Production method of thin-walled low-smoke halogen-free dry loose tube

Abstract

The invention relates to a method for producing thin wall type low-smoke zero-halogen dry loose tubes. The technical scheme optimizes the draw ratio of dies and reduces the head pressure to realize evenly discharging. During high fiber count production, through optical fiber sectioning and tension reducing, the loose tubes cannot be bent, and a snake shape, an S shape and inconsistence of excess lengths are avoided. The loose tube produced by the technical scheme is good in forming, smooth in appearance, uniform in wall thickness, thin in tube wall and small in tube sheath retraction. The loose tube has a dry structure and has no ointment filling, and the wall thickness of the tube is thin and the minimum value is 0.13 mm. The method adopting the technical scheme has the advantages that the optical fiber capacity is high, the cost is low and large-scale popularization and application are facilitated.

Description

technical field [0001] The invention relates to a production method of a loose tube, and specifically designs a production method of a thin-walled low-smoke and halogen-free dry-type loose tube. Background technique [0002] The loose tube is a sleeve made of polypropylene or nylon that can loosely place the optical fiber in the cable to protect the optical fiber from internal stress and external side pressure. Generally, it can only be seen after stripping the sheath of the optical cable, and it is mainly used to protect the optical fiber. With the rapid development of the communication industry, the requirements for optical cables are getting higher and higher, especially reducing the diameter of optical cables, which puts forward higher requirements for the production of optical cables, especially the need to reduce the thickness of loose tubes. The current loose tube structure The dry-type casing is non-grease-filled, and the wall thickness is relatively large, usually ...

AI Technical Summary

Problems solved by technology

With the rapid development of the communication industry, the requirements for optical cables are getting higher and higher, especially reducing the diameter of optical cables, which puts forward higher requirements for the production of optical cables, especially the need to reduce the thickness of loose tubes. The current loose tube structure Dry-type casing is non-grease-filled type, and the wall thickness is relatively large, usually reaching about 0.3mm. The advantage of this is that it is easier to realize in terms of technology. There will be more good products, so the larger the wall thickness, the chance of producing defective products will be reduced; the second is that the wall thickness is large, the shrinkage is stable, and the casing will not be distorted at room temperature; There are the following technical problems: 1) Due to the thin wall of the loose tube, it is easy to twist the tube into an S shape during production; 2) The excess length is inconsistent, and the excess length is not easy to control; 3) The appearance of the produced loose tube Nodular, uneven thickness; 4) The wall thickness of the produced loose tube is uneven, easy to break; 5) The debugging process is long during the production process, wasting materials; in view of the current rapid development of the communication industry, the requirements for communication capacity are increasing High, it is particularly important to develop a thin-walled low-smoke halogen-free loose tube, which can accommodate more optical fibers and provide communication capacity under the premise of the same size

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