On April 3rd, the new type of polylactic acid electric energy metering box developed by the State Grid Zhejiang Electric Power Company was put into trial application in Hangzhou, Huzhou, Wenzhou, Taizhou and Zhoushan.
Currently, the shells of low-voltage electrical equipment are mostly made of petroleum-based plastics such as polycarbonate/polyacrylonitrile plastic alloys and sheet molding compounds. Polylactic acid materials, which possess insulation, high strength and environmental protection properties, are an alternative to traditional plastics. Their raw materials come from renewable plant resources like corn and sugar cane, and after disposal, they can be completely degraded into carbon dioxide and water through composting in natural conditions. The promotion and application of related technologies and standards will contribute more intelligent solutions from the field of power to the management of plastic pollution.
To promote the application of polylactic acid in the electrical equipment field, the R&D team of State Grid Zhejiang Electric Power has, in response to technical bottlenecks such as the high brittleness, insufficient heat resistance, and short outdoor lifespan of polylactic acid, conducted a five-year technological research and development effort. They have jointly enhanced the "force-heat-fire retardant performance" of polylactic acid, resolving the issues of brittle fracture and high-temperature deformation of the material; they have solved the problem of balancing the service life and degradation rate of the material, establishing a material aging mechanism response model and life monitoring plan; and they have overcome the technical difficulty of large-scale stable production of metering boxes, achieving coordinated guarantee of mechanical properties and heat resistance during the molding process.
Through experimental verification, the impact strength of the new polylactic acid electric energy metering box has been enhanced to 95 kilojoules per square meter, the heat load deformation temperature has been increased to 115 degrees Celsius, and the flame retardant grade has reached V0 level (the highest level). While maintaining a degradation rate of over 99%, it ensures a service life of more than 15 years in outdoor environments. This not only meets the stability requirements for long-term operation but also aligns with the green and intelligent upgrade needs of the smart grid.
