Easily stripped optical cable and preparation method thereof
By designing a double-layer sheath structure and an easy-tear section on the optical cable, the problems of difficult stripping and fiber optic cable damage are solved, achieving easier stripping and improved construction efficiency, while maintaining the cable's strength.
Patent Information
- Application Number
- CN202511056184.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-30
- Publication Date
- 2025-11-07
AI Technical Summary
Existing optical cables are difficult to strip, and the optical fibers are easily cut, resulting in low construction efficiency.
Design an easy-strip optical cable with a double-layer sheath structure. The first sheath layer has multiple first easy-tear sections arranged radially and a second easy-tear section arranged axially. The easy-tear sections are formed by ultraviolet laser etching, and the second sheath layer is formed by vacuum sizing process to protect the easy-tear sections, ensuring that the optical cable is easy to handle when stripping.
This makes the optical cable easy to strip, reduces the risk of fiber optic cable cutting, improves construction efficiency, and avoids stress concentration due to bending through the second sheath layer, ensuring the strength of the optical cable.
Smart Images
Figure CN120908952A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of easy-to-strip optical cable, and particularly relates to an easy-to-strip optical cable and a preparation method thereof. BACKGROUND
[0002] The current communication technology is changing rapidly, and with the gradual acceleration of the process of fiber to the home construction, people's communication mode has not been limited to traditional telephone communication, broadband Internet business, and the comprehensive wiring system of fiber to the home has become a research topic. The existing comprehensive wiring system mainly connects voice communication equipment, data equipment, electronic communication equipment and network equipment of each office building through the mode of comprehensive wiring of single-mode optical fiber, multi-mode optical fiber and category 6 unshielded twisted pair.
[0003] When connecting the communication equipment of different floors of office buildings, the optical cable needs to be stripped, and each optical fiber subunit in the outer sheath is branched out to be connected with the network equipment. The optical fiber subunit of the existing optical cable is firmly protected by the loose tube, the reinforcing member, the water-blocking structure and the outer sheath, and it is difficult to strip, and a stripping knife needs to be used to cut the sheath structure to take out the internal optical fiber subunit. The outer diameter size of the optical cable for building construction is often within 10 mm, and it is difficult to control the cutting force of the stripping knife in the actual construction process. If the force is too large, the optical fiber may be cut, and if the force is too small, the optical cable cannot be effectively stripped, resulting in low stripping efficiency and seriously affecting the construction efficiency of the optical cable. SUMMARY
[0004] In view of one or more of the above defects or improvement needs of the prior art, the present application provides an easy-to-strip optical cable to solve the problem that the existing optical cable is difficult to strip and the optical fiber is easily cut.
[0005] To achieve the above-mentioned purpose, the present application provides an easy-to-strip optical cable, which comprises: at least one optical fiber unit, a loose tube arranged on the outer periphery of the optical fiber unit, and an outer sheath arranged on the outer periphery of the loose tube; The outer sheath is a double-layer structure, and comprises a first sheath layer arranged adjacent to the loose tube and a second sheath layer wrapped on the outer periphery of the first sheath layer; The first sheath layer is provided with a first easy-to-tear part in the radial direction, the first easy-to-tear part is a plurality of, and the plurality of first easy-to-tear parts are arranged in the axial direction, and a second easy-to-tear part is arranged between each adjacent two first easy-to-tear parts, the second easy-to-tear part is arranged in the axial direction of the first sheath layer, and the tensile strength of the first easy-to-tear part and the second easy-to-tear part is lower than that of the second sheath layer.
[0006] As a further improvement of the present application, the first sheath layer is made of polyvinyl chloride, and the polyvinyl chloride is doped with a photoinitiator; and the second sheath layer is made of polyethylene. The first tearable part is formed by irradiating the surface of the first sheath layer with ultraviolet laser.
[0007] As a further improvement of the present application, the second tearable part is low-density polyvinyl chloride.
[0008] As a further improvement of the present application, a reinforcing member is further included, the reinforcing member is arranged in pairs, and the reinforcing member is embedded at both ends of the outer sheath, and the second tearable part is arranged on the side of the second sheath layer away from the two reinforcing members.
[0009] As a further improvement of the present application, the surface of the second sheath layer further has an identification color bar, and the identification color bar is arranged corresponding to the first tearable part.
[0010] As a further improvement of the present application, the thickness of the second sheath layer is 0.1-0.2 mm, and the transmittance of the second sheath layer to ultraviolet light is greater than 80%.
[0011] The present application further includes a preparation method of the easy-to-peel optical cable, which comprises the following steps: S1, pulling the optical fiber unit, and extruding a loose tube around the optical fiber unit; S2, pulling the loose tube, extruding a first sheath layer around the loose tube, etching the first sheath layer, and forming a first tearable part and a second tearable part on the first sheath layer; S3, forming a second sheath layer around the first sheath layer by vacuum sizing process to obtain the easy-to-peel optical cable.
[0012] As a further improvement of the present application, the step S2 comprises: applying ultraviolet curing resin to the etching part of the first sheath layer, and selectively exposing the ultraviolet curing resin coating area to ultraviolet light through a mask plate; removing the ultraviolet curing resin in the unexposed area to form an exposed area on the surface of the first sheath layer corresponding to the first tearable part and the second tearable part; selecting SF6 and O2 mixed gas to etch the first sheath layer by plasma reaction to form the first tearable part and the second tearable part on the surface of the first sheath layer.
[0013] As a further improvement of the present application, in step S2, the plasma radio frequency power is 100-1000 w, the flow rate of SF6 and oxygen is 50-500 sccm, the pressure is 10-100 mTorr, and the etching rate is 1-10 μm / min.
[0014] As a further improvement of the present application, a marking process is further included after step S3: forming identification color bars on the surface of the second sheath layer, the identification color bars being arranged one-to-one corresponding to the first tearable parts.
[0015] The above technical features can be combined with each other as long as they do not conflict with each other.
[0016] In general, the above technical solutions conceived by the present application have the following beneficial effects compared with the prior art: (1) The easily-opened optical cable of the present application forms the first tearable part and the second tearable part on the first sheath layer. The first tearable part forms an easily-cut part along the radial direction of the optical cable, and the second tearable part forms an easily-tearable part along the axial direction of the optical cable. When the optical cable needs to be opened, only the first tearable part needs to be cut off by the opening knife. The first tearable part itself has low strength, so that the first tearable part and the first sheath layer can form two kinds of cutting resistance to indicate the operator to cut along the first tearable part only, complete the opening of the optical cable, and then the operator can tear the second tearable part along the axial direction of the optical cable. At this time, the second tearable part corresponds to the separation of the first sheath layer, thereby completing the manual opening of the optical cable. At the same time, the second sheath layer is arranged outside the first sheath layer, and the second sheath layer forms a protection outside the first sheath layer to avoid the first tearable part being exposed outside. When the optical cable is bent, coiled, and threaded, the second sheath layer restrains and protects the first sheath layer to avoid the bending stress concentrating on the first tearable part during construction or coiling, thereby causing the rupture of the optical cable, and ensuring the use strength of the optical cable. BRIEF DESCRIPTION OF DRAWINGS
[0017] Fig. 1 is the overall structure schematic diagram of the easily-opened optical cable in the embodiment of the present application; Fig. 2 is the axial cross-sectional structure schematic diagram of the outer sheath of the easily-opened optical cable in the embodiment of the present application; Fig. 3 is the surface structure schematic diagram of the first sheath layer in the embodiment of the present application; Fig. 4 is the flowchart schematic diagram of the preparation method of the easily-opened optical cable in the embodiment of the present application.
[0018] In all the drawings, the same reference signs represent the same technical features, specifically: 1, optical fiber unit; 2, loose tube; 3, first sheath layer; 4, second sheath layer; 5, reinforcing member; 6, water-blocking powder; 7, first tearable part; 8, second tearable part; 9, identification color bar. DETAILED DESCRIPTION
[0019] In order to make the objects, technical solutions and advantages of the present application clearer, the following further describes the present application with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely intended to explain the present application and not to limit the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.
[0020] In the description of the present application, it should be understood that, unless otherwise specified, the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is merely for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.
[0021] In addition, unless otherwise specified, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.
[0022] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0023] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can be 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, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.
[0024] Embodiment: Please refer to Figs. 1-4 The easy-to-peel optical cable in the preferred embodiment of the present application comprises at least one optical fiber unit 1, a loose tube 2 arranged on the outer periphery of the optical fiber unit 1, and an outer sheath arranged on the outer periphery of the loose tube 2. Specifically, the outer sheath in the present application has a double-layer structure, which comprises a first sheath layer 3 arranged adjacent to the loose tube 2, and a second sheath layer 4 wrapped on the outer periphery of the first sheath layer 3. The first sheath layer 3 is provided with a first tearable part 7 in the radial direction, and the first tearable part 7 is a plurality of first tearable parts 7 arranged in the axial direction, and a second tearable part 8 is arranged between every two adjacent first tearable parts 7, the second tearable part 8 is arranged in the axial direction of the first sheath layer 3, and the second tearable part 8 connects the two first tearable parts 7 arranged in the axial direction into one body, and the tear strength of the first tearable part 7 and the second tearable part 8 is lower than the tear strength of the first sheath layer 3.
[0025] Specifically, the easy-to-peel optical cable in the present application forms the first tearable part 7 and the second tearable part 8 on the first sheath layer 3. The first tearable part 7 forms an easy-to-cut notch in the radial direction of the optical cable, and the second tearable part 8 forms an easy-to-tear part in the axial direction of the optical cable. When the optical cable needs to be peeled, only the first tearable part 7 needs to be cut off along the first tearable part 7 by a peeling knife, and the first tearable part 7 itself has low strength, so that the first tearable part 7 and the second sheath layer 4 can form two kinds of cutting resistances to indicate the operator to cut only along the first tearable part 7, complete the opening of the optical cable, and then the operator can tear the first tearable part 7 in the axial direction of the optical cable, at this time the second tearable part 8 corresponds to the separation of the second sheath layer 4, and then the manual peeling of the optical cable is completed. At the same time, the second sheath layer 4 is arranged outside the first sheath layer 3 in the present application, and the second sheath layer 4 forms a protection outside the first sheath layer 3, avoiding the first tearable part 7 exposed outside. When the optical cable is bent, coiled, and threaded, the second sheath layer 4 restrains and protects the first sheath layer 3, avoiding the bending stress concentrated at the first tearable part 7 during construction or coiling, thereby causing the fracture of the optical cable, and ensuring the use strength of the optical cable.
[0026] Further, as an optional embodiment of the present application, the first sheath layer 3 is made of polyethylene (PE) or polypropylene (PP), and the first and second tearable parts 7 and 8 are formed by etching process. PE and PP are common sheath materials for optical cable production, and no additional improvement or adjustment of the sheath material formula is needed in the production process of the first sheath layer 3. On the other hand, the dry etching process of mixing fluorine-based gas and oxygen can effectively etch and remove PE and PP to form the relatively weak first and second tearable parts 7 and 8. Based on the etching process, the first and second tearable parts 7 and 8 are thinned in the radial thickness direction of the optical cable (the etching direction), so that the radial thickness of the first and second tearable parts 7 and 8 is lower than the radial thickness of the first sheath layer 3.
[0027] Further, as an optional embodiment of the present application, the second sheath layer 4 is made of polyvinyl chloride (PVC), and the second sheath layer 4 is formed by vacuum sizing process. Since the first and second tearable parts 7 and 8 are formed on the surface of the first sheath layer 3, the first and second tearable parts 7 and 8 are thinner than the first sheath layer 3, which makes the first sheath layer 3 form a rough structure. When the conventional extrusion process is used, the second sheath layer 4 will have uneven thickness, local defects or bubble problems during extrusion, resulting in unqualified optical cable production. Therefore, the second sheath layer 4 is formed by vacuum sizing process to avoid the influence of the first and second tearable parts 7 and 8 on the formation of the second sheath layer 4.
[0028] Optionally, the first tearable part 7 in the present application forms a fan-shaped tearable area along the radial direction of the easy-to-strip optical cable, and the fan-shaped tearable area corresponds to the lower knife trajectory of the stripping knife, facilitating the stripping knife.
[0029] Optionally, the first tearable part 7 in the present application forms a strip-shaped tearable area along the radial direction of the optical cable, and the first tearable part 7 forms a point-shaped tearable area on the surface of the optical cable and extends along the radial direction. This form of the first tearable part 7 can reduce the stripping time of the optical cable to a small extent.
[0030] Further, as an optional embodiment of the present application, the present application further comprises a reinforcing member 5, the reinforcing member 5 is arranged in pairs, and the reinforcing member 5 is embedded in both ends of the outer sheath, and the second tearable part 8 is arranged on the side of the second sheath layer 4 away from the two reinforcing members 5. In order to facilitate stripping and branching of the optical fiber unit 1, each optical fiber unit 1 is usually not suitable for twisted arrangement, so the center of the optical cable does not arrange the reinforcing member 5. The reinforcing member 5 is embedded in the outer sheath to increase the overall tensile and bending properties of the optical cable.
[0031] Further, as an optional embodiment of the present application, the thickness of the first sheath layer 3 is 0.4-0.6 mm, and the thickness of the second sheath layer 4 is 0.1-0.2 mm.
[0032] Optionally, water-blocking powder 6 is doped between the loose tube 2 and the first sheath layer 3 of the easy-to-strip optical cable.
[0033] Further, for the easy-to-strip optical cable in the present application, the present application also corresponds to a preparation method of an easy-to-strip optical cable, which comprises the following steps: S1, pulling the optical fiber unit 1, and extruding and molding the loose tube 2 on the outer periphery of the optical fiber unit 1; S2, pulling the loose tube 2, extruding the first sheath layer 3 on the outer periphery of the loose tube 2, etching the first sheath layer 3, and forming the first and second easy-to-tear parts 7 and 8 on the first sheath layer 3; S3, forming the second sheath layer 4 on the outer periphery of the first sheath layer 3 by vacuum sizing process to obtain the easy-to-strip optical cable.
[0034] The preparation method of the easy-to-strip optical cable in the present application adopts etching process to form the first and second easy-to-tear parts 7 and 8 on the first sheath layer 3, which makes the optical cable sheath layer form a weak area for easy stripping, and facilitates the rapid stripping of the optical cable. Secondly, the vacuum sizing process is used to form the second sheath layer 4 on the outer periphery of the first sheath layer 3, which can protect the first sheath layer 3, avoid the first and second easy-to-tear parts 7 and 8 being exposed, and cause damage to the optical cable during use. The vacuum sizing process for forming the second sheath layer 4 avoids the uneven structure on the first sheath layer 3 causing uneven thickness, local defects or bubbles during extrusion of the second sheath layer 4, and ensures the stable formation of the easy-to-strip optical cable.
[0035] Further, as an optional embodiment of the present application, the etching of the first sheath layer 3 in step S2 to form the first and second easy-to-tear parts 7 and 8 on the first sheath layer 3 specifically comprises: applying ultraviolet curing resin to the etching position of the first sheath layer 3, and selectively exposing the ultraviolet curing resin coating area to ultraviolet light through a mask plate; removing the ultraviolet curing resin in the unexposed area to form an exposed area on the surface of the first sheath layer 3 corresponding to the first and second easy-to-tear parts 7 and 8; selecting SF6 and O2 mixed gas to etch the first sheath layer 3 by plasma reaction to form the first and second easy-to-tear parts 7 and 8 on the surface of the first sheath layer 3.
[0036] Further, in the etching process, the plasma radio frequency power is 100-1000w, the SF6 and oxygen flow is 50-500sccm, the pressure is 10-100mTorr, and the etching rate is 1-10μm / min.
[0037] Further, as an optional embodiment of the present application, the SF6 and oxygen plasma etching in the etching process needs to be carried out in a vacuum environment, and the etching of the first sheath layer 3 is a continuous process, so an additional plasma etching machine is needed to provide a reaction chamber for the etching of the first sheath layer 3, the reaction chamber has a via for the input and output of the first sheath layer 3, and provides a radio frequency power supply and a gas distribution device to realize the mixing of SF6 and oxygen; in addition, a vacuum system and a gas treatment system are also provided to treat the gas in the reaction chamber and to vacuum the via of the first sheath layer 3 to ensure the vacuum in the reaction chamber. In addition, ultraviolet curing resin coating equipment, degumming and cleaning equipment, etc. are also provided to carry out the processes of gluing, degumming and cleaning of the first sheath layer 3, which will not be described here.
[0038] Further, as an optional embodiment of the present application, the ultraviolet curing resin on the surface of the first sheath layer 3 is coated by spraying process, and the first easy-to-tear part 7 and the second easy-to-tear part 8 are located on the same side of the optical cable, so the ultraviolet curing resin only needs to be sprayed towards one side of the first sheath layer 3, and only needs to ensure that the spraying area covers the area where the first easy-to-tear part 7 and the second easy-to-tear part 8 are located during the spraying process.
[0039] Optionally, in order to ensure that the ultraviolet curing resin is stably coated on the surface of the first sheath layer 3, pre-baking can be carried out after the ultraviolet curing resin is coated, by baking the surface of the first sheath layer 3 at 60-80℃, so that the ultraviolet curing resin adheres to the surface of the first sheath layer 3, and reduces the bubbles inside the coating structure formed by the ultraviolet curing resin.
[0040] Further, as an optional embodiment of the present application, since the present application needs to introduce an etching process in the process of preparing the optical cable, and the etching efficiency of the optical cable is lower than the actual production process of the optical cable. Therefore, after the first sheath layer 3 is formed, a cable structure with the first sheath layer 3 is temporarily stored on a wire storage rack, and then the cable structure on the wire storage rack is discharged and etched by etching process to form the first easy-to-tear part 7 and the second easy-to-tear part 8 on the first sheath layer 3, and then the second sheath layer 4 is formed on the surface of the first sheath layer 3 by vacuum sizing process to obtain the easy-to-peel optical cable.
[0041] Further, as an optional embodiment of the present application, in step S3 of the present application, after the cooling process, a marking process is further included, which is mainly used to form the identification color bar 9 corresponding to the first tearable part 7, so as to facilitate subsequent optical cable stripping. The marking process can use laser marking or ink jet printing, and the specific form is not limited.
[0042] Optionally, the optical cable product information can also be printed on the surface of the optical cable sheath through the marking process.
[0043] Next, taking an 8-core center bundle tube type easy-to-strip optical cable as an example, a conventional PE sheath cable, a PVC sheath cable, a double sheath cable, and the easy-to-strip optical cable of the present application are prepared respectively, and the stripping strength of each cable type is compared.
[0044]
[0045] Through the above comparative examples, taking an 8-core 8mm diameter center bundle tube type indoor optical cable with a sheath thickness of 0.8mm as an example, it can be seen that when a conventional PVC or PE optical cable is used, the mechanical properties are relatively beneficial, and the single-point stripping time is more than 30s, and the PE sheath cable can reach 2-5min, and the stripping efficiency is low; the overall tensile strength and stripping difficulty of the PE+PVC double sheath cable are between the PVC cable and the PE cable, and the stripping time is more than 1min. The easy-to-strip optical cable obtained by using the easy-to-strip optical cable preparation method of the present application has some damage to the overall strength, basically meets the use of indoor optical cable, but the ring cutting difficulty and axial stripping tension are smaller, and the ring cutting force is close to 10N (hand ring cutting), and the overall stripping difficulty is greatly reduced.
[0046] Those skilled in the art will readily understand that the above description is only preferred embodiments of the present application and is not intended to limit the present application, and any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.
Claims
1. An easy-to-open cable, characterized by, The utility model relates to a kind of easy-to-peel optical cable, including: At least one optical fiber unit, loose sleeve is provided at the outer periphery of the optical fiber unit, the outer periphery of the loose sleeve is provided with outer sheath; The outer sheath is double-layer structure, and the outer sheath includes the first sheath layer adjacent to the loose sleeve, and the second sheath layer wrapped in the outer periphery of the first sheath layer; Wherein, the first sheath layer is provided with first tearable part along radial direction, the first tearable part is multiple, and multiple first tearable part is arranged along axial direction, and the first tearable part extends along the axial direction of the first sheath layer, to form weak area along radial direction on the surface of the first sheath layer; Second tearable part is provided between every two adjacent first tearable part, and the second tearable part is arranged along axial direction, and the second tearable part is integrated with the first tearable part of adjacent two interval arrangement.
2. The easy open cable of claim 1, wherein, The first sheath layer is prepared from polyethylene or polypropylene, and the first tearable part and the second tearable part are formed by etching process.
3. The easy open cable of claim 1, wherein, The first tearable part and the second tearable part are lower than the first sheath layer along the radial thickness of the optical cable.
4. The easy open cable of claim 1, wherein, The second sheath layer is prepared from high-density polyethylene, and the second sheath layer is formed by vacuum sizing process.
5. The easy open cable of claim 1 wherein, It further includes reinforcing member, the reinforcing member is arranged in pairs, and the reinforcing member is embedded in the two ends of the outer sheath respectively, and the second tearable part is arranged on one side of the second sheath layer relative to the reinforcing member.
6. The easy open cable of claim 1, wherein, The surface of the second sheath layer also has identification color bar, and the identification color bar is arranged corresponding to the first tearable part.
7. A method of making an easy-to-peel optical cable, characterized by, The utility model relates to a kind of easy-to-peel optical cable, including: S1, optical fiber unit is pulled, and loose sleeve is formed by extrusion at the outer periphery of optical fiber unit; S2, loose sleeve is pulled, and the first sheath layer is extruded on the outer periphery of loose sleeve, and the first sheath layer is etched, to form the first tearable part and the second tearable part on the first sheath layer; S3, the second sheath layer is formed by vacuum sizing process on the outer periphery of the first sheath layer, to obtain easy-to-peel optical cable.
8. The method of claim 7, wherein the optical cable is prepared by the steps of: The step S2 includes: Ultraviolet curing resin is coated on the etching site of the first sheath layer, and ultraviolet light is used to carry out selective exposure on the ultraviolet curing resin coating area through mask plate; Ultraviolet curing resin in unexposed area is removed, to form exposed area corresponding to the first tearable part and the second tearable part on the surface of the first sheath layer; SF6, O2 mixed gas is selected, and the first sheath layer is etched by plasma reaction, to form the first tearable part and the second tearable part on the surface of the first sheath layer.
9. The method of claim 7, wherein the optical cable is prepared by the steps of: In step S2, the plasma radio frequency power is 100-1000w, the flow of SF6 and oxygen is 50-500sccm, the pressure is 10-100mTorr, and the etching rate is 1-10 μm / min.
10. The method of claim 7, wherein the optical cable is prepared by the steps of: After step S3, it further includes the printing process: identification color bar is formed on the surface of the second sheath layer, and the identification color bar is arranged corresponding to the first tearable part one by one.