The injection process is a conformation process of thermoplastic polymeric materials that has great economic and technologic significance. Much research has been devoted to determining the optimal process conditions. On the other hand, the recycled polymeric materials, produced at the end of a product's life, are an important source of prime materials that can be used to obtain products with good quality and low costs as compared to conventional products. Taking both aspects into consideration, this study has been dedicated to the material study and modeling, in order to determine the parameters used during the processing. A rheological behavior model of the different blends has been developed that can be calculated from simple laboratory tests, whose results have been used as a simulation parameter of the injection process.

Injection molding of recycled thermoplastic materials is a possible alternative for the manufacture of new products and is becoming increasingly important in the industrial sector. Due to the ease with which recycled materials can be mixed, and as so little is known about the process characteristics required to obtain products in optimum conditions, this paper proposes an evaluation criterion for the processability of different blends of recycled materials (ABS/PC blends). With this aim in view, a multicriteria optimization methodology has been developed to evaluate and determine the optimum process conditions that guarantee the ideal final qualities of the products considered from different aspects. The results obtained are used to determine the material processability index of the blend (MPI).