Indian Journal of Textile ResearchVol. 10, September 1985, Pp. 91-96

Needle-Punched Non-Woven Jute Floor Coverings: Part I-Influenceof Fibre and Process Variables on Tensile Properties of Fabrics

A K SENGUPTADepartment of Textile Technology, Indian Institute of Technology,

New Delhi 110016, Indiaand

A K SINHA and C R DEBNATHJute Technological Research Laboratories, 12, Regent Park, Calcutta 700040, India

Received 14 December 1984';accepted 4 February 1985

The structure and properties of non-woven jute fabrics were studied with reference to the characteristics of fibre, web,reinforcing material and needle-loom variables. The needle-punched jute web had very poor strength and dimensional stabilitybut incorporation of a suitable reinforcing material improved the strength and dimensional stability of the non-wovenremarkably. The tensile properties ofnon-wovens were strongly dependent on those of the refinforcing materials. Non-wovensmade from woollenized jute fibre showed superior tensile properties in comparison with those of non-wovens made fromuntreated fibres.

Keywords: Jute floor coverings, Needle penetration, Needling density, Non-wovens, Random-laid web, Reinforcing material,Tensile properties

The load-extension curve of a needle-punched non-woven fabric is characterized by two deformationregions. The initial region shows negligible resistanceto deformation, and this is followed by a jammed, stiffregion. In the initial stage of extension, fibres arepulled straight, helped by slippage at crossover points,with only a nominal development of tension. This isfollowed by the building up of transverse forces fromthe fibres under tension passing round and into fibrepegs, resulting in a steep rise in load with a smallincrease in extension.

In this study, non-woven fabrics from jute(untreated as well as treated with a batching oilemulsion) and woollenizedjute fibres of varying rangesin structure and properties were prepared by needle-punching random-laid webs. The effects of fibre,process, and machine variables on the tensileproperties of these fabrics are reported.

Experimental ProcedureWoollenization of jute fibres-Jute W 2-grade (IS:

271-1975) was used for woollenization. The root-endof the jute reed (244-305 em) was cut, and the reeds insmall bundles were immersed in 18% (w/v) sodiumhydroxide solution at 30°C. The liquor-to-materialratio was 20: 1 and the immersion period, 45 min.Following the alkali treatment', the fibres werethoroughly washed in running water. The washedfibres were soured with 1% acetic acid for 10 min,washed again till neutral, and finally dried in air.

Openingoffibres-Jute (W rgrade) in reed form wasfed into a Midhurst opener, which gave a mesh-free,stapled fibre-mass. The fibre length distributionpattern of opened jute reed is shown in Fig. 1. Both themean and model lengths of the opened fibres werefound to be about 2.5 em with a fineness of 2.3 tex. Thewoollenized jute fibres (2.1 tex) were also similarlyopened.

Treatment with batching oil emulsion-Raw jutefibres are difficult to process as a large amount ofdroppings and fly are generated during web formationas well as during needle-punching. Moreover, the webobtained is uneven. These difficulties were overcomeby treating the jute with a batching oil emulsion(batching oil 20%, soap 0.5%, water 79.5%) of 30% byweight of raw jute. The treated jute was conditionedfor 72 h before further processing.

Preparation of web- Random-laid web wasobtained by feeding the opened fibres in a Callaghan

30

> 20uzw::>e 100:U.

o 3 4 5FIBRE LENGTH, em

6

Fig. I-Fibre length distribution pattern of Midhurst-opened Jutereed (W-2 grade)

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INDIAN J TEXT RES, VOL. 10, SEPTEMBER 1985

ran do webber, comprising a hopper feeder, pre-opener, and a randomizer unit.

Preparation of needle-punched non-woven fabrics-Needle-punched fabrics were prepared by needle-punching the random-laid web with and withoutreinforcing material. The reinforcing materials usedwere: Jute hessian (54 ends x 48 picks/dm - 300 g/m ');cotton bandage cloth (120 ends x 88 picks/dm-40 g/rrr'); cotton gauge cloth (60 ends x 50 picks/dm- 30 g/m"); and polyethylene film (0.045 mm thick-ness, 47 g/rrr'). Where jute hessian was used at thecentre of web, two passes were given in the needlingzone, the sample being reversed after the first pass.Needle-punching of all the fabrics was carried out in aJames Hunter laboratory fibre locker, Model 26.Needle penetration was kept at 14.3 mm for all thesamples except the ones where needle penetration wasthe variable.

Woollenization in the fabric form-Woollenizationof needle-punched non-woven jute fabric was carriedout in a manner similar to that used for the jute fibredescribed earlier.

Area shrinkage and weight loss due to woollen i-zation were found to be 24.9 and 9.4% respectively.

Tensile testing-From each sample of needle-punched non-woven fabrics and reinforcing materials,ten specimens were used for the tensile tesr'. Thetensile tests of the samples were carried out on anInstron tester. The test conditions" of the sampleswere: test specimen size, 10 x 2.5 cm; cross-head speed"5 cm/min; and chart speed, 20 ern/min.

The stress of the samples was computed as:Fabric stress (g/tex)

Load (g)Area density of fabric x Specimen width

(g/m ') (mrn)

Results and DiscussionTreatment of jute with batching oil emulsion-

Needle-punched non-woven fabric prepared fromemulsion-treated fibres shows a higher stress than thefabric prepared from raw jute (Fig. 2). This is,presumably, due to the greater pliability of treated jutefibres, which leads to better consolidation and lesserfibre breakage during the needling operation+". Thehigher consolidation of the emulsion-treated fibre isreflected in the higher fabric densities (Table I). Therupture of fibres during needling is also higher for theuntreated jute. The initial modulus of fabric madefrom emulsion-treated jute is lower than that of thefabric made from untreated jute fibres (Table I). Thus,while the emulsion treatment has reduced the inter-fibre frictional coefficient, which is reflected in theinitial modulus values, a higher consolidation

92

2·5 A

2·0 B)(

SENGUPTA et al.: NEEDLE-PUNCHED NON-WOVEN JUTE FLOOR COVERINGS: PART I

extensibility of the reinforcing material. Initially, thelarge extension of the reinforced non-woven is due tothe removal of crimp of the reinforcing material (jutehessian cloth). Fig. 3 also shows that the needled,woollenized jute (without scrim) has a significantlylower stress value than the reinforcing material (jutehessian cloth, 300 g/rrr'), whereas the stress value of thereinforced non-woven occupies an intermediateposition.

Influence of reinforcing material weight/web weightratio-The effect of reinforcing material weight/webweight ratio on tenacity is shown in Fig. 4. The samereinforcing jute hessian cloth (300 g/rrr') was used in allthe webs of varied weights. The tenacity increases withincrease in the reinforcing material weight/web weightratio for both jute and woollenizedjute non-wovens upto a certain level following which the tenacity curvegradually tends to flatten. Increase in tenacity with

50,-------

2'5

"~ 2·0 002(J\ B~

Fig. 5-Effect of various reinforcing materials used at the base ofweb on stress-strain characteristics of non-woven [(A) jute hessian.300 gim2; (B) cotton bandage cloth. 40 g/m ': (0cotton gauge cloth.

30 g/m '; and (D) polyethylene film. 47 g/rn"]

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INDIAN J TEXT RES, VOL. 10, SEPTEMBER 1985

2· 0 r-----------;~--__,5 A

" 4!

~ 3C/lC/lWcr 2I-C/l

./~:..----- 0

oL-~§E~~+-~~~~~4 6 8 10 30 '50 70

STRAIN, -t;

Fig. 6-Stress-strain characteristics of reinforcing materials: (A) jutehessian, 300 g/m ': (B) cotton bandage cloth. 40 g/m '; (C) cotton

gauge cloth. 30 g/m ': and (D) polyethylene film. 47 g/m!

Table 3-Effect of Different Reinforcing Materials Used atthe Base of Jute Web on Initial Modulus of Fabric

[Jute web used with each reinforcing material, 270 g/m ': needlepenetration, 15.3 rnrn; and need les/crn 2 • 36]

Reinforcing material Initial Initialmodulus of modulus ofreinforcing non-woven

material g/texg/tex

Jute hessian 30.0 4.17(54 ends x 48 picks/drn - 300 glm2)Cotton bandage cloth 11.1 2.38(120 ends x 88 pick s/dm - 40 g/rn 2)Polyethylene film 5.0 0.54(47g/m2)Cotton gauge cloth 3.1 0.67(60 ends x 50 picks/dm+Sug/m ')

wovens. Hence, the strength and elongationcharacteristics of the non-wovens closely follow thoseof the reinforcing materials.

Influence of the location of reinforcing material-Thestress-strain behaviours of non-wovens usingreinforcing material (jute hessian cloth, 300 g/rrr') atthe base and at the centre of web are shown in Fig. 7.The non-wovens in which the reinforcing material isused at the centre of web show an initial higherresistance to slippage but a lower value of ultimatestress compared to that for the non-wovens in whichreinforcing material is used at the base of web. Thisreduction in stress might be due to the extent ofdamage to the reinforcing material, which is higherwhen it is at the centre of web since the number ofbarbs acting through the reinforcing material while atthe centre of web is expected to be more than when it isused at the base of web for the same needlepenetration.

Influence of woollenization in fibre and in fabricforms-Fig. 8 shows the stress-strain characteristics ofneedle-punched jute fabric, needle-punched woolle-

94

)(

1·5q,--0'~tJ')III 1·0wa::rtJ')

0·5

2 4 6STRAIN, -i:

Fig. 7-Stress-strain characteristics of non-wovens having jutehessian (300 g/rn ') at the centre of web ( x - x - x - x ) and at thebase of web (--) [Needle-punched fabric wt, 505 g/rrr'; 2 x 23

needles/em+ (two passage); and needle penetration. 14.3 rnrn]

o 8

l·Sr----------A

-------,

~ 10Ol

If)

If)

wC(I-

tIl 0'5

c

o 2 468STRAIN, -i;

10

Fig. 8-Stress-strain characteristics of reinforced needle-punchedfabrics: (A) jute fabric (WI, 909 g/m '); (B) woollenized jute fabric (WI.908 g/rrr'), and (e) jute fabric woolleruzed in fabric form (WI.880 g/nr') [Reinforcing jute hessian used at the base on non-wovens.

300 g/m '; needle penetration. 14.3 mrn; 36 needles/em']

nized jute fabric, and needle-punched jute fabricwoollenized in fabric form.

With woollenization in the fabric form, a muchlower modulus (Table 4) and a considerably higherelongation at break are observed, although tenacityremains largely unaffected. The lowering of modulusand the increase in extensibility are associated with thedevelopment of crimp in the reinforcing material aswell as in the fibres due to woollenization. Thus, theinitial high yield region in the stress-strain curve of thespecimen woollenized in the fabric form is essentiallydue to the straightening of crimp during tensiledeformation.

Influence of needling density-Figs 9a and 9b showthat both the tenacity and extension of reinforced non-

SENGUPTA et al.: NEEDLE-PUNCHED NON-WOVEN JUTE FLOOR COVERINGS: PART I

7~--------------~(b)

~-:~~4~~O""~ x x ~~ 3 xw

880 0.22 3.3Fig. 9-Effect of needling density on (a) tenacity and (b) extension of

391 0.15 26.7 reinforced non-wovens [(0) jute 590 g/m", and ( x) \\ oollenizedjute 560 g/m", both including reinforcing jute hessian. AJO g/m ':

288 0.09 0.Q2 needle penetration. 14.3 mm]

Table 4 +Effect of Type of Fibre and Woollenization ofJute Fabric after Needling on Density and Initial Modulus of

Fabrics

[Needles/em:', 36; needle penetration. 14.3 rnrn; and weight ofreinforcing jute hessian, 300g/m2]

Fabric Fabricweight densityg/m? g/crn'909 0.18908 0.21

Type of fabricand process

Initialmodulus

g/tex

7.710.0

I

Jute non-woven. needle-punchedWoollenized jute non-woven.needle-punchedNeedle-punched jute fabricwoollenized in fabric fromWoollenized jute non-woven.needle-punchedWoollenized jute withoutreinforcing jute scrim.needle-punchedJute scrim 13.4

'.

300

wovens decrease with increase in needling density. Thetensile properties of the webs are likely to improve witha greater degree of entanglement of fibres. butsuccessive needling action damages the structures ofboth web and reinforcing material, as is evident fromFig. 10, where individual contributions of web andreinforcing material towards strength vis-a-visneedling density are shown. Since reinforcing materialis the main contributor to the stress-straincharacteristics of needle-punched non-wovens, theprogressive damage to the reinforcing material beginsat the very start of the needling operation, whereas inthe web it starts after reaching a certain level ofneedling density. Figs 9a and 9b show that the damagein jute non-wovens is higher than in wooJlenized jute.Since raw jute fibre is stiffer than wooJlenized jute.fibre breakage during needling with raw jute is higherand the exposure of the reinforcing material to thebarbs is also. thus. higher.

The densities of non-wovens (Fig. 11) show thatwhile the fabric density increases with needling density.the consolidation achieved with woollenized jute ismuch higher at comparable needling densities in themedium to high ranges. At low needling densities.however. the non-wovens prepared from raw jute havea higher density. This is because the woollenized jutebatt has a higher loft and needs more intense needlingfor consolidation.

Influence o{ needle penelralioll---The effects ofneedle penetration on stress-strain properties of juteand woollenized jute reinforced non-wovens areshown in Fig. 12.The stress decreases with increase inneedle penetration for both jute and woollenized jutenon-wovens. The fall of stress for jute non-wovens isgreater at the highest penetration than for woollenized

JOI25k

~20~~ 15 au 017o Eu u~ ;015~

wool ieruzed Jute(5~

~---jute (552 gl m 2)

013~~~~ __ ~~ __ ~~ __ ~~10 12 1" 16 1 B

NEEDLE PENETRATION, m rn

Fig. II-Effect of needling on fabric density [Reinforcing jutehessian used at the base on non-wovens. 300 g.rn ']

jute non-wovens. since the breakage of jute fibres at ahigher needle penetration is expected to be higher.Thus. bare barbs disengaged from the fibres due to thebreakage of fibres might have resulted in greaterdamage to the reinforcing material also. Theindividual contribution of web as well as of reinforcingmaterial towards the strength properties of non-wovens due to varied needle penetrations can be betterunderstood from Fig. 13.The figure shows clearly thatincrease in the needle penetration decreases thestrength of the reinforcing material considerably,whereas web strength increases initially. reaches apeak, and then falls. Hemic and Sultan" observed

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INDIAN J TEXT RES. VOL. 10, SEPTEMBER 1985

WOOLLENIZEDJUTE 1

fabric wt ,545g/m2

JUTEfabric wl,552g/rrf 1

2· 5 2

" 2· °2;(]I