1.  DYING OF ARAMID FIBRES
BY: MUDDASSAR HASSAN
ROLL NO. 85

2. What are aramid fibers
 These are also called aromatic polyamides
 Those polyamides,which have aromatic six
carbon rings in polymeric chain

3. Main types of aramid fibers
 Technora (made by Teijin of Japan)
 Conex (made by Teijin)
 Kevler (made by Dupont)
 Nomex (made by Dupont)

4. Good Qualities of fibers
 Good heat resistance
 High tenacity & modulus of rigidity
 Non flammability
 Greater sticking temperature
 Aramid dominate over glass fibers,and
carbon fibers in all over the world market
 Stiffest &Toughest than even carbon and
steel

5.  High modulus five times greater than
polyester
 Excellent in tension
 Good chemical resistance
 Compactness and solidity of molecular
structure
 In dry air,at 260C Aramid shrink only 2%
 By Sputter etching, depth of shade
increased considerably

6. DISADVENTAGES
 No substantivity to dyes
 No environment friendly
 Poor UV resistance
 Rapid loss of strength with flexing ,folding
&flogging
 Low light fastness,even spun dyed yarn
 Very expensive
 Poor in compression than glass

7. Main physical properties
 Melting poit371C
 Tenacity 5.3gmden at 65%RH&70F
 Specific gravity of fiber is 1.38
 Tg 275C

8. Dying of nomex with Basic dyes
 Fiber (2dtex50mm)
 Fabric form GSM (265gm
Washing
Nomex in fiber form are washed in Vald henriksen
FBK MACHINE.
In fabric form,Walter Franke dying apparatus

9. Recipe for washing
 Nonionic surfactant 1gl
 Trisodiun phosphate dodecahydrate1gl
 Liqour ratio 30:1
 Washing condition
 Start at 40C &temperature raised to80C for 30
min
 Rinsing with hot and cold for 10 min

10. Dying procedure
 Polycolor zeltex AG machine, used for dying
 Resipe
 Dye 2% o.w.f (Special dye, CI Basic 41)
 Sodium nitrate 20gl
 Career benzyl alcohol 70 gl
 Acetic acid 2.5gl (60%)
 Liqour ratio 20:1

11. After treatment process
 Materials are treated with 2gl nonionic
surfectant for 20 min at 95C
 Acetic acid added to maintain PH to 3
 Hot &cold rinsing
 Fixation was carried out fir 30sec at 200C

12. Dyeing of Technora and conex with
disperse dyes
Three commercial disperse dyes are used
1)Terasel yellow3GW(CI Disperse yellow54)
2)resolin red FB(CI Disperse Red 60)
3) Resolin blue FB (CI Disperse blue56)
DYING CONDITION
Temperature 190 &time 60 min
Dying machine
Mini –colour (Texam GIKEN)

13. Recipe
 Disperse dye (4-24%o.w.f)
 Dispersing agent (Disper VG) Nonionic
surfectant 0.5gl
 Acetic acid 0.2gl & PH to4.2
 Liqour ratio15:1
 Dying temp is raised at 2degCmin
 Maintaining temp to 190C for 60 min
 Reduction clearing is carried out twice

14. Dyeing of Nomex type430filament
yarn
 Three commercial basic dyes are use for dying
 CI Basic blue54 (CIBB-54)
 CI Basic red29 (CIBR-29)
 CI Basic redGL22(CIBR22)
 Dyeing Procedure
 Weight of skein of yarn(2.5)
 Infinite Liqour ratio140:1
 Commercial dyestuff (10% o.w.f)

15.  Using no career
 Temperature of dying range of 80 to 100C

16. Approaches to improve
dyebility of aramid fibers
 More polar solvent
 Pretreatment of liquid ammonia
 Using benzyl alcohol as carrier

17. Pretreatment with liquid
ammonia
 Pretreatment fibers with liquid
ammonia,substantivity towards basic dye
increase quite significantly
 Condition of pretreatment process
 Immersing 2.5g m-aramid in 100ml liquid
ammonia
 Time 10 min &at 40 C
 Rinsing with hot and cold water

18. Dependence of light fastness properties on
pretreatment & dyeing procedure
 CI Basic fastness to light
 A B C
 Yellow 28 3 3-4 4-5
 Orange 22 1 3 4
 Red46 1 2 3
 Red29 1 4 4-5
 Blue 49 1 3-4 3-4
 A : Without pretreatment, dyed without career
 B : Without pretreatment,dyed with 70 gl benzyl alcohol
 C : Pretretment with liquid ammonia,dyed without
carrier

19. Conclusion
 Pretreatment of aramid fibers with liquid
ammonia can not only increase substantivity for
basic dyes,but also light fastness properties, as
comparing with those of fibers dyed
conventionally with basic dyes using career
benzyl alcohol

20. Effect of polar solvent on dyebility of
aramid fiber
 These are three high polar solvents
 Dimethyl formamide
 Dimethyl acetate
 Dimethyl sulfoide
These solvents provide chemical energy to
fibers,permitting rearrangement of the polymer
chain through breakage and reformation of
interchain hydrogen bonding

21. Factor of changing solvent diffusion in
nomex fiber
 1)Molecular volume
Mol vol = Mol.wtr * 10 24N
Where r is density
N is Avogedro number
2)Temperature of corresponding to onset of
shrinkage.

22. Exhaust dyeing of treated
nomex yarns
 Exhaustion of CIBB54 at 100C
 At 30 min
 Attaining max degree of structural modification
 Order of increasing exhaustion rate
 DMF<DMAc<DMSO
 In DMF,90% of dye liquor being exhausted after
4hours
 In DMAc&DMSO leads to very rapid exhaustion
 95% of dye liquor being exhausted in 45 minutes

23.  Untreated yarns dyed according to commercial
dying procedure in presence of Dymex career
resulted in low exhaution45% of dye liquor
 Temperature dependence of exhaustion
rate
 With DMF A slight decrease in rate occurs when
treatment temperature decreases from 100 to 50C
 Considerable larger decrease in rate occurs on
reducing temp of treatment to further to 40C
 With DMAc major change in exhaustion rate
occurs between samples treated at 82.2&75C

24. Influence of treatment time on
exhaustion rate
 An increase in treatment time, leads to faster
exhaustion rate
 Temp from 30 sec to 30 min,solvent diffusion
 And polymer interaction are considerably faster
 But exhaustion rate is unaffected
 Structural modification changes also depends on
treatment time

25. Conclusion
 Optimum condition of dying 100c and 30
minutes then substrate is readily dyeable in
atmosphere pressure
 After solvent treatment ,loss of polymer chain
orientation and or formation of void takes place
 Solvent treated fabric leads to attain greater
dyebility at expense of initial modulus and tensile
strength
 Elimination of larger amount of careers

26.  Lower dyeing temperature and shorter dyeing
time (significant benefit)

27. Effect of varying liquid ammonia pretreatment time
&dying temp
pretreatment Dying KS Wash fast-
time temp VALUE -ness
inC
0.2 130 12.1 3-4
5 130 12.4 3-4
10 130 10.8 3-4
30 130 11.0 3-4
30 100 10.6 3-4

28.  Method of removing ammonia
 Rinsing
 Rinsing &drying
 Evaporation without rinsing
 Treatment Tensile strength Extension
 step mNtex (%)
 A 270 48
 B 230 64
 C 213 47
 D 222 27
 E 243 43
 A Raw fiber B; Pretreatment 15 min in liquid
ammonia
 C; Pretreated fiber dyed with basic dye D; Untreated fiber dyed with
basic dye using benzyl alcohol E; Untreated fabric dyed with basic
but without career( Effect of pretretment and dying method on fiber
strength and extension)

29. Influence of sputter etching in
shade of dyed fabrics
 The aramid fabric Technora dyed with CI
Disperse54 etc, are treated by sputter etching and
argon low-temperature plasma
 Sputter etching is effective I increasing color
depth of dyed Technora
 As a decrease of L* for blue and red dyeing and
considerable increase in C*for all three colors
 These effects on dyed Technora are slightly less
with low temperature plasma treatment

30.  No significant effect on CONEX FABRIC
 Basic purpose of sputter etching is to
produce deeper shade deeper and or more
vivid colors on dyed aramid fabric without
actually increasing concentration dye
 Technora caused by sputter etching is
thought to be due to formation of
Microcrates during treatment that severely
restrict the reflection of incident light

31.  Name of device used for sputter etching,
Shinku-kiku RFS-200
 Depth of shade is measured with colorEye
MS2020 Spectrophotometer under illuminant
D65 AND WITH 10 OBSERVER
 Spectrophotometer calculate value lightness L*
and color difference E in CIELAB color space
 CONDITION OF SPUTTER ETCHING
 Pressure of 20 pa
 Power rating of 100 Wt
 Time of treatment from 30 to 300sec

32. References
 JSDC Volume111 Mach 1995,page72
 JSDC Volume 111 March 1995 ,page 111
 TRJ April 1986, page 254
 JSDC Volume 110 JulyAug , page228,1994
 Encyclopedia of textile finishing by
H.K.ROUETTE
 Man made fibers, page408 By R.W.Moncrieff
 www.dupont product.com