A full-dry type air-blowing micro-beam light unit, optical cable, preparation method and device thereof

Abstract

The application discloses a kind of full dry type air blowing microbeam light unit, optical cable, its preparation method and device.The light unit includes: light unit sheath, outer layer optical fiber and inner layer optical fiber;The outer layer optical fiber is arranged on the circumference, preferably the outer layer optical fiber is arranged closely on the circumference, forming a circular outer ring;The outer surface of the light unit sheath and the optical fiber is closely attached;The inner layer optical fiber is received in the outer ring formed by the outer layer optical fiber;The inner layer optical fiber and the outer layer optical fiber are filled with water-blocking resin between the inner layer optical fiber and the outer layer optical fiber, and between the inner layer optical fiber.The application combines the design of outer layer optical fiber and inner layer optical fiber, the outer side of outer layer optical fiber closely attaches to light unit, there is no water penetration space between outer layer optical fiber and light unit sheath, so outer layer optical fiber does not need water-blocking treatment, between inner layer optical fiber and outer layer optical fiber, water-blocking resin is filled in the gap, the laying distance of air blowing microcable is improved, clean and environmentally friendly, and the welding efficiency is high.

Description

Technical Field

[0001] This invention belongs to the field of optical fiber communication, and more specifically, relates to a fully dry air-blown micro-beam optical unit, an optical cable, and its preparation method and apparatus. Background Technology

[0002] Currently, my country's telecommunications industry is developing rapidly. Under the guidance of the "Broadband China" strategy, the construction of "all-optical networks" is progressing vigorously. 4G networks have been fully and deeply developed, while 5G network technology is being cultivated. At present, 5G network technology is at a leading level globally, and China is entering a high-speed channel of information development. With the arrival of the big data era, the application of cloud computing data centers, smart buildings, and the Internet of Things, especially the "East Data West Computing" project, has been officially and fully launched, accelerating the rational layout, supply and demand balance, and green and intensive development of China's data centers. The core backbone network, local area network, access network, and equipment room of optical fiber communication have placed higher demands on the fiber core capacity of optical cables. More and more large-core-count optical cables are being used to meet the continuously growing information transmission volume and the rapid development of urban broadband network construction. To this end, the optical cable industry has continuously researched and protected optical fibers, such as placing optical fibers in loose tubes, filling the loose tubes with fiber grease, and then filling the outer loose tubes with water-blocking grease to further isolate moisture. This increases costs, and the grease is not environmentally friendly and is difficult to remove during use, thus causing great inconvenience to users during construction. Therefore, people look forward to the emergence of optical cables without grease filling. Although there are dry / semi-dry optical cables both domestically and internationally, dry refers to the absence of grease filling, and the use of water-blocking powder or water-blocking yarn as filling materials; semi-dry refers to the use of grease filling in the loose tube, and water-blocking powder or water-blocking yarn or other water-blocking materials filling in the cable core.

[0003] However, the use of water-blocking powder and water-blocking yarn inevitably increases the cable diameter and reduces cable rigidity. The increased cable diameter leads to a higher cross-sectional area ratio between the microcable and the duct's inner diameter when laying optical cables of the same capacity; while the reduced cable rigidity causes the air-blowing power to be absorbed by the cable's deformation. These two issues ultimately limit further increases in the laying distance of air-blown microcables. Summary of the Invention

[0004] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a fully dry air-blown micro-beam optical unit, an optical cable, its preparation method, and an apparatus. The purpose is to minimize the use of water-blocking elements by arranging the outer optical fibers of the fully dry air-blown micro-beam optical unit in a circular outer periphery and stacking the inner optical fibers within it, filling the space between the inner and outer optical fibers with water-blocking resin, and ensuring the outer optical fibers are tightly attached to the optical unit sheath. This reduces the diameter of the optical cable while increasing its rigidity, thereby comprehensively improving the air-blown laying distance. This solves the technical problem of existing fully dry air-blown micro-cables where increased cable diameter and reduced rigidity limit further increases in air-blown laying distance.

[0005] To achieve the above objectives, according to one aspect of the present invention, a fully dry air-blown micro-beam optical unit is provided, comprising: an optical unit sheath, an outer optical fiber, and an inner optical fiber;

[0006] The outer optical fibers are arranged along the circumference, preferably arranged close together on the circumference to form a circular outer ring;

[0007] The optical unit sheath is in close contact with the outer surface of the optical fiber;

[0008] The inner optical fiber is housed within the outer ring formed by the outer optical fiber;

[0009] Water-blocking resin is filled between the inner and outer optical fibers, as well as between the inner optical fibers.

[0010] Preferably, the water-blocking resin of the all-dry air-blown microbeam unit has a water absorption and expansion rate of ≥45ml / g (21℃, 65%RH) and a filling rate between 20% and 30%.

[0011] Preferably, in the all-dry air-blown microbeam unit, the specific modulus (23°C, 2.5% elastic deformation) of the water-blocking resin is between 50 and 80 MPa.

[0012] Preferably, in the all-dry air-blown microbeam unit, the water-blocking resin is a photocurable water-blocking resin, and the photocurable water-blocking resin encapsulates the inner optical fiber to form a water-blocking resin coating, the thickness of the water-blocking resin coating being 3-6 μm.

[0013] Preferably, the water-blocking resin of the all-dry air-blown microbeam unit is epoxy acrylate resin, which contains 15-45 wt% sodium polyacrylate.

[0014] The epoxy acrylate resin comprises:

[0015] 50-70 parts of acrylate prepolymer, 4-6 parts of UV curing agent, and 10-15 parts of UV photoinitiator.

[0016] Preferably, in the all-dry air-blown microbeam unit, the number of inner fiber fibers is n. i and the number n of the outer optical fibers o satisfy:

[0017]

[0018]

[0019] Where [] is the Gaussian function, π is the straight angle, r is the fiber radius, and R is the maximum inner diameter of the optical unit sheath.

[0020] Preferably, the all-dry air-blown micro-beam optical unit has an inner layer fiber count of n. i =3, the number of outer optical fibers n o =9.

[0021] According to another aspect of the present invention, a fully dry air-blown optical cable is provided, which is a stranded optical cable, a central tube optical cable, or a micro-bundle optical cable; an outer sheath is provided on its outer side, wherein the static friction coefficient of the outer sheath is ≤0.25 and the dynamic friction coefficient is ≤0.15.

[0022] When it is a stranded optical cable, the all-dry air-blown optical cable includes multiple all-dry air-blown micro-beam optical units provided by the present invention; the multiple all-dry air-blown micro-beam optical units are stranded together;

[0023] When it is a central tube type optical cable, the all-dry air-blown optical cable includes one or more all-dry air-blown micro-beam optical units provided by the present invention housed in the central sleeve.

[0024] When it is a micro-beam optical cable, the fully dry air-blown optical cable of the present invention includes the fully dry air-blown micro-beam optical unit and its outer sheath.

[0025] According to another aspect of the present invention, a method for fabricating the aforementioned all-dry air-blown microbeam unit is provided, comprising the following steps:

[0026] n i After the surface of the optical fiber is coated with water-blocking resin, it is then combined with n o The optical fibers are arranged in a bundle, making the n o The optical fiber is located in the n-th layer coated with water-blocking resin. i The optical fibers are arranged in a circular pattern on the outer side;

[0027] The optical unit sheath material is extruded from the outside of the optical fiber bundle and cured under radial pressure to form the air-blown micro-beam optical unit.

[0028] According to another aspect of the present invention, an apparatus for fabricating the all-dry air-blown microbeam unit is provided, comprising an optical fiber bundle arrangement mold and a sheath pressure forming cavity.

[0029] The fiber bundle arrangement mold, in accordance with the direction in which the fiber travels, includes, in sequence, an inlet mold, a coating assembly, and an outlet mold; the inlet mold has n... i The coating assembly includes an inner layer hole and an outer layer hole evenly arranged around the circumference; the coating assembly includes a water-blocking resin coating head and a UV curing lamp; the outlet mold has an inner layer hole and an outer layer hole evenly arranged around the circumference.

[0030] The inlet module n i Each inner layer hole corresponds to the position of the unique inner layer hole of the outlet mold, and each outer layer hole of the inlet mold corresponds to the position of each outer layer hole of the outlet mold.

[0031] The inner fiber passes through the inner hole of the inlet mold, is coated with water-blocking resin by the water-blocking resin coating head of the coating component, and is cured by the UV curing lamp of the coating component. Multiple inner fibers pass through the inner hole of the outlet mold together. The outer fiber passes through the outer hole of the inlet mold and exits through the corresponding outer hole of the outlet mold.

[0032] The sheath pressure forming cavity has an inlet, a pressure chamber, and an outlet; the pressure chamber has an air inlet and a sealing cavity, the air inlet is used to inject gas into the sealing cavity to increase the pressure inside the pressure chamber; the sheath material extruded onto the surface of the outer optical fiber is shaped inside the pressure chamber and then exits from the outlet.

[0033] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0034] This invention combines the design of outer and inner optical fibers. The outer optical fiber is closely attached to the optical unit, and there is no water seepage space between the outer optical fiber and the optical unit sheath. Therefore, the outer optical fiber does not require water-blocking treatment. The gap between the inner and outer optical fibers is filled with water-blocking resin, which has good water-blocking performance. The optical fiber density of the air-blown microcable is close to the theoretical value, which reduces the cable diameter, increases the laying distance of the air-blown microcable, and is clean, environmentally friendly, and has high splicing efficiency. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the all-dry air-blown microbeam unit structure provided by the present invention;

[0036] Figure 2 This is a schematic diagram of the fiber bundle arrangement mold structure of the fabrication device for a fully dry air-blown micro-beam optical unit;

[0037] Figure 3 This is a schematic diagram of the sheath pressure forming cavity structure of the fabrication device for a fully dry air-blown microbeam unit;

[0038] Figure 4 This is a schematic diagram of the cross-sectional structure of the all-dry water-blocking micro-optical cable provided in Example 2;

[0039] Figure 5 This is a schematic diagram of the cross-sectional structure of the all-dry central tube type miniature air-blown optical cable provided in Example 3;

[0040] Figure 6 This is a schematic diagram of the cross-sectional structure of the fully dry stranded water-blocking micro air-blown optical cable provided in Example 4.

[0041] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1 is optical fiber, 2 is water-blocking resin, 3 is optical unit sheath, 4 is outer sheath, 5 is water-blocking yarn or water-blocking powder, 6 is loose tube, 7 is reinforcing member, 8 is steel strip layer, 21 is inlet mold, 211 is inner layer hole of inlet mold, 212 is outer layer hole of inlet mold, 22 is coating assembly, 23 is outlet mold, 231 is inner layer hole of outlet mold, 232 is outer layer hole of outlet mold, 31 is inlet, 32 is pressure chamber, 321 is air inlet, 322 is sealed cavity, and 33 is outlet. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0043] The all-dry air-blown microbeam unit provided by this invention, such as Figure 1 As shown, it includes: an optical unit sheath, an outer optical fiber, and an inner optical fiber;

[0044] The outer optical fibers are arranged along the circumference, preferably arranged close together on the circumference to form a circular outer ring;

[0045] The optical unit sheath is in close contact with the outer surface of the optical fiber;

[0046] The inner optical fiber is housed within the outer ring formed by the outer optical fiber.

[0047] Using dry water-blocking elements such as water-blocking powder or water-blocking yarn significantly increases the cable diameter because these elements are filled into loose tubes or wound around the optical fiber. Water-blocking resin, due to its denser structure, is suitable for manufacturing smaller-diameter air-blown microcables. However, also due to the denser structure of water-blocking resin, optical units filled with it experience more stress when bent compared to those using water-blocking powder or yarn.

[0048] Water-blocking resin is filled between the inner and outer optical fibers, as well as between the inner optical fibers.

[0049] To balance the bending loss caused by the water-blocking resin and the outer diameter of the optical unit, this invention utilizes the principle of fiber stacking, dividing the optical fiber into an outer layer and an inner layer. The outer layer is arranged closely in a circular shape, forming a circular cavity. After accommodating the inner layer, the inner cavity still has sufficient space to accommodate the water-blocking resin. This fiber stacking method, compared to tightly stacked fiber bundles, hardly increases the cable diameter. Furthermore, filling the gap between the inner and outer fibers with the water-blocking element prevents further increase in cable diameter. The optical unit designed in this invention, suitable for air-blown microcables, has a cable diameter almost equivalent to that of an air-blown micro-beam optical unit without water-blocking elements, and the fiber density is close to the theoretical value. Moreover, the water-blocking element, placed in the gap between the inner and outer fibers, minimizes the stress increase caused by the dense water-blocking resin during cable bending. Simultaneously, because the cable diameter is smaller than that of water-blocking powder or yarn, the bending performance is correspondingly improved. Therefore, although this invention uses dense water-blocking resin as the water-blocking element, the bending loss is not significantly increased compared to dry water-blocking elements using loose water-blocking powder or yarn. Simultaneously, the rigidity of the air-blown microcable optical unit is improved. By comprehensively optimizing both the diameter and stiffness of the air-blown microcable, the laying distance of the air-blown microcable can be increased.

[0050] Furthermore, by optimizing the parameters of the water-blocking resin, such as its modulus, water absorption swelling rate, and filling rate, the water-blocking performance and flexural loss were further improved.

[0051] The water-blocking resin has a water absorption swelling rate ≥45ml / g (21℃, 65%RH) and a filling rate between 20% and 30%. The test method for the water absorption swelling rate of the water-blocking resin refers to the "People's Republic of China Telecommunications Industry Standard YD / T 1115.2-2001". A lower filling rate results in less bending stress caused by the water-blocking resin at the center of the optical cable during normal use, minimizing bending loss. Combined with the corresponding water absorption swelling rate parameters, this ensures effective water blocking in case of seepage.

[0052] The specific modulus (23°C, 2.5% elastic deformation) of the water-blocking resin is between 50 and 80 MPa.

[0053] The water-blocking resin is a photocurable water-blocking resin, which coats the inner optical fiber to form a water-blocking resin coating with a thickness of 3–6 μm. This method of using photocurable water-blocking resin to coat the inner optical fiber ensures a uniform axial distribution of the water-blocking resin, while maintaining it stably within the outer ring formed by the outer optical fiber, between the inner and outer optical fibers, and between the inner optical fibers themselves, without overflowing. This avoids increasing the diameter of the air-blown microcable or even leading to increased bending loss.

[0054] The water-blocking resin is preferably an epoxy acrylate resin containing 15-45 wt% sodium polyacrylate. The epoxy acrylate resin comprises: 50-70 parts of acrylate prepolymer, 4-6 parts of UV curing agent, and 10-15 parts of UV photoinitiator;

[0055] The above analysis shows that a fixed fiber arrangement, forming a stable stacking of outer and inner fibers, is particularly important. To achieve a stable stacking structure, the number of inner fibers, n... i and the number n of the outer optical fibers o satisfy:

[0056]

[0057]

[0058] Where [] represents the Gaussian function, π is the straight angle, r is the fiber radius, and R is the maximum inner diameter of the optical unit sheath. At this time, n o Theoretically, this represents the maximum number of outer optical fibers, which are closely packed together and support each other to form a relatively stable circumference. For the inner optical fibers, according to packing theory, an area ratio of 0.85 is close to the upper limit; higher ratios may not result in a stable packing structure, or the gaps may not be large enough to fill with sufficient water-blocking resin. Conversely, a ratio below 0.5 results in excessively large gaps between the inner and outer fibers, hindering the formation of a stable packing structure.

[0059] In the preferred embodiment, for a 12-core air-blown micro-beam unit, the number of inner fibers n i =3, the number of outer optical fibers n o =9.

[0060] In addition, it has a fixed fiber arrangement and the advantage of high fusion splicing efficiency.

[0061] In order to form a stable arrangement of outer and inner optical fibers in the air-blown microcable optical unit provided by the present invention, the present invention also provides a method and apparatus for manufacturing the air-blown microcable optical unit.

[0062] The method for fabricating a fully dry air-blown microbeam unit provided by this invention includes the following steps:

[0063] n i After the surface of the optical fiber is coated with water-blocking resin, it is then combined with n o The optical fibers are arranged in a bundle, making the n o The optical fiber is located in the n-th layer coated with water-blocking resin. i The optical fibers are arranged in a circular pattern on the outer side;

[0064] The optical unit sheath material is extruded from the outside of the optical fiber bundle and cured under radial pressure to form the air-blown micro-beam optical unit.

[0065] The optical unit sheath material is cured under radial pressure, ensuring a tight fit between the sheath and the outer optical fiber, thus increasing fiber density. The inner side of the optical unit sheath forms a petal-like curved surface that mates with the circumferentially arranged outer optical fiber, such as... Figure 1 As shown, the maximum inner diameter R of the optical unit sheath is the maximum distance between the geometric center of the optical unit's cross-section and the inner side of the outer sheath. This ensures that there is almost no gap between the inner and outer optical fibers of the optical unit sheath, eliminating the need for water-blocking elements due to the absence of any water seepage space.

[0066] To achieve inner fiber positioning and outer fiber circumferential arrangement, this invention provides a fabrication apparatus for a fully dry air-blown micro-beam optical unit, including an optical fiber bundle arrangement mold, an extruder, and a sheath pressure forming cavity.

[0067] The fiber bundle arrangement mold, such as Figure 2 As shown, in order of the direction the optical fiber travels, it includes an inlet mode, a coating assembly, and an outlet mode; the inlet mode has n... i The coating assembly includes an inner layer hole and an outer layer hole evenly arranged around the circumference; the coating assembly includes a water-blocking resin coating head and a UV curing lamp; the outlet mold has an inner layer hole and an outer layer hole evenly arranged around the circumference.

[0068] The inlet module n i Each inner layer hole corresponds to the position of the unique inner layer hole of the outlet mold, and each outer layer hole of the inlet mold corresponds to the position of each outer layer hole of the outlet mold.

[0069] The inner fiber passes through the inner hole of the inlet mold, is coated with water-blocking resin by the water-blocking resin coating head of the coating component, and is cured by the UV curing lamp of the coating component. Multiple inner fibers pass through the inner hole of the outlet mold together. The outer fiber passes through the outer hole of the inlet mold and exits through the corresponding outer hole of the outlet mold.

[0070] The extruder extrudes sheath material onto the surface of the arranged optical fibers, which then enters the sheath pressure forming chamber located downstream of the fibers.

[0071] The sheath pressure forming cavity, such as Figure 3 As shown, it has an inlet, a pressure chamber, and an outlet; the pressure chamber has an air inlet and a sealed cavity, the air inlet is used to inject gas into the sealed cavity to increase the pressure inside the pressure chamber; the sheath material extruded onto the surface of the outer optical fiber is shaped inside the pressure chamber and then exits from the outlet.

[0072] A fully dry air-blown micro-bundle optical cable is a stranded optical cable, a central tube optical cable, or a micro-bundle optical cable, wherein the outer sheath has a static friction coefficient ≤0.25 and a dynamic friction coefficient ≤0.15.

[0073] When it is a stranded optical cable, the all-dry air-blown optical cable includes multiple all-dry air-blown micro-beam optical units provided by the present invention; the multiple all-dry air-blown micro-beam optical units are stranded together;

[0074] When it is a central tube type optical cable, the all-dry air-blown optical cable includes one or more all-dry air-blown micro-beam optical units provided by the present invention housed in the central sleeve.

[0075] When it is a micro-beam optical cable, the fully dry air-blown optical cable of the present invention includes the fully dry air-blown micro-beam optical unit and its outer sheath.

[0076] The following is an example:

[0077] Example 1: 12-core air-blown microcable optical unit and its fabrication

[0078] A fully dry-blown microbeam unit, such as Figure 1 As shown, it includes an optical unit sheath and 12 colored optical fibers; the colored optical fibers are G.652D fiber, G.657A1 fiber, G.657A2 fiber, or G.654E fiber; the multiple optical fibers are distinguished by full-color coloring; the surface of the cured circular fiber bundle is printed with markings.

[0079] Nine outer optical fibers arranged closely around the circumference form a circular outer ring, while three inner optical fibers arranged naturally in the center are housed within the outer ring formed by the outer optical fibers.

[0080] The outer colored fiber has a diameter of 245–255 μm;

[0081] The inner optical fiber located in the center is a water-blocking colored optical fiber, which is coated with a light-cured water-blocking resin layer on the outside. The water-blocking material of the cured water-blocking resin layer includes the following raw materials by weight:

[0082] The composition includes 50-70 parts of acrylate prepolymer, 4-6 parts of UV curing agent, and 10-15 parts of UV initiator; the diameter of the colored fiber is 245-255 μm.

[0083] The diameter of the water-blocking colored optical fiber is 250-260 μm, and the thickness of the water-blocking layer is 3-6 μm.

[0084] The outer diameter of the optical unit sheath is 1.25mm ± 0.05mm, the minimum thickness of the optical unit sheath is 0.15mm, the maximum inner diameter R of the optical unit sheath is 0.475 ± 0.025mm, and in this embodiment, η is taken as 0.85.

[0085] The optical unit sheath is in close contact with the outer surface of the optical fiber; the sheath material is low-density polyethylene, medium-density polyethylene, high-density polyethylene, polytetrafluoroethylene, low-smoke halogen-free polyethylene, or nylon.

[0086] The blown micro-beam optical unit in this embodiment is produced on an imported Austrian MS bundler and a domestically produced fiber optic bundler at a production speed of 100-300 m / min. The manufactured fiber bundle meets the requirements of YD / T1460.3-2006 in terms of geometric dimensions, mechanical properties, environmental performance, and other indicators.

[0087] To achieve inner fiber positioning and outer fiber circumferential arrangement, this invention provides a fabrication apparatus for a fully dry air-blown micro-beam optical unit, including an optical fiber bundle arrangement mold, an extruder, and a sheath pressure forming cavity.

[0088] The fiber bundle arrangement mold, such as Figure 2 As shown, in order of the direction the optical fiber travels, it includes an inlet mode, a coating assembly, and an outlet mode; the inlet mode has n... i The coating assembly includes an inner layer hole and an outer layer hole evenly arranged around the circumference; the coating assembly includes a water-blocking resin coating head and a UV curing lamp, with a 3-5 cm interval between them; the outlet mold has an inner layer hole and an outer layer hole evenly arranged around the circumference.

[0089] The inlet module n i Each inner layer hole corresponds to the position of the unique inner layer hole of the outlet mold, and each outer layer hole of the inlet mold corresponds to the position of each outer layer hole of the outlet mold.

[0090] The inner fiber passes through the inner hole of the inlet mold, is coated with water-blocking resin by the water-blocking resin coating head of the coating component, and is cured by the UV curing lamp of the coating component. Multiple inner fibers pass through the inner hole of the outlet mold together. The outer fiber passes through the outer hole of the inlet mold and exits through the corresponding outer hole of the outlet mold.

[0091] The extruder extrudes sheath material onto the surface of the arranged optical fibers, which then enters the sheath pressure forming chamber located downstream of the fibers.

[0092] The sheath pressure forming cavity, such as Figure 3 As shown, it has an inlet, a pressure chamber, and an outlet; the pressure chamber has an air inlet and a sealed cavity, the air inlet is used to inject gas into the sealed cavity to increase the pressure inside the pressure chamber; the sheath material extruded onto the surface of the outer optical fiber is shaped inside the pressure chamber and then exits from the outlet.

[0093] The specific production method is as follows:

[0094] Three colored optical fibers are passed through the inner layer holes of the fiber bundle arrangement mold, and nine optical fibers are passed through the outer layer holes of the fiber bundle arrangement mold, which are evenly arranged along the circumference.

[0095] A circular dry water-blocking fiber bundle is formed by coating the colored fiber with 3-6 μm photocurable water-blocking resin through the inner hole and then curing it with ultraviolet light.

[0096] The optical unit sheath material is extruded from the outside of the optical fiber bundle and cured under radial pressure. An air inlet is connected to maintain the pressure inside the sealed cavity at 2.5 ± 0.5 Ba, thus forming the air-blown micro-beam optical unit.

[0097] Example 2: All-dry water-blocking miniature optical cable

[0098] The all-dry, water-blocking micro-optical cable provided in this embodiment has the following cross-sectional structure: Figure 4 As shown, it includes a fully dry-blown microbeam unit, which is covered by a protective sleeve with a thickness of 0.15mm. The sleeve is made of a high-density material with a friction coefficient of ≤0.25 in static mode and ≤0.15 in dynamic mode.

[0099] Example 3: All-dry central tube miniature air-blown optical cable

[0100] The central tube type high-core-count micro optical cable provided in this embodiment, such as Figure 5 As shown, it comprises a loose tube located within a reinforcing member, a protective layer located outside the reinforcing member, and a sheath layer extruded over the protective layer. The tube is characterized by containing several 12-core air-blown micro-cable optical units as provided in Embodiment 1, with multiple water-blocking yarns or powders filling the gaps between the loose tubes. The gaps formed by the loose tube, reinforcing member, and protective layer contain a filling material. The filling material can be water-blocking yarn or water-blocking powder; the gaps formed by the loose tube, reinforcing member, and protective layer contain a filling material, which is water-blocking yarn or water-blocking powder. The material of the loose tube is polybutylene terephthalate, polypropylene, or polytetrafluoroethylene. The material of the reinforcing member is steel wire or glass fiber reinforced molding rod. The inner layer of the outer sheath is a steel strip layer, the material of which is steel strip, aluminum strip, or steel wire. The material of the outer sheath is low-density polyethylene, medium-density polyethylene, high-density polyethylene, polytetrafluoroethylene, low-smoke halogen-free polyethylene, or nylon.

[0101] Example 4: All-dry stranded water-blocking miniature air-blown optical cable

[0102] The central tube type high-core-count micro optical cable provided in this embodiment, such as Figure 6 As shown, it comprises a central reinforcing member, six 12-core air-blown microcable optical units as provided in Embodiment 1, water-blocking yarn, and an outer sheath. The six 12-core air-blown microcable optical units are twisted together, and each has an outer sheath. The outer sheath is hollow and contains several strands of water-blocking yarn. The outer sheath is made of low-density polyethylene, medium-density polyethylene, high-density polyethylene, polytetrafluoroethylene, low-smoke halogen-free polyethylene, or nylon.

[0103] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A fully dry air-blown microbeam unit, characterized in that, include: Optical unit sheath, outer optical fiber, and inner optical fiber; The outer optical fibers are arranged along the circumference and are arranged close together to form a circular outer ring; the outer optical fibers are not water-blocking treated. The optical unit sheath is in close contact with the outer surface of the optical fiber, and the inner side of the optical unit sheath forms a petal-shaped curved surface that matches the circumferentially arranged outer optical fiber. The inner optical fiber is housed within the outer ring formed by the outer optical fiber; Water-blocking resin is filled between the inner optical fiber and the outer optical fiber, and between the inner optical fibers; the water-blocking resin is a photocurable water-blocking resin, and the photocurable water-blocking resin coats the inner optical fiber to form a water-blocking resin coating.

2. The all-dry air-blown microbeam unit as described in claim 1, characterized in that, Under test conditions of 21℃ and 65%RH, the water-blocking resin has a water absorption swelling rate ≥45ml / g, and the water-blocking resin filling rate is between 20% and 30%.

3. The all-dry air-blown microbeam unit as described in claim 1, characterized in that, The modulus of the water-blocking resin is between 50 and 80 MPa under test conditions of 23°C and 2.5% elastic deformation.

4. The all-dry air-blown microbeam unit as described in claim 1, characterized in that, The thickness of the water-blocking resin coating is 3~6 μm.

5. The all-dry air-blown microbeam unit as described in claim 2 or 3, characterized in that, The water-blocking resin is an epoxy acrylate resin containing 15-45 wt% sodium polyacrylate. The epoxy acrylate resin comprises: 50-70 parts of acrylate prepolymer, 4-6 parts of UV curing agent, and 10-15 parts of UV photoinitiator.

6. The all-dry air-blown microbeam unit as described in claim 1, characterized in that, The number of inner layer optical fibers and the number of outer optical fibers satisfy: ； ； in, It is a Gaussian function. It is a straight angle For fiber radius, This represents the maximum inner diameter of the optical unit sheath.

7. The all-dry air-blown microbeam unit as described in claim 6, characterized in that, Number of inner optical fibers The number of outer optical fibers .

8. A fully dry air-blown optical cable, characterized in that, It can be a stranded optical cable, a central tube optical cable, or a micro-bundle optical cable; It is provided with an outer protective sleeve on the outside, wherein the static friction coefficient of the outer protective sleeve is ≤0.25 and the dynamic friction coefficient is ≤0.15; When it is a stranded optical cable, the all-dry air-blown optical cable includes a plurality of all-dry air-blown micro-beam optical units as described in any one of claims 1 to 7; the plurality of all-dry air-blown micro-beam optical units are stranded together; When it is a central tube type optical cable, the all-dry air-blown optical cable includes one or more all-dry air-blown micro-beam optical units as described in any one of claims 1 to 7 housed in the central sleeve. When it is a micro-beam optical cable, the all-dry air-blown optical cable is the all-dry air-blown micro-beam optical unit as described in any one of claims 1 to 7, and its outer sheath.

9. The method for fabricating a fully dry air-blown microbeam unit as described in any one of claims 1 to 7, characterized in that, Includes the following steps: Will After the surface of the optical fiber is coated with water-blocking resin, it is in contact with... The optical fibers are arranged in a bundle, making the... The optical fiber is coated with water-blocking resin. The optical fibers are arranged in a circular pattern on the outer side; The optical unit sheath material is extruded from the outside of the optical fiber bundle and cured under radial pressure to form the air-blown micro-beam optical unit.

10. The fabrication apparatus for a fully dry air-blown microbeam unit as described in any one of claims 1 to 7, characterized in that, Includes fiber bundle arrangement mold and sheath pressure forming cavity; The fiber bundle arrangement mold, in accordance with the direction in which the fiber travels, includes, in sequence, an inlet mold, a coating assembly, and an outlet mold; the inlet mold has... The coating assembly includes an inner layer hole and an outer layer hole evenly arranged around the circumference; the coating assembly includes a water-blocking resin coating head and a UV curing lamp; the outlet mold has an inner layer hole and an outer layer hole evenly arranged around the circumference. The entrance module Each inner layer hole corresponds to the position of the unique inner layer hole of the outlet mold, and each outer layer hole of the inlet mold corresponds to the position of each outer layer hole of the outlet mold. The sheath pressure forming cavity has an inlet, a pressure chamber, and an outlet; the pressure chamber has an air inlet and a sealing cavity, and the air inlet is used to inject gas into the sealing cavity.

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