Based on the results of the operation curves, we can define that the variability of VI0 in the range of 0.5-0.8 must be
reduced using the appropriate raw materials to produce a quality product. On the other hand, it is necessary to handle
the following operating variables: a) screw speed: 30-45 rpm, b) temperature: 270-300 oC and c) humidity: 0.01-
0.02 %.