Dual-path gas injection system for physical foaming process and gas injection method thereof

Abstract

The invention relates to a dual-path gas injection system for a physical foaming insulation process and a gas injection method of the gas injection method, aiming at improving the foaming degree of a leakage cable, ensuring the foaming stability and the foaming uniformity while achieving high foaming degree, improving the performances of a product and reducing the production cost. The dual-path gas injection system and the gas injection method of the gas injection method are particularly suitable for a physical foaming process of a polyethylene insulation material. The dual-path gas injection system comprises a carbon dioxide gas injection device and an octafluorocyclobutane gas injection device; the carbon dioxide gas injection device comprises a quantitative gas injection needle, a gas path, a gas injection machine and a gas bottle; the gas bottle is connected with the gas injection machine after being connected with a gas pipe, the gas injection machine stores gas until reaching the set pressure, the gas pipe is connected with the quantitative gas injection needle to inject the gas with the set pressure into a plastic extruding machine, the gas is dissolved in a polyethylene foam material in a molten state to form fine cell structures; and the octafluorocyclobutane gas injection device comprises a nitrogen gas bottle, an octafluorocyclobutane gas bottle, a frequency converter, a metering pump, a reducing valve, a gas pipe, a proportional valve, a dual-direction sealing joint and a quantitative gas injection needle.

Description

technical field [0001] The present invention relates to a dual-path gas injection system and its gas injection method used in the physical foaming insulation process. It proposes a solution to the problem of how to increase the foaming degree of leaky cables. While achieving a high foaming degree, Ensure the stability and uniformity of the foaming process, which not only improves the performance of the product, but also reduces the production cost. It is especially suitable for the physical foaming process of polyethylene insulation materials. Background technique [0002] At present, the physical foaming of leaky cables generally uses nitrogen or carbon dioxide single gas for physical foaming. The foaming degree of nitrogen gas can only reach about 70%, while the foaming cells of carbon dioxide are relatively large, which easily leads to large cells in the foaming layer. The insulation layer of the cable core wire is the main medium for transmitting communication signals. ...

AI Technical Summary

Problems solved by technology

[0002] At present, the physical foaming of leaky cables generally uses nitrogen or carbon dioxide single gas for physical foaming. The foaming degree of nitrogen gas can only reach about 70%, while the foaming cells of carbon dioxide are relatively large, which easily leads to large cells in the foaming layer. The insulation layer of the cable core wire is the main medium for transmitting communication signals. Therefore, the quality of the insulation layer processing technology directly affects the performance index of the leaky cable. The defect caused by single gas foaming seriously restricts the electrical performance and Cost of production

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