Simultaneous Dyeing and Fire-retardant Finishing of Jute Fabric Using an Acid Dye and Selective F-R

Simultaneous Dyeing and Fire-retardant Finishing of Jute Fabric Using an Acid Dye and Selective F-R Finishing Chemicals A K Samanta 1, Kashmita Bhattacharya2 University of Calcutta, Dept. of Jute and Fibre Technology ijtaksamanta@hotmail.com1, kashmita.bh@gmail.com2 Abstract Conventionally decorative quality jute furnishing fabrics are dyed and then chemically finished as per functional requirement by two step sequential process. An attempt has been made to combine these two step process into a single step process by developing simultaneous (combined) dyeing (acid dyeing) and fire-retardant finishing process in one step by pad-dry-cure method. H2O2 bleached jute fabric has been dyed with selective acid dyes (1%) and chemically finished with different concentrations of Ortho-Phosphoric Acid, Ammonium sulphamate and Di-ammonium phosphate for fire retardant finish, by both conventional two-step sequential process and single-step simultaneous process by pad-dry-cure technique. One-step simultaneous application of Ortho-Phosphoric Acid, Ammonium sulphamate and Di-ammonium phosphate along with 1% acid dye on H2O2 bleached jute fabric shows an improvement in the surface colour strength compared to that of ordinary H2O2 bleached jute fabric when separately dyed with 1% acid dye and subsequently finished the same fire retardant agent. Both the process two stage conventional acid dyeing and fire-retardant finish and single stage simultaneous pad-dry-cure process of acid dyeing and fire retardant finish, show at par fire retardant performance. This single bath technique thus offers advantages of reduction in processing cost, saving in energy and reduction in time of treatments as well as better colour value and at per fire retardant performance.

Keywords Acid Dye; Ammonium Sulphamate; Dyeing; Di-ammonium Phosphate; Fire Retardant Finishing; Jute Fabric; Ortho-phosphoric Acid; Simultaneous Dyeing and Finishing

Introduction Jute and jute based fabrics are gaining popularity as different decorative products for home textiles (furnishing , upholstery floor mats, shopping bags etc.) in the domestic and international field due to its eco-friendliness and biodegradability character. Chemically, jute is lignocellulosic and physically it is a coarser variety of natural bast fibre which is agro renewable. India’s major production of jute goods is limited to conventional jute yarn and fabric products used in either packaging or carpet backing etc.; however there is an increasing demand of dyed variety of decorative jute fabrics. From market survey and need assessment made by this department, it is revealed that grey/bleached and dyed jute fabrics having requisite fire-retardant have good market demand as coarser variety of fire retardant textiles for protection against fire in variety of end uses like car upholstery/accessories, kitchen apron and gloves, furnishing/curtains and floor coverings of public hall/theatre, fire-retardant Tenting and as brattice clothes in mines etc. For these applications, production of jute decorative fabrics or products with attractive colours and fire retardant finishes is important. The technical problems of the conventional exhaust process of dyeing (using dye-bath vat or jigger machine) is laborious , higher energy and time consuming and also it requires much higher water consumption both for dyeing and also in washing (for removing un-fixed dyes). Both dyeing and finishing of jute require a lot of fuel and energy in the form of steam, manpower and electricity. In this age of fuel and energy crisis, it is desirable to develop such process formulations which would result in reduction of process steps by way of combining two or three steps together into one step requiring lower energy, water and time consumption for achieving reduced process cost. Therefore, appropriate combination of multi-step processes a single-step process for both dyeing and specific chemical finishing for any textiles assumes high importance. Some earlier reports are available in literature [1,2,24,25] on single-step combined dyeing and resin finishing of jute based fabrics, and on simultaneous dyeing and easy care crease resistant finishing for cotton and its blends Textiles and Light Industrial Science and Technology, Vol. 4, No. 1—June 2015 2304-9421/15/01 001-16 Š 2015 DEStech Publications, Inc. doi: 10.12783/tlist.2015.0401.01

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A K Samanta, Kashmita Bhattacharya

[21,22,23] . Fire retardant finishing of textiles with different fire-retardant agents and corresponding mechanism, theory and application procedure etc are available in review by Horrocks [10] .Some detail of further research work [3,4,5,30,31,32,33] on fire-retardant finishing and/or different chemical modification and thermal behavior of such modified jute and cotton fabrics is also available. One patent [11] is available on simultaneous dyeing and fire retardant finishing on Aramid fibre. In an earlier publication, details of fire-retardant agents and application procedures on cellulosic and synthetics are available in details [34]. However, no study has been reported so far on simultaneous dyeing and fire retardant finishing of jute fabric. With this background information in mind, one-step simultaneous dyeing and fire retardant finishing of jute fabric using an acid dye and Urea-DAP or Urea-Ortho Phosphoric Acid or Urea- Ammonium Sulphamate has been attempted in the present work. This one step technique (replacing conventional two stage process of acid dyeing and fire retardant finishing) is expected to offer advantages of reduction in processing cost, saving in water and energy consumption, reduction in time of treatment as well as better or at least at par colour value, colour fastness and fire retardant performance.

Materials & Methods Materials 1) Jute Fabric Raw ex-loom, plain weave, fine Hessian 100% jute fabric of decorative variety with 6 ends/cm(count 256 tex), 5 picks/cm(count256 tex), 275 g/m2 (area density) was used in the present work. After conventional desizing and scouring [6, 13] (using 4 gpl Na2CO3, 1 gpl non-ionic detergent, at pH 9.0 by heating at 80°C for 30 min) followed by conventional 3% (on weight of fabric) H2O2 bleaching [14, 26] (hot, at 85°C for 2 h) with usual additives (sodium metasilicate, NaOH, EDTA, non-ionic wetting agent Lissapol-D using laboratory jigger with MLR 1:5), the fabric weight (area density) became 255 g/m2.

2) Chemicals and Dyes Laboratory reagent grade Diammonium phosphate (DAP) and Ammonium Sulphamate (AS) of Loba Chemie Pvt.Ltd., Mumbai, Urea (Nice Chemicals Pvt.Ltd., Kochi), Ortho-Phosphoric acid (OP) (85%) of S D Fine Chem.

Ltd., Mumbai . Acid dye, Acid Red F2R (CI Acid Red 151), supplied by Dye Chem, India was used.

OH NaO3S

N=N

N=N

CI ACID RED 151 (ACID RED F2R)

Methods Conventional Two-Step Sequential Dyeing (with Acid Dye) and Fire-retardant Finishing (with Urea-DAP or UreaOP or AS) 1) Dyeing of Jute with Acid Dye Exhaust Method For 20 g of fabric sample, 0.25 g of acid dye was used (1% depth of shade) in 400 ml (fabric to liquor ratio i.e.

MLR 1:20) aqueous solution of 5% glauber salt and a requisite volume of 5% Alum was added to adjust pH to 44.5. The dyeing [7, 28, 29] was carried out for 1 h at 90°C (± 50C), in Infra Colour Dyeing Machine (Make- RB Electronic Engg Pvt Ltd) after which the dyed sample was squeezed, neutralized with 1% NaOH solution, followed by soaping with 5 gpl non-ionic soap or detergent at 50°C for 15 min (instead of 45 min as in ISO-II method) [16] and finally washed in cold water and dried in air.

2) Application of Flame Retardant Finishing Treatments with different Formulations Jute fabrics dyed with Acid dye in exhaust method were padded (100% weight pick-up) with following flame retardant formulations as given below followed by drying at 100° C for 10 min and curing at 140°C for 5 min.

Simultaneous Dyeing and Fire-Retardant Finishing of Jute Fabric Using an Acid Dye and Selective F-R Finishing Chemicals

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Based on reported literature [4, 5],the following to optimum formulations developed in this laboratory with varying concentrations of fire-retardant agents.

TABLE 1. FORMULATION OF SIMULTANEOUS AND SEQUENTIAL DTEING AND FIRE RETARDANT FINISHING

Formulation Variations used for simultaneous dyeing and F-R finishing Formulation for sequential dyeing and F-R finishing

Formulation-A Urea-10-30% and DAP 515%

Formulation-B Urea-5%-20% and OP 412%

Urea-20% and DAP 10%

urea-10% and (OP) -8%

Formulation-C Urea-10%-25% and AS 10-30% urea-20% and (AS) 20%

3) One Step Simultaneous Acid Dyeing and Flame Retardant Finishing Pad-dry-cure Process i) One Step Simultaneous Acid Dyeing and Fire Retardant Finishing with Urea-DAP, Urea- OP and Urea-AS Bleached jute fabric samples were soaked in a solution containing different concentrations of DAP with Urea as mentioned in formulation A in Table 1, with 1% acid dye and non-ionic detergent (Nonidet P-40). The samples were then padded at 100% expression using a laboratory padding mangle (with two-dip and two-nip technique). Finally, the padded fabrics were dried at 1000C for 5 min followed by curing at 140°C for 5 min.

After curing, the fabric samples were washed in cold water and soaped with 5 gpl non-ionic soap at 50°C for 15 min, followed by final washing in cold water and drying in air.

The above procedure one step simultaneous acid dyeing (with 1% acid dye Red-F2R) and Fire-retardant finishing was repeated using different percentages of formulation B and C in table 1.

Testing and Evaluation All the untreated and treated jute fabric samples were conditioned [16] for 48 h at 65% (±2%) RH and 270C (±20C) as per standard method IS: 6359-1971, for each testing method described below: 1) Determination of Fabric Stiffness (bending Length) The bending length of the selected fabric samples were measured as per IS-6490-1971 method using Cantilever type SASMIRA fabric stiffness tester.

2) Measurement of Tensile Properties (tenacity) Breaking tenacity of selected fabric samples were measured by the raveled strip method as per IS-1969-1985 method ((ISI (BIS) Handbook of Textile Testing1982) using an Instron (Model-1445) CRT-Universal tensile tester with a traverse speed of 100 mm/min and a pretension of 0.5 N. The final gauge length (sample size) of the fabric sample was 50 mm.x 20 mm. under the two jaws.

3) Measurement of Surface Colour Strength Surface colour strength of untreated, differently treated and dyed and / or finished jute fabric sample was estimated in terms of K/S values by measuring the surface reflectance of each fabric sample at the respective λmax using a Macbeth 2020-plus reflectance spectrophotometer along with associated Colour-Lab plus software for converting the reflectance value to K/S value using Kubelka Munk’s equation (C H Giles 1974; E R Trotman 1975) as follows:

(1 – R λmax )2 K/S

=

α CD

2 R λmax Where, K = coefficient of absorption.

S = coefficient of scattering.

R λmax = reflectance of the substrate at maximum absorbance wavelength.

CD = concentration of dye.

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A K Samanta, Kashmita Bhattacharya

The K/S value (surface colour strength) is considered as an index for surface dye uptake, i.e. higher the K/S value, higher is the surface dye-uptake of the sample.

4) Measurement of Colour Difference Index (CDI) ∆E x ∆H Colour difference Index (CDI) = ∆C x MI Colour difference index of dyed and differently treated jute fabric was estimated in terms of CDI by measuring ∆E, ∆C, ∆H and MI values of each sample irrespective of their sign and direction may be utilized to obtain a single colour parameter to be known as colour difference Index (CDI values) by the following proposed empirical relationship: Closer to CDI values (ie. CDI max –CDI min) under any one set of dyeing condition or pre dyeing treatment conditions, more is the uniformity of colour distribution and better is the dispersion of colour across the plane/surface area of the textile fabric. Higher CDI values thus indicate some lesser uniformity for non-uniform treatment /fixation.

5) Measurement of Colour Fastness to Washing Colour fastness to washing was determined using SASMIRA launder-O-meter as per IS: 3361-1984 (ISO-II) method [16] (using 5gpl soap, MLR 1:50, 500C (±20C) temperature and 45 min washing time). Change in the depth of colour of the dyed fabric and the extent of staining on the adjacent white fabric was determined using grey-scales and the grey-scale rating was also confirmed / corrected through a computer aided Macbeth 2020plus reflectance spectrophotometer by relevant colourlab Plus software.

6) Measurement of Colour Fastness to Light The light fastness of the dyed and/or finished jute fabric samples was evaluated as per BS 1006: BOI: 1978 method .The fabric samples (10cm long x 2.5cm wide) were exposed to 500 watt Philip UV-light using a Shirley (SDL) MBTF-microsal fade-O-meter along with simultaneous exposure of eight different blue wool standard fabrics (BS 1006: BOI: 1978) having known light fastness rating from 1-8. The light fastness rating was then assessed by comparing the extent of fading of the sample with that of the corresponding blue wool standard fabrics after different hours of exposure to MBTF lamp in SDL microscal fade-O-meter.

7) Measurement of Colour Fastness to Crocking / Rubbing Dry Rubbing fastness of the dyed samples was determined using a SDL electronic crockmeter (make: Shirley Development Ltd.) as per IS: 766-1956 method (ISI (BIS) Handbook of Textile Testing1982).

8) Determination of Limiting Oxygen Index Limiting Oxygen Index (LOI) are critical oxygen index values indicating the relative measure of flammability of any materials or textiles. LOI values of selected untreated and treated fabric samples were determined in a standard LOI tester (Make: S C Dey & Co. Kolkata) as per ASTM-D-2863-77 method [4, 5, 8].

9) Vertical Flammability Test Selected untreated and treated jute fabric samples of specified length (315mm length and 50 mm wide) were exposed to a standard flame for a specified time (for jute it is 12 sec, as standardized earlier in this laboratory) and was allowed to burn in Standard flammability tester(Make: Paramount, India,) following IS : 11871-1986 standard method[30]. The fabric samples were mounted vertically in a specimen holder and were then exposed to a standard flame of specified height (38 mm) exposed at 90° with the specimen for 12 second and is left for burning, to note flame spread time, afterglow time, and char length (in cm) after the burning.

Simultaneous Dyeing and Fire-Retardant Finishing of Jute Fabric Using an Acid Dye and Selective F-R Finishing Chemicals

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Results and Discussions Effect of One-Step Simultaneous Dyeing and Fire Retardant Finishing by Pad-Dry-Cure Process on Fire Retardant Performance of Jute Fabric The fire retardant properties of each formulations (Urea-DAP , Urea-OP and Urea-AS) on jute fabric in both two step conventional and one step simultaneous dyeing and FR finishing are investigated for different concentration of FR agents in terms of LOI value, flame spread time, afterglow time, char length and relevant results are shown in Table no. 2, 3 and 4.

LOI value of control bleached jute fabric is found to be 20.5, flame spread time is 55 sec and after glow time is 49 sec. Jute fabric dyed with 1% Acid Red F2R also showed similar fire retardant property at par with that found for bleached jute fabric. Different concentrations of urea and DAP (Formulation A in table 1) are applied on jute fabric in one step simultaneous dyeing and FR finishing method . Lower concentration of Urea (10%) and DAP(5 %) does not show much fire retardant action. However, moderate fire retardancy is achieved at Urea (20%) and DAP (7%) , showing LOI value as 34 . On application of higher amount of Urea (25% and 30%) and DAP (10%, 12% and 15%) achieved excellent fire retardancy showing LOI value 38 and char length between 2.00 to 2.30 cm. In two step conventional process of sequential dyeing and FR finishing method using 20% Urea and 10% DAP showed LOI value 38.5 and char length 1.9 cm. The similar fire retardant property(LOI>=36) also can be achieved by formulations 2b, 2e, 3b, 3c, 3d, 3e, 4d and 4e but considering the minimum loss of tenacity and maximum surface colour strength, Formulation -3c is found to be the best.

Different concentrations of urea and OP (Formulation B in table 1) are applied on jute fabric. OP and Urea treated jute fabric achieved effective fire retardancy at all level of concentrations used and LOI value observed to 30.5 to 38.5 . On application of higher amount of Urea (15% and 20%) and OP (8%, 10% and 12%) achieved excellent fire retardancy showing LOI value 38.5 and char length 2.00 to 2.54 cm. In two step conventional process of sequential dyeing and FR finishing method with Urea (10%) and OP (8%) showed LOI value 38 and char length 2.54 cm. The similar fire retardant properties are also found in formulation 5e,6c, 6d, 6e, 7c, 7d, 7e, 8c, 8d and 8e. But considering the minimum loss of tenacity and maximum surface colour strength formulation 6-e is the best.

Different concentrations of urea and AS (Formulation C in table 1) are applied on jute fabric. AS and Urea treated jute fabric achieved effective fire retardancy at all level of concentrations used and LOI value observed to 30.12 to 39.25. On application of higher amount of Urea (20% and 25%) and AS (20%, 25% and 30% ) achieved excellent fire retardancy showing LOI value 39.25 and char length 1.30 to 1.60 cm. In two step conventional process of sequential dyeing and FR finishing method with Urea (20%) and AS (20%) showed LOI value 38.65 and char length 1.60 cm.

The similar fire retardant property can be achieved by formulation 10d, 11d, 11e, 12c, 12d and 12e. But considering the minimum loss of tenacity and maximum surface colour strength formulation 11-c is the best.

Reaction Mechanism Phosphorylation reaction of jute: The cellulose and hemi-cellulose of jute reacts with phosphoric acid (Diammonium phosphate also on heating converts to Phosphoric Acid) at elevated temperature to form phosphate ester. H3PO4 at high temperature reacts with the hydroxyl groups of jute fibre. Based on reported literature [9, 27], the Scheme1, 2 and 3 shows the postulated reaction mechanism leading to formation of phosphorylated jute (II, III and IV).

Hence, H3PO4 is the main fire retardant agent but function of Urea is manifold i.e. reduction of acidic degradation e.g. moderate fire retardancy, have some buffer action, facilitates formation of phosphate ester with cellulose, reduces acidity of the formulation, reduces loss in tenacity and swells cellulose to enhance penetration [10].

Reaction mechanism of Urea-Ammonium Sulphamate - The mechanism of reaction based on the formation of cyanic acid from urea explains in the mechanism as shown in scheme 4.

The formation of cyanic acid takes place at temperatures upwards of 140ºC and it seems that this active fragment reacts with sulphamic acid to form urea-sulphonic acid & this urea sulphonic acid reacts with jute’s aldehyde group (–CHO).

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A K Samanta, Kashmita Bhattacharya

As this reaction is performing under acidic pH due to acid dye, it acts as self catalyzed reaction. The complex which formed with the primary cellulose of jute obtained by blocking C6 position. (Levo glucosan). The fire retardant chemical works both in primary and secondary position which are shown in the above reaction mechanism and responsible for the good FR property of ammonium sulphamate [17, 18, 19, 20].

Reaction Scheme 1 O ‖ Jute-Cell-CH2OH + HO ---P---OH → | OH (Jute Cellulose I) (Phosphoric Acid)

O ‖ Jute-Cell-CH2-O-P-OH | OH (Phosphorylated jute cellulose II)

Reaction Scheme 2 (a) 2 NH2-CO-NH2 → NH2CONHCONH2 + ΝΗ3 (Di-urea) (b) O ‖ NH3-P-OH → H3PO4+ NH3 | NH3 (C) O O ‖ ‖ Jute-Cell-CH2-O-P-OH + 2NH3 → Jute-Cell-CH2-O-P-NH2 + 2H2O | | OH NH2 (Phosphorylated jute cellulose II) (Ammonium salt of Phosphorylated jute cellulose III) (d) O O ‖ ‖ Jute-Cell-CH2-O-P-OH + NH2-CO-NH2 → Jute-Cell-CH2-O-P-NH-CO-NH2 | | OH N (Diurea salt of phosphorylated jute cellulose) /

\ H CO-NH2

(IV)

Reaction Scheme 3 OH H | | Jute-C-C-OH + H+

→

OH H OH H | | . | |.

Jute-C-C-OH → Jute-C-C - + H2O → Further dehydration until complete char formation

| | | | | | HH H H H H H (Jute Cellulose) (Proton from Lewis Acid)

Reaction Scheme 4 (a) NH2 -CO-NH2 → NH4 OCN → NH3 + HOCN Urea

Cyanic acid

(b) HOCN + NH2O SO2NH4 → NH2CO-NHSO3NH4+ NH3 (Ammonium Sulphamate) (Ammonium ureasulphonate) (c) Jute-Cell-CHO + NH2CO-NHSO3NH4 → Jute-Cell-CH=NCONH-SO3NH4 (d) Jute-Cell-CH2OH + NH4OSO2NH2 → Jute-Cell-CH2-OSO2NH2 + H2O + NH3

Simultaneous Dyeing and Fire-Retardant Finishing of Jute Fabric Using an Acid Dye and Selective F-R Finishing Chemicals

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Effect of One-Step Simultaneous Dyeing and Fire Retardant Finishing by Pad-Dry-Cure Process on Physical Properties of Jute Fabric It is observed from the relevant data of table 2, 3 and 4 that during only dyeing of conventional 3% H2O2 bleached jute fabric with 1% selective acid dye (without any finishing) at pH 4-5, there is an unavoidable loss in tenacity of around 10% due to removal of some water / acid hydrolysable components of jute along with minor fibre shedding from the jute fabric during dyeing and washing. There is also a marginal reduction in breaking extension value.

This reduction in warp-way tenacity in this case should be viewed as an effect of some degree of acidic degradation of jute during dyeing (with acid dye) at pH 4.0 to 5.0.

TABLE 2. EFFECT OF APPLICATION OF SELECTIVE ACID DYE, UREA AND DAP BY ONE-STEP SIMULTANEOUS PAD-DRY-CURE METHOD ON MECHANICAL PROPERTIES OF JUTE FABRIC

Physical properties

Treatments

(Nil Control Bleached Jute) Dyeing with 1% acid dye(Red F2R, exhaust process) without any FR finishing chemicals Two-step sequential application of 1% acid dye (Red F2R) exhaust process followed by Urea 20%-DAP 10% (Formulation –A) Single step simultaneous dyeing (1% acid dye Red F2R) and F-R finishing (using following variations by paddry-cure technique)

Flammability properties Vertical flammability test

Limiting Oxygen Index (%)

Loss in Tenacity (%)

Elongation (%)

Bending Length (cm)

Surface Colour Strength (K/S value at λmax)

---

6.2

4

0.76

2(BEL)

55.0

(BEL)

20.5

10

5.37

3.6

6.25

2 (BEL)

55.0

(BEL)

20.5

40.5

3.77

4.2

7.21

8

4

1.90

38.5

Flame Spread Time(sec)

After Char Length Glow (cm) Time(sec)

Formulation 1a

DAP 5%

29

3.62

3.8

6.41

5

33

6.00

30

Formulation 1b

DAP 7%

36

3.85

3.9

6.67

5

30

5.20

32.5

44.5

4.04

4.2

7.32

6

25

4.30

34

52

4.10

4.2

7.56

6

16

3.60

34.5

60

4.16

4.4

7.75

6

10

2.54

35

2

50

10

24

Acid Dye 1% DAP 10% Formulation 1d Urea 10 DAP 12% % Formulation 1e DAP 15% Formulation 1c

Washed Fabric 1c Formulation 2a

DAP 5%

24

3.80

3.8

6.14

7

30

5.08

30

Formulation 2b

DAP 7%

30

4.16

3.8

7.16

7

12

2.54

34.5

35

4.22

4

7.35

10

6

3.80

35.0

45

4.27

4.2

7.86

10

6

2.54

36.5

52

4.54

4.2

7.90

--

--

1.90

37

2

50

9

26

Formulation 2c Formulation 2d Formulation 2e

Acid dye 1% DAP 10% Urea DAP 12% 20% DAP 15%

Washed Fabric 2c Formulation 3a

DAP 5%

16

4.29

3.9

6.95

5

5

3.17

32

Formulation 3b

DAP 7%

24

5.03

3.9

7.20

7

2

3

36.5

30.5

5.10

4.2

8.26

--

--

2.00

38.0

45

5.45

4

8.21

--

--

1.27

38.5

50

5.69

4

8.32

10

--

1

39

5

40

8

27

Formulation 3c Formulation 3d Formulation 3e

Acid dye 1% DAP 10% Urea DAP 12% 25% DAP 15%

Washed Fabric 3c Formulation 4a

DAP 5%

17.5

4.26

4

6.98

10

7

3.20

34

Formulation 4b

DAP 7%

26

5.01

4.1

7.25

7

5

3.00

35

37

5.21

4.1

7.76

--

--

2.70

35.5

49

5.48

4.3

8.25

--

--

2.30

36

55

5.62

4.4

8.35

--

--

2.30

38

3

45

9

27.5

Formulation 4c Formulation 4d Formulation 4e Washed Fabric 4c

Acid dye 1% DAP 10% Urea DAP 12% 30% DAP 15%

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A K Samanta, Kashmita Bhattacharya

TABLE 3. EFFECT OF APPLICATION OF SELECTIVE ACID DYE , UREA AND OP BY ONE-STEP SIMULTANEOUS PAD-DRY-CURE METHOD ON MECHANICAL PROPERTIES OF JUTE FABRIC

Physical properties Bendin Loss in g Elongatio Tenacity Length n (%) (%) (cm)

Treatments

(Nil Control Bleached Jute) Dyeing with 1% acid dye(Red F2R, exhaust process) without any FR finishing chemicals Two-step sequential application of 1% acid dye (Red F2R) exhaust process followed by Urea 10%- OP 8% (Formulation-B) Single step simultaneous dyeing (1% acid dye Red F2R) and F-R finishing (using following variations by pad-dry-cure technique) Formulation 5a OP 4% Formulation 5b

Acid dye 1% Formulation 5d Urea 5% Formulation 5e Formulation 5c

Flammability properties Surface Colour Strength (K/S value at Îťmax)

Limiting Oxygen Index (%)

Vertical flammability test

---

4.12

4

0.756

Flame Spread Time(sec) 2 (BEL)

55.0

Char Length (cm) (BEL)

20.5

10

4

3.6

6.25

2 (BEL)

55.0

(BEL)

20.5

42

2.39

4.3

7.23

4

4

2.54

38

After Glow Time(sec)

21

2.58

3.7

6.62

5

16

BEL

30

OP 6%

35.6

2.24

3.8

6.56

4

10

10.00

30.5

OP 8%

44

2.65

3.7

7.45

4

7

10.16

32

OP 10%

56

2.87

4.1

7.65

8

6

6.35

35

OP 12%

67

2.99

4.2

7.92

Washed Fabric 5c

8

5

5.50

36

2

40

12

24

Formulation 6a

OP 4%

15

2.17

3.8

6.41

6

10

BEL

30.5

Formulation 6b

OP 6%

27

3.24

4.2

7.24

10

2

2.90

33

Formulation 6c

OP 8%

30

3.61

4.3

8.25

--

--

2.00

38

OP 10%

57

3.72

4.3

8.86

8

--

1.50

38.5

OP 12%

65

3.85

4.4

8.90

--

--

1.30

38.5

5

35

8

27

Acid dye 1% Formulation 6d Urea 10% Formulation 6e Washed Fabric 6c Formulation 7a

OP 4%

14.5

2.46

3.8

6.98

4

10

4.30

32

Formulation 7b

OP 6%

28

2.65

3.8

7.22

5

4

3.50

36

Acid dye Formulation 7c 1% Formulation 7d Urea 15% Formulation 7e

OP 8%

37

3.07

3.9

7.62

--

--

2.54

36.5

OP 10%

45

3.39

4

8.20

--

--

2.54

37

OP 12%

58

3.59

4.2

8.44

--

--

2.00

38

2

45

10

27.5

Washed Fabric 7c Formulation 8a

OP 4%

17

1.24

3.9

6.95

6

8

4.50

32.0

Formulation 8b

OP 6%

25.4

2.17

4

7.52

6

4

3.60

34.5

Formulation 8c

OP 8%

37.5

2.46

4

7.87

8

3

3.00

38

OP 10%

41

3.69

4.1

8.36

8

--

2.50

38.5

OP 12%

55

3.71

4.2

8.47

10

--

2.00

38.5

2

40

10

27

Acid dye 1% Formulation 8d Urea 20% Formulation 8e Washed Fabric 8c

In two step conventional and sequential dyeing and fire-retardant finishing process using Urea (20%) and DAP (10%) show a loss in tenacity around 40 % in Table 2. In one step simultaneous dyeing and FR finishing process, the percentage loss in tenacity increases as the amount of DAP increases. Formulation 3c shows a moderate loss in tenacity around 30-31%, whereas higher amount of DAP application shows higher loss around tenacity of 50% to 60% in other causes.

In two step conventional and sequential dyeing and FR finishing process using Urea (10%) and OP (8%) shows a loss in tenacity around 40-42% in Table 3. For one step simultaneous dyeing and FR finishing process the same trend is followed, where, the percentage loss in tenacity increases as the amount of OP increased. Formulation 6c shows a moderate loss in tenacity around 30%, whereas higher amount of OP application shows higher loss around tenacity of 58% to 67% in other cases.

Simultaneous Dyeing and Fire-Retardant Finishing of Jute Fabric Using an Acid Dye and Selective F-R Finishing Chemicals

9

TABLE 4. EFFECT OF APPLICATION OF SELECTIVE ACID DYE, UREA AND AS BY ONE-STEP SIMULTANEOUS PAD-DRY-CURE METHOD ON MECHANICAL PROPERTIES OF JUTE FABRIC

Physical properties Treatments

(Nil Control Bleached Jute) Dyeing with 1% acid dye(Red F2R, exhaust process) without any FR finishing chemicals Two-step sequential application of 1% acid dye (Red F2R) exhaust process followed by Urea 20%-AS 20% (Formulation –C) Single step simultaneous dyeing (1% acid dye Red F2R) and F-R finishing (using following variations by pad-drycure technique) Formulation 9a AS10% Acid Formulation 9b AS15% Dye Formulation 9c AS20% 1% Formulation 9d AS25% Urea Formulation 9e AS30% 10 % Washed Fabric 9c Formulation 10a Formulation 10b Formulation 10c Formulation 10d Formulation 10e Washed Fabric 10c Formulation 11a Formulation 11b Formulation 11c Formulation 11d Formulation 11e Washed Fabric 11c Formulation 12a Formulation 12b Formulation 12c Formulation 12d Formulation 12e Washed Fabric 12c

Acid dye 1% Urea 15%

Acid dye 1% Urea 20%

Acid dye 1% Urea 25%

Flammability properties

Limiting Surface Vertical Oxygen Bending Loss in Colour flammability test Elongatio Index (%) Length Tenacit Strength n (%) (cm) y (%) (K/S value Flame Spread After Glow Char Length at Îťmax) Time(sec) Time(sec) (cm) --6.2 4 0.76 2(BEL) 55.0 (BEL) 20.5 10

5.37

3.6

6.25

2 (BEL)

55.0

(BEL)

20.5

18.84

5.82

3.8

7.06

-----

3

2.3

36.93

10.12

4.49

3.9

5.82

4

6

3.4

30.12

14.25

4.25

4.2

6.12

4

6

2.0

31.34

24.46

4.10

4.5

7.24

6

4

1.8

34.85

26.21

3.95

4.7

7.86

---

3

1.5

36.74

29.35

3.82

5.1

7.93

---

3

1.5

37.10

4

5

2.3

30.12

AS10%

13.46

4.42

4.1

5.98

6

4

3.2

35.00

AS15%

16.15

3.88

5.6

6.30

6

4

1.8

36.33

AS20%

27.69

4.88

5.1

6.70

8

3

1.8

36.96

AS25%

26.33

4.20

5.2

7.32

-----

2

1.6

37.18

AS30%

26.54

3.85

5.2

8.35

-----

----

1.5

38.37

5

4

2.2

31.23

AS10%

21.82

4.72

5.0

6.30

6

3

2.6

32.37

AS15%

26.07

4.12

3.7

7.70

8

2

1.8

34.57

AS20%

27.23

5.15

4.5

8.09

-----

----

1.6

38.65

AS25%

27.46

5.80

5.0

8.33

-----

----

1.5

38.78

AS30%

27.82

4.68

4.8

8.45

----

----

1.4

38.85

6

3

1.9

31.30

AS10%

19.61

5.31

3.8

6.32

7

4

2.1

33.96

AS15%

22.69

5.41

4..4

7.59

10

2

1.8

36.57

AS20%

24.21

5.03

4.7

8.11

----

---

1.6

38.67

AS25%

28.46

5.21

3.9

8.20

-----

---

1.4

38.75

AS30%

28.84

4.89

4.6

8.55

----

---

1.3

39.25

6

3

2.1

31.32

The loss of tenacity for fire retardant finished jute fabrics treated with combination of urea and H3PO4 , may be also due to the acidic degradation by H3PO4 during curing.

The bending length of these fire retardant finished jute fabrics are found to be marginally increased with the increase in concentration of H3PO4 and di-ammonium phosphate causing the fabric handle to become relatively stiffer. The stiffness so imparted is perhaps also due to the effect of phosphorylation reaction.

In two step conventional and sequential dyeing and fire-retardant finishing process using Urea (20%) and AS (20%) showed a loss in tenacity around 18.81% as shown in Table 4. In one step simultaneous dyeing and FR finishing process, the percentage loss in tenacity increases as the amount of AS increases. Formulation 11c shows a moderate loss in tenacity around 27.23%, whereas higher amount of AS application shows higher loss around tenacity of 28.46% in other cases.

10

A K Samanta, Kashmita Bhattacharya

The loss of tenacity for fire retardant finished jute fabrics treated with combination of urea and AS may be also due to the acidic degradation by sulphamic acid during curing.

The bending length of these fire retardant finished jute fabrics are found to be marginally increased with the increase in concentration of ammonium sulphamate causing the fabric handle to become relatively stiffer.

Effect of One Step Simultaneous Dyeing And Fire-retardant Finishing on Surface Appearance and Colour Values of Jute Fabric Corresponding surface colour strength (K/S value) brightness index, metamerism index, colour differences (∆E and ∆L, ∆a and ∆b) and colour difference index ( CDI) values etc for 3% H2O2 bleached control jute fabric dyed with selective acid dye, jute fbric subjected to conventional two step process of acid dyeing and fire retardant finishing and jute fabric subjected to one step simultaneous acid dyeing and fire-retardant finishing using different concentrations of Urea –DAP, OP and AS of are shown in Table 5, 6 and 7. There is an increase in the colour strength (K/S) value at λmax from 0.75 (for 3% H2O2 bleached control fabric) to 6.25 (for dyed fabric) after dyeing of the bleached jute fabric with a selective acid dye (Acid-Red F2R) for 1% (on weight of fabric) depth of shade.

In two step conventional and sequential dyeing and Fire-retardant finishing by acid red F2R (1%) and Urea-DAP, corresponding K/S value at λmax is 7.2 , whereas the same obtained by single step simultaneous dyeing and Fireretardant finishing a slightly higher K/S value is found with increase in amount of DAP and Urea in Table-5. The same trend is also found with urea-OP and Urea- AS fire retardant formulation for increase in OP and AS in Table6 and 7 respectively. The increase in surface colour strength for one step simultaneous dyeing and Fire-retardant finishing may be due to the acidic degradation cum structural loosing effect in jute fibre due to this action of DAP or OP supported with higher swelling by Urea.

TABLE 5. COLOUR STRENGTH, BRIGHTNESS INDEX, METAMERISM INDEX, CDI VALUE AND RELATED COLOUR PARAMETER OF UREA-DAP TREATED JUTE FABRICS DYED WITH ACID RED F2R BY BOTH TWO STEP SEQUENTIAL AND SINGLE STEP SIMULTANEOUS PROCESS

Treatments

K/S ‫גּ‬max

(Nil Control Bleached Jute)

0.756

-

-

-

-

-

-

38.34

-

-

Acid Red F2R Dyed Jute Sequential application of 1% acid dye & finishing with Formulation-A Simultaneous dyeing and finishing (with Formulation A) DAP 5% Formulation 1a Acid Formulation 1b DAP 7% dye 1% Formulation 1c DAP 10% Urea Formulation 1d DAP 12% 10% Formulation 1e DAP 15%

6.25

57.14

34.64

45.25

4.15

36.06

27.65

23.60

14.25

3.07

--

7.21

55.60

31.30

45.74

4.39

36.60

27.78

8.64

14.26

2.95

--

Formulation 2a Formulation 2b Formulation 2c Formulation 2d Formulation 2e Formulation 3a Formulation 3b Formulation 3c Formulation 3d Formulation 3e Formulation 4a Formulation 4b Formulation 4c Formulation 4d Formulation 4e

Acid dye 1% Urea 20%

Acid dye 1% Urea 25%

Acid dye 1% Urea 30%

∆E

∆L

∆a

∆b

∆C

∆H

BI

MI

CDI4 CDImax - min

6.41

62.94

37.19

49.23

12.45

43.03

26.97

4.05

16.16

2.44

6.67

60.64

38.22

45.65

11.30

40.52

25.52

3.65

14.52

2.63

7.32

59.61

39.42

42.87

12.67

37.55

24.27

3.49

13.57

2.83

7.56

58.92

38.50

45.82

11.42

41.52

25.42

3.85

13.26

2.72

7.75

58.56

38.76

42.65

10.33

36.21

24.79

4.05

13.46

2.69

DAP 5%

6.14

62.73

40.28

46.39

12.67

40.61

25.75

3.26

14.65

2.71

DAP 7%

7.16

61.60

38.66

47.09

9.08

39.64

26.99

4.24

15.14

2.77

DAP 10%

7.35

65.74

41.04

49.58

13.36

43.75

26.87

2.77

16.37

2.46

DAP 12%

7.86

60.85

37.62

46.25

12.20

40.26

25.82

4.04

14.89

2.62

DAP 15%

7.90

62.59

40.07

46.13

13.55

40.81

25.42

3.11

14.87

2.62

DAP 5%

6.95

54.25

38.52

39.55

6.25

30.26

26.76

4.65

12.58

3.81

DAP 7%

7.20

56.95

39.61

40.35

6.79

32.56

24.78

4.44

12.33

3.70

DAP 10%

8.26

59.39

41.10

42.11

8.02

34.68

25.19

3.74

12.99

3.32

DAP 12%

8.21

60.42

44.52

42.53

9.52

34.24

24.56

3.54

13.08

3.31

DAP 15%

8.32

62.38

46.56

40.10

10.73

34.18

23.56

2.82

13.15

3.26

DAP 5%

6.98

64.40

38.50

50.15

12.24

43.76

27.39

3.76

16.36

2.46

DAP 7%

7.25

62.92

38.75

49.85

11.85

42.20

27.40

3.80

16.16

2.40

DAP 10%

7.76

63.95

38.99

49.50

10.92

42.60

27.47

3.86

15.93

2.58

DAP 12%

8.25

64.04

42.56

46.62

12.85

41.65

27.88

2.58

14.92

2.87

DAP 15%

8.35

64.14

43.97

44.79

13.16

39.45

24.96

2.15

14.46

2.80

0.39

0.31

0.5

0.47

Simultaneous Dyeing and Fire-Retardant Finishing of Jute Fabric Using an Acid Dye and Selective F-R Finishing Chemicals

11

TABLE 6. COLOUR STRENGTH, BRIGHTNESS INDEX, METAMERISM INDEX, CDI VALUE AND RELATED COLOUR PARAMETER OF UREA-OP JUTE FABRICS DYED WITH ACID RED F2R

Treatments K/S ‫גּ‬max (Nil Control Bleached Jute) 0.756 Acid Red F2R Dyed Jute 6.25 Sequential application of 1% acid dye & 7.23 finishing with Formulation-B Simultaneous dyeing and finishing (with Formulation B) Formulation 5a OP 4% 6.62 Formulation 5b Acid dye OP 6% 6.56 Formulation 5c 1% OP 8% 7.45 Formulation 5d Urea 5% OP 10% 7.65 Formulation 5e OP 12% 7.92

∆E 57.14 58.33

∆L 34.64 35.16

∆a 45.25

∆b 4.15

∆C 36.06

∆H 27.65

BI 38.34 23.60 6.61

MI 14.25

CDI4 CDImax - min 3.07 --

46.21

5.50

37.43

27.65

14.37

2.99

--

59.81 57.96 57.17 59.72 59.90

38.47 40.87 40.80 40.36 41.10

45.14 40.59 39.56 43.20 42.18

7.73 6.42 6.24 8.43 8.24

37.30 32.63 31.61 35.84 36.85

26.56 24.99 24.59 25.55 25.85

4.61 4.28 4.42 3.95 4.32

14.09 12.85 12.08 13.43 13.95

3.02 3.45 3.68 3.17 3.01

0.67

Formulation 6a Acid dye Formulation 6b 1% Formulation 6c Urea Formulation 6d 10% Formulation 6e

OP 4% OP 6% OP 8% OP 10% OP 12%

6.41 7.24 8.25 8.86 8.90

59.83 59.48 57.74 59.83 59.58

38.61 37.39 38.42 38.55 38.65

44.68 45.51 42.53 41.23 41.65

9.56 8.21 6.95 5.61 5.95

37.67 37.84 34.60 32.87 33.65

25.87 26.58 25.68 25.51 26.21

4.56 5.21 5.14 5.30 5.21

13.60 13.97 12.97 12.67 12.50

3.02 2.99 3.30 3.66 3.71

0.72

Formulation 7a Acid dye Formulation 7b 1% Formulation 7c Urea Formulation 7d 15% Formulation 7e

OP 4% OP 6% OP 8% OP 10% OP 12%

6.98 7.22 7.62 8.20 8.44

64.26 64.44 63.52 60.97 62.52

39.40 39.57 38.90 38.35 39.25

49.53 49.87 49.06 46.50 48.45

11.14 10.00 10.71 9.15 10.02

42.72 42.55 42.11 39.13 40.14

27.43 27.86 27.35 26.73 27.85

3.72 3.66 3.80 4.39 4.21

16.04 16.15 15.99 14.88 14.98

2.57 2.61 2.58 2.79 2.89

0.32

Formulation 8a Acid dye Formulation 8b 1% Formulation 8c Urea Formulation 8d 20% Formulation 8e

OP 4% OP 6% OP 8% OP 10% OP 12%

6.95 7.52 7.87 8.36 8.47

62.26 62.44 61.52 60.97 61.52

38.40 38.57 37.90 37.35 38.42

48.53 48.87 48.06 45.50 47.45

10.14 9.00 9.71 9.15 10.02

41.72 41.55 41.11 40.13 41.14

26.43 26.86 26.35 25.73 26.85

4.72 4.66 4.80 5.39 4.61

15.99 14.88 14.98 15.94 15.69

2.46 2.71 2.63 2.45 2.55

0.26

The colour difference values (∆E and ∆L, ∆a, ∆b and CDI) of different variations of Urea- DAP, Urea- OP and UreaAS are also tabulated in table 4, 5 and 6. Relevant results indicate that Formulation 3c (using Urea-25% and DAP 10%) in Table -4 and Formulation 6c (Urea-10% and OP- 8%) in table 5 and Formulation 11c (Urea-20% and AS20%) in table 6 show higher K/S values than that of same dyeing and finish obtained by two stage conventional process with minimum ∆b i.e. less tonal change to blue and yellow, with lesser tenacity loss percentage.

The observed reduction in Brightness index for dyeing only and more on dyeing and finishing by two step conventional process and further more by one step simultaneous dyeing and Fire Retardant finishing, may be explained by the increase in diffused reflection for dye molecules and finishing chemicals fixed or adhered to jute changing its reflection pattern making it more diffused to reduce the overall brightness. However the best two formulations 3c, 6c and 11c show quite a lower MI, indicating a better closer match possibility in any case.

Effect of One Step Simultaneous Dyeing and Finishing on Fastness Properties of Jute Fabric Table 8 indicate the colour fastness to wash, light and rubbing for acid dyed jute fabric, acid dyed and FR finished jute fabric obtained by conventional two step process of acid dyeing and fire retardant finishing and acid dyed and fire retardant finished jute fabric obtained by one step simultaneous dyeing and FR finishing by pad-dry-cure process.

Bleached jute fabric dyed (by exhaust process) with 1% acid dye using selective acid dye, (Acid-Red F2R) without any fire retardant finishing shows colour fastness to wash 2-3 (change in shade) and 3 (Staining on cotton). Colour Fastness to wash for acid dyed and fire retardant finished jute fabric obtained by two-step sequential process of exhaust dyeing with 1% acid dye (Acid Red F2R) followed by fire-retardant finishing using 20% Urea and 10%

12

A K Samanta, Kashmita Bhattacharya

DAP does not alter/change, but light fastness and rubbing fastness increases by one grade, while for acid dyed and FR finished jute fabric obtained by single step simultaneous acid dyeing and FR finishing with 10% Urea and 8% OP rub-fastness is improved by 1.5 grade, light fastness is improved by 1 grade and wash fastness is also improved by 1/2 grade as compared to that of only dyed (without FR finish) jute fabric. Colour Fastness to wash for acid dyed and fire retardant finished jute fabric obtained by two-step sequential process of exhaust dyeing with 1% acid dye (Acid Red F2R) followed by fire-retardant finishing using 20% Urea and 20% AS does not alter/change, but light fastness and rubbing fastness increases by one grade.

TABLE 7. COLOUR STRENGTH, BRIGHTNESS INDEX, METAMERISM INDEX, CDI VALUE AND RELATED COLOUR PARAMETER OF UREA-AS JUTE FABRICS DYED WITH ACID RED F2R

CDImax –

Treatments

K/S ‫גּ‬max

∆E

∆L

∆a

∆b

∆C

∆H

BI

MI

CDI4

(Nil Control Bleached Jute) Acid Red F2R Dyed Jute Sequential application of 1% acid dye & finishing with Formulation-C Simultaneous dyeing and finishing (with Formulation C) Formulation 9a AS10% Acid Formulation 9b AS15% Dye 1% Formulation 9c AS20% Formulation 9d Urea 10 AS25% % Formulation 9e AS30%

0.756 6.25

57.14

45.25

4.15

36.06

27.65

3.07

--

58.33

46.21

5.50

37.43

27.65

38.34 23.60 6.61

14.25

7.06

34.64 35.16

14.37

2.99

--

5.82 6.12 7.24 7.86 7.93

51.28 53.09 52.99 52.53 51.99

27.64 32.38 33.12 33.44 33.86

42.44 41.36 40.82 40.04 39.12

8.06 7.72 6.68 6.15 5.10

34.88 33.77 32.23 31.56 30.27

25.42 25.10 24.96 24.48 24.36

6.12 5.92 5.47 5.26 4.96

13.10 13.02 12.74 12.46 11.92

2.85 3.03 3.22 3.27 3.51

0.66

min

Formulation 10a Formulation10b Formulation 10c Formulation10d Formulation 10e

Acid dye 1% Urea 15%

AS10% AS15% AS20% AS25% AS30%

5.98 6.30 6.70 7.32 8.35

54.59 54.54 54.80 53.24 53.18

32.55 33.41 34.97 35.57 35.74

43.06 42.41 41.49 39.28 39.06

8.18 7.70 7.62 5.12 5.02

35.62 34.83 33.96 30.89 30.75

25.54 25.40 25.02 24.95 24.65

6.36 6.10 5.96 5.59 5.36

13.15 13.14 12.98 12.79 12.55

2.98 3.03 3.11 3.36 3.40

0.42

Formulation 11a Formulation11b Formulation11c Formulation11d Formulation 11e

Acid dye 1% Urea 20%

AS10% AS15% AS20% AS25% AS30%

6.30 7.70 8.09 8.33 8.45

55.29 54.53 53.98 52.94 52.80

32.28 32.53 33.11 34.16 34.02

44.08 43.24 40.61 40.00 39.94

8.45 6.73 6.09 6.01 5.92

36.66 35.19 32.44 32.20 32.11

25.90 25.02 24.79 24.45 24.04

6.41 6.07 5.89 5.53 5.23

13.61 12.72 12.44 11.92 11.62

2.87 3.05 3.32 3.37 3.40

0.53

Formulation 12a Formulation12b Formulation 12c Formulation12d Formulation 12e

Acid dye 1% Urea 25%

AS10% AS15% AS20% AS25% AS30%

6.32 7.59 8.11 8.20 8.55

56.60 56.70 56.29 55.07 54.90

35.00 36.16 36.33 39.73 39.92

43.51 42.76 42.08 37.53 37.16

9.20 8.86 8.79 6.76 6.32

36.48 34.31 35.01 30.03 29.95

25.16 24.09 24.05 23.64 23.22

5.17 5.60 4.80 4.16 4.02

13.40 12.92 12.54 11.39 11.13

2.91 3.08 3.08 3.81 3.82

0.91

TABLE 8. EFFECT OF APPLICATION OF SELECTIVE ACID DYE AND UREA AND OP OR DAP OR AS BY ONE-STEP SIMULTANEOUS PAD-DRY-CURE METHOD ON COLOUR FASTNESS PROPERTIES OF JUTE FABRIC

Treatment and Formulation No. Acid Red F2R Dyed Jute Sequential application of 1% acid dye & finishing with Formulation-A Simultaneous dyeing and finishing (with Formulation 3C) Sequential application of 1% acid dye & finishing with Formulation-B Simultaneous dyeing and finishing (with Formulation 6c) Sequential application of 1% acid dye & finishing with Formulation-C Simultaneous dyeing and finishing (with Formulation 11c)

Fastness to wash (ISO II) St. on Change in shade cotton 2-3 3 2-3 3

Fastness To Light

Fastness to Rubbing (Dry)

3 4

2-3 3-4

3-4

3-4

4

4

3

3

4

3-4

3-4

4

4

4

3-4

3-4

3

3

2-3

3

4

3

Simultaneous Dyeing and Fire-Retardant Finishing of Jute Fabric Using an Acid Dye and Selective F-R Finishing Chemicals

13

TABLE 9. COMPARATIVE ANALYSIS OF COST EFFECTIVENESS

Items

Bleaching chemicals (6% H2O2, SMS, NID, etc) Eco –friendly dye, Chemicals & Dyefixer (2%) Water & Effluent treatment Wages Steam Electricity Fire Retardant finishing Chemicals Water and Effluent Treatment Manpower Steam Electricity

Cost add-on (in Rs) / linear metre Two-step sequential Single step Single step Two-step sequential application of 1% acid simultaneous simultaneous application of 1% acid Single step simultaneous Dyeing and FR Dyeing and FR dye (Red F2R) by dye (Red F2R) by Dyeing and FR Finishing Finishing with 1% Finishing with 1% exhaust process exhaust process with 1% (acid Red F2R) followed by FR followed by FR and Urea-20% and AS (acid Red F2R) and acid (Red F2R) and finishing with Urea Urea-25% and DAP Urea-10 % and OP finishing with Urea 20% by pad-dry-cure 20% and DAP 10% by 10% by pad-dry- 8% by pad-dry-cure 20% and AS 20% by process. pad-dry-cure process. cure process process pad-dry-cure process.

Dyeing Cost 0.95- 1.00

0.95- 1.00

0.95- 1.00

0.95- 1.00

0.95- 1.00

2.50 - 3.20

2.50 - 3.20

2.50 - 3.20

2.50 - 3.20

2.50 - 3.20

0.05 – 0.10

NIL

NIL

0.05 – 0.10

NIL

0.40 - 0.50 1.50 -1.75 0.25 -0.30

NIL NIL NIL NIL NIL NIL Fire-Retardant Finishing Cost

0.40 - 0.50 1.50 -1.75 0.25 -0.30

NIL NIL NIL

4.4-5.0

4.40-5.00

3.50-4.00

5.0-5.50

5.00-5.50

0.35-0.40

0.35-0.40

0.35-0.40

0.35-0.40

0.35-0.40

0.45-0.50 0.45-0.50 0.45-0.50 NIL NIL NIL 0.25-0.30 0.25-0.30 0.25-0.30 Drying Cost in Cylinder Drying Range Machine 0.3-0.40 0.3-0.40 0.3-0.40 0.66-0.70 0.66-0.70 0.66-0.70 0.42-0.50 0.42-0.50 0.42-0.50 Curing Cost in Stenter 0.3-0.40 0.3-0.40 0.3-0.40 1.9-2.2 1.9-2.2 1.9-2.2 0.80-1.0 0.80-1.0 0.80-1.0

0.45-0.50 NIL 0.25-0.30

0.45-0.50 NIL 0.25-0.30

Manpower Steam Electricity

0.3-0.40 0.66-0.70 0.42-0.50

Manpower Steam Electricity Total cost for blending to dyeing and FR finishing

0.3-0.40 1.9-2.2 0.80-1.0 15.48-18.25

13.28-15.60

12.38-14.60

15.98-18.75

0.3-0.40 0.66-0.70 0.42-0.50 0.3-0.40 1.9-2.2 0.80-1.0 13.78-16.10

The increase in light fastness may be considered as an effect of antioxidant nature of Phosphate group anchored to C6 group (-CH2OH) of cellulose, that again coupled with –NH2 or –NH3 end group retards photo initiated reaction for UV-light/Sun light fading.

The improvement of rubbing fastness after acid dyed jute fabric with F-R finishing either by sequential or by simultaneous one step process can be viewed as masking effect of some cross linked polyureas possibly additionally formed creating a thin film of polyureas over the dyed fabric surface. Half grade higher improvement of rubbing fastness by single step simultaneous dyeing and FR finishing may be explained by possibly higher amount of dye-penetration assisted by padding pressure in pad-dry-cure process.

Wash fastness depend on either insolubilisation of dye present/anchored in the fibre on type of anchoring bond/ interactional force restricting dye molecules to come out from the fibre substrate. As F-R finishing either by conventional two step process or by simultaneous one step process has no direct relevance to type of dye-fibre anchoring force being created between jute and acid dye, there is hardly any improvement in wash fastness in both the processes/ techniques. However, single step simultaneous process of acid dyeing and FR finishing (using 10% Urea and 8% OP) show less staining and ½ grade improvement or 20% Urea and 10% DAP in wash fastness, which can be viewed as an additional effect of possible interaction of –NH3 group of aminated phosphate groups (shown

14

A K Samanta, Kashmita Bhattacharya

in reaction-3) under acidic condition (by influence of DAP or OP) during curing so that acid dye (DSO3-) is more firmly remained anchored to FR modified jute, however at higher alkalinity/ vigorous wash the same can be hydrolyzed.

Assumptions Fabric Used: 51”- 6 ends/cm X 5 pick/cm; 292 GSM or ~ 275 g / square metre; After bleaching fabric weight became 255 g/m2.

•

Cost of acid dye (DYECHEM INTERNATIONAL) @ ~Rs. 310/Kg

•

Steam generated by coal , Electricity Rs. 5/- per unit of Kwatthour

•

Cost will vary for varying percentage shade and dye requirement

•

Rate of the Above mentioned Fire-Retardant Chemicals (Commercial Grade) i) Urea Rs. 12/- per Kg, ii) DAP Rs. 45/-per Kg iii) OP Rs. 75/-per kg, iv) AS Rs. 80/- per kg

Analysis of Techno-economic Viability and Cost Effectiveness between Conventional Two Step Sequential Process and Single Step Simultaneous Process of Acid Dyeing FireRetardant Finishing of Jute Fabric Table 8 shows the comparative cost add-on per linear meter of jute fabric for two step conventional process of acid dyeing and FR finishing and two optimized recipe for simultaneous acid dyeing (with 1% acid Red F2R) and FR finished (using Urea-25% and DAP 10% or Urea-10% and OP 8% ) by pad-dry-cure process. Relevant comparative cost analysis shows that production cost for single step simultaneous dyeing and FR finishing is Rs. 13.28-15.60 (for Urea-DAP recipe), Rs. 12.88-14.10 (for Urea-OP recipe) and Rs. 13.78 - 16.10 (for Urea-AS recipe) per meter of jute fabric, which is much less than that required for two stage sequential acid dyeing and FR finishing.

This is because of saving water and effluent treatment cost, wages of workers, electricity, steam etc. required for dyeing in exhaust method which are absent in one step simultaneous acid dyeing and FR finishing by pad-dry-cure method. Moreover, among the two optimized recipe for single step simultaneous acid dyeing and FR finishing, the processing cost of the FR recipe containing urea and ortho phosphoric acid is cheaper than the FR recipe containing urea and di-ammonium phosphate. This is because of the requirement of less percentage of application of urea along with ortho-phosphoric acid FR recipe than that required in of urea and di-ammonium phosphate FR recipe.

Conclusions •

From the present study it is revealed that simultaneous dyeing (with an acid dye) and fire retardant finishing with Urea- DAP, Urea- OP and Urea- AS on bleached jute fabric is found to be optimum for Urea 25% and DAP 10% concentration, Urea 10% and OP 8% concentration and Urea 20% and AS 20% concentration respectively. Irrespective of the technique followed, the surface colour strength of simultaneous dyed and fire-retardant finished (by single step process) jute fabric is found to increase with an increase the percentage of application of all the fire-retardant finishing chemicals from and beyond which it almost tends to level off.

•

Dyeing of jute fabric with acid dye and fire retardant finishing (with Urea-DAP, Urea- OP and Urea-AS ) can be easily carried out in one-step simultaneous dyeing and FR finishing process by pad-dry-cure method. The surface colour strength and improvement in fire retardant property thus obtained by the single step simultaneous process of acid dyeing and FR finishing is found to be at par with that obtained by conventional two-step sequential process of dyeing and fire retardant finishing, the former showing improved light fastness and rubbing fastness as well.

•

Single step simultaneous dyeing (with acid dye) and fire retardant finishing (with Urea-DAP , Urea-OP and

Simultaneous Dyeing and Fire-Retardant Finishing of Jute Fabric Using an Acid Dye and Selective F-R Finishing Chemicals

15

Urea-AS) of jute fabric by pad-dry-cure technique offers savings in energy, process time and operational cost, giving satisfactory colour strength and improvement in fire-retardant property as compared to the conventional two-step sequential dyeing and FR finishing process.

ACKNOWLEDGEMENT

The authors express their sincere thanks to, National Jute Board, MOT, GOI, for grant-in-aid to this institute/Dept., for JTM-R&D Project-10(Development of Fire-retardant finishing of jute fabric) and JTM-R&D Project-8 (Computerised colour matching & Print design for jute fabric).

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A K Samanta, Kashmita Bhattacharya

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[1] Prof. (Dr). Ashis Kumar Samanta, is presently Head of the Dept. and Professor in Textile Chemistry of Dept. of Jute and Fibre Technology of Calcutta University, He is an Eminent Educationist cum Research Scientist in Textile Technology area specialized in Chemical Processing of Textiles having special expertise and contribution in Natural Dyeing, Functional finishing, Computer aided Colour Matching and Print design. His academic and research experience span over 27 years with 1.5 years industrial experience. He has contributed more than 180 papers in reputed national and international journals. He also published 3 important books and 2 international book chapters and 11 training manual. He has taken instrumental role in implementing more than 16 Govt. Sponsored Projects as Project Investigator/ Coordinator.

He is presently Chairman of National Committee of BIS on dyes and chemicals and many other bodies. He has guided many Ph D and M Tech scholars. He is also active reviewer of many international journals.

[2] Mrs. Kashmita Bhattacharya did her M Tech in Textile Technology, at present she is pursuing her Ph D under the guidance of Prof. (Dr). Ashis Kumar Samanta at Calcutta University. She has 5 years of research experience in Textile Technology area with 2.5 years industrial experience Govt. Textile Mill. She has presented many papers in national and international conferences and has published 2 research papers in renowned journals.