In order to improve dye-affinity, four methods to introduce tertiary nitrogen groups into segmented poly (urethane-urea) elastic fibers were tested.
Introducing tertiary nitrogen group into terminal end groups did not provide a degree ofdye adsorption that was sufficient to improve dye-affinity. The tertiary nitrogen group copolymerized in soft segments had the greatest effect on dye-affinity. In particular, copolymerization of polyester-diols synthesized from adipic acid and 2-methyl-2- (N, N'-dimethylaminomethyl) -1, 3-propanediol (Abbreviated as NPM), with polytetramethyleneglycol (PTMG) provided the greatest increase in the the degree of dye adsorption. With an increase of the content of tertiary nitrogen, the degree of dye adsorption proportionally increased. Dye-affinity of SPUU was improved by copolymerization of as little as 10 parts of polyesterdiol in the soft segments. Furthermore copolymerization of PTMG and polyester-diol in the soft segments improved elastic recovery at low temperatures.
Dye-affinity was also improved by copolymerization of NPM and propylenediamine in the hard segments. However the improvement was inferior to that obtained by copolymerization of the soft segments.
It is probable that dye molecules can be diffused more easily into regions containing soft segments than into those containing hard segments because of the crystalline structure of hard segments. Copolymerization of hard segments had a negative influence on instantaneous elastic recovery due to disordering of the physical cross-linking.

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Noise in weaving mills becomes much louder with increasing speed of weaving machine. One of the sources of the noise is the collision of healds caused by shedding motion on a jet loom. It was clarified in our previous report that the sound caused by shedding motion was significantly connected with heald motion during a period of shedding motion. In this report, therefore, its frequency characteristic was investigated using a Short Time Fourier Transform in order to relate the sound to the heald motion in a period of shedding motion. Power spectrum of sound showed a feature near the upper dead point of shedding motion when healds collided the heald bar. Superposing sound pressure signals during several periods of shedding motion, we found that some peaks of power spectrum were emphasized near the upper dead point of shedding motion.

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