Theoretical Analysis and Experimental Study on the Coating Removal from Passenger-Vehicle Plastics for Recycling by Using Water Jet Technology

Abstract

The recovery and utilization of automotive plastics are a global concern because of the increasing number of end-of-life vehicles. In-depth studies on technologies for the removal of coatings from automotive plastics can contribute to the high value-added levels of the recycling and utilization of automotive plastic. The liquid waste generated by removing chemical paint by using traditional methods is difficult to handle and readily produces secondary pollution. Therefore, new, clean, and highly efficient techniques of paint removal must be developed. In this article, a method of coating removal from passenger-vehicle plastics was generated based on high-pressure water jet technology to facilitate the recycling of these plastics. The established technology was theoretically analyzed, numerically simulated, and experimentally studied. The high-pressure water jet equipment for the removal of automotive-plastic coatings was constructed through research and testing, and the detailed experiments on coating removal rate were performed by using this equipment. The results showed that high-pressure water jet technology can effectively remove coatings on the surfaces of passenger-vehicle plastics. The research also revealed that the coating removal rate increased as jet pressure (P) increased and then decreased when jet moving speed (Vn) increased. The rate decreased as the distance from nozzle to work piece (S nw ) and the nozzle angle (Φ) increased. The mathematical model for the rate of removal of coatings from bumper surfaces by water jet was derived based on the experiment data and can effectively predict coating removal rate under different operating conditions.