Performance evaluation of selected fabric softeners

Some methods and variables of importance in softener evaluation were examined. A subjective, paired‐comparison panel method is recommended for softening measurement, and a dye wicking method seems most reliable for rewettability measurement. Use of these methods shows that softening tends to decrease and rewettability to increase with unsaturation and introduction of ether groups in bridging radicals and with reduction of alkyl chain length, in a word with increasing hydrophilicity of various radicals. Rewet data are particularly sensitive to these effects. For excellent softening, two long chain alkyl groups are apparently required, and these should be at least C16 and more preferably C18 in length.