Development of an Electrostatic Separator for Recycling Plastic Materials

为了回收和再利用塑料材料，有必要按塑料材料的种类进行分类和收集。本研究的目的是开发一种用于静电分离和收集塑料的分离器。要求塑料微粒的极性和电荷量随塑料的种类而异。将待分离的塑料物料提供到固定在振动式冷冻机上的塑料板上，并通过摩擦充电进行充电。样品塑料颗粒为PMMA、PC、HDPE、LDDE和pp，分别使用PC或PMMA振动板进行充电试验，其充电特性与摩擦充电系列一致。而电荷量则小至<正负bbb3muc /kg。采用带塑料薄膜的振动板增加电荷量，降低板的表面电荷，PMMA的电荷量达到+10muC/kg， PC的电荷量达到-15muC/kg。根据实验结果，确定了待分离塑料材料的种类和振动板的种类。因此，构建了两级分离器。采用PC膜振动板和PMMA膜振动板分别作为一级给料机和二级给料机。对三种塑料材料的混合试样进行了分离试验。第一阶段收集了90%的PMMA颗粒，第二阶段分离了PC和HDPE。实验表明，通过选择沉积在振动给料机上的塑料薄膜的种类，可以对不同种类的塑料物料进行分离

To recycle and reuse plastic material, it is necessary to separate and collect by the kind of plastic materials. The purpose of this research is to develop an separator for separation electrostatically and collecting plastics. It is required the condition that the polarity and the amount of charge acquired by plastic particles are depending on the kind of plastic. The plastic materials to be separated are provided onto a plastic plate fixed on a vibrating freeder and are charged by friction charging. The sample plastic particles are PMMA,PC,HDPE,LDDE,and PP.AS a result of charging test using PC or PMMA vibrating plate, the charging characterisitcs were consistent with friction charging series. However, the charge quantity is as small as <plus-minus>3muC/kg. The vibrating plate with plastic film was used to increase the charge quantity to reduce the surface charge of the plate and the charge quantity reached +10muC/kg for PMMA and -15muC/kg for PC.From the experimental results, the kind of plastic materials to be separated and the kind of vibrating plate were decided. Thus, two-stage separator was constructed. The vibrating plate with PC and PMMA film were used as the first and the second stage feeder, respectively. The tests to separate micxed sample of three kind of plastic materials were carried out. Ninty percent of PMMA particles was collected at the first stage and the PC and HDPE were separated at the second atage. It was shown experimentally that by choosing the kind of plastic film deposited on the vibrating feeder, and kind of plastic materials could be separate