also provides shearing and thus can influence theological behavior example 1 was a polypropylene composition containing 500 parts per million by weight ppm bis 2 4 di tert butylphenyl pentaerythritol diphosphite sold under the trademark ultranox 626 by ge specialty chemicals inc 250 ppm of a hindered phenolic compound sold under the trademark irganox 3114 by b f goodrich 500 ppm calcium stearoyl lactate sold under the trademark pationic 930 by patco polymer additives div american ingredient co the polyproylene base resin used in the compositions of the examples was himont profax 6301 resin comparative example 2 has a polypropylene composition as an example 1 but 500 ppm of calcium stearate was used in place of the calcium stearoyl lactate test method polypropylene is compounded with additives our laboratory compound method 450 u00b0 f stock temperature using a 24 1 l d 1 34 2 stage screw with a maddox mixer between stages a screen pack composed of 20 100 500 100 20 mesh screens is utilized polypropylene is re extruded using a 3 4 34 brabender extruder with a single stage screw 2 1 compression having a maddox mixer 6 34 from the screw tip the output of the extruder is throttled to a 1 4 34 diameter focus on a screen pack the screen pack is composed of 20 100 1400 u00d7 125 100 20 screens back pressure is set to 200 300 psi the extrusion is performed at 600 u00b0 f stock temperature operating the extruder at 10 rpm for 50 min and 50 rpm for 10.