trisnonylphenol phosphite and no tris 2 4 di tert butylphenyl phosphite exhibited lower fiber mfi 39 s at the low quench air rates than either the material containing 600 ppm tris 2 4 di tert butylphenyl phosphite or the material containing a mixture of 500 ppm tris 2 4 di tert butylphenyl phosphite and 100 ppm trisnonylphenol phosphite this result suggest that a stabilization system that uses trisnonylphenol phosphite as a stand alone melt processing stabilizer may be more efficient than a combination of trisnonylphenol phosphite and tris 2 4 di tert butylphenyl phosphite as shown in fig6 fiber tenacity increases as fiber mfi decreases thus at a given set of fiber processing conditions materials processed with a stabilization system that leads to lower fiber mfi also exhibit higher tenacities the results of the maximum spinning speed tests for both spin trials are reported in table iv the materials containing no trisnonylphenol phosphite did not break at spinning speeds up to 2625 mpm the maximum capability of the machine all of the materials that contained trisnonylphenol phosphite broke at spinning speeds less than 2625 mpm the material that contained 600 parts trisnonylphenol phosphite could not be loaded onto a godet roll for testing due to excessive breaks at the die as discussed above fiber spinning was extremely difficult for all of the samples for the processing conditions used herein table iv maximum spinning speed results ppm tris 2 4 di ppm max spin tert butylphenyl trisnonylphenol speed st dev trial.