Removal of PVC from Mixed Plastic Waste by Gravity Separation Process

Plastics recycling has become an established national industry in Korea. However, it is still in its infant stage and experiences growing pains. Mixed plastic waste generated from households after hand picking and/or mechanical sorting processes amounts to 870,000 ton per year in Korea and most of them are finally end up with landfill and/or incineration due to lack of separation technologies and economical reasons. These plastic waste can not be used as raw materials for chemical and/or thermal recycling because of its high content of PVC (upto 4.0 wt.%). In the present work, gravity separation system has been developed to remove PVC from the mixed plastic waste. The separation system consists of air separation unit, shredding/grinding units, feeder, density separator, de watering units, pulp separator, plastic recovery system, wastewater treatment system, etc. The main objective of this process to be developed is to achieve high separation efficiency of polyolefins (PE, PP, PS) with less than 0.3 wt.% PVC content and less than 10% moisture content in the final products. The system with a capacity of 0.5 ton per hour is developed and operational results are presented.