BOPET基镀铝薄膜静电场中表面吸附能力的研究

Surface Adsorption Capacity of BOPET-based Al-Coated Film in Electrostatic Field

目的通过对一种双向拉伸聚酯(BOPET)基镀铝薄膜表面高压静电场中吸附能力的研究,找到提高高压静电提取灰尘足迹能力的途径。方法使用普通提取灰尘足迹用高压静电提取仪,对BOPET基镀铝薄膜表面施加高压静电场,控制电极与镀铝薄膜之间的距离,并采用不同粒径的Si O2颗粒对薄膜在静电场中的吸附能力进行表征。使用光学显微镜、电子显微镜、XRD分析技术及精密分析天平,对薄膜组织结构进行了研究,分析了在高压静电场环境中影响薄膜表面静电吸附能力的原因,并对引起变化的因素进行了讨论。结果 BOPET薄膜在静电场中会向下压紧物体表面,压紧和静电吸附力会随高压电极与镀铝薄膜表面距离的变化而不同。薄膜对颗粒的吸附能力与其带电量显著相关,随颗粒带电量的增加,薄膜表面的吸附能力明显增强。减小电极与薄膜之间的距离可增大薄膜附近的电场强度,是提高其表面静电吸附能力的有效途径。结论 BOPET基镀铝薄膜在高压静电场中会与其下的地面构成平板电容器。静电场中颗粒所带电荷的大小与其形状显著相关,微米颗粒所带电荷较多,从而在BOPET薄膜表面的吸附增重率最大。随电极与薄膜间距离的增加,电场强度降低,颗粒所带电量同时减小,吸附增重率迅速降低,15~10 mm的距离为电场对不同颗粒的静电吸附能力变化最大区间。

The work aims to improve footprint extraction capability of the BOPET aluminum-plating film in electrostatic field by studying adsorption capacity of a biaxially-oriented polyester film（BOPET） surface in high voltage electrostatic field. High voltage electrostatic field was applied to the surface of BOPET-based Al-coated film with a common electrostatic footprint extractor for dust footprint extraction use. Distance between electrode and the Al-coated film was controlled, and absorption efficiency of the film in electrostatic field was characterized with different sized Si O2 particles. Film microstructure was studied with optical microscope, electron microscope, XRD analysis technology and precision analytical balance. Causes affecting elec-trostatic adsorption capacity of the film surface in high-voltage electrostatic field were analyzed. Factors leading to the changes were discussed as well. The BOPET film would push down object surface in electrostatic field, the compaction and electrostatic adsorption force were significantly associated with carried charge. The adsorption capacity of film surface significantly improved as carried charge of the particles increased. Reducing the distance between the electrode and film could increase electric field intensity near the film, which was an effective way of improving the surface electrostatic adsorption capacity. The BOPET-based Al-coated film will constitute a plate condenser with the ground beneath in high-voltage electrostatic field. Electrical charge carried by the particles in electrostatic field is significantly related to particle shape. Microparticles carried much more electric charge, hence adsorption mass gain rate of the BOPET film surface is the highest. As the distance between the electrode and film increases, the electric field intensity decreases, electric quantity carried by particles declines and adsorption mass gain rate decreases rapidly. The greatest change in electrostatic adsorption capacity of electric field to different particles is present in the distance of 15~10 mm.