阴极电泳漆膜缩孔产生的原因及解决方法

从钢板表面状态和电泳车身烘干过程分析了阴极电泳漆膜产生缩孔的主要原因,在此基础上,通过采取强化脱脂效果、加强电泳工艺参数控制、保持电泳漆烘干室清洁和严禁使用硅酮类材料等措施解决了有关问题。     

如何改善车身磷化膜与涂料的配套性能

磷化膜作为涂装车身底层材料应具有提高涂层的耐蚀性。增加涂层与车身基材的附着力。防止漆膜与车身基材发生化学反应；减缓涂层破损锈蚀在涂层下的扩展速度。特别在近几年阴极电泳工艺的采用，对磷化膜的化学稳定性即耐酸碱性要求越来越高。如果磷化膜与涂料配套不良，直接影响涂层与金属基材的保护作用，很难达到车身10年无穿孔腐蚀、5年外表面不生锈的防锈目标。实践表明，未磷化好的电泳涂层远不如未磷化的电泳涂层的耐蚀性好，其原因是磷化膜没有完全满足阴极电泳涂装的要求。     

阳极系统对阴极电泳漆膜厚度的影响

电泳漆膜厚度是评价电泳漆膜质量的重要指标之一。分析了影响电泳漆膜厚度的因素,并通过试验对这些因素逐一进行了排查。在此基础上,采取了相应的整改措施,使电泳漆膜厚度和膜厚合格率得到大幅度提高,解决了因电泳漆膜薄及局部不上漆而导致的生锈等质量问题。     

卡车底盘涂装工艺的改进

传统的卡车底盘涂装通常采用车架整体电泳+总装装配下线后进行补漆的工艺.该工艺防腐效果一般,底盘容易发生锈蚀或漆面粉化问题.为提高卡车底盘的耐蚀性和耐候性,集瑞联合卡车股份有限公司采用车架散件电泳后装配、在总装对几大件进行预装后再喷涂底盘面漆的工艺,彻底解决了上述腐蚀等问题,极大地提高了底盘的涂装质量.     

热镀锌钢板的质量对涂装前处理和电泳的影响

以热镀锌钢板代替电镀锌钢板是汽车生产商为降低成本而采取的主要措施之一。通过SEM和EPMA观察了国产某热镀锌钢板在电泳涂装前、后的表面状态,还对其与某进口热镀锌钢板在粗糙度方面的差别进行了比较。结果显示,国产热镀锌钢板需要进一步提高质量来满足涂装前处理和电泳的要求。     

宇通创立客车行业首个电泳标准

经济发展到了充分竞争的买方市场阶段,不少企业已真正意识到标准的力量,标准时代已经来临,得标准者得天下已成为企业的共识。靠标准提高竞争力,靠标准拓宽市场,越来越多的高素质企业已通过创立标准,走上了一条平稳且快速的发展之路。     

Simultaneous determination of berberine, matrine and oxymatrine in traditional Chinese medicines by using nonaqueous capillary electrophoresis

A rapid method for the simultaneous determination of berberine (BBR), matrine (MT) and oxymatrine (OMT) by nonaqueous capillary electrophoresis (NACE) was developed. Optimum separation of the analytes was obtained on a 50cm×50μm i.d. fused-silica capillary using a non-aqueous buffer system of 70mM ammonium acetate, 7.0% acetic acid and 10% acetonitrile at 25kV and 20℃. The relative standard deviations (R.S.D.) of the migration times and peak areas of the three active components were 0.06%-0.20% and 0.12%-3.41% for berberine, 0.11%-0.60% and 0.74%-1.63% for matrine, 0.15% and 0.45% for oxymatrine, respectively. Detection limits of berberine, matrine and oxymtrine were 0.18μg/mL, 4.08μg/mL and 4.16μg/mL, respectively. In the tested concentration range, good linear relationships (0.9992 for berberine, 0.9988 for matrine and 0.9988 for oxymatrine) were observed. The linear calibration ranges were 0.45-360.0μg/mL for berberine, 8.16-408.0μg/mL for matrine and 20.8-416.0μg/mL for oxymatrine. This method has been successfully applied to the phytochemical analysis of alkaloids extracts from two commonly used traditional Chinese herbal drugs: Sophora flavescens Ait. (Kushen) and Cortex phellodendri chinensis (Huangbai) and their medicinal preparations.