Needle-Punched Non-Woven Jute Floor Coverings: Part II-Dynamic Loading Behaviour and Abrasion Resistance.

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Indian Journal of Textile Research Vol. 10. December 1985. Pp. 141-146 Needle-Punched Non-Woven Jute Floor Coverings: Part II-Dynamic Loading Behaviour and Abrasion Resistance.

1 Indian Journal of Textile Research Vol. 10. December Pp Needle-Punched Non-Woven Jute Floor Coverings: Part II-Dynamic Loading Behaviour and Abrasion Resistance. /' A K SENGUPTA Department of Textile Technology. Indian Institute of Technology. Ne Delhi India and A K SINHA and C R DEBNA TH Jute Technological Research Laboratories. 12 Regent Park. Calcutta India Received 15 March 1985: accepted 17 April 1985 Closeness of structure and structural rigidity of reinforcing material in the non-ovens influence the recovery after dynamic loading and the abrasion resistance. Decrease in the ratio of the reinforcing material eight to eb eight generally reduces the thickness loss on dynamic loading and abrasion resistance. Plucking of fibres is a more predominant phenomenon than friction-cutting in the abrasion resistance of non-ovens. Plucking is more evident ith oollenied jute at lo needling density and lo penetration. Woolleniation of jute in the fabric form improves both recovery against repeated loading and abrasion resistance considerabl~ Keyords: Abrasion resistance. Dynamic loading. Floor coverings. Jute. Needle-punched fabrics. Non-ovens The objective of the study as to make the needlepunched non-ovens from jute and oollenied jute fibres for use in floor coverings, underfelts, sports mats, substitutes for carpet and carpet tiles, etc. Such fabrics are believed to increase greatly the ear life and comfort factors of the products. Increase in ear life and comfort depends upon several factors, the most obvious being the ability to absorb energy applied by foot alking, i.e. stress applied, and providing a cushioning layer hich covers any irregularities in the floor surface so as to reduce stress and enhance the ability to resist abrasion and heat retention, etc. To investigate these effects, dynamic loading and abrasion resistance of needle-punched non-ovens ere considered in the study. Experimental Procedure Preparation of needle-punched non-ovens- To obtain fabrics of varying ranges in properties a change in the structure of the fabrics as made by taking various area densities of ebs ( g/rn'') both from jute and oollenied jute l fibres using different reinforcing materials, such as jute hessian (54 ends x 48 picks/drn glm 2), cotton bandage cloth (120 ends x 88 picks/drn=- 40 g/m '), cotton gauge cloth (60 ends x 50 picks/drn-. 30 g/rn ') and polyethylene film (47 g/rn ') at the base or centre of the eb. The eb is generally a random-laid one and, together ith the reinforcing material, as bonded by needle-punching ith varying needling parameters (needling density, needles/cm/; and needle penetration, mm). Dynamic loading- A WIRA dynamic loading machine, hich simulates the compression caused by a person alking on a carpet, as used to produce compression impacts on the needle-punched nonovens. Thickness of the samples at 20 g/cm ' pressure as measured at to places beteen the to longitudinal extremities of the boundary of the area to be compressed. The thicknesses of the samples in to places ere re-measured as before immediately after impacts ere made, the chosen totals for jute nonovens being 25, 50, 100, 150,200 and 250, and for oolleniedjute non-ovens, 25, 50, 100, 150,200,250 and 300. The maximum numbers of impacts for jute non-ovens and oollenied jute non-ovens ere selected on the basis of the maximum thickness loss. Abrasion resistance- Depth abrasion resistance of needle-punched non-ovens as measured by using a CSI Stoll quarter-master universal ear tester, Model CS-220. For measuring the number of required to remove a predetermined thickness of material from the sample, the electrical depth micrometer as used, hich automatically registers the end point. The fixed depth of abrasion as chosen in such a manner that in no instance as the reinforcing material in contact ith the abradant. This as true for all the samples. The test conditions ere: Abrasion load, g; 141

2 Abradant specifications. ater-proof silicon carbide paper C-320, XQ7; and Depth of abrasion, mm. Results and Discussion INDIAN J. TEXT. RES.. VOL. 10. DECEMBER Nt't'dl~/cm 2 Needle penl'tration, 14 3mm. Unlreall'd Dynamic Loading Effect of hatching oil emulsion treatment- Treatment of jute fibres ith batching oil reduces inter-fibre friction and improves pliability. A higher consolidation caused by improved peg formation results in less strain per fibre in the vertical column of pegs. and the loering of inter-fibre friction results in better recovery. Thus the per cent thickness loss reduces ith the treatment as may be seen from Fig.l. Effect of reinforcing material eight to eh eight ratio- When the ratio is high, i.e. eb eight is lo, the load per fibre ill be higher for a given number of impacts. Thus. as load per fibre increases the strain on fibre ill also increase, resulting in poorer recovery. Fig. 2 shos the recovery characteristics of fabrics in terms of thickness loss under different of impact. As the eb eight (for a constant reinforcing material eight) increases. the thickness loss reduces at first and then goes up again for very high eb eight. The reason for poorer recovery (high thickness loss) of nonovens made ith high eb eights (i.e. lo reinforcing material eight/eb eight ratio) is attributable to the fact that the recovery of fibres from deformation is hindered by the frictional resistance of the neighbouring fibres, this resistance increasing ith increase in the number of fibres in the batt. Thus, there appears to be an optimum ratio of reinforcing material eight to eb eight belo or above hich recovery characteristics under dynamic loading are likely to be poorer. Effect of type of reinforcing material- The effect of various reinforcing materials, such as jute hessian, bandage cloth, gauge cloth and polyethylene film, used at the base of eb on dynamic loading is shon in Fig. 3. The structural rigidity and openness of structure of the reinforcing material play an important role in the thickness loss on dynamic loading. Resistance to deformation of the vertical fibre column (peg) reduces ith the increased open and loose structure of the reinforcing material. Lateral displacement of the fibre columns (pegs) occurs at higher impacts of dynamic loading. hich causes reduction in the thickness of non-ovens. This phenomenon is especially true for loose and easily deformable scrims in hich the fibre pegs are not firmly secured ith the reinforcing material. A confirmation of this statement may be obtained from the tuft ithdraal force data obtained ith WIRA tuft ithdraal tensiometer(table I). The tuft ithdraal force is highest for jute hessian scrim and loest for gauge cloth. The thickness loss is, UJ Z ~ 50 u :I: I NO.OF IMPACTS Fig. I-Effect of treatment of jute fibres ith batching oil emulsion on dynamic loading of non-oven [Needle-punched fabric t, 454 g/m! including reinforcing jute hessian 300 g/m"] O~--'~~~-+--~~-L~ o NO. OF IMPACTS Fig. 2 - Effect of reinforcing material eight to eb eight ratio on dynamic loading of needle-punched jute fabric [Ratio- (1) (2) (3) (4) and (5) 1.82] ~ 70 ọ.. 60 W 550 :I: I- 300 Fig. 3- Effect Of various reinforcing materials used at the base of eb on dynamic ioading of non-ovens [( 1)Jute hessian, 300/m 2 ; (2) bandage cloth. 40 g/m2;(3) gauge cloth. 30 g/rrr': and (4) polyethylene film. 47 g/rn '] thus, highest for gauge cloth and decreases ith increase in tuft ithdraal force. With increase in the number of impacts. the punch holes of the polyethylene film increase in sie, resulting in poorer anchorage of the pegs. Effect of jabric type - Fig. 4 shos the influence of impact loading on three types of fabrics. The ability to recover from deformation is highest for jute non- 142

3 SENGUPTA et af.: NEEDLE-PUNCHED NON-WOVEN JUTE FLOOR COVERINGS: PART II Table I-Tuft Withdraal Force of Non-Wovens Having Different Reinforcing Materials [Test area. 4 mm x 2.5 mm; Wt of jute eb. 270 g/rrr'; Needles/em'. 36; Needle penetration mrn] Reinforcing material Jute hessian Cotton bandage cloth Cotton gauge cloth Polyethylene film Tuft ithdraal force g/mg oven oollenied in fabric form. This is folloed by fabric made from oollenied jute fibre hile the fabric made from ra jute fibre shos the poorest recovery. The oolleniation process imparts crimp to the fibres and in the case of sample oollenied in fabric form the jute yarns of the reinforcing scrim also develop crimp. Crimp improves resiliency and hence the ability to bounce back toard the original shape after the removal of load. Effect of position of reinforcing material in the eb- Fig. 4 shos that there is hardly any difference in the thickness loss hether the position of the reinforcing material is at the base or at the centre of the eb. These findings also correspond ith the average of cumulative thickness loss folloing the total number of impacts (Table 2). Effect of needling density- The results of the effect of needling density on recovery after fixed of dynamic loading are given in Table 3. At high needling density. particularly ith jute non-ovens, the reinforcing material at the base ruptures", Hence, the ability of the reinforcing material to secure the fibre pegs becomes less, and once the fibre pegs slip, they cannot recover on removal of load. In oollenied jute, ith less needling density, the fibre pegs are not very ell secured ith the reinforcing material; also, the number of pegs formed is less. This results in a higher thickness loss. Higher needling density is required to secure the pegs in the reinforcing material. Similar observations have been recorded by Hearle and Sultan? and Smith:' for fabrics ith higher loft. Effect of needle penetration- The vertical column (peg) height of the fibre strand as ell as the number of fibres forming the column is expected to be greater ith increase in the needle penetration since it is very much likely that each needle ill carry a greater number of fibres ith more barbs. As a result. thickness loss ould be expected to be less ith increase in needle penetration as shon in Figs 5(a) and (b). With ra jute, hoever, thickness loss increases after a certain level of needle penetration ;!- 0 -' 50 UJ x:: 40 ~ :x: ~ 30 Jute hessian used at the base of fabric. 300g / m2 Needle penetration. 14'3 mm 36 Needles/em l_-.., 2 o NO OF IMPACTS Fig. 4- Effect offabric type on dynamic loading of non-ovens:'( I) Jute. 909 g/m"; (2) oollenied jute, 908 g/m '; and (3) jute fabric oollenied in fabric form. 880 g/m ' Table 2 - Effect of Position of Reinforcing Material in the Web on Dynamic Loading [Needled fabric eight. 505 g/m? (including reinforcing jute hessian 300 g/rrr'): Needles/em'. 2 x 23 (to passes); Needle penetration mm] Position material At base At centre of reinforcing in the eb 3 Av. cumulative thickness loss ("0) for 250 impacts Table 3-- Effect of Needling Density on Dynamic Loading [Needle penetration, 14.3 mm; Jute hessian used at the base of all fabrics, 300 g/rn '] Needling density Jute Av. cumulative thickness loss, 00 (590 g.rn ') for 250 impacts ~60(~).... _. ~ 50 "...J, ~ " Needle penetr a tio n Z :<: ~ 11 1 mm u 30 14'3 mm... ::c 17 5 m m 20~ ~~ ~~~J o roo 200 (b) No. OF IMPACTS Woollenied jute (560 grrr') for 300 impacts Need Ie penetration Jr-X 11'1mm mm mm o Fig Effect of needle penetration on dynamic loading of needlepunched fabrics: (a) jute (t, 552 g, m 'j. and (b) oollenied jute (t, 545 gim') -- both including reinforcing jute hcssian (300 g m ') 143

4 INDIAN J. TEXT. RES. VOL. 10. DECEMBER 1985 oing to much damage to the reinforcing material as ell as to fi bres 1. Abrasion Resistance Effect of hatching oil emulsion treatment- The abrasion resistance results of non-ovens made of untreated jute fibres and jute treated ith oil emulsion are included-in Table 4. Here the abrasion resistance of emulsion-treated jute non-ovens is significantly higher than that of untreated jute non-ovens. This is due to the fact that the surface friction is expected to be less in emulsion-treated jute non-ovens. Moreover. the greater consolidation achieved in the emulsion treated jute", oing to its loer initial modulus, reduces the tendency of fibres being plucked from the matrix. Thus. both plucking and friction cutting are reduced hen the fibres are treated ith ajute batching oil emulsion before needle punching. resulting in a higher abrasion resistance. Effect of reinforcing material eight to eb eight ratio -- The resistance to abrasion is closely related to plucking and friction cutting of fibres. It has been visually observed that plucking is the most predominant cause offailure during the attritive action of the abradant, particularly hen the eb eight is high. This is to be expected, as, for the same needling density. a higher eb eight ill result in lesser anchorage of fibres into the scrim. Thus. it is observed that ith both oollenied jute and jute fabrics. an increase in the ratio of the reinforcing material to eb eight increases the abrasion resistance of the fabric (Fig.6). For similar eights. the fabrics made from oollenied jute demonstrate loer abrasion resistance at lo ratios of reinforcing material to eb eight. The increase in voluminosity of the eb due to crimp developed during oolleniation necessitates a higher degree of needling to reduce the tendency of plucking. Effect of type of reinforcing material ~ Once again, the type of reinforcing material has a decisive effect on the abrasion resistance of the reinforced non-ovens. Here also, the structural rigidity and openness of the structure! of reinforcing material play important roles. The results are given in Table 5. Here, among the three samples using fabric scrims, the one ith jute hessian shos the highest abrasion resistance folloed by bandage and gauge cloth respectively. The tendency of plucking of fibres is expected to be the least in jute hessian cloth reinforced non-oven since the fibre pegs are likely to be more firmly secured by the rigid structure of the reinforcing material. Fabrics in hich polyethylene film is used as scrim sho higher abrasion resistance than the fabric ith gauge cloth, but loer than the fabrics made ith hessian and bandage cloth scrims. Although pegs are secured in the polyethylene films through punching holes ith the needles during needling, the film yields very easily and the holes gro larger during abrasion. Effect of position of reinforcing material - The abrasion resistance results of non-ovens using reinforcing material at the base of eb as ell as at the centre of eb are given in Table 6. The abrasion resistance is significantly higher hen the reinforcing material is used at the centre of eb. It is expected that plucking of fibres ould be less due to better anchorage of fibres ith the reinforcing material hen it is used at the centre of eb. 7or ~ t. of reinforcing jute hesslan,300g/m 2 '" '"u 60 o-, u ~ 50 ~III III ~ 40 o '1,i 30 CD '" N. edl s/cm 2 jn. dl e p. ne trallon, 14 3mm O. plh of abrasion, mm 20~O--~0~.5--~1 ~O--~1~5--~2~ 0~~2~5~~3~ O~~35 REINFORCING MATERIAL l./ WE B i. RATIO Fig. 6- Effect of reinforcing material eight to eb eight ratio on abrasion resistance of non-ovens Table 5 - Effect of Different Reinforcing Materials Used at the Base of Web on Abrasion Resistance [Jute eb eight. 270 gm"; Needles-ern", 36;. Needle penetration mm; Depth of abrasion ( in.)] Table 4 Effect of Batching Oil Emulsion Treatment of Jute Fibres on Abrasion Resistance Reinforcing material [JU!~ hcssian used at base of eb. 300 g m ': Needles em". 55; Needle penetration mm; Depth of abrasion mm (10/1000 in.] Type of fibre in eb Abrasion resistance Untreated jute Jute treated ith oil emulsion Jute hessian (54 ends x 48 picksdm -330 g.rrr') Cotton bandage cloth ( 120 ends x 88 pieks!dm 40 g.m ') Cotton gauge cloth (60 ends x 50 picks 30 gm ') Polyethylene Iilm (47 grn ') Abrasion resistance

5 SENGUPTA et al.: NEEDLE-PUNCHED NON-WOVEN JUTE FLOOR COVERINGS: PART II Effect of fabric type- The abrasion resistances of jute non-oven, oollenied jute non-oven and jute non-oven oollenied in fabric form are given in Table 7. The abrasion resistance of non-oven oollenied in fabric form is significantly higher than that of jute and oollenied jute non-ovens. This may be due to the fact that the jute non-oven oollenied in fabric form yields easily oing to its crimp in the reinforcing fabric and fibres (developed in the oolleniation process of the hole jute nonoven fabric}. Thus, almost escaping the action of abrasion, this is analogous to hat happens ith a stretch fabric. Moreover, the surface of this nonoven becomes plain and smooth because of oolleniation in fabric form. Hence, the contact pressure per point during abrasion on this smooth surfaced non-oven is less, hich may be another factor contributing to the high resistance to abrasion. Effect of needling density- In oolleniedjute nonovens, initially at loer needling density the abrasion resistance is lo since plucking is expected to be more because of loose consolidation of fabric at lo needling density. With increase in needling density, plucking of fibres from the surface decreases, resulting in higher abrasion resistance as may be observed from Fig. 7. Excessive needling, hoever, damages the reinforcing material', hich then cannot hold the fibres firmly. The rupture of fibres during needling is comparatively much loer for oollenied jute fibres than for jute fibres'. But at higher needling density, the Table 6- Effect of Position of Reinforcing Material on Abrasion Resistance t. of reinforcing material. 300 g.m ': Needle-punched non-oven t, 505 gm ': Needles/ern", 2 x 23 (to passes through needling one); Depth of abrasion mm ( in.); Needle penetration mrn] Position material of reinforcing Jute hessian at base of eb Jute hessian at centre of eb Abrasion resistance Table 7- Effect of Fabric Type on Abrasion Resistance [Jute hessian used at the base of eb of all fabrics. 300 g/m:': Needles/ern", 36; Needle penetration mrn; Depth of abrasion mm (10/1000 in.)] Type of needle-punched fabric Jute non-oven Woollenied jute non-oven Jute non-oven oollenied in fabric form Fabric t g/m? Abrasion resistance tearing and cutting of fibres along ith damage to the scrim increases the abrasion loss oing to plucking and hence, after an optimum needling density, the abrasion resistance comes don. In the case of jute non-ovens, an increase in needling density is seen to progressively reduce the abrasion resistance. It has been observed that both fibre shredding" and damage to reinforcing material are considerably higherl ith untreated jute non-ovens and these damages progressively increase ith increase in needling density. Thus, abrasion losses due to easy removal of short fibres and plucking of fibres caused because of progressive disintegration of the scrim' ith the increase in needling density are responsible for higher abrasion losses as the needling density is increased. Effect of needle penetration- The effect of needle penetration on abrasion resistance of jute and oollenied jute non-ovens is shon in Fig. 8. During abrasion of non-ovens, the plucking of fibres is greater at loer penetration. This is more so ith oollenied jute. Plucking of fibres reduces as needle penetration increases. It is obvious that a greater number of fibres is expected to be entangled and secured more firmly by the reinforcing material ith a high degree of needle penetration since the number of barbs increases ith increase in needle penetration. Figs 7 and 8 sho that except in the cases of lo needling density and lo needle penetration, the abrasion resistances of needle-punched fabrics made from oollenied jute fibres are higher than those of fabrics made from ra jute fibres. Several factors are responsible for this. Apart from loer fibre shredding and less extensive damage to reinforcing material, the oolleniation process increases extensibility and ork of rupture of a fibre. Abrasion being a series of u ~ <J") Vi a:: o qj a:: CD ~ III ~ v>v De-pth of abrasion, m m NE"e-dle- pe-ne"tration.14 3m 10 Re-inforcing Jute- he-ssian used as a base- of fabrics. 300g/m2, O~ ~ ~~ ~ -L ~ NEEDLESI cm 2 Fig. 7 - Effect of needling density on abrasion resistance of needlepunched fabrics: (I) jute (590 g/m"), and (2) oollenied jute (560 g/rn ') 145

6 INDIAN J. TEXT. RES. VOL. 10. DECEMBER 1985 III OJ u >- u 40 Jute u <{ 30 f-! :l If) cr:: Q If) <{ Cl: CD <{ a 36 Needles! cm2 Depth of abrasion, 0'254m m Needle- punched fabric t, 545 g! m 2 including jute hessian (300g! m 2) NE EDLE PENETRATION,mm Fig. 8- Effect of needle penetration on abrasion resistance of nonovens repeated application of stress. the capacity to absorb punishment hich is related to ork of rupture is enhanced oing to the process of oolleniation. Conclusions (1) Openness and rigidity of the structure of reinforcing material influence the recovery after dynamic loading and abrasion resistance. Closeness of structure and greater rigidity increase recovery after dynamic loading as ell as abrasion resistance. (2) Decrease in the reinforcing material eight to eb eight ratio generally reduces the thickness loss on dynamic loading. The abrasion resistance also follos a similar trend. (3) Jute non-ovens oollenied in fabric form sho higher abrasion resistance oing to greater yielding of the fabric as a hole during abrasion. (4) Plucking rather than friction cutting is the predominant mode of failure against abrasion. Plucking is more ith oollenied jute. at loer needling density and loer needle penetration. At higher levels of consolidation. fabrics made from oollenied jute exhibit higher abrasion resistance than ra jute fabrics oing to higher ork of rupture of the oollenied jute fibres. References I Sengupta A K. Sinha A K and Debnath C R, Indian J Texi Res, 10 (1985) Hearle J W S and Sultan M A I. J Text lnst, 59 (1968) Smith P A, in Needle-felted fabrics. edited by P Lennox-Kerr (Textile Trade Press, Manchester) 1972,66. 4 Sengupta A K. Sinha A K and Debnath CR. Indian J Text Res, 10 (1985)

pain" counted as "two," and so forth. The sum of point, the hour point, and so forth. These data are

pain counted as two, and so forth. The sum of point, the hour point, and so forth. These data are FURTHER STUDIES ON THE "PHARMACOLOGY" OF PLACEBO ADMINISTRATION 1 BY LOUIS LASAGNA, VICTOR G. LATIES, AND J. LAWRENCE DOHAN (From the Department of Medicine (Division of Clinical Pharmacology), and the