Estimation method to achieve desired mechanical properties with minimum virgin polymer in plastics recycling

In the mechanical recycling of plastics, recycled polymers are usually mixed with virgin polymers to achieve the required mechanical properties. Maximizing the use of the recycled polymer requires satisfaction of the necessary properties by minimizing the mixing ratio of the virgin polymer. We propose a method for estimating the mixing ratio based on the equivalent box model combined with the percolation theory (EBM-P). After the EBM-P was verified for blends containing the recycled polymers, the proposed method was applied to assess behaviors of the mixing ratio. Thereby, it was revealed that for the recycled polymer with relatively high mechanical properties, a slight increase in the properties of the recycled polymer leads to a marked decrease in the mixing ratio. The salient benefit of our method is that it not only ascertains the appropriate mixing ratio; it also contributes to assessment of the substitutability of recycled plastics.