Indian Journal of Fibre & Textile ResearchVol. 17, September 1992, pp.136-143

Effects of alkali on linen (Linum usitatissimumiK K Goswami

R&D Department, Jayashree Textiles, Rishra 712 249, Indiaand

A K MukherjeeApplied Chemistry Division, Indian Jute Industries' Research Association, 17, Taratola Road,

Calcutta 700 088, India

Received 22 April 1991; revised received 8 January 1992; accepted 5 May 1992

The effects of sodium hydroxide and sodium carbonate on the properties of linen such as weight loss,reflectance, tensile strength and absorbency have been studied by varying the alkali concentration along withthe variation in temperature and duration of reaction to optimize the scouring conditions prior to bleachingand dyeing/finishing. Experiments were specially designed for finding out correlation between variablefactors and responses. The correlationship between weight loss and reflectance has also been studied. Thestudy suggests the existence of fair correlations between temperature/duration of reaction/concentrationand weight loss/reflectance, whereas tensile strength and absorbency remain poorly influenced. Use ofsodium carbonate (lOg/I) alone for 30 min at near boil (95°C) along with surfactant (2 g/I) is recommended as itresults in saving in chemical cost without any adverse effect on quality.

Keywords: Fluidity, Linen, Linum usitatissimum, Reflectance, Scouring, Weight loss

IntroductionLinen (Linum usitatissimumi holds a specific place

as it has properties very different than those of otherfibres. In particular, the highly oriented andcrystalline structure of the molecules gives the fibrehigh tenacity and resistance to elongation,considerable lustre and rapid moisture absorptionand desorption properties. These properties have ledto the developmen t of a wide variety of characteristictextiles ranging from apparel fabric throughhousehold textiles and furnishings to heavy industrialfabrics and artists' canvas.

Like cotton, flax fibre consists chiefly of cellulose.'.It is distinguished from cotton in that its mainconstituents are associated with intercellularsubstances like lignins, pectins, fat, wax andhemi-cellulose. For comparison, the constituents ofcotton and flax as reported- are given in Table I.

For years, there has been a rising demand for linenouter-wear garments. This trend may be attributednot only to high image of linen or the risingappreciation of natural fibres but also to its positivephysiological properties:'. Hence, improvement inthe quality of product or cost reduction in processwould benefit the industry producing linen textiles.The present investigation aims at studying the effectsof alkali on linen with a view to obtain optimum

process condition for scouring linen textiles prior tobleaching and dyeing/finishing.

2 Materials and Methods

2.1 Materials

2.1.1 FabricGrey linen fabric (66 tex x 66 tex, plain weave, 220

g/rn", ISO ends and 158 picks per dm) was used.

2.1.2 ChemicalsSodium carbonate, sodium hydroxide, surfactant

and hydrochloric acid, all of A.R. grade, were used.

Table I-Constituents of cotton and flax

Constituent Unretted flax Retted flax Cotton%

Cellulose 56.5 64.1 82.7Hemi-cellulose 15.4 16.7 6.7Pectin 2.5 1.8Lignin 2.5 2.0Fat and wax 1.3 1.5 0.6Water solubles 10.5 3.9 1.0Moisture 10.0 10.0 10.0

2.2 Methods

GOSWAMI & MUKHERJEE: EFFECfS OF ALKAli ON UNEN

2.2.1 ScouringThe fabric sample along with alkali solution was

placed inside a reaction vessel and heated over athermostatically-controlled heater equipped with astirrer. The material-to-liquor ratio was maintainedat I :30. The pH of the solution was monitored by acalibrated digital pH meter. After the completion ofreaction, the sample was washed, neutralized, driedand conditioned at 65 ± 2% RH and 27 ± 2°e.

2.2.2 Determination of Weight LossThe change in fabric weight (oven dry basis) was

determined using the following equation:

Weight loss (%) =Original weight - Final weight

x 100Original weight

2.2.3 Measurement of ReflectanceThe reflectance of samples was measured by colour

computer (JAY PAK 4800 II computer colourprediction system of MIL TON ROY) under identicalconditions. The representative values of yellownessindex (YI), whiteness index (WI) and redness index(RI) are reported.

2.2.4 Determination of Tensile StrengthThe tensile strength of samples was determined as

per IS 1969-1985.

137

2.2.5 Measurement of AbsorbencyIt was measured as per the method outlined in

literature". Lower seconds indicate that the materialis more absorbent.

2.2.6 Measurement of pHThe pH of alkali solutions under various process

conditions at different time intervals was measured atroom temperature and the values are given in Table2.

2.3 Response CodesWeight loss(%), Yellowness index (ASTM),

Whiteness index (Hunter), Redness index, Warptensile strength (Njmrn), Weft tensile strength(Nrmrn) and absorbency (seconds) for 1st set ofexperiment (sodium carbonate reaction) and 2nd setof experiment (sodium hydroxide reaction) have beencoded as Yl.I, Y2.1, Y3.1, Y4.1, Y5.1, Y6.1, Y7.1 andY1.2, Y2.2, Y3.2, Y4.2, Y5.2, Y6.2, Y7.2 respectivelyand are reported in Tables 3 and 4.

3 Results and DiscussionCritical relationship establishment by statistical

technique: This exercise aims at establishingrelationship between process variables, viz.temperature (t), duration of reaction (d),concentration of alkali (c), and responses coded in 2.3.The relationships between variables and variousresponses are shown in Fig.l.

Table 2--pH profile (at room temp .. 32°C) of alkali solutions under various process conditions at different time intervals

Sl. Process condition pH at time interval (min)No.

I

23

4567

89

10II1213141516

Alkalitype

NazCo,

NaOH

240Conc. Temp. 0 30 60 120g/I 'C

5 30 9.91 9.83 9.64 9.5210 30 9.98 9.78 9.73 9.6915 30 10.17 9.94 9.91 9.795 95 9.86 9.51 9.40 9.31

10 95 9.95 9.56 9.45 9.3015 95 10.11 9.60 9.44 9.380.5 30 10.71 10.58 10.40 10.101.0 30 10.98 10.90 10.85 10.802.0 30 11.17 11.11 11.07 10.964.0 30 11.42 11.28 11.20 11.216.0 30 11.60 11.60 11.49 11.400.5 95 10.60 10.10 9.70 9.401.0 95 10.90 10.45 10.38 10.162.0 95 11.10 10.85 10.71 10.654.0 95 11.46 11.11 11.03 10.966.0 95 11.62 11.14 11.14 11.05

9.489.619.70

9.6510.0010.9011.1711.35

138 INDIAN J. FIBRE TEXT. RES., SEPTEMBER 1992

SI.No.

I23456789

101112131415161718192021222324252627282930GreycontrolWater-treatedcontrol-do--do-

Table 3--Experimental conditions and observed responses for sodium carbonate treatment

Temp.·C(t)

Duration Concentration Weight lossmm gJI %(d) (c) (YJ.I)

303030303030303030303030606060606060~6060959595959595959595

303030606060

120120120240240240

303030606060

120120120303030606060

120120120

510155

10155

10155

10155

10155

10155

10155

10155

10155

1015

3.834.825.374.115.265.994.885.936.575.536.447.785.636.286.596.286.867.066.857.247.489.45

10.1010.6810.3112.8413.10II. \013.4413.82

Yellownessindex

(ASTM)(Y2.1)

41.3641.2841.2040.8440.5439.7440.0741.8341.4942.4941.2642.1238.9438.1939.4338.7439.3639.6338.9837.5438.3336.5934.6736.6634.6936.9235.4935.9136.0834.0646.52

42.74

39.8839.03

Whitenessindex

(Hunter)(Y3.1)

15.4215.5815.3115.8316.3116.8716.7614.9814.9014.3115.5116.2317.3018.3116.9917.6917.3816.8817.2418.9917.8820.6222.0419.3421.8519.6920.6520.5420.8022.4411.43

12.46

15.0215.12

Rednessindex(Y4.1)

9.849.829.519.709.769.429.619.859.429.869.76

10.278.869.109.089.109.419.279.899.028.899.348.378.398.378.798.108.458.818.16

11.33

Warptensile

strengthNjrnm(Y5.l)

15.0414.6015.3216.9116.7616.9916.8915.0815.6215.9716.2416.5814.9516.2615.6915.5015.7415.1114.3414.4416.8517.4016.4014.8814.3615.4813.0014.8814.6615.3818.37

11.17 14.76

Wefttensile

strengthNzmm(Y6.1)

18.8917.5618.5218.3617.8417.3316.9418.0217.8018.1518.8816.4017.0218.6820.6019.6318.8017.8218.3518.1117.6418.1019.4216.9319.1318.9014.5419.0219.2717.7320.06

16.64

16.8116.98

Absorbencys

(Y7.1)

21.5610.1115.2216.0010.5612.447.55

12.0013.4411.119.88

13.5570.7738.4427.0057.7713.0030.8835.2233.2220.0032.4447.0033.3328.5570.2218.7717.11

102.8845.56

2484.00

97.00

80.0070.00

30 30 1.27

2.313.65

Experiment nos 10-12 and control (Table 3) and16-20 and 51-54 (Table 4) have been excluded fromthe above exercise. For the application of statisticaltechnique, standard literature" was referred to andthe help of computer was taken. However, thestandard forms of correlation equations are asfollows:

9595

30120

Y=~+~~+~~+~~+~~+~~+~~+ B7X1X2 + B8X1X3 + B9X2X3 •••••• Quadratic...(2)

9.629.56

15.6315.53

where bo is the intercept; BI B9, thecoefficients; and XI, X2 and X3 represent t, d & crespectively.

The relationship details covering multiplecoefficient of correlation (R), coefficient ofdetermination (R2) and linear equation for Yl to Y4are summarized in Tables 5 and 6. It is observed thatfactors t, d & c have direct bearing on weight loss andreflectance (particularly YI & WI). The coefficients ofcorrelation obtained clearly show that the variables t,d & c influence the weight loss, YI and WI to asignificant extent (R > 0.9) and RI to a considerable

GOSWAMI &: MUKHERJEE: EFFECTS OF AlXAIJ ON UNEN 139

Table ~Experimental conditions and observed responses for sodium hydroxide treatmentSl. Temp. Duration Concentration Weight loss Yellowness Whiteness Redness Warp Weft AbsorbencyNo. 'C nun gfl 0/0 index index index tensile tensile' s

(I) (<I) (c) (YI.2) (ASTM) (Hunter) (Y4.2) strength strength (Y7.2)(Y2.2) (Y3.2) Nrmm N/mm

(Y5.2) (Y6.2)I 30 30 0.50 3.13 40.47 15.21 9.10 15.08 16.99 38.\02 30 30 1.00 3.68 40.78 15.07 9.32 16.37 14.84 19.003 30 30 2.00 3.90 38.99 16.97 9.37 15.50 20.00 21.634 30 30 4.00 4.64 41.31 14.85 9.82 16.00 17.89 20.005 30 30 6.00 5.44 40.76 15.24 9.66 16.30 21.01 21.186 30 60 0.50 :U8 41.87 14.26 9.73 14.00 15.68 32.547 30 60 1.00 4.00 42.76 13.30 9.70 15.33 16.77 14.368 30 60 2.00 4.36 40.35 15.98 9.93 15.63 19.70 25.459 30 60 4.00 5.10 40.51 15.32 9.35 16.01 17.26 26.27

10 30 60 6.00 5.69 40.78 15.25 9.66 15.70 19.62 22.27II 30 120 0.50 3.77 42.24 13.98 9.80 12.24 14.89 28.8112 30 120 1.00 4.42 41.28 14.60 9.42 14.81 16.87 12.54\3 30 120 2.00 4.90 39.79 16.\0 9.41 16.44 21.00 32.5414 30 120 4.00 6.27 39.37 16.37 9.22 13.00 18.42 31.2715 30 120 6.00 6.80 39.15 16.67 9.34 15.14 19.20 31.8116 30 240 0.50 4.13 41.53 14.70 9.81 15.16 16.26 23.2717 30 240 1.00 4.73 42.88 13.04 9.48 14.20 16.64 12.8118 30 240 2.00 5.55 39.20 16.69 9.28 14.53 19.98 21.2719 30 240 4.00 6.42 39.77 16.38 9.69 15.41 17.28 18.9020 30 240 6.00 6.94 39.97 15.87 9.38 16.34 17.06 18.7221 60 30 0.50 4.65 39.93 15.97 9.40 14.18 18.01 19.6322 60 30 1.00 5.07 40.56 15.21 9.32 14.70 18.99 12.7223 60 30 2.00 5.91 38.65 16.84 8.89 15.14 20.32 34.3624 60 30 4.00 7.17 39.49 16.23 9.14 15.32 16.91 20.9025 60 30 6.00 8.24 39.24 16.44 9.18 14.19 14.78 15.7226 60 60 0.50 4.91 40.77 15.\0 9.37 15.17 18.71 18.6Y27 60 60 1.00 5.81 40.71 14.86 9.08 14.29 15.43 17.8128 60 60 2.00 6.77 37.77 17.97 8.99 15.52 19.14 28.0029 60 60 4.00 8.04 38.49 16.84 8.57 15.18 17.56 18.5430 60 60 6.00 9.17 39.56 15.93 8.87 14.82 15.29 13.7231 60 120 0.50 5.39 40.02 15.49 8.95 15.89 17.80 31.1032 60 120 1.00 6.25 39.00 16.50 8.79 15.48 15.99 13.6333 60 120 2.00 7.73 38.55 17.08 9.11 LU8 17.32 20.7234 60 120 4.00 9.20 38.19 17.11 8.55 15.24 17.12 20.7235 60 120 6.00 10.10 38.36 17.19 8.82 14.65 17.14 15.9036 95 30 0.50 6.99 39.17 16.49 8.86 14.14 15.05 24.2737 95 30 1.00 8.37 38.07 16.60 8.04 15.67 17.73 33.2738 95 30 2.00 11.08 36.57 19.03 8.60 14.58 19.21 27.1839 95 30 4.00 14.20 36.00 19.87 8.70 14.29 21.24 21.9040 95 30 6.00 15.42 36.14 19.22 8.50 15.08 22.46 24.2741 95 60 0.50 7.46 38.61 18.08 9.89 15.78 18.04 19.1842 95 60 1.00 9.75 36.92 17.84 7.85 16.26 16.32 24.3643 95 60 2.00 12.64 38.02 17.19 8.45 14.75 18.90 26.3644 95 60 4.00 15.94 37.04 18.40 8.64 13.47 18.26 36.7245 95 60 6.00 17.03 36.46 18.79 8.48 13.02 15.56 20.8146 95 120 0.50 8.oi 37.55 17.66 8.41 15.19 16.66 33.2747 95 120 1.00 10.67 38.41 16.86 8.47 13.07 17.52 22.4548 95 120 2.00 14.31 38.28 17.17 8.74 13.48 16.21 29.4549 95 120 4.00 17.78 36.01 19.64 8.68 12.80 16.94 26.2750 95 120 6.00 20.34 35.17 20.18 8.28 13.55 14.68 14.4551 95 120 7.00 20.79 35.71 20.51 8.3052 95 120 8.00 21.21 35.36 20.74 8.17

~ 53 95 120 9.00 21.24 36.M 18.86 8.11I 54 95 120 10.00 21.51 36.52 19.49 8.36

140 INDIAN J. FIBRE TEXT. RES., SEPTEMBER 1992

22 No2C0320

NoOH

Fig. I--Effect of temperature and duration of reaction on weight loss, yellowness index, whiteness index and redness index at variousconcentrations of Na2CO] and NaOH [(0) 30°Cj30 rnin, (e) 30°Cj60 min. (D) 30°CjI20min, (- - -) 30°Cj24Omin, (.) 6O°Cj30rnin, (,6)

6O°Cj60 min. (.) 60T/120 min. (x) 95T/30 min. (<8) 95"Cj60 min, and (--) 95"Cj120 min]

Sl.No.

Responsecode

Table 5-Relationship between factor and response (1st experimental set)

Equation Coefficient for Regression equation against respective response code & equation orderlinear/quadratic '

R R2

YI.I Linear 0.95 0.90 YI.I = + (100.5503 x 10- 3) t+ (168.4656 x 10-4) d+ (157.3333 x 10- 3) c- 1.1039360.99 0.97

2 Y2.1 Linear 0.94 0.88 Y2.1=-(81O.4899x 10-4) 1-(470.3704 x 10-5) d-(\OO.()()()(} x 1O-5)c+43.80250.93 0.86

3 Y3.1 Linear 0.93 0.86 Y3.1= +(790.4637 x 1O-4)1+(419.5767x 10-5) d-(221.11 II x 1O-4)c+13.1 4880.92 0.85

4 Y4.1 Linear 0.87 0.76 Y4.1=-(173.8320x 10-4) 1-(174.6032 x 10-6) d-(324.4444 x 1O-4)c+10.532 00.85 0.72

R - Multiple coefficient of correlation; and R2 - Coefficient of determination.

Sl.No.

Responsecode

Table 6-Relationship between factor and response (2nd experimental set)

Equation Coefficient for Regression equation against respective response code & equation orderlinear/quadratic

R R2

Y1.2 Linear 0.93 0.86 Y1.2= (124.6861 x 10- 3) 1+ (203.3175 x 10-4) d+ (990.0053 x 10- 3) C - 3.69900.99 0.98

2 Y2.2 Linear 0.87 0.76 Y2.2 = - (534.7402 x 10-4) 1- (449.0476 x 10- 5) d- (292.5365 x 10-3) c+ 43.47190.91 0.82

3 Y3.2 Linear 0.84 0.70 Y3.2 = + (452.1837 x 10-4) 1+ (332.2222 x 10- 5) d+ (276.8964 x 10-3) c+ 12.83020.88 0.77

4 Y4.2 Linear 0.77 0.60 Y4.2= - (145.4068 x 10-4) 1- (162.0635 x 10- 5) d- (281.5171 x 10-4) c+ 10.11840.75 0.57

GOSWAMI & MUKHERJEE: EFfECT'S OF AlKAU ON liNEN 141

4276 •00.. 0.. o·or"U

E ,0

"'~ '00:~ 0

0Oroo• -0

c •..•0 0

~>• 00 0-

0 .=086 0 0.. 0 0> Y2·2,·Q-3574 00 0

0 3517Yl·]+1.1 95

0

1382 313 2034

extent (R> 0.77), whereas the tensile strength(R <0.45) and absorbency (R <0.56) remain poorlyinfluenced. Significant to considerablecorrelationships observed between weight loss andYI/WI/RI are shown in Fig.2. These findings suggestthe existence of safe scope for manipulation of factorsor independent variables (t. d & c) for controlling theresultant responses like weight loss, YI and WI whileusing sodium carbonate or sodium hydroxide.Scientific and methodical exploration of processcondition was thus attempted for optimization. Thesystem enables ease in prediction of responses too.With the increased weight loss the correspondingchange in YI/WI/RI is attributable to removal ofintercellular materials like water solubles (includesdirt, etc.), hemi-cellulose and undefined colouringmaterials. The poor correlationship of tensilestrength is presumably due to complicating factorslike shrinkage during wet treatment, the nature ofremoval of intercellular materials andnon-significant increase in fluidity" even at much

....uc

"'~111-

~N~ >~-..> r = 0 88

V21 = +0 6776Y1-1.o+1.37837

4183 •o 00 0

• oo

0 •••0

000

o •o

• 0o

3400~3~8-3------------~~

....uc

oo 0

o 8• 0°0• r = 0 87

.0 V31=+0662I.Yllo 000 + 12'8968

00

o 0 0°

o

149

383 1362

9·89 0 0 0 •o 0

•• 0•• 0"U o.c~ • •"'~t>c-"U..cr '=0.82 _0

810 Vl.l=-01519Yll+l0315.;>0

383 1382W~ighl Loss (Y 11) :,.

eoooo 00

higher weight loss as confirmed by loweralkali-solubility? (Table 7). The absorbency oflinenwas drastically changed just on water treatment as canbe seen from data for control experiment (Table 3).Further, scouring also· improves absorbency asconfirmed by other researchers. Saturation andnon-lineari ty of absorbency against the changed I. d& c are attributed to uneven elimination of waxy andallied intercellular materials. Experimental resultsreported in Table 8 confirm that the application of

Table 7-Weight loss vs. fluidity and alkali solubility

Expt Weight Cuprammonium AlkaliNo. loss fluidity (poises -I) solubility

% at 20·C %

Grey control 1.6 13.7I (Table 4) 3.13 2.0 13.350 (Table 4) 20.34 2.3 1.1

I (Table 3) 3.83 2.1 13.130 (Table 3) 13.82 1.9 3.8

• 2018 o• oo

oo

133 •313r---------------~20)4

903 ,,0. 0.•.....~ _, 0

'"

_ • .oClO·

o 0: c:; :0 ••c>- •• 0 '.0~- 0°0.0

cr

785r =068

·Y4·2 =-0 0809Y12+o 968&7

313 2('~'Wl'lghl loss(Vl 2),"'

Fig. 2--Scatterdiagram depicting the relationship ofweight loss (Y 1.1 & Y 1.2) with yellowness index (Y2.1 & Y2.2), whiteness index(Y3.1 & Y3.2) and redness index (Y4.1 & Y4.2)

142 INDIAN J. FffiRE TEXT. RES., SEYI'EMBER 1992

Table 8-Comparison of experimental results obtained from various feasible combinations for optimization

Expt Experimental Avg. ± Q 95%'No. condition

t/d/cdc2/S

Ratio(W1:Wt loss)Weight loss

%Whiteness

indexYellowness

index

I23456789

10II

Controlprocessconditiont - temperature in ·C; d - duration of reaction in min; CI - sodium carbonate in g/I; C2 - sodium hydroxide in g/I; and.f - Surfactant in g/1." Confidence interval.

95/30/5/Nil/Nil95/30/5/Nil/295/30/Nil/ I/Nil95/30/Nil/ I/295j30/Nil/ I. 5/Nil95/30/5/ I/Nil95/30/5/1/295/30/ 10/Nil/295/30/ 10/2/Nil95/30/10/2/295/120/l0/Nil/2

9.40±0.129.45±0.118.42±0.128.49±0.239.50±0.309.16±0.699.12±0.229.51 ±0.30

10.05±0.341O.06±0.1213.80±0.20

95/120/10/2/2 16.01 ±0.12

IS.II ±0.2219.62±0.3015.94±0.2016.62±0.32IS.62±0.4517.62±0.24IS.74±0.3520.05±0.47IS.79±0.1919.69±0.2620.87±0.50

37.SI ±0.2037.02±O.304O.03±0.3239.66±0.3635.0S±0.473S.03±O.2437.11 ±O.3435.0S±O.4737.19±0.2036.46±O.2234.4S±O.50

1.93

2.081.891.961.961.92

2.052.221.871.961.51

21.59±0.23 34.60±0.50 1.35

Table 9-Relationship between whiteness index and weight loss

Targeted Predicted

Whiteness Weightindex loss. %

Whiteness index Weight loss. %

Y3.1 Y3.2 YI.I YI.2

10.72 18.9220.010.0 19.52 17.20

surfactant improves the absorbency level (around 1.5sfor experiment no.8). The relationships betweenpredicted weight loss/Wl and targeted weightloss/Wl (Table 9) conform to [he actual data. Thisauthenticates the efficacy of statistical tool andsuggests that sodium carbonate alone is moreefficient. Ratio maximization technique (Table 8)suggets that condition for expt. no. 8 is ideal; however,maximum whiteness could be attained under thecondition for expt. no. I I. The whiteness for expt.no. I I is insignificantly different from that for controlinternational process, whereas the weight loss issignificantly less.

4 Conclusions4.1 Technique of correlating factors like

temperature, duration of reaction and concentrationof alkali with responses like weight loss, YI. WI and RIis established.

4.2 Fair prediction of weight loss, YI and WI isfeasible, whereas tensile strength and absorbencyremain unpredictable.

4.3 Weight loss is highly correlated to YI and WI.Hence, in linen, weight loss itself may be consideredthe barometer for quality control.

4.4 Use of sodium carbonate alone as alkali alongwith surfactant is justified as per the novel techniqueof ratio maximization.

4.5 The optimum scouring process condition forlinen has been worked out as 95/30/IO/Nil/2, i.e.sodium carbonate (lOg/I), sodium hydroxide (Nil),surfactant (2 g/I) at near boil (95°C) for 30 min, whichis economical without any adverse effect on quality:

4.6 Discontinuation of use of caustic soda inexisting mixed alkali scour process is advised whichwill result in saving in chemical cost without anyadverse effect on quality.

AckoowledgementThe authors gratefully acknowledge the support

received from MrG L Moondra, Mr AN Choudharyand Mr H C Daga of Mjs Jayashree Textiles and Dr SR Ranganathan, former Director, IlIRA. They arealso thankful to Mr N C Pan and Mr A Chakravortyfor valuable assistance.

ReferencesI Angstmann D. Pretreatment ofhardfibres (BASF). July 1987.

2.2 Trotman E R. Textiles scouring & bleaching (Griffin. London).

1965. 22.

GQSWAMI & MUKHERJEE: EFFECTS OF ALKAU ON UNEN 143

3 Hamilton I T, Textiles. IS (1986) 30.4 Trivedi S S & Vaidya A A, Textile auxiliaries and finishing

chemicals (ATlRA, Ahmedabad), 1975, 156.5 Charles R Hicks, Fundamental concepts in the design of

experiments. 3rdedn (Holt, Rinehart and Winston, New York),1982, 165.

6 British standards specifications BS:3090, Method for

determination of cuprammonium fluidity of linen (BritishStandards Institution, London), 1959.

7 Indian standards specifications IS:4972, Method fordetermination of alkali solubility (Indian Standards Institution,New Delhi), 1968.

8 Vander Beke R, Scouring and bleaching of cellulosic materials(Centexbel, Brussels, Belgium), 1982, 3.