Air-blowing micro cable suitable for high-temperature and high-humidity construction environment

Abstract

The invention discloses an air-blowing micro-cable suitable for a high-temperature and high-humidity construction environment, and belongs to the technical field of optical cable design and manufacture, the air-blowing micro-cable comprises a cable core and a sheath layer, the sheath layer is divided into an inner sheath layer and an outer sheath layer, the outer sheath layer is made of fluoroplastic, and the outer sheath layer is made of fluoroplastic. By utilizing the characteristics that the fluoroplastic can keep rigidity unchanged at a high temperature and can also keep better surface smoothness and low friction coefficient at a high humidity, the problem that the air-blowing micro cable cannot be constructed in a high-temperature and high-humidity environment is solved, and the air-blowing performance and the construction efficiency of the air-blowing micro cable are improved. According to the air-blowing micro-cable suitable for the high-temperature and high-humidity construction environment, construction of the air-blowing micro-cable in the high-temperature and high-humidity environment is achieved, the problems that the air-blowing micro-cable is poor in air-blowing effect and low in construction efficiency due to temperature and humidity changes of the air-blowing environment are solved, the influence of the environment does not need to be considered in air-blowing laying construction, and the construction efficiency of the air-blowing micro-cable is improved. The window period of optical cable construction is widened, and the air blowing distance and the air blowing efficiency are further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of optical cable design and manufacturing, and specifically relates to an air-blown microcable suitable for a high-temperature and high-humidity construction environment. Background Art

[0002] The air-blowing laying method of optical cable is to blow the optical cable into a pre-buried pipe by using high-pressure airflow. Compared with the traditional laying method, it can effectively improve the efficiency of optical cable laying and save construction costs.

[0003] The maximum air-blowing distance that can be achieved when constructing air-blown microcables using the air-blowing method is generally affected by the following factors: (1) The material and inner wall smoothness of the pipeline; the material and inner wall smoothness of the pipeline will affect the magnitude of the friction force, thereby affecting the air-blowing distance of the air-blown microcable. (2) The material and structure of the air-blown microcable; the material, structure, diameter and length of the air-blown microcable will affect the friction and resistance of the air-blown microcable in the pipeline, thereby affecting the air-blowing distance. (3) Gas pressure and flow rate; the gas pressure and flow rate will affect the propulsion force and speed of the air-blown microcable in the pipeline, thereby affecting the air-blowing distance. (4) The temperature and humidity of the construction environment; high temperature and high humidity environment will affect the material properties of the air-blown microcable, thereby affecting the air-blowing distance. (5) The operating techniques and conditions during the construction process; the operating techniques and conditions during the construction process will affect the friction and resistance of the air-blown microcable in the pipeline, thereby affecting the air-blowing distance.

[0004] Generally speaking, when constructing air-blown micro-cables, weather with suitable temperature and low humidity is selected. If the temperature is too low, the water in the pipeline will freeze, affecting the air-blowing effect; if the temperature is too high, the cable sheath material will become soft, the friction will increase, and the air-blowing distance and construction efficiency will be affected; correspondingly, if the humidity is too high, the moisture in the pipeline will increase, aggravating the formation of water droplets and water film in the pipeline, further affecting the air-blowing effect. At present, the construction temperature range of air-blown micro-cables is 5℃~30℃, and the humidity is 30%~70%. Due to the limitations of the construction environment, air-blown micro-cables can only be constructed in specific periods to ensure construction efficiency and quality. Summary of the invention

[0005] In response to one or more of the above defects or improvement needs of the prior art, the present invention provides an air-blown microcable suitable for a high temperature and high humidity construction environment, which can perform air-blowing construction in a high temperature and high humidity environment and improve the air-blowing efficiency.

[0006] To achieve the above-mentioned purpose, the present invention provides an air-blown microcable suitable for high temperature and high humidity construction environments, which includes a cable core and a sheath layer wrapped around the outer periphery of the cable core, the sheath layer includes an inner sheath layer and an outer sheath layer arranged in sequence from the inside to the outside, and the material of the outer sheath layer is fluoroplastic.

[0007] As a further improvement of the present invention, the thickness of the inner sheath layer is 0.3-0.4 mm, and the thickness of the outer sheath layer is 0.1-0.2 mm.

[0008] As a further improvement of the present invention, the fluoroplastic is any one of polytetrafluoroethylene, fluorinated ethylene-trifluoroethylene copolymer, and fluorinated polymer;

[0009] and / or

[0010] The material of the inner sheath layer is high-density polyethylene.

[0011] As a further improvement of the present invention, at least one open cable is arranged between the cable core and the sheath layer.

[0012] As a further improvement of the present invention, the sheath layer is formed by extruding the inner sheath layer material and the outer sheath material through double-layer co-extrusion using an extruder.

[0013] As a further improvement of the present invention, a plasticizer is added to the fluoroplastic, and the content of the plasticizer is 5% to 15%.

[0014] As a further improvement of the present invention, the plasticizer is one or more of polytetrafluoroethylene powder, polyethylene, polypropylene, liquid paraffin, amorphous polyolefin, phenolic resin, polyether ketone plasticizer, and polyurethane plasticizer.

[0015] As a further improvement of the present invention, an interface agent or an adhesive is added to the inner jacket layer material and / or the outer jacket layer material to improve the compatibility and adhesion between the inner jacket layer and the outer jacket layer.

[0016] As a further improvement of the present invention, the sheath layer is formed by sequentially extruding the inner sheath layer material and the outer sheath layer material using an extruder, and an adhesive layer is provided between the inner sheath layer and the outer sheath layer to bond the outer sheath layer to the inner sheath layer.

[0017] As a further improvement of the present invention, a heat insulating layer is further provided between the inner sheath layer and the outer sheath layer to isolate the inner sheath layer from the external high temperature environment.

[0018] The above-mentioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0019] In general, compared with the prior art, the above technical solution conceived by the present invention has the following beneficial effects:

[0020] (1) The air-blown microcable of the present invention is suitable for a high-temperature and high-humidity construction environment. The outer sheath of the air-blown microcable is divided into an inner sheath layer and an outer sheath layer, and the material of the outer sheath layer is set to fluoroplastic. The fluoroplastic can maintain unchanged rigidity at high temperatures and maintain good surface smoothness and low friction coefficient at high humidity. The problem that the air-blown microcable cannot be constructed in a high-temperature and high-humidity environment is solved, and the air-blowing performance and construction efficiency of the air-blown microcable are improved.

[0021] (2) The air-blown microcable suitable for high-temperature and high-humidity construction environments of the present invention is formed by extruding an inner sheath material and an outer sheath material in a double-layer co-extrusion manner using an extruder to ensure the bonding between the inner sheath layer and the outer sheath layer; at the same time, an interface agent or adhesive is added to the inner sheath layer material and / or the outer sheath layer material to further improve the compatibility and adhesion between the inner sheath layer and the outer sheath layer, thereby avoiding delamination or peeling of the sheath layer during use of the air-blown microcable and improving the service life of the product.

[0022] (3) The air-blown microcable of the present invention is suitable for a high-temperature and high-humidity construction environment. A heat-insulating layer is provided between the inner sheath layer and the outer sheath layer to separate the inner sheath layer from the high-temperature environment. This prevents the inner sheath layer from becoming soft due to the influence of the environment when the air-blown microcable is constructed at high temperature, thereby affecting the overall performance of the microcable.

[0023] (4) The air-blown microcable of the present invention, which is suitable for a high-temperature and high-humidity construction environment, realizes the construction of the air-blown microcable in a high-temperature and high-humidity environment, and solves the problem that the air-blowing effect of the air-blown microcable deteriorates and the construction efficiency decreases due to changes in the temperature and humidity of the air-blowing environment. The air-blowing laying construction no longer needs to consider the impact of the environment, which broadens the window period for optical cable construction, and further improves the air-blowing distance and air-blowing efficiency, and has good application prospects and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 Schematic diagram of the overall structure of an air-blown microcable suitable for a high-temperature and high-humidity construction environment in an embodiment of the present invention;

[0026] In all the drawings, the same reference numerals represent the same technical features, specifically: 1. reinforcement member; 2. colored optical fiber; 3. casing; 4. water-blocking material; 5. water-blocking layer; 6. inner sheath layer; 7. outer sheath layer; 8. open cable. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like 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 invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0030] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0032] Example:

[0033] See also Figure 1 In a preferred embodiment of the present invention, the air-blown microcable suitable for a high-temperature and high-humidity construction environment comprises a cable core and a sheath layer wrapped around the outer periphery of the cable core.

[0034] like Figure 1 As shown in the figure, the cable core in the preferred embodiment includes a reinforcement member 1, an optical unit and a water-blocking layer 5, wherein the reinforcement member 1 is arranged in the middle of the cable core; the optical unit is composed of a plurality of colored optical fibers 2 and a sleeve 3 coated on the outer periphery of the colored optical fibers 2, and the plurality of optical units are twisted and arranged on the outer periphery of the reinforcement member 1 by layer twisting, and the water-blocking layer 5 is coated on the outer periphery of the twisted optical units. The water-blocking layer 5 in the preferred embodiment can be made of water-blocking powder, water-blocking yarn or water-blocking tape.

[0035] Preferably, a water-blocking material 4 is further provided between the reinforcement member 1 and the optical unit. The water-blocking material 4 may be water-blocking powder, water-blocking yarn or water-blocking paste.

[0036] Preferably, at least one cable stripping rope 8 is provided between the cable core and the sheath layer to facilitate the cable stripping operation in the subsequent construction process. Figure 1 As shown in FIG. 1 , two opening ropes 8 are provided in the preferred embodiment and are symmetrically arranged relative to the cable core.

[0037] Furthermore, the sheath in the preferred embodiment includes an inner sheath layer 6 and an outer sheath layer 7 arranged in sequence from the inside to the outside, wherein the inner sheath layer 6 is made of conventional HDPE (high-density polyethylene) material to reduce the preparation cost of the sheath structure; the thickness of the inner sheath layer 6 is further preferably 0.3-0.4 mm; the material of the outer sheath layer 7 is fluoroplastic, and its thickness is preferably 0.1-0.2 mm. When the air-blown microcable using fluoroplastic as the material of the outer sheath layer 7 is air-blown in a high-temperature construction environment, the heat generated when the outer sheath layer 7 and the air-blown pipeline are rubbed is low, and the rigidity can be maintained unchanged at high temperatures, and the friction resistance of the entire optical cable will not increase due to softening. At the same time, fluoroplastic has excellent water resistance and corrosion resistance, and can maintain good surface smoothness and low friction coefficient even in high humidity or water conditions, thereby reducing the friction between the air-blown microcable and the pipeline, improving the air-blowing distance and air-blowing efficiency, and solving the problem that the air-blown microcable cannot be constructed in a high-temperature and high-humidity environment.

[0038] Preferably, the fluoroplastic can be any one of PTFE (polytetrafluoroethylene), ETFE (fluorinated ethylene-trifluoroethylene copolymer), FEP (fluorinated polymer), and more preferably PTFE, which has an extremely low friction coefficient and good chemical stability, can withstand high temperature, high pressure and erosion of corrosive media, and further optimizes the performance of the air-blown microcable structure. Among them, the PTFE grades suitable for extrusion processing include PTFE F4, PTFE F40, PTFE F104, PTFE F104C, PTFE F201 and PTFE F202.

[0039] The following are the static friction coefficient and dynamic friction coefficient data of air-blown micro cables using PTFE F104 and HDPE as the outer sheath material in air-blown pipes of different materials under standard temperature and humidity conditions:

[0040] Outer sheath material / air blowing pipe material Static friction coefficient Dynamic friction coefficient PTFE F104 / Steel Air Blowing Pipe 0.15 0.10 HDPE / Steel Air Blowing Pipe 0.23 0.18 PTFE F104 / Polyurethane Air Blowing Pipe 0.20 0.14 HDPE / Polyurethane Air Blowing Pipe 0.25 0.19 PTFE F104 / PVC air blowing pipe 0.25 0.20 HDPE / PVC air blowing pipe 0.34 0.26 PTFE F104 / PE air blowing pipe 0.19 0.13 HDPE / PE air blowing pipe 0.25 0.19

[0041] It can be seen from the above data that the static friction coefficient and dynamic friction coefficient of the air-blown micro-cable using PTFE as the outer sheath material in air-blown pipes of different materials are both smaller than those of the air-blown micro-cable using HDPE as the outer sheath material.

[0042] Furthermore, in the preferred embodiment, when the sheath layer is produced, the inner sheath layer material and the outer sheath layer material are preferably extruded by an extruder in a double-layer co-extrusion manner to improve the integrity and adhesion between the inner sheath layer 6 and the outer sheath layer 7. At the same time, since the minimum thickness of the sheath layer extruded by the extruder is limited, the double-layer co-extrusion method can use the total thickness of the inner sheath layer 6 and the outer sheath layer 7 as the extrusion thickness of the extruder, which can better control and reduce the diameter and weight of the air-blown microcable, and facilitate the air-blowing installation construction.

[0043] Generally speaking, when using an extruder for extrusion, the extrusion temperature of PTFE is generally between 327 and 371°C, and the screw speed is generally between 10-50rpm; while the extrusion temperature of HDFE is generally between 160-260°C, and the screw speed is generally between 10-50rpm. The extrusion conditions of the two materials are quite different.

[0044] In order to achieve double-layer co-extrusion preparation of the inner sheath layer 6 and the outer sheath layer 7 and adapt to the production and processing of air-blown micro cables, it is preferred to add a small amount of filler or plasticizer to the PTFE melt to reduce the extrusion temperature of PTFE, while improving the fluidity and processing properties of PTFE, making PTFE easier to process and shape.

[0045] Preferably, the plasticizer may be one or more of polytetrafluoroethylene micropowder, polyethylene, polypropylene, liquid paraffin, amorphous polyolefin, phenolic resin, polyetherketone plasticizer, polyurethane plasticizer and the like.

[0046] More preferably, the amount of plasticizer added is controlled between 5% and 15%, which can be determined according to actual production requirements.

[0047] Furthermore, since the inner sheath material HDPE and the outer sheath material PTFE are two materials with different chemical and physical properties, during the double-layer co-extrusion process, the adhesion between HDPE and PTFE is limited, which is insufficient to ensure the firm bonding of the two materials, and problems such as stratification and peeling are prone to occur. Therefore, in actual production, it is preferred to add an interface agent or adhesive to HDPE and / or PTFE to improve the compatibility and adhesion between the inner sheath layer 6 and the outer sheath layer 7, to ensure that after extrusion molding, the material of the inner sheath layer 6 and the material of the outer sheath layer 7 can be firmly bonded, to avoid problems such as stratification and peeling, and to improve the performance and service life of the product.

[0048] Preferably, the interface agent may be any one or more of a silane coupling agent, a phenolic resin, an organic titanium compound, etc.; the adhesive may be any one or more of an epoxy resin, a polyurethane, an acrylate, etc.

[0049] Of course, in actual production, the sheath layer can also be formed into an inner sheath layer 6 and an outer sheath layer 7 by extruding the inner sheath layer material and the outer sheath layer material in sequence using an extruder, and an adhesive layer is also provided between the inner sheath layer 6 and the outer sheath layer 7 to bond the outer sheath layer 7 to the inner sheath layer 6 to ensure the adhesion between the inner sheath layer 6 and the outer sheath layer 7.

[0050] Preferably, a heat insulating layer is provided between the inner sheath layer 6 and the outer sheath layer 7 to isolate the inner sheath layer 6 from the external high temperature environment and prevent the overall performance of the air-blown microcable from being affected by the softening and shrinkage of the inner sheath layer 6 in the high temperature environment.

[0051] The air-blown microcable suitable for high-temperature and high-humidity construction environments in the present invention realizes the construction of air-blown microcables in high-temperature and high-humidity environments, and solves the problem that the air-blowing effect of the air-blown microcable is deteriorated and the construction efficiency is reduced due to changes in temperature and humidity in the air-blowing environment. The air-blowing laying construction no longer needs to consider the impact of the environment, which broadens the window period for optical cable construction and further improves the air-blowing distance and air-blowing efficiency, and has good application prospects and promotion value.

[0052] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An air-blown microcable suitable for high temperature and high humidity construction environments, comprising a cable core and a sheath layer wrapped around the outer periphery of the cable core, characterized in that: The sheath layer comprises an inner sheath layer and an outer sheath layer which are arranged in sequence from the inside to the outside, and the material of the outer sheath layer is fluoroplastic.

2. The air-blown microcable suitable for high temperature and high humidity construction environment according to claim 1, characterized in that: The thickness of the inner sheath layer is 0.3-0.4 mm, and the thickness of the outer sheath layer is 0.1-0.2 mm.

3. The air-blown microcable suitable for high temperature and high humidity construction environment according to claim 2, characterized in that: The fluoroplastic is any one of polytetrafluoroethylene, fluorinated ethylene-trifluoroethylene copolymer, and fluorinated polymer; and / or The material of the inner sheath layer is high-density polyethylene.

4. The air-blown microcable suitable for high temperature and high humidity construction environment according to claim 3, characterized in that: At least one open cable is also arranged between the cable core and the sheath layer.

5. The air-blown microcable suitable for high temperature and high humidity construction environment according to any one of claims 1 to 4, characterized in that: The sheath layer is formed by extruding the inner sheath layer material and the outer sheath material in a double-layer co-extrusion manner using an extruder.

6. The air-blown microcable suitable for high temperature and high humidity construction environment according to claim 5, characterized in that: A plasticizer is also added to the fluoroplastic, and the content of the plasticizer is 5% to 15%.

7. The air-blown microcable suitable for high temperature and high humidity construction environment according to claim 6, characterized in that: The plasticizer is one or more of polytetrafluoroethylene powder, polyethylene, polypropylene, liquid paraffin, amorphous polyolefin, phenolic resin, polyether ketone plasticizer, and polyurethane plasticizer.

8. The air-blown microcable suitable for high temperature and high humidity construction environment according to claim 7, characterized in that: An interface agent or adhesive is also added to the inner jacket layer material and / or the outer jacket layer material to improve the compatibility and adhesion between the inner jacket layer and the outer jacket layer.

9. The air-blown microcable suitable for high temperature and high humidity construction environment according to any one of claims 1 to 4, characterized in that: The sheath layer is formed by sequentially extruding the inner sheath layer material and the outer sheath layer material using an extruder, and an adhesive layer is arranged between the inner sheath layer and the outer sheath layer to bond the outer sheath layer to the inner sheath layer.

10. The air-blown microcable suitable for high temperature and high humidity construction environment according to claim 9, characterized in that: A heat insulation layer is also provided between the inner sheath layer and the outer sheath layer to isolate the inner sheath layer from the external high temperature environment.

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