Research On EPS Emulsion Binder And Its Key Prearation Technology For Foundry

Expanded Polystyrene (EPS) is one of the plastics with most widely application in the world. EPS can not be degradated in environmen because of the chemical properties is stable. the polystyrene plastics are mostly one-time use, so it causes a increasingly serious environmental pollution problem. On the other hand,it is a waste of reused resource. As a result, the recovery and utilization technology of waste EPS attainds more attention in all the world. The aim of research on the exploitation of EPS emulsion binder for foundry is,not only to provide a effective method for the EPS recovery,but also to promote a new way of foundry's development.This research is mainly about how to make use of waste EPS to synthesis the Binder for foundry. By taking EPS as main raw material, a new sand binder is developed with emulsification method and modification method.And CO2 is used for hardening to increase the productivity of molding and core-making.Firstly,in order to dissolve EPS,appropriate solvents were selected in accordance with the molecular structure and chemical properties of EPS and the optimal quantity of solvents was selected. Nxet,EPS solution was emulsified on the basis of the colloid chemistry.Many experiments were used to ascertain the time and the temperature of emulsification and water content of the emulsifier.Secondly, properties of EPS emulsion binder were improved by modifing. The types and the optimal range of modifiers were found out by experiments. The optimum formula and technological parameters were determined by orthogonal test method.In the next, the EPS sand was hardened by CO2, the hardening technological parameters were optimized.Besides, the mixing technology of the EPS sand and mixer time of binder were identified.Finally,by means of the performance tests of the sand with EPS emulsion binder such as the as-gassed strength,the final strength (σ24),the serviceable time of sand,collapsibility and gas evolution. Besides,production test and the analysis of economy were made. It has good technological properties. Through production test,the EPS emulsion binder can meet the basic requirement of the foundry.