| STUDIES ON IMPARTING SOFTNESS TO COIR FIBRE / YARN |
| by I.R.Anto, PK.Ravi and U.S.Sarma, Proceedings of the International Workshops on Wet Processing
of Coir 9-9 Dec.1997, Aleppey
|
On examination of the table III the colour of the bleached and softened vycome yarn is slightly more yellowish than the bleached but not softened ionatural vycome coir yarn. The percentage elongation at break shows an increase for softened and bleached coir yarn in comparison to natural coir yarn whereas the breaking load decreases.
In order to achieve softened coir yarn with slight changes in the brightness of its natural colour the vycome coir yarn treated with NaOH solution in concentrations of 10%, 20%, and 50% on the weight of the material for 30o at a temp of 60-70o C keeping a ml ratio 1:10. It was then washed thoroughly in water and neutralized with 0.1% sulphuric acid and again washed and dried at room temp. The softened samples were bleached with hydrogen peroxide under hot process
The breaking load and EB results are detailed in Table IV |
| TABLE IV BREAKING LOAD AND EB% OF VYCOME COIR YARN SOFTENED & BLEACHED |
| |
| Sl. No
|
Type of Coir yarn
|
Breaking Load Kg.
|
E.B %
|
| 1
|
Natural vycome coir
yarn
|
15%
|
13.00
|
| 2
|
10% NaOH solution
|
9.50
|
6.66
|
| 3
|
20% NaOH solution
|
9.00
|
6.66
|
| 4
|
50% NaOH solution
|
8.75
|
10.83
|
|
| |
| BLEACHED (HOT PROCESS) |
| |
| 1
|
Natural vycome coir
yarn
|
14.00
|
8.00
|
| 2
|
10% NaOH solution
|
13.50
|
17.50
|
| 3
|
20% NaOH solution
|
10.50
|
11.66
|
| 4
|
50% NaOH solution
|
9.25
|
12.50
|
|
| |
| On examination of the softened coir yarn, it is seen that the there is not much difference in colour of the yarn softened and bleached with 50% (onw) caustic soda compared to the unsoftened and bleached coir materials. Since there is not much effect on the breaking load values also, it is inferred that the treatment of caustic soda @ 50% on the weight of material and subsequent bleaching would yield softened coir yarn of comparable brightness and breaking load to that of natural coir yarn. |
| |
| Treatment with Vegetable (castor) oil |
| Attempts were made to soften the coir fibre using vegetable oil-water emulsion as per the following receipe. |
Ingredients A B
Vegetable oil. g 40 40
Water, ml 204 204
Ultra von JU.ml 12 12
Urea.g -- 48 |
| |
Both the emulsions were made up to 1000 ml. And divided into two equal parts of 500 ml. each. The halves of receipe-A were sprayed uniformly on 6kg. each of cleaned DF fibre treated with coirret and kept under piled conditions for 22 hours and 44 hours respectively.
The same experiment was conducted under similar conditions with the receipe B where urea was also incorporated. A control was also prepared by spraying 1000 ml. of water on 12 kg.of same fibre and divided into two equal halves and kept for 22 hours respectively in piled conditions.
The parallelised fibre were placed in baskets of motorised ratt for commencing spinning by three women spinners simultaneously. |
| The following parameters were recorded while spinning |
| Quality of coir fibre used for spinning |
| Texture and pliability |
| Production in metre per hour |
| Number of breakages and spinning defects occurred. |
| The yarn spun from the treated and control were also examined for runnage, scourge, breaking load, twist per foot and elongation at break. All the results are recorded in Table V |
| |
| Table V: Characteristics of coir yarn spun from vegetable oil treated fibres. |
| |
| Sl.No
|
Type of coir fibre used for
spinning
|
Qty.produced in m/h
|
Bo.of breakages
|
Spinning defects
|
Texture in terms of point
|
Pliability in terms of point
|
Scorage
|
Runnage
|
Twist per ft.
|
Breaking load /kg.
|
EB%
|
| 1
|
Coirret treated DF fibre sprayed
with water and kept for 22 hrs.(control)
|
262
|
4
|
12
|
10
|
10
|
12
|
232.5
|
22
|
25
|
30
|
| 2
|
-do-
sprayed with vegetable oil
(22 hrs)
|
266
|
3
|
8
|
13
|
13
|
11
|
181.8
|
20
|
22.2
|
38
|
| 3
|
-do-
sprayed with vegetable oil &
Urea (22hrs)
|
284
|
2
|
4
|
14
|
13
|
12
|
277.7
|
22
|
20.7
|
39
|
| 4
|
-do-
Sprayed with water and kept for 44 hrs
(control)
|
250
|
3
|
4
|
10
|
10
|
11
|
215
|
22
|
20.5
|
28.7
|
| 5
|
-do-
Sprayed with vegetable oil
44 hrs.
|
306
|
2
|
2
|
13
|
13
|
11
|
208.3
|
20
|
20.4
|
27.0
|
| 6
|
-do-
Sprayed with vegetable oil &
Urea(44 hrs)
|
318
|
1
|
3
|
13
|
13
|
12
|
222.2
|
20
|
22.0
|
33.0
|
|
| |
| On examination of the table V the following observations are made. |
| 1. The quantity of coir yarn spun per hour is more for the treated ones than the control. More output for vegetable oil-uses treated DF fibre than one treated with vegetable oil only for both fibres piled for 22 hrs and 44 hrs respectively. |
| 2. The vegetable oil-urea treated yarn showed less spinning defects and breakages during spinning than the other two. The control fared inferior to both the treated fibres. |
| 3. The runnage is highest for vegetable oil-urea combination and vegetable oil treated one fared better than control |
| 4. The scorage and twist are more or less the same for all the six varieties of yarn. |
| 5. The texture and pliability was improved by 30% compared to control |
| 6. All the spinners experienced that the fibres treated with vegetable oil and vegetable oil-urea combination were soft to touch easy to draw the fibres from the basket and release and regulate the feeding with no pinching of hand by the fibres especially the fibres treated with vegetable oil-urea combination |
| 7. Hairiness is less in coir yarn from treated coir fibres |
| 8. The breaking strength is slightly less for yarns from treated fibres piled for 22 hrs. whereas it is slightly more for yarns from treated fibres piled for 44 hrs compared to the control p;iled for 22 hrs and 44 hrs.respectively. |
| |
| RESULTS AND DISCUSSIONS |
| The coir fibre/yarn were treated with a number of textile softeners for imparting a soft and supple feel to the material in simple process. The softness achieved on coir fibre/yarn is measured visually and by the feel of the hand on touch, since no instrument is available to measure the degree of softness imparted to a coir fibre/yarn. A “Flexural Rigidity Tester” was designed and developed at CCRI based upon standard loop method. This method suits beat for this highly heterogeneous had fibre. It is made use of measuring the relative degree of softness imparted to coir fibre by different processing chemicals. The coir fibres were selected at random and converted into rings by winding them around a glass/PVC tube and allowed to set for 12 hours. The ring is then placed in the instrument and a constant load is applied on the bottom of the ring and the deformation is measured. The flexural rigidity which is a characteristic for estimating the degree of softness is calculated with the help of the following formula. |
Flexural Rigidity (Gf) = 0.0047 mg (2 Πr)2 Cos ¯
Tan ¯
Where mg. = weight of load applied
r = radius of the ring
d= deformation of lower end of ring
¯= 493 d
2 Πr |
| The table VI shows the flexural rigidity and percentage improvement in softness obtained with coir fibres treated with different softeners. |
| |
| TABLE VI - FLEXURAL RIGIDITY AND PERCENTAGE IMPROVEMENT IN SOFTNESS OF COIR FIBRE |
| |
| Batch No
|
Sample
|
Status
|
Flexural
Rigidity G (f)-gcm2
|
Percentage of Softening
|
| 1
|
1) Retted coir fibre
2) Treated with sodium
hydroxide |
Control
Softened |
1.1642
0.8772 |
--
24.65 |
| II
|
1) Retted coir fibre
2) Treated with
Bactosol
CE
3) Treated with x500 |
Control
Softened
Not softened
|
1.826
1-705
2.150 |
--
6.620
17.741(-) |
| III
|
1) Retted coir fibre
2)
Treated with Alfalina-CS-100
3) Treated with Silcosoft 100 |
Control
Softened
Softened
|
1.630
1.314
1.481 |
19.32
9.14 |
| IV
|
1) Retted fibre
2)
Treated with Sursoft-500 |
Control
Not Softened |
1.602
1.924 |
--
20.09(-) |
| V
|
1) Retted coir fibre
2)
Treated with sodium hydroxide |
Control
Softened |
1.082
0.906
|
--
16.26 |
| VI
|
1)Retted Coir fibre
2)Treated with Alfaline-CS-100 |
Control
Softened |
0.952
0.946 |
--
0.63 |
| VII
|
1) Retted Coir fibre
2) Treated with 20
% sodium
hydroxide |
Control
Softened |
1.630
1.302 |
--
20.12 |
| VIII
|
1) Retted Coir fibre
2) Treated with x500
Mixture
|
Control
Not Softned |
1.377
1.685 |
--
22.36(-) |
|
| |
| CONCLUSION |
It is seen that the caustic soda performed best in imparting softness to coir fibre/yarn, even though it leads to a huge quantity of toxic effluent. The cost of treatment is low.
The micro emulsions of amino silicone softeners imparted a very silky and soft feel to coir fibre/yarn. However the cost of treatment is exorbitantly high.
The vegetable oil-urea combination treatment to DF fibre pretreated with coirret offers better yarn which yielded more output, possessed uniform texture in continuous length, easy to draw the fibres from the basket, release and regulate the feeding with no pinching to the hand. The subsequent bleaching and dyeing operations did not required any additional chemicals or process such as scouring is an advantage to exploit the process commercially as the cost of treatment is very low.
It is difficult to recommend a single recipe for softening the coir. Depending upon the end uses the process has to be selected. It is desirable to process the coir fibre/yarn using caustic soda followed by a treatment of micro emulsions of amino silicone softeners for achieving soft and supple feel to coir materials for highly valuable products. For common usage, application of vegetable oil-water emulsion on coir fibre is desirable. |
| |
| ACKNOWLEDGEMENT |
| The authors are grateful to FAO for providing fund to conduct the studies. Thanks are also due to Coir Board for providing facilitates and encouragement and also for their kind permission to publish this paper |
| BIBLIOGRAPHY |
1.JV.Bhat et al, Coir, Oct.1973, Vol.XVIII PP 21
2.J.T.Marsh,”An Introduction to Textile Finishing”5th edn., Chapman & Hall Ltd, London. 1953,522-535
3.WB.Achwal, Colourage, 1992, PP, 91-96.
4.V.A.Shenai, Chemical Weekly, March 1, 1994 PP 125-132 Chemical Abstracts:-
5.Action of sodium Hydroxide on Cellulose, J.S.Rumbold CA, Vol 24, 1930, 1971
6.Gelatinizing and softening Agents, chemische Werke Huls Gm, bH, CA 51, 1957,
11763
7.Softening agents, Farbwek Hocehst, L Corthner, A-Siebert and L Mack, CA 51,
1957, 11763
8.Softening agents for textile fibre, A.S.Denis CA 25, 1931,827
9.Softening Cellulosic Materials, SOC POOR LA FABRUATION DE LA SOLE
RHODLASETA, CA 25, 1931, 5287
10.Softening Vegetable yarn or Fibres, CARL HAMEL AG Ger, 536, 080, CA 25,
1931, 5579
11.Solvent, softening and Gelatinizing Agent for cellulose, DEUTSCHE
HYDRSERWEREKE AG, CA 26 1932, 2316
12.Softening Agent for Rayon, IG FARBENING AGE Glietenberg, CA, 26, 1932,4965
13.Gelatinizing and Softening Agent, R Muller & Hubke, CA 27, 1933, 2577
14.Softening textile materials such as Rayon, G. Kalischer, J. Musslcin and R. Muller,
CA 29, 1935, 622. |
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