Technical-economic study of PVC-based formulations intended to industrial 3-wire electric cables, using a full factorial design methodology

In the present study, full factorial designs were used to model and optimize the mechanical properties of PVC-based formulations constituting three-core power cables: sheathing, insulation and stuffing, while respecting the standards in force, and aiming for a minimum cost. The effects of 4 parameters: plasticizer content (X1), filler content (X2), stabilizing agent content (X3) and the kind of plasticizer were investigated on the following properties: Density (D), Hardness (H), Elongation at break (EB) and Fracture resistance (FR), as well as the price (DA/kg of formulation). The desirability-based optimization gave the following values: EB = 214.72%, FR = 19.94 MPa and Price = 116.71 DA/kg for the sheathing; EB = 198.11%, FR = 4.38 MPa and Price = 61.73 DA/kg for the stuffing; EB = 207.84%, FR = 19.35 MPa and Price = 102.73 DA/kg for the insulation. The study revealed also that the order of significance of the effects on the mechanical properties was: X1>X2>X3 and that the use of cheapest plasticizer did not affect greatly the mechanical properties.