foamable pellets of example 1 were tumble blended with 5 by weight pmma plexiglass vs 100 pellets available from rohm and hass co the blend was extruded and coated onto 24 awg copper conductor under the following conditions ______________________________________1 inch extruder 24 1 l d extruder zone cross forming 1 2 3 gate head die______________________________________ 210 230 285 240 240 230conductor 24 awgscrew speed 50 rpmline speed 500 fpmdie water bathdistance 2 34 foamable pvdf foamable pvdffoam insulation of example 1 of example 1properties control with 5 pmmawall u00d7 10 sup 3 in 6 7density g cc 1 01 1 10dielectric strength 283 486 v mil ______________________________________ the process conditions were run in a manner which gave the unmodified pvdf foam a dielectric strength less than 2 kv in order to emphasize the effect of pmma which in this example increases the dielectric strength well above the 2 kv requirement a foamed pvdf jacket insulation suitable for encasing a group of insulated primary wire was prepared from a foamable pvdf prepared according to example 1 ______________________________________1 inch extruder cable crosshead pressure type temperature profile die b1 b2 b3 gate crosshead tip______________________________________ 200 u00b0 c 230 280 230 230 300extruder speed 46 rpmline speed 20 fpmgate pressure 4000 psi______________________________________ the foamed jacket insulation formed had a density of 0 80 g cc and a wall thickness of 65 mils such a jacket has.