Study of timber crossarms coated with castor oil-based polyurethane resins: electrical and mechanical tests

While many countries, including Norway, have long used laminated wood to great advantage as an alternative material for transmission and distribution line supports, the traditional crossarms made of native wood species are still commonly employed in Brazil. This continued use of wood is attributed mainly to its low cost compared with other elements of the power supply system. However, environmental considerations and the shorter lifetime of wood have changed this situation, intensifying the research in this area. This work discusses two reforested wood species, Slash Pine (Pinus elliottii) and Lemon Eucalyptus (Eucalyptus citriodora), coated with castor oil-based polyurethane resins, as an alternative material for distribution line crossarms, from the standpoint of their mechanical and electrical properties and their low cost. A complete description is also given of the entire coating process.