Indian Journal of Textile Research Vol. 10, December 1985. Pp. 158-162

Influence of Carding Conditions on Rotor Performance and Quality"

ANUP K RAKSHIT and N BALASUBRAMANIAN Bombay Textile Research Association. Bombay 400086. India . Received 4 April 1985; accepted Iu July 1985

~he influence of card production rate on the performance of open-end (OE) machine and yarn quality was studied by using two low-grade trashy and a waste mixing containing a high proportion of . A lower card production rate improved card cleaning efficiency. reduced trash level in . achieved better nep removal efficiency and brought down the opening roller waste on OE machine. Lower card production rate also showed 55% reduction in end-breakage rate in an OE machine. marked improvements in OE yarn strength, evenness and incidence of Uster Classimat faults. particularly the very short thick, long thick, and long thin types... ./

Keywords: Carding conditions, Rotor spinning, Spinning performance, Yarn quality

Low-grade cottons and mixings, often containing plant, while the waste mixing was run in the mill at a good amount of waste, are commonly used in different card production rates to examine the effect on open-end (OE) spinning in order to exploit their OE yarn quality and performance. potential for dealing with short- length and for Pilot plant studies-The card production rate was reducing mixing cost. Cleaning and opening of the varied by changing the doffer speed, the sliver hank material pose problems in conventional being kept constant on an M.M.C. India roll HP machinery and information is often sought about the card". All card slivers were given two passages of optimum card production rates to get satisfactory drawing and spun into yarn on a Suessen's OE spin results on high-production (HP) cards. Nerurkar ' tester at a rotor speed of 40,000 rpm and T.M. of 5.4. found that OE spinning was more sensitive to carding of 14s and 22s Ne were spun from V -797 and B- conditions than . Simpson and Louis+' 1007 cottons respectively. The opening roller waste found that the trash accumulation in rotor was much was estimated by processing about 5 kg of sliver lower and that end-breakage rate reduced and yarn sample. strength improved with double-carded sliver. Earlier Mill study-The waste mixing was processed on work at BTRA 4 showed that tandem carding Laxmi-Rieter Cristallina cards". The mills were improved OE yarn quality mainly in waste mixing. running the cards at a doffer speed of 20 rpm. Since the This paper reports the results of a detailed mixing contained 80% comber noil, satisfactory investigation of the influence of card production rate carding was not obtained and the web was neppy. To on the quality of yarn and performance in OE improve carding quality, the doffer speed was reduced spinning. to 8 rpm. The material processed at the two card production rates was channelized up to a full length Materials and Methods Autocoro OE machine after one drawing passage. End Two cottons, V-797 (l4s Ne), B-I007 (22s Ne), and breakage was studied on an OE machine. The Uster one waste mixing with 80% comber noil were used. The Classimat-Il was used to determine the incidence of fibre properties are given in Table I. The two cottons yarn faults in the two yarn samples by scanning about were processed at different card production rates to 2-3 lakh metres length per sample. The instrument study the effect on OE yarn quality in the BTRA pilot classifies yarn faults into 23 classes based on the length and cross-sectional size of faults.

"Part of the paper presented at the 26th Joint Technological Results and Discussion Conference of the Ahmedabad 's Research Trash content and cleaning efficiency of card-The Association, Ahmedabad, the Bombay Textile Research relationship between the card production rate and card Association, Bombay, the Northern India Textile Research Association. Ghaziabad, and the South India Textile Research Association. Coimbatore, held at AT1RA. Ahmedabad, on 7-8 bThe names of the cards are given mainly for improving the February 1985. understanding of the work.

158 RAKSHIT and BALASUBRAMANIAN: INFLUENCE OF CARDING CONDITIONS ON ROTOR SPINNING cleaning efficiency is shown in Fig. 1. With increase in improved with reduction in card production rate card production rate the cleaning efficiency of card because of the intensive carding action. goes down with both cottons. As a result, the trash At a higher card production rate, nep level tends to content in the card sliver goes up (Fig. 2). The increase further at drawing. Inferior quality of carding improvement in cleaning efficiency at a lower at the higher card production rate may be responsible production rate is because of more intensive action for the nep generation at drawing. both at the licker-in and flat regions. With waste mixing, nep level in card sliver could not Card waste-The effect of card production rate on be counted as it was excessive. Comparison of plush card waste was studied at mills with 8 and 20 rpm of boards prepared from pinches of fibres taken out from doffer on the waste mixing. The results (Table 2) show a known weight of the card sliver sample showed a about a unit increase in waste per cent at 8 rpm of noticeable reduction in nep incidence with material doffer, which mainly came from an increase in flat made at lower card production rate. This is clear from strips. Fig. 3. Nep content in card and drawing slivers-The results Opening roller waste-The opening roller waste of nep level in the lap cotton, card and drawing slivers percentages are plotted against the card production are given in Table 3. Nep removal at card significantly rates in Fig. 4. The opening roller waste increases with

Table I-Physical Properties of Fibres

Cotton Fibre length by Micronaire Fibre Maturity Fibre bundle comb sorter value strength Mature Half Immature (Pressley) Mean Effective Short % mature % 3 mm, g/tex length length fibres % mm mm % V-797(l4s Ne) 21.4 25.9 12.8 4.25 59 18 23 23.8 B-l007(22s Ne) 24.0 31.I 18.8 4.03 64 16 20 25.1 Waste mixing with 80% 16.1 30.4 59.1 2.71 54 15 31 24.8 comber noil of 60s mixing (IOs Ne)

Table 2-Effect of Card Production Rate on Card Waste in Waste Mixing

Card Doffer Waste, % production speed rate rpm Licker-in Flat strips Fly from Fly from Total kgjh Waste flat region doffer region 6 8 2.16 3.03 1.64 0.15 6.98 15 20 2.39 2.05 I.21 0.22 5.87

1·0 -&- V-797 COTTON (145 Ne 1 ~ V-797 COTTON(145 Ne 1

o ...•.. 8-1007 COTTON( 225 Nel -b- B -1007 COTTON (225 Ne; a: 09 u"'" ~ 85 a: >- ~ 0·8 u z oJ) w U o u, ~ 07 u, u w 75 o ~ z IO'6 oJ) z "'" w"'" ~ u-' 05

65 04

8 12 16 6 12 16 CARD PRODUCTI ON RATE, kg I h CARD PRODUCTION RATE, kg/h Fig. 1- Effect of card production rate on card cleaning efficiency Fig. 2-Effect of card production rate on trash in card sliver

159 INDIAN 1. TEXT. RES., VOL. 10, DECEMBER 1985

Table 3-Neps in Lap Cotton and in Card and Drawing Slivers

Cotton Doffer Card Neps/g in speed production rpm rate Lap Card 1st Passage 2nd Passage kg(h sliver drawing drawing sliver sliver V-797 8 5 153 134 187 155 16 10 153 126 176 172 24 15 153 167 227 225 B-l007 8 4 177 109 117 124 16 8 177 148 151 157 24 12 177 190 192 223

~ b Fig. 3- Photographs of plush boards prepared from card sliver at (a) higher card production rate, and (b) lower card production rate

increase in card production rate. This is because of the Evenness and imperfections, namely neps and thick higher level of trash present in the input sliver at higher places, in all the counts markedly came down when the card production rates. doffer speed was reduced (Table 4). Reduction in neps Yarn qualily-The physical properties of l Os, 14s was prominent. The results emphasize the need for and 22s Ne OE yarns at various card production rates restricting the doffer speed to a low level even in HP are given in Table 4. Both CLSP and single thread cards while processing trashy cottons and waste strength of all the counts showed improvement upon mixings so as to get satisfactory yarn quality. Mills reducing the card production rate. Better carding planning to go in for OE spinning installation would quality at lower card production rate improves the do well to take this into account and provide for an yarn tenacity. adequate number of cards to avoid back material

160 RAKSHIT and BALASUBRAMANIAN: INFLUENCE OF CARDING CONDITIONS ON ROTOR SPINNING

Table 4-Effect of Card Production Rate on Yarn Quality in Cottons and Mill Waste Mixing

Cotton Card Card Actual Corrected Corrected Single Elongation Uster Imperfections (Nominal dofTer production count lea CLSP thread at break evenness per 100m count, Ne) speed rate Ne strength strength % U% rpm kgjh Ib g Thin Thick Neps -50% +3 +3 V-797 (l4s) 8 5 13.7s 107.4 1503 379.8 7.6 11.2 10 14 108 16 10 13.8s 100.0 1400 372.5 7.6 11.5 12 28 189 24 15 14.2s 100.8 1412 360.4 7.9 12.5 14 36 284 B-1007 (22s) 8 4 20.8s 77.5 1705 282.2 7.6 11.8 14 28 185 16 8 21.6s 76.5 1684 264.8 7.8 12.1 10 33 158 24 12 21.6s 74.5 1640 246.2 7.5 13.0 16 45 307 Mill waste 8 6 10.5s 169.2 1692 539.0 8.1 12.1 6 9 29 mixing (l0s) 20 15 9.7s 156.7 1567 554.0 8.5 13.3 26 29 202

- 145 N•• COUNT Table 5-Effect of Card Production Rates on Incidence of _ 225 N•• COUNT 08 Yarn FalJlts (per 100 km length) ~ 0-7 '!J. ~ Fault Cross-sectional Length Yarn faults at card a: 0-6 w ..J type size of production rate o % faults a: 0-5 cm 6 15 kg/h kgjh i~4 L-/ A + 100 to + 400 0.1-1 75 293 B + 100 to + 400 1-2 11 10 03 C + 100 to + 400 2-4 3 2 D + 100 to + 400 4-8 1 0 4 8 12 16 Total 90 305 CARD PRODUCTION RATE, k 91 h (A+B+C+D) Fig. 4-EfTect of card production rate on opening roller waste Objectionable 0 faults (A4+B4+C4+ shortage even when cards are worked at lower dotTer D4+C3+D3) speeds. Special faults Incidence of 0 E yarn faults- The incidence of yarn E + 100 and above Above 8 0 4 faults at the two card production rates tried in the mills F + 45 to + 100 8-32 9 27 on waste mixing are given in Table 5. The results show G + 45 to + 100 Above 32 I 7 8-32 that incidence of faults has been significantly reduced HI - 30 to -45 1607 5361 H2 - 45 to - 75 8-32 9 145 when the card production rate is brought down from II - 30 to -45 Above 32 46 275 15to 6 kg/h. Objectionable faults in these OE yarns are 12 -45to-75 Above 32 7 122 negligible. A-type faults, which are of very short length Total 1679 5941 and nep-like, show a reduction of 74%, while B, C and (E+F+ .... 12) D type faults are not affected. Long thick faults of'E, F and G type show 67-85% reduction, while long thin faults of H and I type show 71% and 87% reduction respectively with reduction in card production rate. A reduction in end breakage rate can be obtained by lower card production rate leads to more intensive reducing the card production rate from 15 to 6 kg/h. opening and better individualization of fibres and hence the reduction in yarn faults. Conclusions End breakage rate-End breakage was also studied The card cleaning efficiency improved with the on the waste mixing in the mills' Autocoro OE reduction in card production rate and as a result, trash machine at a rotor speed of 57,120 rpm, an opening in card sliver reduced considerably to the extent of roller speed of 8,600 rpm, and a yarn delivery speed of 0.4% at lower card production rates. Nep removal at 89.2 m/min. The results (Table 6) show that 55% card improved significantly with reduction in

161 INDIAN J. TEXT. RES.• VOL 10. DECEMBER 1985

Table 6-Effect of Card Production Rate on End BreakageRate in OE Spinning (Yarn count. 10s Ne)

Card Doffer speed Rotor hours Breaks per 100 rotor hours production rpm observed rate kg/h Rotor Sliver Others Total breaks breaks 6 8 480 9.45 0.05 0.30 9.80 15 20 2016 20.55 1.10 0.50 21.70 production rate. These benefits accrue from the processing trashy low-grade cottons and waste mixings intensive carding action both at licker-in and flat containing a high proportion of noil for getting regions. satisfactory performance of an OE machine and yarn In OE spinning, opening roller waste decreased with quality. the reduction in card production rate. Strength, Uster evenness and imperfections, namely neps and thick Acknowledgement places, of OE yarns also showed a marked The authors are thankful to member mills for improvement upon reducing the card production rate. cooperation in studies. The assistance of their A mill-level study on waste mixing, containing 80% colleagues Shri D.M. Bhatia and Shri D.G. Thombre is comber noil, showed 55% reduction in end breakage also gratefully acknowledged. rate in an OE machine when the card production rate was reduced from 15to 6 kgjh on latest HP cards. The References incidence of Uster Classimat yarn faults, specially very I Nerurkar S K. Indian i Text Res, 4 (1979) 63. short thick (A), long thick (E, F and G) and long thin 2 Simpson J. Am Text RepfBull, Att No 9 (1978) 46. (H and I)was significantly reduced with the lowering of 3 Simpson J and Louis G L. Text Res r, 53 (1983) 551. card production rate. Hence the need for restricting 4 Manohar J S. Rakshit A K and Balasubramanian N. Text Res J, the doffer speed at a low level even in HP cards while 52 (1983) 497.

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