Polypropylene-based high-voltage direct-current cable material and modification and crystallization temperature regulation and control method

Abstract

The invention discloses a polypropylene-based high-voltage direct-current cable material and a modification and crystallization temperature regulation and control method. A nucleating agent modified polypropylene base material can be prepared by the following steps: (1) adding polypropylene and a nucleating agent into a double-screw blending machine for melt blending, and extruding after uniformlyblending by double screws, so as to obtain a polypropylene master batch containing the nucleating agent, wherein the mass of the nucleating agent accounts for 5-10% of the total mass; and (2) addingthe polypropylene master batch containing the nucleating agent and polypropylene into a double-screw blending machine, carrying out melt blending, uniformly mixing through double screws, and extrudingto obtain isotactic polypropylene containing the nucleating agent. According to the crystallization temperature regulation and control method, in the homogenization section of the cable extrusion process, the crystallization temperature and crystallization time in the polypropylene cooling and shaping process are regulated and controlled through given temperature index design control in an isothermal crystallization or non-isothermal crystallization working mode.

Description

technical field [0001] The invention relates to the field of thermoplastic high-voltage cable materials, in particular to a polypropylene-based high-voltage DC cable material and a modification and crystallization temperature control method. Background technique [0002] XLPE insulated cables have been widely used and developed in high-voltage transmission projects because of their advantages such as light weight, high operating temperature, and large transmission power. However, there are many disadvantages in XLPE cables. First of all, cross-linked polyethylene is a thermosetting material, which is infusible and insoluble in most solvents after being formed, which makes its recycling difficult. Secondly, in order to avoid the introduction of impurities in cross-linking, the production process of cross-linked polyethylene is relatively complicated, and the requirements for production and processing equipment are also high. In addition, the by-products introduced in the cr...

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