The objective of this research is to study fiber breakage at different opening roller speeds and investigate the relationship between yarn properties and various opening roller and rotor speeds. The present investigation was carried out on two long staple Egyptian cotton cultivars (Giza 85 and Giza 89) from commercial cotton crop of 2000 season. Auotocoro 288 OE spinning was used to conduct the investigation, using a 31-mm. diameter rotor (cotton type rotor). A 25s, yarn count (23.6 tex) was spun with 4.0 twist factor at three rotor speeds of 70000, 90000 and 110000 rev/min. and with three opening roller speeds of 6600, 8200 and 9500 rev/min., respectively.
The main findings could be summarized as follows:
1. The highest opening roller speed caused a good deal of fiber breakage, which was manifested in shorter UQL, and increased percentage of short fibers less than either ½ or 3/8 inch.
2. Opening roller speed showed no significant effect on fiber strength, elongation % and micronaire reading.
3. Opening roller speed exerted substantial influence on yarn strength and elongation %. Both two properties decreased initially with the increase in opening roller speed and then increased with further increased in the opening roller speed, while yarn irregularity (C.V.%) and yarn imperfections decreased with increasing opening roller speed.
4. Yarn strength increased with increasing rotor speed from 70000 to 90000 rev/min. and thin decreased with the increased in rotor speed up to 110000 rev/min. The effect of rotor speed on irregularity (C.V. %) and yarn imperfections (thin places, thick places and neps) was significant at 0.05 probability level and increased at high rotor speeds.
By: M. A. M. El-Sayed Nadia S. D. Abd El-Gawad
Cotton Research Insti
Submit Date: 12/31/1999 20:00