Polarization processing technology for field joint coating of 3PE pipeline

The radiation crosslinked polyethylene heat shrinking sleeves/strips are mostly used in the field joints coating of 3PE pipeline in China. The edge crack of heat shrinkable sleeve/strip is a serious problem of the field joints, which is directly related to the nonhomogeneity of heat shrinkable sleeve/strip by artificial heating. In order to improve the binding capacity of overlap joint between the coating and PE surface, polarization technology of HDPE surface and polarization processing equipment (polarization processor and the running trolley on pipeline surface) are developed according to the characteristics of 3PE anticorrosion coating. Contrast experiment on HDPE coating surface is respectively carried out on polarization processing, flame treatment and sandblasting/un-sandblasting processing, and the influence of aging processing on polarization processing with different media for HDPE's binding capacity are checked out. Results show that the binding capacity between polarized HDPE surface and coating is improved greatly after polarization, and not reduced apparently after aging treatment.