Production system, method, product and optical cable of all-dry high water-blocking performance optical unit

Abstract

The invention discloses a production system for a fully dry optical unit with high water-blocking performance, which includes a fiber optic twisting member, a bunching die, an electrostatic eliminator, and an extruder arranged in sequence along the advancing path of the optical fiber. The fiber optic twisting member includes a twisting die and a central rotating shaft. The twisting die has a plurality of wire passing through holes, and a power mechanism is connected to the central rotating shaft to drive the central rotating shaft to rotate forward and backward, thereby driving the twisting die to rotate forward and backward as well. The inner cavity of the central rotating shaft is a through hole for the water-blocking yarn to pass through the inner cavity of the central rotating shaft. The bunching die has a bunching hole for gathering the water-blocking yarn passing through the fiber optic twisting member and all the optical fibers together to form a wire harness and then entering the extruder. The electrostatic eliminator is used to remove the static electricity generated by the friction of the wire harness. The extruder is used to extrude a loose tube on the outer periphery of the wire harness. The invention can effectively avoid the phenomena of the water-blocking yarn and the optical fiber sticking to the wall and accumulating in the loose tube, the size of the loose tube can be reduced, the transmission loss can be lowered, and the product cost can be reduced.

Description

Technical Field

[0001] The present invention belongs to the field of optical unit production equipment, and more specifically, relates to a production system, method, product and optical cable of a fully dry high water-blocking performance optical unit. Background Art

[0002] Optical cables can be divided into filled optical cables, semi-dry optical cables and fully dry optical cables according to different water-blocking methods. Among them, filled and semi-dry optical cables mainly use the method of filling grease in the loose tube of optical fibers to achieve the water-blocking effect. However, the grease is often difficult to wipe clean during construction, and at the same time it pollutes the environment, bringing certain inconvenience to the construction of optical cables. Since the fully dry optical cable has no grease filling during the production process, it not only solves many troubles during construction, but also conforms to the concept of green environmental protection. Therefore, the fully dry optical cable will be a major trend in the future development of optical cables.

[0003] The advantage of no grease filling in the loose tube of the fully dry optical cable has been increasingly widely used in the production of optical cables. To ensure the water-blocking performance of the loose tube, water-blocking yarn or water-blocking powder needs to be placed in the loose tube. The water-blocking yarn will not show the phenomena of powder shedding and powder flying, so it has reliable water-blocking performance. At the same time, the manufacturing process is simple and the cost is low. The fully dry optical unit using water-blocking yarn has been widely used. Generally, the loose tube optical unit with high water-blocking performance uses water-blocking yarn as the water-blocking element. However, with the development of technology, in order to increase the optical fiber density, the size of the loose tube is constantly shrinking. However, tests show that in the small-diameter loose tube optical unit, for the same size of the loose tube, the fully dry optical unit using water-blocking yarn as the water-blocking element has a higher transmission loss compared with the fully dry optical unit using water-blocking powder as the water-blocking element. Therefore, the fully dry optical unit using water-blocking yarn is less applied to small-size loose tubes, and its application is limited. Summary of the Invention

[0004] Aiming at the above defects or improvement requirements of the prior art, the present invention provides a production system and method of a fully dry high water-blocking performance optical unit, which uses an optical fiber torsion member to twist the optical fiber forward and backward before entering the loose tube, and a central rotating shaft places the water-blocking yarn at the center of the optical fiber stranding, which can effectively avoid the phenomena of the water-blocking yarn and the optical fiber adhering to the wall and accumulating in the loose tube. Therefore, a larger inner space of the loose tube is not required, and on the premise of using a small-diameter loose tube, the optical fiber transmission performance and water-blocking performance are ensured.

[0005] To achieve the above object, according to one aspect of the present invention, there is provided a production system of a fully dry high water-blocking performance optical unit, including an optical fiber torsion member, a bunching die, an electrostatic eliminator and an extruder arranged in sequence along the advancing path of the optical fiber, and:

[0006] The optical fiber twisting member includes a twisting die and a central rotating shaft fixedly connected together. The twisting die has a plurality of wire passing through holes, and these wire passing through holes are circumferentially and uniformly arranged around the central axis of the central rotating shaft. The wire passing through holes are used for the optical fiber to pass through the twisting die. The power mechanism is connected to the central rotating shaft, and the power mechanism is connected to the optical fiber twisting member to drive the optical fiber twisting member to rotate forward and backward. The inner cavity of the central rotating shaft is a through hole so that the water blocking yarn can pass through the inner cavity of the central rotating shaft;

[0007] The bunching die has bunching holes for bunching together the water blocking yarn and all the optical fibers passing through the optical fiber twisting member to form a wire harness and then entering the extruder;

[0008] The static eliminator is used to remove the static electricity generated by the friction of the wire harness;

[0009] The extruder is used to extrude a loose tube on the outer periphery of the wire harness.

[0010] Preferably, taking the initial position when the twisting die does not rotate as 0°, after the twisting die rotates forward 270° from the initial position, it then rotates backward 270° and returns to the initial position.

[0011] Preferably, the material of the loose tube is PBT, PP, TPE or TPEE.

[0012] Preferably, the outer diameter of the loose tube is 1.2 mm to 4.0 mm.

[0013] Preferably, the number of the optical fibers is 2 to 24.

[0014] Preferably, the number of the wire passing through holes is 6 to 24, and the diameter of the wire passing through holes is 2 mm to 10 mm.

[0015] According to another aspect of the present invention, there is also provided a production method of a fully dry type optical unit with high water blocking performance, using the production system of the fully dry type optical unit with high water blocking performance to produce an optical unit,

[0016] Preferably, the production method of the fully dry type optical unit with high water blocking performance includes the following steps:

[0017] 1) The water blocking yarn and each optical fiber are respectively released from the wire pay-off frames;

[0018] 2) Each optical fiber respectively passes through one wire passing through hole on the twisting die, the water blocking yarn passes through the central rotating shaft, and then the water blocking yarn and all the optical fibers are bunched together into a wire harness through the bunching holes of the bunching die;

[0019] 3) The wire harness passes through the static eliminator and the extruder and then is connected to the traction device;

[0020] 4) The traction device pulls the optical fiber to move forward, while the twisting die rotates forward and backward to twist the optical fiber, and the extruder extrudes the loose tube to wrap the wire harness, thus obtaining the optical unit.

[0021] According to another aspect of the present invention, there is also provided a fully dry high water-blocking performance optical unit, which is characterized in that it is produced by the production system of the fully dry high water-blocking performance optical unit provided by the present invention, and its outer diameter is 1.2 mm to 4.0 mm.

[0022] According to another aspect of the present invention, there is also provided an optical cable, which is characterized in that it includes the fully dry high water-blocking performance optical unit provided by the present invention;

[0023] When the optical cable is a central tube type optical cable, it has one of the fully dry high water-blocking performance optical units, and an outer sheath is provided outside the fully dry high water-blocking performance optical unit;

[0024] When the optical cable is a stranded type optical cable, it has a plurality of the fully dry high water-blocking performance optical units; it also includes a central strength member. The fully dry high water-blocking performance optical units are stranded with the central strength member to form a cable core, and an outer sheath is provided outside the cable core.

[0025] Generally speaking, compared with the prior art by the above technical solutions conceived by the present invention, the following beneficial effects can be achieved:

[0026] When using water-blocking yarn to block water in the loose tube of the optical unit, by twisting the optical fiber forward and backward with the optical fiber twisting member before entering the loose tube, the water-blocking yarn and the optical fiber can be separated as much as possible. Through the hollow central rotating shaft, the water-blocking yarn can pass through and be surrounded by the optical fiber, being in the center of the surrounding, so as to avoid the phenomenon of the water-blocking yarn and the optical fiber being irregularly twisted together and causing wall sticking and accumulation in the loose tube. This not only effectively avoids the production of defective products, but also helps to reduce the size of the loose tube, reduce transmission loss, and reduce product cost. Description of the Drawings

[0027] Figure 1 is a schematic diagram of the production system of the fully dry high water-blocking performance optical unit in the present invention;

[0028] Figure 2 is a schematic diagram of the optical fiber twisting member in the present invention.

[0029] In all the drawings, the same reference numerals are used to represent the same elements or structures, where: 1 - optical fiber, 2 - wire passing through hole, 3 - central rotating shaft, 4 - water-blocking yarn, 5 - bunching die, 6 - extruder, 7 - loose tube, 8 - wire harness, 9 - optical fiber twisting member, 10 - static eliminator. Detailed Embodiments

[0030] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be 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 used 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.

[0031] Through repeated practice, in exploring the problem of high transmission loss of the optical unit using water-blocking yarn, it is found that the adhesive used in the water-blocking yarn causes the water-blocking yarn and the optical fiber to be irregularly intertwined. The water-blocking yarn adheres to the inner wall of the loose tube, which will not only form local accumulation of the water-blocking yarn and the optical fiber, resulting in excessive extra length, but also cause extrusion of the optical fiber, making it stressed. Both will lead to an increase in the transmission loss of the optical fiber in a small-diameter optical unit. In a loose tube with a larger diameter, due to the sufficient internal space of the loose tube, the local accumulation of the water-blocking yarn and the optical fiber is not obvious, and it has little impact on the transmission loss of the optical fiber. With the increasing demand for the continuous improvement of the optical fiber density, the problem that the diameter of the loose tube cannot be further reduced due to the accumulation of the water-blocking yarn becomes more and more obvious. At the same time, the larger diameter of the optical unit, the excessive extra length of the optical fiber and the water-blocking yarn will also increase the cost.

[0032] Referring to Figure 1 , Figure 2 , the production system of the all-dry high water-blocking performance optical unit provided by the present invention includes a fiber twisting member 9, a bunching die 5, an electrostatic eliminator 10, and an extruder 6 arranged in sequence along the advancing path of the optical fiber 1, and:

[0033] The optical fiber twisting member 9 includes a twisting die and a central rotating shaft 3 fixedly connected together. The twisting die has a plurality of wire passing through holes 2, and these wire passing through holes 2 are circumferentially and uniformly arranged around the central axis of the central rotating shaft 3. The wire passing through holes 2 are used for the optical fiber 1 to pass through the twisting die. The number of the wire passing through holes 2 is 6 to 24, the diameter of the wire passing through holes 2 is 2 mm to 10 mm, and the number of the optical fibers 1 is 2 to 24. The power mechanism is connected to the optical fiber twisting member 9 to drive the optical fiber twisting member 9 to rotate forward and backward (first rotate forward in a first direction, and then rotate backward in a second direction opposite to the first direction), so that the twisting die also rotates forward and backward. The power mechanism is preferably connected to the central rotating shaft 3, and drives the twisting die to rotate forward and backward by driving the central rotating shaft 3 to rotate forward and backward. The inner cavity of the central rotating shaft 3 is a through hole, so that the water blocking yarn 4 can pass through the inner cavity of the central rotating shaft 3. After passing through the central rotating shaft 3, the water blocking yarn 4 is surrounded by the optical fiber 1 and is at the center of the stranding of the optical fiber 1. The water blocking yarn 4 is placed at the center of the stranding of the optical fiber 1 mainly to avoid the water blocking yarn 4 directly contacting the inner wall of the loose tube 7 extruded by the subsequent extruder, and to separate the water blocking yarn 4 and the inner wall of the loose tube 7 as much as possible, which can effectively avoid the adhesive on the water blocking yarn 4 causing adhesion between the water blocking yarn 4 and the loose tube 7 or the optical fiber 1 and generating irregular stranding under the action of the high temperature of the material after the loose tube is extruded, thereby reducing the local accumulation of the water blocking yarn and the optical fiber caused by the irregular stranding, and reducing the optical loss caused by the stress accumulation.

[0034] The bunching die 5 has bunching holes for bunching together the water blocking yarn 4 and all the optical fibers 1 passing through the optical fiber twisting member 9 to form a wire harness 8 and then entering the extruder 6;

[0035] The static eliminator 10 is used to remove the static electricity generated by the friction of the wire harness 8; the static eliminator is very important for reducing the local accumulation of the water blocking yarn and the optical fiber. Since the optical fiber needs to be in a free state as much as possible in the loose tube, the unwinding tension should not be too large. Under the action of a small unwinding tension, the electrostatic adsorption force cannot be ignored for the relative position and stranding form between the optical fibers and between the optical fiber and the water blocking yarn. Especially when it is desired to adjust the position between the water blocking yarn and the optical fiber by twisting the optical fiber to avoid the adhesion of the water blocking yarn to the loose tube, if the electrostatic adsorption force is large and the unwinding tension is small, the water blocking yarn may not be adjusted to the inside of multiple optical fibers in the desired form, but still adhere to the loose tube, greatly weakening the function of the optical fiber twisting member for adjusting the position of the optical fiber and the water blocking yarn. Therefore, cooperating with the static eliminator can improve the effect of the twisting member for adjusting the position of the optical fiber and the water blocking yarn, further reduce the probability of the water blocking yarn sticking to the wall, and help to reduce the transmission loss and obtain a light unit with high water blocking performance when producing small-diameter light units using water blocking yarn.

[0036] The extruder 6 is used to extrude a loose tube 7 around the outer periphery of the wire harness 8. Since the loose tube 7 is adopted, there will be a gap between the loose tube 7 and the wire harness 8. Therefore, when the loose tube 7 is extruded, the twisting of the wire harness 8 will not have an adverse effect on the extrusion of the loose tube 7.

[0037] The material of the loose tube 7 is PBT, PP, TPE or TPEE, and the outer diameter of the loose tube 7 is 1.2 mm to 4.0 mm.

[0038] Further, taking the initial position when the twisting die does not rotate as 0°, after the twisting die rotates 270° forward from the initial position, it then rotates 270° backward to return to the initial position, so as to fully disperse between the optical fiber 1 and the water blocking yarn 4.

[0039] According to another aspect of the present invention, there is also provided a production method of a fully dry-type optical unit with high water blocking performance, using the production system of the fully dry-type optical unit with high water blocking performance to produce the optical unit, specifically as follows:

[0040] 1) The water blocking yarn 4 and each optical fiber 1 are respectively released from the pay-off stands.

[0041] 2) Each optical fiber 1 respectively passes through a wire passing through hole 2 on the twisting die, the water blocking yarn 4 passes through the central rotating shaft 3, and then the water blocking yarn 4 and all the optical fibers 1 are gathered together into a wire harness 8 through the gathering hole of the gathering die 5.

[0042] 3) The wire harness 8 passes through the static eliminator 10 and the extruder 6 and is then connected to the traction device.

[0043] 4) The traction device pulls the optical fiber 1 to move forward, and at the same time the twisting die rotates forward and backward to twist the optical fiber 1, and the extruder 6 extrudes the loose tube 7 to wrap the wire harness 8, thus obtaining the optical unit.

[0044] Refer to Figure 1 , 6 optical fibers 1 pass through the wire passing through holes 2 evenly distributed along the circumference. The twisting die and the central rotating shaft 3 are integrated and rotate forward and backward at a suitable speed and pitch, driving the optical fiber 1 to twist forward and backward. The loose tube 7 is released through the inner cavity of the central shaft with the water blocking yarn 4, is located at the center of the optical fiber 1 bundle formed by the twisting of the optical fiber 1, and together enters the gathering die 5 to be gathered into a wire harness 8 and then directly enters the extruder 6 to complete the production of the optical unit.

[0045] Those skilled in the art can easily understand that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. Production system for a fully dry high water-blocking performance optical unit, characterized in that, it includes a fiber optic torsion member, a bunching die, an electrostatic eliminator, and an extruder arranged in sequence along the advancing path of the optical fiber, and: The fiber optic torsion member includes a torsion die and a central rotating shaft fixedly connected together. The torsion die has a plurality of wire passing through holes, and these wire passing through holes are circumferentially and uniformly arranged around the central axis of the central rotating shaft. The wire passing through holes are used for the optical fiber to pass through the torsion die. A power mechanism is connected to the fiber optic torsion member to drive the fiber optic torsion member to rotate forward and backward. The inner cavity of the central rotating shaft is a through hole so that the water-blocking yarn can pass through the inner cavity of the central rotating shaft; The bunching die has bunching holes for gathering the water-blocking yarn and all the optical fibers passing through the fiber optic torsion member together to form a wire harness and then entering the extruder; The electrostatic eliminator is used to remove the static electricity generated by friction of the wire harness; The extruder is used to extrude a loose tube on the outer periphery of the wire harness.

2. The production system for a fully dry high water-blocking performance optical unit according to claim 1, characterized in that, Taking the initial position when the torsion die does not rotate as 0°, after the torsion die rotates forward 270° from the initial position, it then rotates backward 270° and returns to the initial position.

3. The production system for a fully dry high water-blocking performance optical unit according to claim 1, characterized in that, The material of the loose tube is PBT, PP, TPE or TPEE.

4. The production system for a fully dry high water-blocking performance optical unit according to claim 1, characterized in that, The outer diameter of the loose tube is 1.2 mm to 4.0 mm.

5. The production system for a fully dry high water-blocking performance optical unit according to claim 1, characterized in that, The number of the optical fibers is 2 to 24.

6. The production system for a fully dry high water-blocking performance optical unit according to claim 1, characterized in that, The number of the wire passing through holes is 6 to 24, and the diameter of the wire passing through holes is 2 mm to 10 mm.

7. A production method for a fully dry high water-blocking performance optical unit, characterized in that, The production system for a fully dry high water-blocking performance optical unit according to any one of claims 1 to 6 is used to produce the optical unit.

8. The production method for a fully dry high water-blocking performance optical unit according to claim 7, characterized in that, It includes the following steps: 1) The water-blocking yarn and each optical fiber are respectively released from the pay-off frames; 2) Each optical fiber respectively passes through a wire passing through hole on the torsion die, the water-blocking yarn passes through the central rotating shaft, and then the water-blocking yarn and all the optical fibers are gathered together as a wire harness through the bunching holes of the bunching die; 3) The wire harness passes through the electrostatic eliminator and the extruder and then is connected to the traction device; 4) The traction device pulls the optical fiber to advance, and at the same time the torsion die rotates forward and backward to twist the optical fiber, and the extruder extrudes the loose tube to wrap the wire harness, thus obtaining the optical unit.

9. A fully dry high water-blocking performance optical unit, characterized in that, It is produced according to the production system for a fully dry high water-blocking performance optical unit according to any one of claims 1 to 6, and its outer diameter is 1.2 mm to 4.0 mm.

10. An optical cable, characterized in that, It includes the fully dry high water-blocking performance optical unit according to claim 9; When the optical cable is a central tube optical cable, it has one of the all-dry high water-blocking performance optical units, and an outer sheath is provided outside the all-dry high water-blocking performance optical unit; When the optical cable is a stranded optical cable, it has a plurality of the all-dry high water-blocking performance optical units; it also includes a central strength member. The all-dry high water-blocking performance optical units and the central strength member are stranded to form a cable core, and an outer sheath is provided outside the cable core.

Images