Helium-free cooling wire-drawing coating method and device for optical fiber

Abstract

The invention relates to an optical fiber helium-free cooling wiredrawing coating method and device, bare optical fibers are drawn out from an optical fiber wiredrawing furnace, are cooled by air and then enter an optical fiber coater to be subjected to layered coating treatment by resin coating, and the layered coating treatment comprises at least two times of inner coating layer coating and at least one time of outer coating layer coating. The inner coating layer is coated by adopting an inner coating layer resin coating, the outer coating layer is coated by adopting an outer coating layer resin coating, the bare optical fiber enters an ultraviolet curing device for curing treatment after layered coating treatment, and the bare optical fiber is tightly coated with the inner coating layer and the outer coating layer with different elastic moduli after curing treatment. According to the invention, the surface temperature of the optical fiber is isolated by coating the surface of the bare optical fiber with the first inner coating layer, so that the subsequent coating of the inner and outer resin coatings is not or less affected by the temperature of the optical fiber, and the coating of the inner and outer coating layers of the optical fiber is completed; helium is not needed for cooling, so that the wire drawing processing cost is reduced, and the working procedures and the device are simplified.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of optical fiber helium-free cooling drawing coating method and device, belong to optical fiber manufacturing technical field. BACKGROUND

[0002] When optical fiber is drawn, preform is melted at high temperature in drawing furnace, and is drawn into fiber by traction and gravity, then is cooled by helium, enters coating device, and is coated by resin coating on the inner and outer layers of optical fiber, then is treated by ultraviolet curing to produce finished product optical fiber. With the increase of drawing speed, the cooling effect of optical fiber becomes poor, and more helium is usually needed to increase the amount of use for intensive cooling. But the price of helium is high, which leads to the increase of production cost. In order to reduce the amount of helium, the existing technical measures are mostly concentrated in improving the cooling effect of optical fiber or improving the recycling of helium.

[0003] The coating process of optical fiber is usually to coat 1 layer of inner coating layer and 1 layer of outer coating layer. After the bare optical fiber is cooled by helium in the long cooling tube, the temperature is matched with the resin coating, and then 1 layer and 2 layers of coating are respectively coated to reach the target outer diameter. When the outer diameter exceeds the target value, the amount of helium used needs to be adjusted to adjust the temperature of the optical fiber and then control the thickness of the coating layer to control the outer diameter of the optical fiber coating. But when the cooling effect of optical fiber is poor, the inner coating layer is usually coated thin, so that the overall outer diameter is lower than the target value. This phenomenon is particularly serious when high-speed drawing, not only leads to excessive use of helium, but also affects the precision and quality of optical fiber coating. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a kind of optical fiber helium-free cooling drawing coating method and device for the above-mentioned existing problems in the prior art, which not only does not need helium cooling, but also is convenient for coating and control, and can ensure the coating precision and quality.

[0005] The technical scheme of the drawing coating method adopted by the present application to solve the above-mentioned problems is as follows: the bare optical fiber is drawn out from the optical fiber drawing furnace, enters the optical fiber coating device for layered coating treatment after air cooling, the layered coating treatment includes at least 2 times of inner coating layer coating and at least 1 time of outer coating layer coating, the inner coating layer is coated with inner coating layer resin coating, and the outer coating layer is coated with outer coating layer resin coating, and after layered coating treatment, it enters the ultraviolet curing device for curing treatment, and after curing treatment, the bare optical fiber is tightly coated with inner and outer two layers of coating layers with different elastic modulus.

[0006] According to the above scheme, the first inner coating layer is coated on the surface of the bare optical fiber during layered coating treatment, the radial single side thickness of the first inner coating layer is 15-25 μm, or the diameter is 155-175 μm (for 125 μm diameter standard bare optical fiber), and the first inner coating layer insulates the surface temperature of the bare optical fiber.

[0007] According to the above scheme, a second inner coating layer is coated outside the first inner coating layer, and the radial single-side thickness of the second inner coating layer is 12-20 μm, or the diameter is 180-195 μm (for a standard bare optical fiber with a diameter of 125 μm).

[0008] According to the above scheme, one or two outer coating layers are coated outside the second inner coating layer, and the radial single-side thickness of the outer coating layer is 25-32 μm, or the diameter is 240-250 μm (for a standard bare optical fiber with a diameter of 125 μm).

[0009] According to the above scheme, two outer coating layers are coated outside the second inner coating layer, the radial single-side thickness of the first outer coating layer is 17-25 μm, or the diameter is 215-230 μm, and the radial single-side thickness of the second outer coating layer is 8-17 μm, or the diameter is 240-250 μm (for a standard bare optical fiber with a diameter of 125 μm).

[0010] According to the above scheme, the Young's modulus of the inner coating layer resin coating is 1-3 MPa, and the Young's modulus of the outer coating layer resin coating is 500-700 MPa.

[0011] According to the above scheme, the drawing speed is 2000-2800 m / min.

[0012] According to the above scheme, the coating pressure of the inner coating layer resin coating is 3-6 bar, and the coating pressure of the first inner coating layer is the same as or different from that of the second inner coating layer, and the thickness of the inner coating layer is adjusted by adjusting the coating pressure.

[0013] According to the above scheme, the coating pressure of the outer coating layer resin coating is 4-7 bar, and the thickness of the outer coating layer is adjusted by adjusting the coating pressure.

[0014] The technical scheme of the drawing coating device is as follows: a shell is provided with a resin coating cavity, a through hole penetrating the shell from top to bottom is arranged in the middle of the shell, and the resin coating cavity is characterized in that at least two inner coating layer resin coating cavities and at least one outer coating layer resin coating cavity are arranged in the resin coating cavity from top to bottom, the inner coating layer resin coating cavity and the outer coating layer resin coating cavity are respectively connected with an inner coating layer resin coating supply source and an outer coating layer resin coating supply source through an interface, or each coating layer resin coating cavity is respectively connected with a corresponding coating layer resin coating supply source.

[0015] According to the above scheme, the shell includes upper and lower end faces, and the resin coating cavity inside the shell is equipped with upper and lower partitions. The upper and lower end faces and the upper and lower partitions respectively form the resin coating cavity of each coating layer. The upper and lower end faces and the upper and lower partitions are all provided with thread-passing holes aligned vertically, thereby forming a coating channel that runs vertically through the resin coating cavities of each coating layer.

[0016] According to the above scheme, the inner coating resin coating cavity is provided with two layers, including a first inner coating resin coating cavity provided on the uppermost layer of the cavity, and a second inner coating resin coating cavity immediately below it.

[0017] According to the above scheme, the outer coating resin coating cavity is provided with one layer, and the outer coating resin coating cavity is located below the second inner coating resin coating cavity inside the cavity.

[0018] According to the above scheme, the outer coating resin coating cavity is provided with two layers, including a first outer coating resin coating cavity and a second outer coating resin coating cavity. The first outer coating resin coating cavity and the second outer coating resin coating cavity are respectively arranged vertically below the second inner coating resin coating cavity in the cavity.

[0019] According to the above scheme, the resin coating supply source for each coating layer is connected to the resin coating chamber of each coating layer through a control valve.

[0020] The beneficial effects of this invention are: 1. First, an inner coating layer is applied to the bare optical fiber that has not been completely cooled. The coating process achieves several advantages: 1. By applying a first inner coating layer to the bare fiber surface, the fiber surface temperature is isolated, thus minimizing or eliminating the influence of fiber temperature on subsequent inner and outer resin coatings, thereby completing the coating of the inner and outer layers of the fiber; 2. The elimination of helium cooling not only reduces the cost of fiber drawing but also simplifies the process and equipment; 3. By subdividing the coating layers and controlling the pressure of the resin coating, the effect of high fiber surface temperature on coating thinning can be compensated, thereby precisely controlling the thickness and outer diameter of the inner and outer coating layers, ensuring the coating quality and performance of the fiber. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of a coating apparatus according to one embodiment of the present invention.

[0022] Figure 2 This is a cross-sectional view of the coating apparatus in another embodiment of the present invention.

[0023] Figure 3 This is a process flow diagram of an embodiment of a coating method of the present invention. Detailed Implementation

[0024] The method and device of the present application will be further described in detail in conjunction with the embodiments and the accompanying drawings.

[0025] An embodiment of the drawing coating device of the present application is shown in Figure 1 As shown, it comprises a casing 3, the casing comprises upper and lower end faces, an end cover 2 is arranged on the upper end face of the casing, a wire passing and leading-in hole plate 6 is arranged on the lower end face of the end cover, the resin coating cavity in the casing is arranged with upper and lower partitions, the resin coating cavities of each coating layer are respectively formed between the upper and lower end faces and the upper and lower partitions, the inner coating layer resin coating cavities are arranged in two layers, including a first inner coating layer resin coating cavity formed by a first partition 7 arranged at the uppermost layer of the cavity, and a wire passing hole formed in the middle of the partition, a second layer partition 8 arranged in close proximity to the lower side of the first inner coating layer resin coating cavity forms a second inner coating layer resin coating cavity, and a wire passing hole is correspondingly formed in the middle of the second layer partition; the outer coating layer resin coating cavities are arranged in two layers, including a first outer coating layer resin coating cavity and a second outer coating layer resin coating cavity, the first outer coating layer resin coating cavity and the second outer coating layer resin coating cavity are respectively formed by a third layer partition 9 and a fourth layer partition 10 arranged in the cavity in sequence and in close proximity to each other, and a wire passing hole is correspondingly formed in the middle of the third layer partition and the fourth layer partition, and the first outer coating layer resin coating cavity is arranged in close proximity to the lower side of the second inner coating layer resin coating cavity. The wire passing holes formed in the upper and lower partitions are vertically aligned with the wire passing and leading-in hole on the upper end face, and form wire passing holes vertically penetrating through the resin coating cavities in the middle of the casing. Interfaces respectively communicating with the inner coating layer resin coating cavities and the outer coating layer resin coating cavities are arranged on the side face of the casing in close proximity to each other, and an inner coating layer resin coating connector 4 and an outer coating layer resin coating connector 5 are respectively arranged, wherein one end of the inner coating layer resin coating connector communicates with the first inner coating layer resin coating cavity and the second inner coating layer resin coating cavity, and the other end communicates with an inner coating layer resin coating supply source through a control valve, and one end of the outer coating layer resin coating connector communicates with the first outer coating layer resin coating cavity and the second outer coating layer resin coating cavity, and the other end communicates with an outer coating layer resin coating supply source through a control valve. The bare optical fiber 1 is drawn out from the optical fiber drawing furnace, passes through the inner and outer coating layer resin coating cavities through the wire passing holes, and then enters the ultraviolet curing device for curing treatment, thereby completing the optical fiber coating process.

[0026] Another embodiment of the drawing coating device of the present application is shown in Figure 2 The difference between the above embodiment and the present embodiment is that the outer coating layer resin coating cavity is arranged in one layer, and the outer coating layer resin coating cavity is arranged below the second inner coating layer resin coating cavity in the cavity. The other structures are the same as those of the above embodiment.

[0027] The drawing coating method of the present application is shown in Figure 3As shown, the bare optical fiber is drawn out from the optical fiber drawing furnace, enters the optical fiber coating device after air cooling, and is subjected to layered coating treatment with resin coating. The layered coating treatment includes twice inner coating layer coating and twice outer coating layer coating. The inner coating layer is coated with inner coating layer resin coating, and the outer coating layer is coated with outer coating layer resin coating. After the layered coating treatment, the optical fiber enters the ultraviolet curing device for curing treatment. After the curing treatment, the outer surface of the bare optical fiber is tightly coated with two layers of coating layers with different elastic moduli. After ultraviolet curing, the diameter of the optical fiber needs to be measured, and if the outer diameter does not meet the standard, the coating pressure of the coating needs to be adjusted. The coating process of the optical fiber is as follows: a standard bare optical fiber with a diameter of 125 μm passes through a first inner coating layer resin coating cavity, is coated with a first layer of inner coating layer resin coating, and the coating layer has a diameter of 170 μm; the optical fiber passes through a second inner coating layer resin coating cavity, is coated with a second layer of inner coating layer resin coating, and the coating layer has a diameter of 188 μm; the coating pressure of the inner coating layer resin coating is 4-5 bar, the coating pressure of the first inner coating layer is the same as that of the second inner coating layer, the optical fiber passes through a first outer coating layer resin coating cavity, is coated with a first layer of outer coating layer resin coating, and the coating layer of the optical fiber has a diameter of 230 μm; the optical fiber passes through a second outer coating layer resin coating cavity, is coated with a second layer of outer coating layer resin coating, and the coating layer of the optical fiber has a diameter of 245 μm. The coating pressure of the outer coating layer resin coating is 4-5.5 bar, and the required diameter is achieved through multi-layer step-by-step coating.

[0028] In the coating process, the coating types of the first layer of inner coating layer resin coating and the second layer of inner coating layer resin coating are consistent, and the inner coating layer of the optical fiber is finally formed; the coating types of the first outer coating layer resin coating and the second outer coating layer resin coating are consistent, and the outer coating layer of the optical fiber is finally formed. This embodiment is a structure of twice inner coating layer coating and twice outer coating layer coating. After the drawing speed is increased, the temperature of the optical fiber is increased, the first layer of inner coating layer coating after the first layer of inner coating layer resin coating is thinned, but the coating insulates the surface temperature of the optical fiber, so that the second layer of inner coating layer coating is not affected by the temperature of the optical fiber, and the overall thickness of the inner coating layer is not affected after twice coating, so that the diameter of the inner coating layer does not change. By analogy, the overall coating diameter is not affected after the speed is increased, and helium-free drawing can be realized for multi-layer coating.

[0029] The second embodiment of the coating is 2 times of inner coating layer coating and 1 time of outer coating layer coating, the first layer of inner coating layer resin coating is coated, the coating layer diameter is 174 μm; the optical fiber passes through the second inner coating layer resin coating cavity, the second layer of inner coating layer resin coating is coated, the coating layer diameter reaches 186 μm; the size specification of the outer coating through hole is increased to 400-450 μm, and the coating pressure of the outer coating layer resin coating is increased to 6 bar or more, so as to meet the optical fiber coating layer diameter of 245 μm. When the drawing speed is high, by increasing the coating pressure of the inner and outer coating layer resin coatings, the inner coating layer diameter can reach 186-188 μm, and the outer coating layer diameter is stable at 245 μm.

Claims

1. An optical fiber helium-free cooling draw coating process characterized by The bare optical fiber is drawn from the optical fiber drawing furnace, enters the optical fiber coating device after air cooling, and is coated with resin coating for layered coating treatment, the layered coating treatment includes at least two inner coating layers and at least one outer coating layer, the inner coating layer is coated with inner coating resin coating, and the outer coating layer is coated with outer coating resin coating, after the layered coating treatment, the optical fiber is subjected to curing treatment in the ultraviolet curing device, and after the curing treatment, the bare optical fiber is tightly coated with inner and outer coating layers with different elastic moduli.

2. The process of claim 1 wherein The first inner coating layer is coated on the surface of the bare optical fiber, the radial single-side thickness of the first inner coating layer is 15-25 μm, or the diameter is 155-175 μm, and the first inner coating layer insulates the surface temperature of the bare optical fiber.

3. The process of claim 2 wherein The second inner coating layer is coated outside the first inner coating layer, the radial single-side thickness of the second inner coating layer is 12-20 μm, or the diameter is 180-195 μm.

4. The process of claim 3 wherein One or two outer coating layers are coated outside the second inner coating layer, the radial single-side thickness of the outer coating layer is 25-32 μm, or the diameter is 240-250 μm.

5. The process of claim 4 wherein the fiber is cooled by a non-helium cooling gas. Two outer coating layers are coated outside the second inner coating layer, the radial single-side thickness of the first outer coating layer is 17-25 μm, or the diameter is 215-230 μm, and the radial single-side thickness of the second outer coating layer is 8-17 μm, or the diameter is 240-250 μm. ​ 6. The process of claim 1 or 2 wherein The Young's modulus of the inner coating resin coating is 1-3 MPa, and the Young's modulus of the outer coating resin coating is 500-700 MPa.

7. The process of claim 1 or 2 wherein The drawing speed is 2000-2800 m / min.

8. The process of claim 3 wherein the fiber is cooled by a non-helium cooling gas. The coating pressure of the inner coating resin coating is 3-6 bar, the coating pressure of the first inner coating layer is the same as or different from that of the second inner coating layer, and the thickness of the inner coating layer is adjusted by adjusting the coating pressure.

9. The process of claim 4 or 5 wherein The coating pressure of the outer coating resin coating is 4-7 bar, and the thickness of the outer coating layer is adjusted by adjusting the coating pressure.

10. A helium-free cooling and coating device for optical fiber drawing, comprising a housing, a resin coating cavity is arranged in the housing, a through hole is arranged in the middle of the housing, characterized in that At least two inner coating resin coating cavities and at least one outer coating resin coating cavity are arranged in the resin coating cavity in an up-down manner, the inner coating resin coating cavity and the outer coating resin coating cavity are respectively connected to the inner coating resin coating supply source and the outer coating resin coating supply source through interfaces, or each coating resin coating cavity is respectively connected to each corresponding coating resin coating supply source.

11. The optical fiber helium-free cooling and coating draw-down apparatus of claim 10, wherein The shell includes upper and lower end faces, and the resin coating cavities in the shell are provided with upper and lower partitions, and the upper and lower end faces and the upper and lower partitions respectively form each coating resin coating cavity, and the upper and lower end faces and the upper and lower partitions are respectively provided with upper and lower opposite through holes, thereby forming a coating channel penetrating through each coating resin coating cavity in an up-down manner.

12. A fibre optic helium-free cooling and coating draw-down apparatus as claimed in claim 10 or 11, characterised in that The inner coating resin coating cavity is provided with two layers, including a first inner coating resin coating cavity arranged at the uppermost layer of the cavity, and a second inner coating resin coating cavity arranged immediately below the first inner coating resin coating cavity.

13. The optical fiber helium-free cooling and coating draw-down apparatus of claim 10 or 11, wherein The outer coating resin coating cavity is provided with one layer, and the outer coating resin coating cavity is arranged below the second inner coating resin coating cavity in the cavity.

14. The optical fiber helium-free cooling and coating draw-down apparatus of claim 10 or 11, wherein The outer coating layer resin coating cavity is provided with two layers, including a first outer coating layer resin coating cavity and a second outer coating layer resin coating cavity, which are sequentially arranged below the second inner coating layer resin coating cavity in the cavity.

15. The optical fiber helium-free cooling and coating draw-down apparatus of claim 10 or 11, wherein Each coating layer resin coating supply source is communicated with each coating layer resin coating cavity through a control valve.

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