optical fiber ribbon 15, or bundle multiple optical fibers, and one or more optical fiber ribbons 15 and a water-blocking yarn are combined to form an optical fiber bundle 16 by winding the two color wires, and a water-blocking yarn 13 is arranged inside the optical fiber bundle 16, and the water-blocking yarn 13 is made of high-expansion water-blocking yarn, and the color wires 14 bundle one or more optical fiber ribbons 15 and a water-blocking yarn 13 to form an optical fiber bundle 16, and the plurality of optical fiber bundles 16 are twisted into a cable core 1. Prepare one or more optical fiber ribbons 15 and a high-expansion water-blocking yarn, and then prepare two color wires 14, and bundle one or more optical fiber ribbons 15 and a water-blocking yarn 13 by forward and backward winding. The color line 14 is made of 111D polyester yarn, and the polyester yarn can be designed into different colors according to requirements, which is convenient for distinguishing different optical fiber bundles 16. The optical fiber ribbons 15 in any bundle can be distinguished by spraying marks. The pitch of the color line 14 is set to be less than 7cm. The pitch of the color line 14 is made into a small pitch, which can better distinguish the optical fiber bundles 16 directly. Traditional optical fiber bundles 16 often only have codes on the surface of the optical fiber ribbon 15. When the coding is used as the main identification method, it is difficult to quickly distinguish the various optical fiber bundles 16 when the number of cores increases. The different colored yarns in this solution allow construction personnel to quickly separate different optical fibers according to the color line 14, greatly improving the welding efficiency of optical fiber bundles 16 with super large cores.

[0030] like Figure 1, Figure 2 As shown, in order to reduce the friction when the optical cable is laid by air blowing to the external pipeline, a convex strip 5 is arranged on the outer wall of the outer sheath 3, the height direction of the convex strip 5 extends outward along the radial direction of the optical cable, and the length direction of the convex strip 5 extends along the length direction of the air-blown optical cable. The height of the convex strip 5 is set to 0.1-0.4mm, and the height of the convex strip 5 is the distance from the outer sheath 3 to the highest point of the convex strip 5. In order to ensure that the optical cable can be laid by air blowing when entering the external pipeline, the convex strip 5 is spirally wrapped around the surface of the outer sheath, and the pitch of the spiral convex strip 5 is set to be less than or equal to 0.5m. When the pitch is greater than 0.5m, the efficiency of air blowing is not good. Further, when the pitch of the spiral convex strip 5 is set to 0.01-0.5m, there is only one convex strip 5 on any radial surface of the optical cable, and the air blowing effect is better.

[0031] Since the surface of the optical cable is relatively flat, there will be greater friction when the optical cable is laid in the external pipeline, which affects the laying efficiency of the optical cable in the external pipeline. The convex strips 5 are arranged on the surface of the outer sheath 3 to reduce the friction with the external pipeline during laying. Setting different heights of the convex strips 5 can affect the air blowing construction efficiency. When only considering the air blowing effect, the height of the convex strips 5 needs to be set to 0.1-0.5mm to achieve better air blowing laying efficiency:

[0032] After the outer sheath 3 and the convex strip 5 are extruded and molded, they need to enter the sizing die 6 for sizing. When the inner diameter of the sizing die 6 is greater than 0.6-0.8mm of the outer diameter of the air-blown optical cable, the sizing of the optical cable can be guaranteed. When the height of the convex strip 5 is less than 0.05mm, when passing through the sizing die 6, due to the vacuum negative pressure, the convex strip 5 is flattened, and there is no convex strip 5 at this place, and the friction cannot be reduced. If the height of the mold convex strip 5 is set to exceed 0.4mm, when passing through the sizing die 6, the sizing die 6 will scratch the convex strip 5, resulting in the convex strip 5 becoming a groove after the vacuum negative pressure is evacuated, changing the original structure of the convex strip 5, and failing to reduce friction. Therefore, in order to reduce friction, the convex strip 5 can be set on the outer sheath 3, but in order to meet the subsequent sizing process, the height of the convex strip 5 needs to be maintained at 0.05-0.4mm.

[0033]

[0034] Therefore, taking both process requirements and air blowing effects into consideration, in this solution, the height of the convex strip is set to 0.1-0.4 mm.

[0035] On any radial surface of the air-blown optical cable, the shape of the convex strip 5 is an arc or a trapezoid. When the cross-sectional shape of the convex strip 5 is set to a trapezoid, the closer to the outer sheath 3, the larger the size of the convex strip 5 is, so as to ensure the air-blowing effect. The shape of the convex strip 5 is often an arc or a trapezoid, and can also be set to other shapes, as long as it can pass through the sizing die 6. However, if it is set to other shapes, deformation and other problems may occur. For example, a triangle, due to its pointed head, will cause scratches and depressions after entering the sizing die 6. If it is a square or a rectangle, due to the 90° angles on both sides, it is very easy to cause scratches, and finally the convex strip 5 is smoothed. At the same time, when the optical cable is laid to the external pipeline, the air-blowing effect is best when the shape of the convex strip 5 is set to a circular arc or a trapezoid.

[0036]

[0037] The height of the convex strip is the length of the line segment connecting the highest point of the convex strip to the surface of the outer sheath and perpendicular to the tangent of the outer sheath surface; the width of the convex strip is the length of the line segment connecting the two end points of the widest part of the bottom edge of the convex strip.

[0038] α=a:b; 2.4≤α≤1; Wherein, a is the height of the convex strip; b is the width of the convex strip; and α is the ratio of the convex strip height to the convex strip width.

[0039] Furthermore, the ratio of the convex stripe height to the convex stripe width is 2.4:1-1:1.

[0040] When the ratio of the convex strip height to the convex strip width is less than 1:1, that is, when the convex strip height is less than or greater than the convex strip width, the gas friction environment when the optical cable is laid to the external pipeline is not good. When the ratio of the convex strip height to the convex strip width is greater than 2.4:1, the top strength of the convex strip will be reduced, which will not only reduce the yield rate, but also directly affect the gain effect that the convex strip can bring to the optical cable. Therefore, when the ratio of the convex strip height to the convex strip width is controlled between 1-2.4, the convex strip height and the convex strip width can be ensured to be within the same arc length, and a better gas friction environment can be obtained as much as possible, that is, when the central angle is consistent, the higher the surface protrusion, the larger the specific surface area, while ensuring the structural strength.

[0041] A production process for air-blown optical cables, such as Figure 5-Figure 7 As shown, comprising the steps of: S1, the optical fiber 11 is released, a plurality of optical fibers 11 are arranged along the axial direction, a bonding portion 12 connects the plurality of optical fibers 11 to form an optical fiber ribbon 15, and two color wires 14 are wound forwardly and reversely outside one or a plurality of optical fiber ribbons 15 and a water-blocking yarn 13 to form an optical fiber bundle 16; S2, a plurality of optical fiber bundles 16 are twisted to form a cable core 1, which enters a mold after being cabled, and a water blocking tape 2 is arranged on the outside of the cable core 1, and the water blocking tape 2 is set as an ultra-thin water blocking tape 2; S3, the motor drives the spiral head to rotate spirally, driving the mold core to rotate, the cable core 1 extrudes the outer sheath 3 in the mold, the outer sheath 3 is arranged on the water blocking tape layer, the convex strips 5 formed on the outer sheath 3 are spirally wound on the outer sheath 3, and the height of the convex strips 5 is set to 0.1-0.4mm; a reinforcement member 4 is arranged in the outer sheath 3, and the reinforcement member 4 is arranged circumferentially in the inner part of the outer sheath 3 and is evenly arranged; S4, after the outer sheath 3 is solidified, it enters the sizing die 6 for vacuum sizing, and the optical cable is sizing in the sizing die 6 to ensure the roundness of the optical cable.

[0042] like Figure 5 , Figure 6 As shown, the sizing die 6 is a device for sizing the optical cable after preparation, which is set in water. The barrel of the sizing die 6 is a vacuum copper tube. The extruded optical cable passes through the vacuum sizing copper tube to sizing the optical cable to ensure the roundness of the optical cable. The overall length of the sizing die 6 is set to 200-400mm. If the length of the sizing die 6 is less than 200mm, the sizing effect of the optical cable cannot be achieved. If the length of the sizing die 6 is greater than 400mm, the sizing will be too long, and the optical cable will always scratch the surface of the sizing die 6, resulting in an unsatisfactory surface effect. The inner diameter of the sizing die 6 is 0.6-0.8mm larger than the outer diameter of the air-blown optical cable to ensure the sizing of the optical cable.

[0043] After the cable core 1 is extruded with the outer sheath 3 and the convex strips 5, the temperature will be relatively high, so the optical cable needs to be cooled after entering the sizing die 6. In the usual setting, the sizing die 6 is set in water, and the water body and the sizing die 6 perform heat exchange to cool the optical cable. However, only the sizing die 6 is in contact with the external water body, and the cooling effect on the optical cable is limited. Therefore, a plurality of pressure extraction holes 61 are opened on the sizing die 6, and the water set outside the sizing die 6 enters the sizing die 6 through the pressure extraction holes 61, and contacts with the high-temperature optical cable, so as to better cool the optical cable. At the same time, the sizing die 6 can be vacuum-extracted, and the size of the pressure extraction holes 61 is set to 1.5 mm, and the coverage rate of the pressure extraction holes 61 is greater than 50% of the sizing die 6.

[0044] An air-blown optical cable and its production process, wherein a convex strip 5 is arranged on the outside of the outer sheath 3 to reduce the friction between the optical cable and the outer pipe during laying, so that the air-blown laying can be more efficient in cable laying, reduce damage, long-distance cable laying, and reduce labor intensity; at the same time, the height of the convex strip 5 is set to 0.1-0.4mm to ensure that it can pass through the sizing die without causing scratches with the sizing die. After subsequent vacuum negative pressure vacuuming, the convex strip 5 becomes a groove, changing the original convex strip 5 structure. The convex strip 5 is set to a spiral shape for better air-blowing laying. Vacuum sizing is performed in the sizing die 6 to ensure the roundness of the optical cable.

[0045] The above is based on the ideal embodiment of the present invention. Through the above description, relevant personnel can make various changes and modifications without departing from the technical concept of the present invention. The technical scope of the present invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

[0046] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0047] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0048] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. An air-blown optical cable, characterized in that: The invention comprises a cable core (1) and an outer sheath (3) covering the cable core (1); a convex strip (5) is arranged on the outer wall of the outer sheath; the height direction of the convex strip (5) extends outward along the radial direction of the optical cable; the length direction of the convex strip (5) extends along the length direction of the air-blown optical cable; the convex strip (5) is spirally wound around the surface of the outer sheath (3); and the height of the convex strip (5) is set to 0.1-0.4 mm.

2. The air-blown optical cable according to claim 1, characterized in that: On any radial surface of the air-blown optical cable, the cross-section of the convex strip (5) is arc-shaped or trapezoidal; when the cross-section of the convex strip (5) is set to be trapezoidal, the closer to the outer sheath (3), the larger the cross-section size of the convex strip (5).

3. The air-blown optical cable according to claim 2, characterized in that: α=a:b; 2.4≤α≤1； Wherein, a is the height of the convex stripe and b is the width of the convex stripe.

4. The air-blown optical cable according to claim 1, characterized in that: The pitch of the spiral ridges (5) is set to be less than or equal to 0.5 m.

5. The air-blown optical cable according to claim 1, characterized in that: The cable core (1) comprises a plurality of optical fibers (11) and a bonding portion (12) for bonding the plurality of optical fibers (11) discontinuously in the axial direction.

6. The air-blown optical cable according to claim 5, characterized in that: Any bonding portion on any optical fiber is a first reference bonding portion, the adjacent bonding portion on the optical fiber adjacent to the first reference bonding portion is a second reference bonding portion, and the adjacent bonding portion on the optical fiber adjacent to the second reference bonding portion is a third reference bonding portion, and the first reference bonding portion, the second reference bonding portion and the third reference bonding portion are on the same straight line.

7. The air-blown optical cable according to claim 5, characterized in that: Two color wires (14) are arranged outside the plurality of optical fibers (11), and the two color wires (14) are wound forwards and reversely to bundle the plurality of optical fibers (11) into an optical fiber bundle (16).

8. A production process for air-blown optical cables, characterized in that: Including steps, S1, an optical fiber ribbon (15) and a water-blocking yarn (13) are provided, and two colored wires (14) are wound forwardly and reversely on the outside of the optical fiber ribbon (15) and the water-blocking yarn (13) to form an optical fiber bundle (16); S2, a plurality of optical fiber bundles (16) are twisted together to form a cable core (1), and the cable is then put into a mold; S3, the mold rotates, the cable core (1) is extruded into an outer sheath (3) in the mold, and the convex strips (5) formed on the outer sheath (3) are spirally wound around the outer sheath (3); S4, after the outer sheath (3) is solidified, it enters a sizing die (6) for vacuum sizing.

9. The production process of air-blown optical cable according to claim 8, characterized in that: The inner diameter of the sizing die (6) is 0.6-0.8 mm larger than the outer diameter of the air-blown optical cable, and the length of the sizing die (6) is set to 200-400 mm.

10. The production process of air-blown optical cable according to claim 8, characterized in that: A plurality of pressure-extraction holes (61) are provided on the sizing die (6), and the coverage rate of the pressure-extraction holes (61) is greater than 50% of the sizing die (6).

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