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Indian Journal of Fibre & Textile Research Vol. 24, September 1999, pp. 177-1 82

Measurement of hairiness of jute yarns by di screte and integral methods

G Basu, A N Roy, A Maj umder & S N Ghosh

National Institute of Research on Jute and Allied Fibre Technology, 12 Regent Park , Calcutta 7()0 040. India

and

A Mukherjee

Institut e of Ju te Technology, 35 8 all ygunge Circular Road, Calcutta 700 019, Indi :l

Received /0 l illy /998; accepted 26 October 1998

Hai riness of wrap-spun and conventionall y-spun (both sli p draft and apron draft ) jute ya rns has becn detel'mincd by ' integral ' and 'd iscrete' methods . The integral meth od, based on Uster yarn hairi ness index , measures the ' total hair in ess ' of the yarn whil e the discrete mcthod, based on counting the number of protrud ing fi bres of different hair lengths, measures the ' long hairiness' of the yarns. It is round that both ' total' and ' long' hairiness of wrap-spun jute yarns arc appleci,lhl y lower than those of conventionall y-spu n jute yarns. When the data of wrap-spun and convent ionall y-spun ju te yarn ~ ,Ire pooled, the correl ati on coerti cien t between integral and discrete methods is positive and signiticant, but no rel at ionship can he estab li shed when the results of onl y wrap-spun yarn are considered. This is due to the dilTerence in the structures or wrap­spun and conventionall y-s pu n jute yarns. In the case or wrap-spun jute yarn whi ch was wrapped by ei ther l1Ionoril ament or multi fi laments, the struct ure or the staple tibre assembl y is close, compact, parallel and smooth wh il e in the case or conventi onall y-spun jute yarn , the staple ti bre assembly is open, bulky, helical and fu zzy.

Keywords : Discrete method , H ai ri nes~ , Integral method, Jute yarn , Uster hairiness index , Wrap-spun yarn

1 Introduction The demand fo r van ous va lue-added diversified

jute products, e.g. wall coverings, upholsteries, curtains, soft-Iuggages, shoe-upper, etc. , has been increasing day by day . These products are made of jute and jute-blended yarns. Excess ive hairiness of jute yarn ad versely affects its subsequent process ing. Moreover, due to the excessive hairiness of the yarn s, jute products have poor hand Ie and aesthet ic val ue. Besides sheddi ng c, f jute fibres, pic king up of dust quick ly by the protruded fib re'l is also due to the excess ive hairiness of jute yarns whic h is to be reduced if modern high speed weaving and wet processi ng treatments are to be adopted to make high · value di versified jute products. So long jute was enjoying the large and ensured market of woven flex ible packaging materi al where hairiness of yarn and fabrics was of litt le consequ nce . But now the hair-free, smooth synthetic bags made out of HDPE or PP tapes and films are !losing erious threat to jute bags used for packin g foodstuffs :lI1d other commodities . Thus, hai riness u:' jute yarn is to be measured and reduced , if not totally el iminated, not only to explore the high value markets of di versified

jute products but also to reta in the trad itiona l market of fl ex ible packaging materi a l.

Ghosh el a l. t-5 not onl y developed an instrument to

measure the ha iriness of j ute yarns but also ex tensively stud ied the va ri ous fac tors that affect hairiness of jute yarns when they are spun on jute spinni ng machinery. Bhattacharya (' I (l i

fl used the instrument developed by Ghosh e l 01. t and determined the hairi ness of filament-wrapped jute yarns spun in the conventi onal two- legged fl yer-type j ute spinning frame. They observed that the hairiness of spun­wrapped jute yarn made on conventi onal jute spillning frame was far lower than that of all -jute y_trn convent ionall y spun on the same machi ne. The ins trument developed by Ghosh (' I ({ I. I is based un 'discrete ' exploration met hoci fo r J CIt'l" '11 ining 'Iong hairiness ' as explained by Coll -Tortosa and Marcelo7

The Zweigle tester fo r yarn ha iriness measurement is based on the principle of optoelectronics or counting the number of prot rud ing fi bres from yarn surface, as explained by ten Brin k and Top r;.

Chaudhuri et al. '! prepared wrap-spun jute and j Ule­vi scose blended yarns in ho ll ow spindle machine and measured their hairiness in Uster teste r (UT-3) wh ich

178 INDIAN 1. FIBRE TEXT. RES., SEPTEMBER 1999

is based on 'integral' exploration method for determining 'total hairiness' as suggested by ColI­Tortosa and Marcel07

. As explained by Barella lO, this

instrument is based on the principle of electrically measuring the scattered light resulting from the reflection, refraction , deffraction and bending of parallel infrared laser rays falling on the protruding fibres of the yarn body . It gi ves an overall dimensionless numerical value of hairiness in terms of hairiness index which is defined as the ratio of cumulative length of protruding fibres in a unit length of yarn as explained by ten Brink and Topr.

In the present work, hairiness of conventionally­spun (both slip draft and apron draft) all-jute yarns and that of wrap-spun jute yarns (prepared in hollow­spindle spinning machine) has been measured using the two types of instruments mentioned above.

2 Materials and Methods 2.1 Materials

Jute fib res of commercial hess ian warp batch , polypropylene mono- and multi-filaments and poly­ester multi -filament were used. The specifications of these filaments are given in Table I .

2.2 Methods Jute yarn samples of 276 tex w'ere prepared in

three different sp inning machines, vi z. Mackie slip­draft jute sliver spinning machine, Mackie apron-draft jute sli ver sp inning machine and Suessen Parafil -2000 wrap-spinning machine. Five types of wrap­spun yarns with mono- and mu lt i-fil ament as wrapping element and two types of conventional spun yarns were prepared . The slip-draft all-jute yarn and wrap-spun jute yarn s were prepared in New Central Jute Mill s Ltd, West Bengal, using jute fibres of commercial hess ian warp batch. The apron-draft all ­jute yarn was spun in the laboratory from the third­drawn sliver of the same hessian warp batch . The drawn sli ver was brought from jute mill to laboratory in the polyethylene bag so that too much loss of moisture did not occur. Hairiness of the yarns was measured using the JTRL jute yarn hairiness meter at a yarn speed of 27 mlmin . The time interval was 5 s. Hence, the number of protruding hairs in a yarn length of 225 cm was determined by coun ti ng. Three hair-length settings of 3 mm, 5 mm and 7 mm were selected and denoted as II, 12 and 1\ respectively. The number of hairs protruding from the yarn surface at th ree hair·· length settings were recorded separatel y. Fifty such readings fo r each yarn at ench hair-length

setting were taken and their average was computed. These were denoted as nf, n2 and iii respecti vely. The number and length of hairs of each yarn at each hair­length setting were also computed . The number of hairs at each hair-length setting was computed as follows:

(i) number of hairs equal to or greater than 7 111111

=n.;, (ii) number of hairs equal to or greater than 5 mm but

less than 7 mm=(nr/~I)' and number of hairs equal to or greater than 3 mm but less than 5 mm=(17,-n2).

The length of hairs at each hair-l ength setting was computed as follows :

(i) total length of hairs equal to or greater than 7 mm=n.ll l=L.I (assuming 11=7 mm),

(ii) total lengt h of hairs equal to or greater than 5 mm but less than 7 mm=(/7r j'jI) /2=L2 (assuming /2=5 mm), and

(iii)totallength of hairs equal to or greater than 3 mm but less than 5 mm=( 17,-172)1,=L , (assuming 1,=3 mm).

The computed values of the number of hairs and length of hairs at different hair-length settin gs arc given in Table I . The cumul ati ve hair length for each yarn over al l the three settings was also dete rmined (Table I ) . This was computed as L,+L2 +L;.

Measurement of hariness indices of all the ya rn s was made on Usrer Tester 3, fi lted with the attachment to measure hairiness of yarns, at a yarn speed of 100 mlmin for 2.5 mi n.

The correlation coeffici ents betweell the result s of two methods of tests and the standerd error of Y estimati on were determined and are ,,,.ive n in Tab le 2. To establi sh a re lationship between the results from the two testers, cumul at ive hair lengt hs were calculated from the results of discrete meth od and are given in Table 2. The t-test for de termining tlte signi ficance of the corre lation coefficient was also carried out. The line of best fit (Y') for cumulative hair length ot all the yarns was computed and it is shown in Fig. I. Later. correlation coefficient. standard err0r of Y (cun ulati vc hair kngth) estimntion, the significClllce of cOIT'latioll cocfficient and line of best fit (Y") were determincd for wrar­spun jute yarns onl y (Table 2 and Fi g. I ).

.A.

-~

Table 1- Hairiness results of jute yarns

Characteristi cs of yam samples Uster No. of hai rs' at hair-length No. of hairs (non-cumulative) at Length of hairs (non-cumulative) Total

Type Linear density No. of Type and hai riness settings of hair-length settings of in mm at hai r-length settings of (cumulative)

tex wraps colour of index 3 'TIm 5 mm 7 mm 3 mm 5mm 7 mm 3 mm 5 mm 7 mm length of

Jute Fi lament filament (UHI) (/,) (/1) (1; ) ih -il z ilz - il; il; (ii, -il z) I, (iiz- ii; ) Iz fi; l ; hairs, mm

ii, ilz il; =L, =Lz =L; (L ,+Lz+L; ) c::l » en C

Wrap-spun 243 13.33 250 PP mono- 1.45 30.40 6.63 3.86 23 .77 2.77 3.86 71 .3 1 13.85 27 .02 11 2. 18 ~

fi lament ~ (white) s:

tTl » Wrap-spun 300 23.33 350 PPmulti - 5.06 36 .3 1 6.83 0.86 29.48 5.97 0.86 88.44 29.85 6.02 124.3 1

Vl C

filamen t ;;0 tTl

(black) s: m z

Wrap-spun 270 8.89 -150 PET multi- 5.33 10.63 2.14 0.3 1 8.49 1.83 0.3 1 25.47 9. 15 2.17 36.79 -l 0

filament 'Tl

(white) ::I: » ~

Wmp-spun 262 10.00 300 PP multi - 6 .75 30.77 6 .66 2.69 24.11 3.97 2.69 72.33 19.85 18.83 111.01 Z filament m

Vl

(b lack) Vl

0 'Tl "-

Wrap-spun 253 5.56 300 PET multi - 7.49 33.46 7.82 1.97 25 .64 5.85 1.97 76.92 29 .25 13.79 119.96 C filament ttl (whi te) -< »

;;0

COI1\·en - 29J 1-15" 9.47 126.51 37 .3 1 17 .26 89 .20 20.05 17.26 267 .6 100.25 120.82 488.67 Z Vl

ti onal ~

CU OI'en- 290 1-I5J 11 .95 153.77 41. 86 13.49 I 11.91 18.37 23A9 335 .73 9 1.85 164 .-13 592.0 1 ti onal"

" JTR L jute yarn hairiness mete r rCJd ing. "Apro n-draft machine with Baxter fl ye r.

' Sli p-lh·at! machinc wit h t\\'v- legged flyer. "Twist per meta.

-J \.0

180 INDI AN 1. FIBRE TEXT. RES., SEPTEM BER 1999

Table 2- Stati stical parameters

No . o f hairs for all types o f yarns

No. of hairs fo r wrap-spun yarns

No. of hairs for all types of yarns (non-cumulative)

No. of hairs for wrap-spun yarns (non-cumulati ve)

Length of hairs for all types of yarns

Length of hairs fo r wrap-spun yarn s

Total length of hairs for all types o f yarns

Total length of hai rs for wrap-spun yarns

R- Correlation coefficient

3 Results and Discussion

R"II

Standard error o f estimate of Y

R UHIII

Standard erro r o f estimate of Y

R ulI l/t·

Standard error of estimate of Y

R IITfI /, ,,e

Standard error of es timate of Y

R all1t'll);flt

Standard error of estimate of Y

Rwwr k n1; lh

Standard error of estimate o f Y

R aIl tutal k nglh

Standard erro r o f es timate o f Y

R wr:l(l !tHai JI.! I1!; lh

Standard erro r of esti mate o f Y

Table I shows that the wrap-spun jute yarn s are far less hai ry th an the conventi onal a ll-jute yarn . The reduction in the ha iriness of the yarns is refl ected in the paramete rs measured by both integra l method (Uste r ha iriness index) and di sc rete method (number and length of protruding hai rs) . S imilar reduct ion in ha iri ness was reported by Bare ll a ef a l . II with wool, ac rylic fibre , polyamide/acry li c and woo l/ac rylic fi bre blended wrap-spun yarns. The reduction in the hairiness o f wrap-spun yarn t S mainly due to its

Hair-length setting 3 mm 5 mm 7 mill

0 .8 1 0.8 1 o.n

35.5 1 10.55 6. 29

0 .04 0. 11 -0.46

11.73 2.55 1.46

0.8 1 0 .82 o.n

25. 11 4.74 (i. 2<J

0.03 0.48 -(lA5

9.29 1.86 1.46

0.8 1 0 .82 0.78

75.3 1 23.7 44.0 1

0 .03 0.48 -0 .45

27.86 9.3 10.23

0 .8 1

139.69

0 .02

4 1. 83

structure. The staple fibres of these ya rns a re laid para lle l to yarn axi s and instead o f twi sting the stap le fibres a fil ament yarn is wrapped round these para ll e i­la id stap le fibres. As a resul t, the stap le fibres of wrap-spun yarns do not experience tw ist ing and bendi ng to that ex tent duri ng yarn formati on and consequently, generat ion of ha irs in w rap-spun ya rn is restricted . Bhattacharya ef al(, also repo rted that the spun-wrapped j ute yarns made in conventi ona l rove spinnin a machine ex hibit marked reduct ion II, hairines~ though the structure of spu ll -wrapped yarn is different fro m that of wrap-spun yarn .

41.

BASU el al.: MEASUREMENT OF HAIRINESS OF JUTE YAR NS 18 1

800 E E .... ........

~ .. ,

iii ~ 600

......... ...

I'll " • .c: .-/ . ... ....-

0 / ;$

.c: - 400 .. ' ~,.~ Cl

s:: :t.., .!!! '\~

Ql .,'V

> -{~

; 200 I'll

'5 E

·5·; ···· ...

:l -5" U

0 0 2 4 6 8 10 12 14

Uster hairiness index

Fig. I-Relationship between Uster hairi ness index and cumulative length of hairs [S'- Standard error of estimate of Y'= 139.7 mm; and S"-Standard error of estimate of Y"=41.8 3 mm]

When the Uster hairiness indices of all the yarns are compared with the total (cumulative) length of protruding fibres from the yarns, the correlation coefficient is found to be 0 .8 1 which as per the t-test carried out yielded tcol=3.088 >t5. 0.05. Therefore , the degree of association is positively and significantly correlated. It is , therefore, inferred that the two methods of measuring hairiness of jute yarns are well­correlated; the straight line of best fit (Y') with standard error of Y estimations is shown in Fig. I . Similar high degree of correlations (0.871 and 0.825) were reported by Barella l 2 for cotton and cotton/man­made fibre blended yarns respectively spun in a cotton ring spinning system. But when the hairiness of only wrap-spun jute yarns is compared, the correlation coefficient is only 0.02. In other words, no correlation exists as illustrated by the straight line of best fit (Y") shown in Fig. I. After testing a large number of yarns, ten Brink and Topr reported that the overall correlation between the hairiness parameters measured by the two types of instruments was not more than 0.6. They observed that the data from the two instruments were poorly correlated in the range of statistical certainty because the two methods were fundamentally different. Barella 12 also corroborated that view, though for certain yarns he reported quite high degree of correlation . ten Brink and Topr also reported that the yarns having higher level of hairiness were more closely correlated . Later, Coli Tortosa and Marcel07 compared the hairiness parameters measured by two methods and reported that for carded cotton yarns the correlat ion coefficient

was only 0.458 while for combed cotton yarns it was 0.779. They also concluded that fuzz formation depended upon the material preparation . For close structures, there was no dependence of fuzziness on the hairiness index obtained whereas for open structures, a certain relati on was found. In the present study, the wrap-spun jute yarn had close structure while the conventional ly-spun jute yarns had open structure.

In the present study, it has also been observed that jute yarn spun in slip-draft spinning frame with two­legged flyer exhibits higher degree of hairiness than the yarn spun in apron-draft spinning frame with baxter flyer. However, Ghosh et 01.1 .1 reported otherwise. It therefore requires further study. Moreover, it may be noted that the values of Uster hairiness index of wrap-spun jute and blended jute yarns, as reported by Chaudhuri , are usuall y hi gher than those obtained in the present study. This may be due to the higher degree of wraps/m employed in the present study. It is, however, very interesting to note that in the present study the Uster hairiness index of wrap-spun jute yarn with PP monofilament as wrapping element and with 250 wraps/ill is very low (1.45) . Chaudhuri ef al.

9 also reported quite low va lue (1.78) of Uster hairiness index for the yarn with 260 wraps/m. For all other wrap-spun all-jute yarns they found that the Uster indices hovered around 10-1 I . Neither Chaudhuri el al.9 Illade any comment abou t it nor could we explain it from our study. But it has been observed in the present study that though the integral exploration method employed by Uster hairiness technique yields a low Uster hairiness index value (1.45), the discrete exp lorati on technique adopted in the instrument developed by Ghosh et (11. 1

does not corroborate it. From Table I it may be observed that not only the total lengt h of the protruding hairs of this yarn is almost the same as that of other three types of yarns whose Uster hairiness indices are much higher than 1.45 , but the total length of longest protruding hairs (with hair length above 7 mm of this yarn) is also maximum among the five experimental wrap-spun jute yarn s. In other words , with long protruding hairs, thi s yarn may visuall y appear to be quite hairy . Therefore, further studies in thi s direction are required .

4 Conclusions 4.1 'Total' and 'long' hairiness of wrap-spun jute

yarns is much lower than that of conventionall y-spun jute yarns .

182 INDIAN 1. FIBRE TEXT. RES. , SEPTEMBER 1999

4.2 When the results of both conven tional and wrap-spun yarns are taken together, the correl at ion coefficient between integral and discrete methods is pos itive and significant, but no relationship can be establ ished when the results of on ly wrap-spun yarn are considered.

Acknowledgement The authors are thankful to Mis New Central Jute

Mill s, Budge Budge, West Bengal, for providing necessary fac ilities to prepare wrap-spun yarn samples and to the Principal, Institute of Jute Technology, Calcutta, for providing the facilities to carry out Uster hai riness test.

Refel'cnces Ghosh S N, Bhattacharya G K, Jain A K, Sil N K & Mukhopadhyay B N, J TexlIlIsl, 79 ( 1988) 634.

2 Ghosh S N , Bhattacharya G K , Si l N K & M ukhopadhyay B N. Indian .I Tex! Res. 10 ( 1985) 106.

3 Ghosh S N. Bh:ltlacharya G K. Sil N K & Mu khopadhyay B N , III dian J Tex! Res. II ( IYI\6) 161\ .

4 Ghosh S N, Bhattacharya G K. Sil N K & Mukhopadhyay B N, III dian J TexI Res. 12 ( 1987) 61\.

5 Ghosh S N, Bhattacharya G K. Sil I K & 11u~IHll';ldh:-~lY I ~

N, Illdian .l TexI Re.~ . 13 ( 1988) 71. 6 Bhattacharya G K. Ghosh S N & Scn!!upta P . .I 1'1'.11 Asso("'

( 1992) 31. 7 Co ll -Tortosa L & Marce lo F X . Tcxl IJmg. 26 (·1) ( I c)c)7) -I.

S ten Brink A & Topr W. Me/lialld rcxli/"('/". 7'2 (I e)e) I ) 5 I X. E 2 14.

9 Chaudhuri A , Mukherj ec S. Sharma I C, Khatu;l D P & Aditya R N, J Insl EII !).I" (1IIdia ). Te.rl i;lIg Oil'. 75 ( I C) e)-I ) 12.

10 Barclla A , Texi Prog, 24 (3) ( 19'.!3) S. II Barella A & Manich A M. T{'.rl Pmg, 26 (4) tl997) I ). 12 Barella A , Tex! Prog. 24 (3) ( 199)) 14. 13 Ghosh S N. Bhattacharya G K & Scngupta P. Rook of/mll('l"s.

II1!ernaliona/ Sell/illar 011 .11111' lind Allied Fiilr!' : Challgill g G/oba/ Scenario (Nat ional Institu(e or Rese.lITh on Jute and Ailied Fibre Technology. Calclltta) . I '.!'.!X. 12 .