Rodent-resistant optical cable
By designing the inner and outer reinforcing layers with opposite twisting directions and a friction-enhancing layer in the rodent-proof optical cable, the problem of poor force transmission in traditional optical cables is solved, thus improving the mechanical performance and stability of the optical cable.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- FIBERHOME TELECOMMUNICATION TECHNOLOGIES CO LTD
- Filing Date
- 2023-06-14
- Publication Date
- 2026-05-19
AI Technical Summary
Traditional rodent-proof optical cables cannot effectively transmit force when subjected to stress, resulting in insufficient friction between the various layers of the cable and poor mechanical properties.
The inner and outer reinforcing layers are twisted in opposite directions, and the friction between the layers is increased by a friction-enhancing layer to ensure that the force is transmitted sequentially from the outer sheath to the inside. The elongation at break and the twist pitch of each layer are configured in a consistent manner to achieve the layer-by-layer transmission of the force.
It improves the overall mechanical properties of the optical cable, reduces the probability of a certain layer breaking first when the optical cable is under stress, and ensures the effective transmission of force and the stability of the optical cable.
Smart Images
Figure CN116774371B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of optical cable technology, and in particular to a rodent-proof optical cable. Background Technology
[0002] Traditional ADSS optical cables use aramid yarn as the main reinforcing element. During use, incidents of animal chewing causing cable damage and communication interruptions are common. To reduce the economic losses caused by this, major optical cable manufacturers have successively launched various rodent-proof optical cable solutions. Rodent-proof optical cables are mainly divided into two types: chemical protection and physical protection. Chemical protection mainly involves adding chemical agents such as capsaicin into the optical cable to repel animals by emitting a pungent odor. Physical protection mainly uses glass fiber and its derivatives, such as columnar FRP tape and flat FRP tape, armored on the inner sheath surface of the optical cable. When animals chew on the cable, the glass fibers pierce the animal's mouth, thus repelling it.
[0003] Physical protection is more environmentally friendly and harmless to the human body than chemical protection. With the increasing awareness of environmental protection and the continuous optimization of optical cable costs, the protective layer tends to choose glass fiber yarn, which is cheaper and more environmentally friendly. By combining aramid yarn and glass yarn, the optical cable can be rodent-proof while having excellent mechanical properties.
[0004] However, in practical applications, it has been found that optical cables combining aramid yarn and glass yarn have problems such as sheath pull-out and inconsistent breakage of various components under the required force. This is mainly because the surface of the glass yarn layer is relatively smooth, and the friction between the inner and outer sheaths and the glass yarn layer is insufficient. When the optical cable is under stress, the force cannot be transmitted from the outer sheath to the inner layers. In addition, the large difference in elongation at break between glass yarn and aramid yarn, coupled with an unreasonable yarn twisting pitch, causes one layer of yarn to break first when the optical cable is under stress. Insufficient friction and an inappropriate yarn twisting pitch setting together cause the interruption of force transmission when the optical cable is under stress, further leading to poor mechanical performance of the optical cable. Summary of the Invention
[0005] This application provides a rodent-proof optical cable to solve the problem in related technologies where the force cannot be effectively transmitted when the optical cable is under stress.
[0006] This application provides a rodent-proof optical cable, which includes a cable core, an inner reinforcing element, an inner sheath, an inner friction-enhancing layer, an outer reinforcing element, an outer friction-enhancing layer, and an outer sheath arranged sequentially from the inside to the outside along the radial direction of the rodent-proof optical cable.
[0007] The internal reinforcing element includes at least one internal reinforcing layer, and the stranding directions of adjacent internal reinforcing layers are opposite.
[0008] The external reinforcing element includes at least one external reinforcing layer, and the stranding directions of adjacent external reinforcing layers are opposite;
[0009] In the external reinforcing element, the outermost layer is made of glass.
[0010] In some embodiments, the elongation at break and the stranding pitch of each inner reinforcing layer and each outer reinforcing layer are configured such that the change in stranding pitch before and after fracture is the same for each inner reinforcing layer and each outer reinforcing layer.
[0011] In some embodiments, the materials of the inner reinforcing layer and the remaining outer reinforcing layers of the outer reinforcing element are each independently selected from aramid fiber yarn or glass elements.
[0012] In some embodiments, the glass element is glass fiber yarn or glass rod.
[0013] In some embodiments, when the outermost inner reinforcing layer of the inner reinforcing element is a glass element, an additional friction-enhancing layer is provided between the inner reinforcing element and the inner sheath.
[0014] In some embodiments, the material of the additional friction enhancement layer is the same as the material of the inner friction enhancement layer or the material of the outer friction enhancement layer.
[0015] In some embodiments, the stranding direction of the outermost inner reinforcing layer in the inner reinforcing element is opposite to the stranding direction of the innermost outer reinforcing layer in the outer reinforcing element.
[0016] In some embodiments, the internal friction enhancement layer is an electrostatic adsorption layer or an adhesive layer.
[0017] In some embodiments, when the internal friction enhancement layer is an electrostatic adsorption layer, the electrostatic adsorption layer is made of at least one of magnesium carbonate powder, calcium carbonate powder, and water-blocking powder.
[0018] When the internal friction enhancement layer is an adhesive layer, the adhesive layer is made of at least one of silicone, silicone grease, acrylate and polyurethane.
[0019] In some embodiments, the material of the external friction enhancement layer is at least one selected from polyester fiber yarn, aramid fiber yarn, polypropylene fiber yarn, and polyamide fiber yarn.
[0020] The beneficial effects of the technical solution provided in this application include:
[0021] The outermost reinforcing layer of this application uses glass elements, which can physically prevent rodents. Simultaneously, friction-enhancing layers are inserted on both sides of the outer reinforcing element. These layers increase the friction between the layers, ensuring that when the optical cable is under stress, the force is transmitted from the outer sheath inwards, sequentially through the outer reinforcing element, inner sheath, inner reinforcing element, and finally to the cable core. This layer-by-layer force transmission solves the problem of ineffective force transmission between layers in hybrid fiber optical cables in related technologies, ultimately improving the overall mechanical performance of the optical cable.
[0022] This application, through analysis of yarn stress, discovers that when the inner and outer reinforcing layers are twisted according to a specific twisting pitch during stranding, the change in twisting pitch before and after each layer breaks is the same. This ensures the consistency of stress changes in each layer, reduces the probability of a certain layer breaking first, and even avoids the occurrence of a certain layer breaking first. Consequently, it ensures the consistency of stress changes in each layer of the optical cable and the effective transmission of force between each element, thereby improving the overall mechanical performance of the optical cable. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0024] Figure 1 This is a schematic diagram of a rodent-proof optical cable provided in an embodiment of this application;
[0025] Figure 2 A schematic diagram of the structure when the innermost inner reinforcing layer and the outermost outer reinforcing layer are twisted together, as provided in the embodiments of this application;
[0026] Figure 3 This is a schematic diagram of the structural change of the innermost inner reinforcing layer under stress limit strain in the embodiment of this application;
[0027] Figure 4 This is a schematic diagram of the structural change of the outermost reinforcing layer under stress limit strain in an embodiment of this application.
[0028] In the diagram: 1. Cable core; 2. Inner reinforcing layer; 3. Inner sheath; 4. Inner friction reinforcing layer; 5. Outer reinforcing layer; 6. Outer friction reinforcing layer; 7. Outer sheath. Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0030] See Figure 1 As shown, this application embodiment provides a rodent-proof optical cable, which includes a cable core 1, an inner reinforcing element, an inner sheath 3, an inner friction enhancement layer 4, an outer reinforcing element, an outer friction enhancement layer 6, and an outer sheath 7 arranged sequentially from the inside to the outside along the radial direction of the rodent-proof optical cable; wherein, the inner reinforcing element includes at least one inner reinforcing layer 2, and when there are two or more inner reinforcing layers 2, the twisting directions of adjacent inner reinforcing layers 2 are opposite; the outer reinforcing element includes at least one outer reinforcing layer 5, and when there are two or more outer reinforcing layers 5, the twisting directions of adjacent outer reinforcing layers 5 are opposite; in the outer reinforcing element, the outermost outer reinforcing layer 5 is made of glass.
[0031] The outermost reinforcing layer 5 of this application uses glass elements, which can achieve rodent prevention from a physical perspective. At the same time, friction enhancement layers are introduced on both sides of the outer reinforcing element. The friction enhancement layers increase the friction between the layers, ensuring that when the optical cable is under stress, the force can be transmitted from the outer sheath 7 inward, sequentially through the outer reinforcing element, the inner sheath 3, the inner reinforcing element to the cable core 1, realizing the layer-by-layer transmission of force. This solves the problem of ineffective force transmission between the elements of the mixed yarn structure optical cable in related technologies, and ultimately improves the overall mechanical performance of the optical cable.
[0032] Because the elongation at break of glass yarn and aramid yarn differs significantly in related technologies, an unreasonable yarn twisting pitch causes one layer of yarn to break first when the optical cable is under stress, ultimately leading to an interruption in force transmission and further resulting in poor mechanical performance of the optical cable. To address this issue, in this application, the elongation at break and twisting pitch of each inner reinforcing layer 2 and each outer reinforcing layer 5 are configured such that the change in twisting pitch before and after the breakage of each inner reinforcing layer 2 and each outer reinforcing layer 5 is the same.
[0033] This application, through analysis of yarn stress, discovers that when the inner reinforcing layer 2 and the outer reinforcing layer 5 are twisted according to a specific twisting pitch during stranding, the change in twisting pitch before and after each layer breaks is the same. This ensures the consistency of stress changes in each layer, reduces the probability of a certain layer breaking first, and even avoids the occurrence of a certain layer breaking first. Consequently, it ensures the consistency of stress changes in each layer of the optical cable and the effective transmission of force between each element, thereby improving the overall mechanical performance of the optical cable.
[0034] From the above embodiments, the stranding pitch of each inner reinforcing layer 2 and each outer reinforcing layer 5 can be calculated. Specifically:
[0035] Let n be the total number of inner reinforcing layer 2 and outer reinforcing layer 5. And let n be the number of inner reinforcing layer 2 and outer reinforcing layer 5 from 1 to n along the radial direction of the rodent-proof optical cable from the inside to the outside. Obviously, the innermost inner reinforcing layer 2 is numbered 1 and the outermost outer reinforcing layer 5 is numbered n.
[0036] See Figure 2 and Figure 3 As shown, for the innermost inner reinforcing layer 2, the diameter of the stranded device it is stranded with is denoted as D1, the stranding pitch of the inner reinforcing layer 2 is denoted as H1, and the elongation at break is denoted as δ1. Obviously, the stranded device here is the cable core 1.
[0037] The length of the inner reinforcing layer 2 applied to the surface of the stranded device by a stranding pitch is denoted as L1. Then L1 satisfies the following formula (1):
[0038] L1 = [H1] 2 +(π×D1) 2 ] 1 / 2 (1)
[0039] The inner reinforcing layer 2 begins to strain under stress until the moment of fracture. The length of one stranded pitch unfolded at this point is denoted as L1′. L1′ satisfies the following formula (2):
[0040] L1′=L1× (1+δ1) (2)
[0041] The inner reinforcing layer 2 begins to strain under stress until the moment of fracture. At this moment, the stranding pitch is denoted as H1′. Then, H1′ satisfies the following formula (3):
[0042] H1′=[(L1′) 2 -(π×D1) 2 ] 1 / 2 (3)
[0043] The change in the twist pitch before and after the fracture of the inner reinforcing layer 2 is denoted as H1″. H1″ satisfies the following formula (4):
[0044] H1″=H1′-H1 (4)
[0045] See Figure 2 and Figure 4 As shown, for the outermost reinforcing layer 5, the diameter of the stranded device stranded therewith is denoted as D. n The twist pitch of the outer reinforcing layer 5 is denoted as H. n Elongation at break is denoted as δ n Clearly, the stranding device here is the part of the rodent-proof optical cable excluding the outer reinforcing layer 5, the outer friction reinforcing layer 6, and the outer sheath 7.
[0046] The length of the outer reinforcing layer 5 applied to the surface of the stranded device by a stranding pitch is denoted as L. n Then L n The following formula (5) is satisfied:
[0047] L n =[H n 2 +(π×D n ) 2 ] 1 / 2 (5)
[0048] The outer reinforcing layer 5 begins to strain under stress, and the length of one stranded pitch unfolded until the moment of fracture is denoted as L. n ′, then L n ′ satisfies the following formula (6):
[0049] L n ′=L n × (1+δ n (6)
[0050] The outer reinforcing layer 5 begins to strain under stress until the moment of fracture, at which point the stranding pitch is denoted as H. n ′, then H n ′ satisfies the following formula (7):
[0051] H n ′=[(L n ′) 2 -(π×D n ) 2 ] 1 / 2 (7)
[0052] The change in the stranding pitch before and after the fracture of the outer reinforcing layer 5 is denoted as H. n ", then H n "It satisfies the following formula (8):"
[0053] H n " = H n′-H n (8)
[0054] Based on the fact that the changes in the stranding pitch before and after the fracture of the inner reinforcing layer 2 and the outer reinforcing layer 5 are the same in each layer, the following formula (9) can be obtained:
[0055] H n "=H1" (9)
[0056] Combining formulas (1) to (9), we can obtain the following formula (10):
[0057] {(1+δ n ) 2 ×[H n 2 +(π×D n ) 2 ]-(π×D n ) 2} 1 / 2 -H n =
[0058] {(1+δ1) 2 ×[H1 2 +(π×D1) 2 ]-(π×D1) 2} 1 / 2 -H1(10)
[0059] Due to D1, δ1, D n δ n All of these are known quantities in advance. Once the twist pitch H1 is set, the twist pitch H of the nth layer can be obtained. n .
[0060] It should be noted that the glass element can be made of various materials. For example, the glass element can be made of glass fiber yarn or glass rod. Both glass fiber yarn and glass rod can be twisted in either a left-hand or right-hand direction.
[0061] It should be noted that the material of the inner reinforcing layer 2 can be selected from various options. For example, the inner reinforcing layer 2 can be selected from aramid fiber yarn or glass elements.
[0062] When the internal reinforcing element includes at least two internal reinforcing layers 2, each internal reinforcing layer 2 can be independently selected from aramid fiber yarn or glass element.
[0063] In other words, the material of the reinforcing layer 2 in each layer can be the same, different, or partly the same and partly different.
[0064] It should be noted that the material of the outer reinforcing layer 5 can be selected from various options. For example, the outer reinforcing layer 5 can be selected from aramid fiber yarn or glass element.
[0065] When the outer reinforcing element includes at least two outer reinforcing layers 5 in addition to the outermost outer reinforcing layer 5 being a glass element, each of the at least two outer reinforcing layers 5 can be independently selected from aramid fiber yarn or glass element.
[0066] In other words, the materials of each outer reinforcing layer 5 can be the same, different, or some can be the same and some different.
[0067] In a preferred embodiment, when both the inner reinforcing layer 2 and the outer reinforcing layer 5 are only one layer, the inner reinforcing layer 2 is made of aramid fiber yarn, while the outer reinforcing layer 5 is made of glass fiber yarn.
[0068] Because the surface of glass elements is relatively smooth, when the outermost inner reinforcing layer 2 of the inner reinforcing element is made of glass, an additional friction-enhancing layer is provided between the inner reinforcing element and the inner sheath 3 to prevent the interruption of force transmission when the optical cable is under stress due to insufficient friction between the inner reinforcing element and the inner sheath 3. This additional friction-enhancing layer increases the friction between layers, ensuring that when the optical cable is under stress, the force can be transmitted from the inner sheath 3 to the cable core 1, achieving layer-by-layer force transmission.
[0069] In terms of material selection, the material of the additional friction enhancement layer is the same as the material of the inner friction enhancement layer 4 or the material of the outer friction enhancement layer 6.
[0070] Although the inner and outer reinforcing elements are not in direct contact, in order to improve the binding force along the radial direction of the rodent-proof optical cable, the twisting direction of the outermost inner reinforcing layer 2 in the inner reinforcing element is opposite to the twisting direction of the innermost outer reinforcing layer 5 in the outer reinforcing element.
[0071] It should be noted that the material of the internal friction enhancement layer 4 can be selected from various options. For example, the internal friction enhancement layer 4 can be an electrostatic adsorption layer or an adhesive layer.
[0072] When the internal friction enhancement layer 4 is an electrostatic adsorption layer, the electrostatic adsorption layer uses magnesium carbonate powder, calcium carbonate powder, water-blocking powder, etc., which itself has the effect of increasing friction and is applied to the surface of the inner sheath 3 through electrostatic adsorption.
[0073] When the internal friction enhancement layer 4 is an adhesive layer, the adhesive layer is made of silicone, silicone grease, acrylate, polyurethane, etc.
[0074] It should be noted that the material of the external friction reinforcing layer 6 can be selected from a variety of options. For example, the material of the external friction reinforcing layer 6 can be polyester fiber yarn, aramid fiber yarn, polypropylene fiber yarn, polyamide fiber yarn, etc. This material can also form an adhesive effect with the outer sheath 7. It is wrapped around the surface of the outer reinforcing element by a yarn tying machine at a certain pitch and placed between the outer sheath 7 and the outer reinforcing element.
[0075] The present application will be described in detail below through an embodiment.
[0076] See Figure 1 As shown, a rodent-proof optical cable includes a cable core 1, an inner reinforcing layer 2, an inner sheath 3, an inner friction-enhancing layer 4, an outer reinforcing layer 5, an outer friction-enhancing layer 6, and an outer sheath 7 arranged sequentially from the inside to the outside along the radial direction of the rodent-proof optical cable.
[0077] In cable core 1, multiple optical fibers are twisted together on the FRP central reinforcement using a secondary coated sleeve in an SZ twisting manner. To ensure effective water blocking of the cable core, a layer of water-blocking material is applied to both the FRP central reinforcement and the surface of the cable core.
[0078] The inner reinforcing layer 2 is made of aramid fiber yarn, and the yarn specifications can be 8050dtex, 6440dtex or 3220dtex. It is wrapped around the surface of the cable core 1 by an aramid yarn spool. In order to ensure that the aramid fiber yarn is in a left-hand twisted state on the surface of the cable core 1, the aramid yarn spool should be rotated clockwise. The tension of the aramid fiber yarn is 4 to 6N, and the twisting pitch of the yarn is preferably 400 to 800mm. This can ensure the compactness of the aramid fiber yarn twisting on the surface of the cable core 1 and the consistency between each yarn.
[0079] The inner sheath 3 is made of PE material and is applied to the surface of aramid fiber yarn through an extrusion device. To ensure the compactness of the inner sheath 3 and the cable core structure, it is preferred that the straight section of the die cap in the extrusion mold is 6-7mm and the total distance between the die core and the die cap is 10-12mm.
[0080] When the internal friction enhancement layer 4 is magnesium carbonate powder, the magnesium carbonate powder is applied to the surface of the inner sheath 3 through electrostatic adsorption to increase the friction between the inner sheath 3 and the outer enhancement layer 5. The friction value is measured using a fiber optic cable outer sheath covering force measuring device. The comparison between no friction enhancement layer and the application of friction enhancement layer is shown in Table 1 below:
[0081] Table 1
[0082] Output voltage (kV) of the electrostatic generator 0 20~40kV 40~60kV Static friction (N) 236N 500～600N 600～800N
[0083] The specific application method involves providing a powder application device, which mainly includes an electrostatic generator, a powder filling device, and a powder container. Magnesium carbonate powder is transported into the powder container through the powder filling device. At the same time, the powder filling device blows dry gas into the powder container to ensure that the magnesium carbonate powder floats in the container. The electrostatic generator is then activated, and the floating magnesium carbonate powder begins to become charged under the electrostatic generator. When the cable core passes through the powder container, the magnesium carbonate powder is adsorbed onto the surface of the inner sheath 3. The output voltage of the electrostatic generator is 20-60kV. The higher the voltage, the greater the static electricity of the magnesium carbonate powder and the stronger the adsorption capacity. Furthermore, the output voltage can be adjusted according to the needs of friction.
[0084] When the internal friction reinforcing layer 4 is silicone, a silicone application device is provided. This device mainly includes an ultraviolet curing device and a silicone coating device. The silicone is uniformly coated on the surface of the inner sheath 3 by the silicone coating device, and the silicone is cured by the ultraviolet curing device. Furthermore, by adjusting the power of the ultraviolet curing device, the silicone layer is made to be in an adhesive state, thereby increasing the friction between the inner sheath 3 and the outer reinforcing layer 5.
[0085] The outer reinforcing layer 5 is made of glass fiber yarn, and the yarn specification can be 1200tex or 600tex. The glass fiber yarn is wrapped around the surface of the inner friction reinforcing layer 4 through a glass fiber yarn twisting cage. In order to ensure the uniformity of force transmission when the optical cable is under stress, the twisting direction of the glass fiber yarn should be opposite to that of the aramid fiber yarn. At this time, the glass fiber yarn should be in a right-handed state on the surface of the inner friction reinforcing layer 4. The tension of the glass fiber yarn is 2 to 4 N. In order to ensure the consistency between the aramid fiber yarn and the glass fiber yarn, the twisting pitch of the glass fiber yarn needs to be determined according to the twisting pitch of the aramid fiber yarn.
[0086] Specifically, calculations can be performed using formulas (1) to (9) provided above.
[0087] In this embodiment, the diameter of the stranding device of the inner reinforcing layer 2 is D1 = 6.5 mm, the inner reinforcing layer 2 is 20 strands of 6440 dtex aramid fiber yarn, the stranding pitch H1 is 650 mm, and the breaking elongation of the aramid fiber yarn is δ1 = 2.45%.
[0088] The diameter of the stranded device in the outer reinforcing layer 5 is D2 = 9.4 mm. The outer reinforcing layer 5 consists of 15 strands of 1200 tex glass fiber yarn, and the breaking elongation of the glass fiber yarn is δ2 = 2.9%.
[0089] L1 = [H1] 2 +(π×D1) 2 ] 1 / 2 =[650 2 +(π×6.5) 2 ] 1 / 2 =650.3203mm
[0090] L1′=L1×(1+δ1)=650.3203mm×(1+2.45%)=666.2532mm
[0091] H1′=[(L1′) 2 -(π×D1) 2 ] 1 / 2 =[666.2532] 2 -(π×6.5) 2 ] 1 / 2 =665.9405mm
[0092] H1″=H1′-H1=665.9405-650mm=15.9405mm
[0093] L2 = [H2] 2 +(π×D2) 2 ] 1 / 2 =[H2 2 +(π×9.4) 2 ] 1 / 2
[0094] L2′=L2×(1+δ2)=L2×(1+2.9%)=1.029×[H2 2 +(π×9.4) 2 ] 1 / 2
[0095] H2′=[(L2′) 2 -(π×D2) 2 ] 1 / 2 =[(L2′) 2 -(π×D2) 2 ] 1 / 2 =
[0096] [1.05884×H2 2 +51.261] 1 / 2
[0097] H2″=H2′-H2=[1.05884×H2 2 +51.261] 1 / 2 -H2
[0098] Based on H1″=H2″, we can obtain:
[0099] [1.05884×H2 2 +51.261] 1 / 2 -H2 = 15.9405
[0100] Therefore, we can calculate that H2 = 550 mm.
[0101] Table 2 below provides two calculation examples:
[0102] Table 2
[0103]
[0104] The outer friction reinforcing layer 6 is made of polyester fiber yarn, which can be polyester material with specifications of 167tex, 1000dtex, 3000dtex, or 6000dtex. It is wrapped around the surface of the outer reinforcing layer 5 at a certain pitch by a yarn-tying device to increase the friction between the outer reinforcing layer 5 and the outer sheath 7.
[0105] The number of polyester fiber yarns is at least 2, and the twisting direction is opposite. The twisting pitch is adjusted according to the friction requirements. When using 2 3000dtex polyester yarns with a twisting pitch of 50-100mm, the static friction value between the outer sheath 7 and the outer reinforcing layer 5 in the optical cable can meet the range of 700-900N. When using 2 6000dtex polyester yarns with a twisting pitch of 50-100mm, the static friction value between the outer sheath 7 and the outer reinforcing layer 5 in the optical cable can meet the range of 800-1100N.
[0106] The outer sheath 7 is made of PE material and is applied to the surface of the outer friction enhancement layer 6 through the extrusion head device. To further ensure the friction between the outer sheath 7 and the outer reinforcement layer 5, a vacuum device is added at the inlet of the extrusion head device to extract the air between the inner and outer sheaths. Under the action of the friction enhancement layer and the vacuum pressure, the static friction between the outer sheath 7, the outer reinforcement layer 5, and the inner sheath 3 is further enhanced. The optical cable after the sheath enters the take-up device, which includes a tension roller and a gantry take-up frame. The take-up tension of the tension roller is 200-240N, which reduces the further shrinkage of the optical cable with the glass yarn layer structure in the take-up reel.
[0107] The mechanical performance of the existing technology and the rodent-proof optical cable provided in this embodiment are compared in Table 3 below:
[0108] Table 3
[0109]
[0110] As can be seen from the test results in Table 3 above, the mechanical properties of the rodent-proof optical cable can be greatly improved by adopting this application.
[0111] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.
[0112] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0113] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.
Claims
1. A rodent-proof optical cable, characterized in that, It includes a cable core (1), an inner reinforcing element, an inner sheath (3), an inner friction enhancement layer (4), an outer reinforcing element, an outer friction enhancement layer (6), and an outer sheath (7) arranged sequentially from the inside to the outside along the radial direction of the rodent-proof optical cable. The inner reinforcing element includes at least one inner reinforcing layer (2), and when the inner reinforcing element includes at least two inner reinforcing layers (2), the twisting directions of adjacent inner reinforcing layers (2) are opposite. The external reinforcing element includes at least one external reinforcing layer (5), and when the external reinforcing element includes at least two external reinforcing layers (5), the twisting directions of adjacent external reinforcing layers (5) are opposite; In the external reinforcing element, the outermost layer (5) is made of glass; The elongation at break and the stranding pitch of each inner reinforcing layer (2) and each outer reinforcing layer (5) are configured such that the change in stranding pitch before and after fracture is the same for each inner reinforcing layer (2) and each outer reinforcing layer (5). The rodent-proof optical cable satisfies the following formula: {(1+δ n ) 2 ×[H n 2 +(π×D n ) 2 ]-(π×D n ) 2 } 1 / 2 -H n = {(1+δ1) 2 ×[H1 2 +(π×D1) 2 ]-(π×D1) 2 } 1 / 2 -H1 The total number of inner reinforcement layer (2) and outer reinforcement layer (5) is recorded as n. The inner reinforcement layer (2) and outer reinforcement layer (5) are numbered from 1 to n along the radial direction of the rodent-proof optical cable from the inside to the outside. The innermost inner reinforcement layer (2) is numbered as 1, and the outermost outer reinforcement layer (5) is numbered as n. For the innermost inner reinforcing layer (2), the diameter of the stranded device it is stranded with is denoted as D1, the stranding pitch of the inner reinforcing layer (2) is denoted as H1, the elongation at break is denoted as δ1, and the stranded device is the cable core (1). For the outermost reinforcing layer (5), the diameter of the stranded device it is stranded with is denoted as D. n The twist pitch of the outer reinforcing layer (5) is denoted as H. n Elongation at break is denoted as δ n The stranding device is the part of the rodent-proof optical cable excluding the outer reinforcing layer (5), the outer friction reinforcing layer (6) and the outer sheath (7); D1, δ1, D n δ n All these are known quantities. Once the twist pitch H1 is set, the twist pitch H of the nth layer can be obtained. n .
2. The rodent-proof optical cable as described in claim 1, characterized in that: The materials of the inner reinforcing layer (2) and the remaining outer reinforcing layers (5) of the outer reinforcing elements are each independently selected from aramid fiber yarn or glass elements.
3. The rodent-proof optical cable as described in claim 1 or 2, characterized in that: The glass element is glass fiber yarn or glass rod.
4. The rodent-proof optical cable as described in claim 2, characterized in that: When the outermost inner reinforcing layer (2) of the inner reinforcing element is made of glass, an additional friction-enhancing layer is provided between the inner reinforcing element and the inner sheath (3).
5. The rodent-proof optical cable as described in claim 4, characterized in that: The material of the additional friction enhancement layer is the same as the material of the inner friction enhancement layer (4) or the material of the outer friction enhancement layer (6).
6. The rodent-proof optical cable as described in claim 1, characterized in that: The twisting direction of the outermost inner reinforcing layer (2) in the inner reinforcing element is opposite to the twisting direction of the innermost outer reinforcing layer (5) in the outer reinforcing element.
7. The rodent-proof optical cable as described in claim 1, characterized in that: The internal friction enhancement layer (4) is an electrostatic adsorption layer or an adhesive layer.
8. The rodent-proof optical cable as described in claim 7, characterized in that: When the internal friction enhancement layer (4) is an electrostatic adsorption layer, the electrostatic adsorption layer adopts at least one of magnesium carbonate powder, calcium carbonate powder and water-blocking powder; When the internal friction enhancement layer (4) is an adhesive layer, the adhesive layer is made of at least one of silicone, silicone grease, acrylate and polyurethane.
9. The rodent-proof optical cable as described in claim 1, characterized in that: The material of the external friction enhancement layer (6) is at least one of polyester fiber yarn, aramid fiber yarn, polypropylene fiber yarn and polyamide fiber yarn.