Layer-stranded air-blowing micro cable

Abstract

The invention relates to a layer-stranded air-blowing micro-cable, which comprises an outer sheath, a plurality of optical units which are arranged in a stranded manner by taking a reinforcing piece as a center are arranged in the outer sheath, and the surface of the outer sheath is provided with spirally distributed lines with designed sizes; the plurality of lines are uniformly distributed on the circumference of the cross section of the layer-stranded air-blowing micro cable; one part of lines and the other part of lines are symmetrically arranged by taking the diameter of the reinforcer as a symmetry axis; the linearity factor beta of the layer-stranded air-blowing micro cable is smaller than or equal to 0.02, the dynamic friction coefficient is smaller than 0.3, the overall unit density rho of the optical cable is between 0.0005 g / mm < 3 > and 0.0015 g / mm < 3 >, the structural lines are symmetrically and uniformly arranged, so that airflow generated by air blowing uniformly acts on the outer side of the outer sheath to increase the air blowing distance, and meanwhile, due to the fact that the linearity factor and the dynamic friction coefficient are smaller than design values, the air blowing distance is increased. Under the combined action of the two factors, the linear change in the air-blowing process is reduced, the air-blowing force is improved, in addition, the grain size and the overall unit density of the optical cable are specifically limited, and finally the air-blowing distance under a route with more bends is improved.

Description

Technical Field

[0001] The present application relates to the technical field of optical cable manufacturing, and in particular to a layer-twisted air-blown microcable. Background Art

[0002] With the vigorous development of fiber-to-the-home and metropolitan area networks, the use of stranded air-blown microcables is becoming more and more widespread; accompanied by the shortage of urban land and pipeline resources, stranded air-blown microcables are facing a variety of complex routes, and routes with more bends will require better air-blowing performance to meet the laying requirements.

[0003] In the related technology, the air blowing performance of the layer-twisted air-blown microcable is affected by many factors, which are reflected in the optical cable, including the surface texture of the optical cable, the friction coefficient, and the weight, outer diameter, and linearity of the optical cable that affect the airflow. Currently, many patents for related products in the industry have conducted research on the shape of the texture on the surface of the optical cable, changing the shape of the texture to change the air blowing airflow, but not limiting the size of the texture. Through a large amount of test data, it is found that the texture size (depth, size) and linearity factor, optical cable weight, outer diameter, etc. have a great influence on the air blowing performance of the optical cable, and the air blowing performance is manifested as the air blowing distance.

[0004] Therefore, how to design air-blown optical cables to increase the air-blowing distance to ensure smooth laying of optical cables is an urgent problem to be solved. Summary of the invention

[0005] The embodiment of the present application provides a layer-twisted air-blown microcable to solve the problem in the related art that simply changing the texture shape of the air-blown optical cable is difficult to meet the requirements of the air-blowing distance for a route with more bends.

[0006] In a first aspect, a layer-twisted air-blown microcable is provided, comprising an outer sheath, wherein a plurality of optical units are arranged in the outer sheath and are twisted around a reinforcement member, wherein a surface of the outer sheath is provided with spirally distributed patterns, wherein the number of the patterns is multiple and the patterns are evenly distributed on the circumference of a cross section of the layer-twisted air-blown microcable; a portion of the patterns is symmetrically arranged with another portion of the patterns with the diameter of the reinforcement member as the symmetry axis;

[0007] The linearity factor β of the stranded air-blown microcable is ≤0.02.

[0008] In some embodiments, the lowest point of the pattern is on an extension line; the extension line is a straight line formed by the intersection of two adjacent optical units and the center point of the layer-twisted air-blown microcable;

[0009] The range of the texture depth d of the texture is:

[0010]

[0011] The width of the pattern

[0012] Among them, the vertical distance d from the lowest point of the texture to the highest point of the outer sheath is the texture depth, the lateral distance L between the left and right end peaks of the texture is the texture width; h is the thickness of the outer sheath, D1 is the diameter of the light unit, D0 is the diameter of the reinforcement; n is the number of light units, or n is the sum of the number of light units and the number of filling elements.

[0013] In some embodiments, the lowest point of the pattern is located in a region formed by two adjacent extension lines; the extension line is a straight line formed by the intersection of two adjacent optical units and the center point of the layer-twisted air-blown microcable;

[0014] The range of the texture depth d of the texture is:

[0015] The range of the width L of the lines is: 0.5D1≤L≤D1;

[0016] The vertical distance d between the lowest point of the pattern and the highest point of the outer sheath is the pattern depth, the lateral distance L between the left and right crests of the pattern is the pattern width; h is the thickness of the outer sheath, and D1 is the diameter of the optical unit.

[0017] In some embodiments, the weight and size of the stranded air-blown microcable satisfy the relationship:

[0018] Wherein, ρ is the overall unit density of the optical cable, and 0.0005g / mm 3 <ρ<0.0015g / mm 3 ; M is the overall unit weight of the optical cable, h is the thickness of the outer sheath, D1 is the diameter of the optical unit, and D0 is the diameter of the reinforcement.

[0019] In some embodiments, the dynamic friction coefficient of the stranded air-blown microcable is less than 0.3.

[0020] In some embodiments, the number of the light units is six, and the number of the patterns is two.

[0021] In some embodiments, the number of the light units is six, and the number of the patterns is six.

[0022] In some embodiments, the layer-twisted air-blown microcable further includes a filling element; the filling element has the same diameter as the optical unit; and the optical unit and the filling element are twisted and arranged with the reinforcement member as the center.

[0023] In some embodiments, the number of the light units is three, the number of the filling elements is three, and the number of the patterns is two or six.

[0024] In some embodiments, the stranded air-blown microcable has 36-144 optical fiber cores.

[0025] The beneficial effects of the technical solution provided by this application include:

[0026] The embodiment of the present application provides a layer-twisted air-blown microcable, including an outer sheath, wherein a plurality of optical units are arranged in the outer sheath and twisted around a reinforcement member as the center, and the surface of the outer sheath is provided with spirally distributed textures; the number of textures is multiple, and their sizes meet the design sizes calculated by the formula, and are evenly distributed on the circumference of the cross section of the layer-twisted air-blown microcable; a part of the textures is symmetrically arranged with another part of the textures with the diameter of the reinforcement member as the symmetry axis; the linearity factor β of the layer-twisted air-blown microcable is ≤0.02. The above structure has reasonable texture sizes and symmetrical and uniform arrangement, so that the airflow generated by the air blowing acts evenly on the outside of the outer sheath and forms an optimal thrust to increase the air blowing distance. At the same time, since the linearity factor is less than the design value, the two factors work together to reduce the linear changes in the air blowing process and increase the air blowing force, and finally increase the air blowing distance in a route with more bends. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 A schematic cross-sectional view of a first type of layer-twisted air-blown microcable in Embodiment 1 provided in an embodiment of the present application;

[0029] Figure 2 A schematic cross-sectional view of a second type of layer-twisted air-blown microcable in Embodiment 1 provided in an embodiment of the present application;

[0030] Figure 3 A schematic cross-sectional view of a layer-twisted air-blown microcable in Embodiment 2 provided in the embodiments of the present application;

[0031] Figure 4 A schematic diagram of the three-dimensional structure of a layer-twisted air-blown microcable provided in an embodiment of the present application;

[0032] Figure 5 A diagram of a linearity testing method provided in an embodiment of the present application.

[0033] In the figure: 1. reinforcement; 2. optical unit; 3. outer sheath; 4. texture. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0035] Explanation of terms in this application:

[0036] The linearity factor (or linear factor) of an optical cable refers to the ratio of the maximum amplitude between the optical cable and two parallel lines to the length of the optical cable after the optical cable is taken off the reel, straightened at both ends and released horizontally.

[0037] The dynamic friction coefficient of the optical cable is a physical quantity that measures the friction resistance of the optical cable under dynamic friction conditions. It reflects the resistance encountered by the optical cable during movement. The size of the dynamic friction coefficient directly affects the convenience and durability of the optical cable during laying, recycling and daily maintenance.

[0038] The overall unit weight of the optical cable is the weight of one unit length of the optical cable; one unit is one meter, ten meters, etc.; the overall unit density of the optical cable is the ratio of the overall unit weight of the optical cable to the size of each component of the optical cable.

[0039] The reason for the generation of this application is that with the shortage of urban land and pipeline resources, layer-twisted air-blown microcables are facing a variety of complex routes. Routes with more bends will require better air-blowing performance to meet the laying requirements.

[0040] In the related technology, the air blowing performance of the layer-twisted air-blown microcable is affected by many factors, which are reflected in the optical cable, including the surface texture of the optical cable, the friction coefficient, and the weight, outer diameter, and linearity of the optical cable that affect the airflow. Currently, many patents for related products in the industry have conducted research on the shape of the texture on the surface of the optical cable, changing the shape of the texture to change the air blowing airflow, but not limiting the size of the texture. Through a large amount of test data, we found that the texture size (depth, size) and linearity factor, optical cable weight, outer diameter, etc. have a great influence on the air blowing performance of the optical cable. It is necessary to comprehensively optimize the surface texture size, friction coefficient, and optical cable weight, outer diameter, linearity, etc. of the optical cable to meet the smooth laying of optical cables under complex routes.

[0041] Therefore, the embodiment of the present application provides a layer-twisted air-blown microcable to solve the problem in the related art that simply changing the texture shape of the air-blown optical cable is difficult to meet the requirements of the air-blowing distance for routes with more bends.

[0042] A layer-stranded air-blown microcable, comprising an outer sheath 3, a plurality of optical units 2 twisted around a reinforcement member 1 being arranged in the outer sheath 3, and spirally distributed patterns 4 being arranged on the surface of the outer sheath 3;

[0043] There are multiple lines 4, which are evenly distributed on the circumference of the cross section of the stranded air-blown microcable; one part of the lines 4 is symmetrically arranged with another part of the lines 4 with the diameter of the reinforcement 1 as the symmetry axis;

[0044] The linearity factor β of the stranded air-blown microcable is ≤0.02.

[0045] In the above structure, since the texture 4 is symmetrically and evenly arranged, the airflow generated by the air blowing acts evenly on the outside of the outer sheath 3 to increase the air blowing distance. At the same time, since the linearity factor is less than the design value, the three factors work together to reduce the friction and linear changes during the air blowing process, and increase the air blowing force, ultimately increasing the air blowing distance in a route with more bends.

[0046] The following are explanations for the above effects:

[0047] refer to Figure 5 The test method of the linearity factor β of the air-blown microcable is to take a length of L from the reel of the reeled optical cable, fix one end of the optical cable and untwist the cable. Two people straighten the optical cable along a straight line and place it on a horizontal ground. Both people let go at the same time. When the optical cable is still, test the maximum amplitude D between the two parallel lines of the optical cable crest and trough. During the experiment, the optical cable length is 10m≤L≤20m. For example, when the optical cable length is 10m, the axial deviation distance of the optical cable should be ≤0.2m. When the optical cable length is 20m, the axial deviation distance of the optical cable should be less than 0.4m.

[0048] The small linearity factor also leads to a small amplitude during the air blowing process, which makes the linear change during the air blowing process small, and is more conducive to laying on routes with more bends.

[0049] Furthermore, the dynamic friction coefficient of the layer-twisted air-blown microcable is less than 0.3. The smaller the dynamic friction coefficient, the smaller the resistance. By changing the outer sheath material of the optical cable, the influence of the dynamic friction coefficient of the optical cable of this structure on the air blowing efficiency can be changed. Therefore, any material that can make the dynamic friction coefficient less than 0.3 can be used.

[0050] In some preferred embodiments, in order to comprehensively improve the air blowing effect, the texture size of the texture 4, that is, the depth and size, is set:

[0051] The first setting form, refer to Figure 1 and Figure 2

[0052] The lowest point z1 of the pattern 4 is on the extension line; the extension line x is a straight line formed by the intersection point z2 of two adjacent optical units 2 and the center point z3 of the layer-twisted air-blown microcable;

[0053] The range of the texture depth d of texture 4 is:

[0054]

[0055] Texture 4 Width

[0056] Among them, the vertical distance d from the lowest point of the line 4 to the highest point of the outer sheath is the line depth, and the lateral distance L between the wave peaks at the left and right ends of the line 4 is the line width; h is the thickness of the outer sheath 3, D1 is the diameter of the light unit 2, and D0 is the diameter of the reinforcement 1; n is the number of light units 2, or n is the sum of the number of light units 2 and the number of filling elements.

[0057] This form corresponds to the case where the lowest point of the corresponding pattern 4 is on the extension line. In addition, the layer-twisted air-blown microcable also includes a filling element; the filling element has the same diameter as the optical unit 2; the optical unit 2 and the filling element are twisted around the reinforcement member 1; and the sum of the number of the optical unit 2 and the filling element is n.

[0058] The second setting form, refer to Figure 3

[0059] The lowest point of the pattern 4 is located in the area formed by two adjacent extension lines; the extension line is the intersection of two adjacent optical units 2 and the middle of the layer-twisted air-blown microcable.

[0060] The straight line formed by the center points;

[0061] The range of the texture depth d of texture 4 is:

[0062] The width L of the pattern 4 is in the range of: 0.5D1≤L≤D1;

[0063] The vertical distance d between the lowest point of the pattern 4 and the highest point of the outer sheath is the pattern depth, the lateral distance L between the left and right crests of the pattern 4 is the pattern width; h is the thickness of the outer sheath 3, and D1 is the diameter of the optical unit 2.

[0064] The above two forms both have specific limits on the depth and width of the lines 4, but the air blowing distance is also related to the weight and size of the optical cable, so there are also the following settings:

[0065] refer to Figure 1 , the weight and size of the layer-twisted air-blown microcable satisfy the relationship:

[0066] Where ρ is the overall unit density of the optical cable, and 0.0005g / mm 3 <ρ<0.0015g / mm 3 ; M is the overall unit weight of the optical cable, h is the thickness of the outer sheath 3, D1 is the diameter of the optical unit 2, and D0 is the diameter of the reinforcement member 1.

[0067] To illustrate the specific effects of the above settings, please refer to the actual experiments conducted below, which provide two embodiments, specifically:

[0068] Embodiment 1 (corresponding to Figure 1 and Figure 2 in the form of

[0069] The first embodiment of the present invention is a layer-stranded optical cable with 96 optical fiber cores, which includes one central reinforcement member, six optical unit sleeves, two binding yarns wrapped around the cable core, an outer sheath, and sheath surface patterns.

[0070] Among them, the central reinforcement is 1.7mm, the optical unit sleeve is 1.55mm, the outer sheath thickness is 0.6mm, and the outer diameter of the optical cable is 6.0mm.

[0071] In this embodiment, there are 6 surface lines on the circumference of the cable cross section, which are symmetrical along the center, and the lowest point of the lines is located on the extension line of the intersection of the two sleeves and the center of the cable. According to the formula for the width of the lines It can be seen that the cable texture L of this embodiment is 3 mm.

[0072] The optical cables with different groove depths were tested by air blowing, and the results are shown in Table 1.

[0073] Table 1

[0074]

[0075]

[0076] According to Table 1, it can be found that when the width of the optical cable is constant, the depth of the texture satisfies the formula The air blowing performance is better.

[0077] Furthermore, in this embodiment, six stripes are spirally distributed on the surface of the outer sheath along the axial direction of the optical cable.

[0078] Further, the linearity of the optical cable was explored, and the experimental method was referred to Figure 3 : Take a 10m long optical cable from the reel of the reeled optical cable, fix one end of the optical cable and untwist it. Two people straighten the optical cable and place it on the horizontal ground. Both people let go at the same time. When the optical cable is still, test the maximum amplitude D between the two parallel lines of the optical cable crest and trough. The linearity of the optical cable is changed by different optical cable production processes. The air blowing test data is shown in Table 2.

[0079] Table 2

[0080]

[0081] According to Table 2, it can be found that when the linearity factor of the optical cable is ≤0.02, the optical cable has better air blowing performance.

[0082] Furthermore, by changing the outer sheath material of the optical cable, the influence of the dynamic friction coefficient of the optical cable of this structure on the air blowing efficiency is investigated. The experimental method refers to the circular drum method (2.5π method) in standard YD / T 1460.1, and the experimental data are shown in Table 3.

[0083] Table 3

[0084]

[0085] According to Table 3, when the dynamic friction coefficient of the optical cable is less than 0.3, the optical cable has better air blowing performance.

[0086] Since the outer diameter and weight of the optical cable also have a great influence on the air blowing performance, and the outer diameter and weight can be comprehensively reflected in the optical cable density. Furthermore, this embodiment keeps the outer diameter of the optical cable unchanged, changes the overall unit weight of the optical cable by changing the density of the optical cable raw material, and keeps other factors unchanged, and examines the influence of the overall unit density of the optical cable on the air blowing performance. The overall unit density formula of the optical cable is: The results are shown in Table 4.

[0087] Table 4

[0088]

[0089] According to Table 4, when the density of the optical cable is between 0.0005-0.0015 g / mm3, the optical cable has better air blowing performance.

[0090] From the above, it can be found that when the lowest point of the cable grain is on the extension line of the intersection of the two tubes and the center of the cable, the grain depth meets The linearity satisfies the linearity factor β≤0.02, the dynamic friction coefficient is less than 0.3, the density ρ is between 0.0005-0.0015g / mm3, and the optical cable has good air blowing efficiency.

[0091] Embodiment 2 (corresponding to Figure 3 in the form of

[0092] The second embodiment is a layer-stranded optical cable with 36 optical fiber cores, which includes 1 central reinforcement member, 3 optical unit sleeves, 3 filling ropes, 2 binding yarns wrapped around the cable core, an outer sheath, and spirally distributed patterns on the surface of the sheath.

[0093] Among them, the central reinforcement is 1.9mm, the outer diameters of the optical unit casing and the filling rope are both 1.7mm, the outer sheath thickness is 0.45mm, and the outer diameter of the optical cable is 6.2mm.

[0094] In this embodiment, there are two surface lines on the circumference of the optical cable cross section, and the lowest point of the lines is not on the extension line of the intersection of the two sleeves and the center of the optical cable. The formula will not apply because The value may be greater than the jacket thickness.

[0095] Air blowing verification was carried out on optical cables with different groove depths, and the results are shown in Table 5.

[0096] Table 5

[0097]

[0098] According to Table 5, it can be found that when the lowest point of the grain is not on the extension line of the intersection of the two tubes and the center of the optical cable, the grain depth satisfies the formula The air blowing performance is better.

[0099] Furthermore, this embodiment further explores the width of the grain, selects one of the structures with better air blowing performance in Table 1, keeps the grain depth unchanged, and only changes the grain width. The experimental data is shown in Table 6.

[0100] Table 6

[0101]

[0102] According to Table 6, when the lowest point of the cable texture is not on the extension line of the intersection of the two tubes and the center of the cable, the width L of the cable surface texture is in the range of 0.5D1-D1, and the air blowing efficiency is better.

[0103] Further, the linearity of the optical cable was explored, and the experimental method was referred to Figure 3 The linearity of the optical cable is changed, and the air blowing test data is shown in Table 7.

[0104] Table 7

[0105]

[0106] According to Table 7, it can be found that when the linearity factor of the optical cable is ≤0.02, the optical cable has better air blowing performance.

[0107] Furthermore, by changing the outer sheath material of the optical cable, the influence of the dynamic friction coefficient of the optical cable of this structure on the air blowing efficiency is investigated. The experimental method refers to the circular drum method (2.5π method) in standard YD / T 1460.1, and the experimental data are shown in Table 8.

[0108] Table 8

[0109]

[0110] According to Table 8, when the dynamic friction coefficient of the optical cable is less than 0.3, the optical cable has better air blowing performance.

[0111] Since the outer diameter and weight of the optical cable also have a great influence on the air blowing performance, and the outer diameter and weight can be comprehensively reflected in the overall unit density of the optical cable. This scheme examines the influence of the optical cable density on the air blowing performance by changing the unit weight of the optical cable while keeping other factors unchanged. The formula for the overall unit density of the optical cable is: The results are shown in Table 9.

[0112] Table 9

[0113]

[0114]

[0115] According to Table 9, when the density of the optical cable is between 0.0005-0.0015 g / mm3, the optical cable has better air blowing performance.

[0116] From the above, it can be found that when the lowest point of the cable grain is not on the extension line of the intersection of the two tubes and the center of the cable, the grain depth meets The width of the grain meets The linearity satisfies the linearity factor β≤0.02, the dynamic friction coefficient is less than 0.3, the density ρ is between 0.0005-0.0015g / mm3, and the optical cable has good air blowing efficiency.

[0117] Through the above description, there are several forms of layer-twisted air-blown micro cables, such as:

[0118] Form 1: The number of light units 2 is six, and the number of patterns 4 is two.

[0119] Form 1: The number of light units 2 is six, and the number of patterns 4 is six.

[0120] Form 2: The number of optical units 2 is three, the number of filling elements is three; the number of lines 4 is two or six. The number of optical fiber cores of the above-mentioned medium-layer twisted air-blown micro-cable is 36-144. The air-blown micro-cable formed by the above scheme can reach an air-blowing distance of more than 1500m in curved routes, and the construction efficiency is increased by more than 1 times.

[0121] The verification of the above embodiments shows that the number of the stranded air-blown microcable lines is multiple, and their sizes meet the design sizes calculated by the formula, and are evenly distributed on the circumference of the cross section of the stranded air-blown microcable; one part of the lines is symmetrically arranged with the other part of the lines with the diameter of the reinforcement as the symmetry axis; the linearity factor β of the stranded air-blown microcable is ≤0.02. The above structure has reasonable line sizes and symmetrical and uniform arrangement, so that the airflow generated by the air blowing acts evenly on the outside of the outer sheath and forms an optimal thrust to increase the air blowing distance. At the same time, since the linearity factor is less than the design value, the two factors work together to reduce the linear changes in the air blowing process and increase the air blowing force, and finally increase the air blowing distance under a route with more bends.

[0122] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying 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 a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0123] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0124] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A layer-twisted air-blown microcable, comprising an outer sheath (3), wherein a plurality of optical units (2) are arranged in the outer sheath (3) and are twisted around a reinforcement member (1), and wherein a spirally distributed pattern (4) is arranged on the surface of the outer sheath (3), characterized in that: The number of the lines (4) is multiple and evenly distributed on the circumference of the cross section of the stranded air-blown microcable; a portion of the lines (4) and another portion of the lines (4) are symmetrically arranged with the diameter of the reinforcement (1) as the symmetry axis; The linearity factor β of the stranded air-blown microcable is ≤0.

02.

2. The layer-stranded air-blown microcable according to claim 1, characterized in that: The lowest point of the pattern (4) is on an extension line; the extension line is a straight line formed by the intersection of two adjacent optical units (2) and the center point of the layer-twisted air-blown microcable; The range of the texture depth d of the texture (4) is: The width of the lines (4) The vertical distance d between the lowest point of the pattern (4) and the highest point of the outer sheath is the pattern depth, the lateral distance L between the wave crests at the left and right ends of the pattern (4) is the pattern width; h is the thickness of the outer sheath (3), D1 is the diameter of the light unit (2), and D0 is the diameter of the reinforcement (1); and n is the number of light units (2), or n is the sum of the number of light units (2) and the number of filling elements.

3. The stranded air-blown microcable according to claim 1, characterized in that: The lowest point of the pattern (4) is located in the area formed by two adjacent extension lines; the extension line is a straight line formed by the intersection of two adjacent optical units (2) and the center point of the layer-twisted air-blown microcable; The range of the texture depth d of the texture (4) is: The width L of the lines (4) is in the range of: 0.5D1≤L≤D1; The vertical distance d between the lowest point of the pattern (4) and the highest point of the outer sheath is the pattern depth, the lateral distance L between the wave crests at the left and right ends of the pattern (4) is the pattern width; h is the thickness of the outer sheath (3), and D1 is the diameter of the optical unit (2).

4. The stranded air-blown microcable according to claim 1, characterized in that: The weight and size of the stranded air-blown microcable satisfy the relationship: Wherein, ρ is the overall unit density of the optical cable, and 0.0005g / mm 3 <ρ<0.0015g / mm 3 ; M is the overall unit weight of the optical cable, h is the thickness of the outer sheath (3), D1 is the diameter of the optical unit (2), and D0 is the diameter of the reinforcement (1).

5. The stranded air-blown microcable according to claim 1, characterized in that: The dynamic friction coefficient of the layer-twisted air-blown microcable is less than 0.

3.

6. The layer-stranded air-blown microcable according to any one of claims 1 to 5, characterized in that: The number of the light units (2) is six, and the number of the patterns (4) is two.

7. The layer-stranded air-blown microcable according to any one of claims 1 to 5, characterized in that: The number of the light units (2) is six, and the number of the patterns (4) is six.

8. The layer-stranded air-blown microcable according to any one of claims 1 to 5, characterized in that: The layer-twisted air-blown microcable also includes a filling element; the filling element has the same diameter as the optical unit (2); the optical unit (2) and the filling element are twisted and arranged with the reinforcement member (1) as the center.

9. The layer-stranded air-blown microcable as claimed in claim 8, characterized in that: The number of the light units (2) is three, the number of the filling elements is three, and the number of the patterns (4) is two or six.

10. The layer-stranded air-blown microcable according to any one of claims 1 to 5, characterized in that: The number of optical fiber cores of the layer-twisted air-blown microcable is 36-144 cores.

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