3PE管道补口的极化处理技术

Polarization processing technology for field joint coating of 3PE pipeline

国内3PE管道采用辐射交联聚乙烯(PE)热收缩套/带进行补口,存在的主要问题是热收缩套/带边缘开裂,其原因与人工加热热收缩套/带的不均匀性有直接关系。为提高涂料与PE搭接处的粘结力,针对3PE防腐层的技术特点,开发了高密度聚乙烯(HDPE)表面极化处理技术,包括极化处理器和管道表面行走小车在内的极化处理设备。对HDPE防腐层表面进行极化处理、火焰处理、喷砂处理和未处理的对比试验,考核了在不同介质下的老化处理对极化处理后HDPE粘结力的影响,结果表明:HDPE表面经极化处理后,涂料在PE表面的粘结力大幅提高,且老化处理后粘结力没有明显损失。

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.