Development of the Bumper-to-Bumper Recycling Technology

From the viewpoint of waste treatment and natural resources conservation,there is a strong demand for the study of the technology whereby automotive coated bumpers collected from the market can be recycled into brand-new bumpers. One of the major subject matters for recycling bumper material is to retain the impact resistance of the substrate by separating out the flaky coating film.

This is to report “Sandwich Injection Molding Technology” to fill the core layer with granulated polypropylene(PP) of used bumpers and the skin layer with virgin PP resin,eliminating the separation process of coated film from the substrate. Core layer material contains high-density-polyethylene(HDPE) additive which improves the impact resistance that may have been deteriorated by coating film residue. Also,the function of HDPE and mechanism to improve the characteristics of molded material are analyzed.

Additionally,predicted filling ratio of core material through CAE simulation and appropriate molding condition for the bumpers applying “Sandwich Injection Molding Technology” are reported.