Project

1. Laminated Fabrics based on
Kevlar & Spectra for Inflatables
Presented by
Ramnath Kumar– 2018TTF2068
Under the supervision of
PROF. MANGALA JOSHI
PROF. B. S. BUTOLA
Dept. of Textile & Fibre Engineering
IIT Delhi

2. Introduction
Military
Applications
Surveillance
Telecommunication
Relay
Non-rigid inflatable has very simple structure, light weight, easy
fabrication, lower cost for fabrication & maintenance
ADRDE Aerostat Russian Airship

3. Objective
Broad objective
Specific objective
To make a multilayered laminate based on high performance
fabric and polymeric films having high gas barrier and weather
resistance property
a) To improve the adhesion between the fabric and films by use
of plasma treatments
b) Optimization of adhesive formulations against peel strength
and weather resistance
c) Preparation of laminated structures
d) Characterization and testing for weather resistance and gas
barrier property

4. Materials
Serial
No
Fabric type Fibre type Yarn linear
density (tex)
Fabric sett
(inch-1)
Aerial density
(g m-2)
1 Spectra UHMWPE 45 ± 1 42 x 42 150 ± 5
2 Kevlar Para Aramid 45 ± 1 31 x 31 110 ± 5
Serial
No
Film name Film type Gas permeability
(L m-2 day-1)
Thickness
(µm)
Aerial density
(g m-2)
1 Mylar BOPET 1.35 12 20
2 Tedlar PVF 1.72 36 50
Fabric specification
Film specification
Other chemicals
• PU synthetic Adhesive
• Cross linker
• UV additives

5. Approach
Adhesive layer
PVF film
Adhesive layer
BOPET film
Laminate 1
230 g m-2
Adhesive layer
PVF film
Adhesive layer
PVF film
Laminate 2
260 g m-2
BOPET film
Adhesive layer
PVF film
Adhesive layer
Laminate 3
230 g m-2
PVF film
Adhesive layer
PVF film
Adhesive layer
Laminate 4
260 g m-2

6. Process
Fabric &
Films
Plasma
treatment
Adhesive
applying
Laminate
making
Accelerated
weathering

7. Methodology
Adhesive formulation
Adhesive +
Solvent
Add UV
additives
Sonication for
10 minutes
Solvent
Adhesive
Elmasonic Elmasonic
Sonication for
20 minutes
Crosslinker
UV additives
Add
Crosslinker

8. Methodology
Laminate preparation
Fabric
(washed)
Apply the
adhesive by knife
Stacking of films
(Plasma treated)
Curing by
compression moulding
Laminate

9. Results
[Plasma treatment]

10. Effect of plasma
0 10 20 30 40
20
30
40
50
60
70
80
Contact
angle
(degree)
Plasma dose (J/cm2
)
He
He/O2
(70:30)
He/N2
(60:40)
(a)
0 10 20 30 40
20
30
40
50
60
70
Contact
angle
(degree)
Plasma dose (J/cm2
)
He
He/O2
(70:30)
He/N2
(60:40)
(b)
Effect of Plasma dose & Plasma gas
BOPET PVF

11. Effect of plasma
0 2 4 6 8 10
20
30
40
50
60
70
80
Contact
angle
(degree)
Exposure time (min)
PVF film
BOPET film
(a)
0 2 4 6 8 10
25
30
35
40
45
50
55
60
65
Surface
Energy
(mN/m)
Exposure time (min)
PVF film
BOPET film
(b)
Effect of Plasma exposure time
Optimized time: 8 min

12. Drop shape images
Plasma
He/O2
Untreated PVF Treated PVF
70º 20º
Untreated BOPET Treated BOPET
Plasma
He/N2
24º
76º

13. AFM images
Before Plasma After Plasma
BOPET
20 µm
(a)
Ra = 4.24 nm
20 µm
(b)
Ra = 12.96 nm
PVF
20 µm
(c)
Ra = 7.83 nm
20 µm
(d)
Ra = 128.97 nm

14. Peel strength [ASTM D1876-08]
Effect of crosslinker
0.5 1.0 1.5 2.0 2.5 3.0 3.5
6
8
10
12
14
16
Peel
strength
(N/cm)
Cross-linker content (%)
PVF-Fab (before plasma)
PVF-Fab (after plasma)
(a)
76 mm
76 mm
Pull
Pull
(a)
(b)
Sample specimen

15. Peel strength [ASTM D1876-08]
Effect of crosslinker
0.5 1.0 1.5 2.0 2.5 3.0 3.5
10
12
14
16
18
Peel
strength
(N/cm)
Cross-linker content (%)
PVF-BOP (before plasma)
PVF-BOP (after plasma)
(c)
0.5 1.0 1.5 2.0 2.5 3.0 3.5
12
13
14
15
16
17
18
19
20
Peel
strength
(N/cm)
Cross-linker content (%)
PVF-PVF (before plasma)
PVF-PVF (after plasma)
(d)
0.5 1.0 1.5 2.0 2.5 3.0 3.5
8
9
10
11
12
13
14
15
16
17
Peel
strength
(N/cm)
Cross-linker content (%)
BOP-Fab (before plasma)
BOP-Fab (after plasma)
(b)

16. 8.9
9.5
11.3
14.7
10.4
12.2
14.8
15
10.2
11.3
14.4
15.6
12.2
14.2
15.3
16.2
14.4
15.1
15.6
17.1
17.1
19.2
18.9
19.5
0
5
10
15
20
25
Without additive With UV absorber With UV absorber +
Antioxidant
With UV absorber +
Antioxidant + HALS
Peel strength (N/cm)
PVF-KEV BOP-KEV PVF-SPC
BOP-SPC PVF-BOP PVF-PVF
Peel strength [ASTM D1876-08]
Effect of additives

17. Peel strength
Effect of weathering
Sample
code
Decrease %
After 100 h After 200 h
PVF-KEV 6.1 10.2
BOP-KEV 5.3 8.0
PVF-SPE 5.8 9.6
BOP-SPE 4.9 7.4
PVF-BOP 3.5 5.2
PVF-PVF 2.1 3.1
14.7 15 15.6 16.1
17.1
19.5
13.2 13.8 14.1 14.9
16.2
18.9
0
5
10
15
20
25
PVF-KEV BOP-KEV PVF-SPE BOP-SPE PVF-BOP PVF-PVF
Peel strength (N/cm)
Before exposure 100 h exposure
200 h exposure

18. Results
[Spectra based laminates]

19. Tensile properties [IS: 7016 (Part II)]
735
749
763
731
725
734
749
763
730
723
700
710
720
730
740
750
760
770
Spectra S1 S2 S3 S4
Tensile strength (N/cm)
Before exposure 100 h exposure
4.5
5.2
5.1
5.7
6.1
4.7
5.1
5.1
5.9
6.3
0
1
2
3
4
5
6
7
Spectra S1 S2 S3 S4
Breaking extension (%)
Before exposure 100 h exposure
Spectra based samples
(a) (b)

20. Gas barrier [ASTM D1434-82]
Spectra based samples
0.05
0.08
0.07
0.12
0.06
0.1
0.09
0.16
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
S1 S2 S3 S4
Helium
gas
permeability
(L
m
-2
day
-1
)
Before exposure 100 h exposure
S1 exhibits
higher gas
barrier property

21. Results
[Kevlar based laminates]

22. Tensile properties [IS: 7016 (Part II)]
805
812
820
798
791
804
809
816
793
788
770
780
790
800
810
820
830
Kevlar K1 K2 K3 K4
Tensile
strength
(N/cm)
Before exposure 100 h exposure
200 h exposure
(a)
6.2 6.3 6.6
7.1
8.2
5.9 6 6.1
6.9
7.8
0
1
2
3
4
5
6
7
8
9
Kevlar K1 K2 K3 K4
Breaking
extension
(%)
Before exposure 100 h exposure
200 h exposure
(b)
Kevlar based samples

23. Tearing properties [MIL-C-21189]
321
511
477
435
448
401
0
100
200
300
400
500
600
Cut Slit Tear strength (N/cm)
Before exposure
Tear strength increases after making
laminates than that of fabric
6
4
1.25
3
Direction
of Pull
Slit
Sample specimen
Method 5100 of
Federal Requirement 191A
“Textile Test Methods”
Dimensions
in inches
Distance
between
clamps

24. Gas barrier [ASTM D1434-82]
0.18
0.22
0.21
0.25
0.2
0.24
0.27
0.28
0
0.05
0.1
0.15
0.2
0.25
0.3
K1 K2 K3 K4
Helium
gas
permeability
(L
m
-2
day
-1
)
Before exposure 100 h exposure 200 h exposure
K1 exhibits
higher gas
barrier property
Kevlar based samples

25. UPF [AATCC 183:2004]
257
1704
1994
1999
1999
1985
96
409
1263
1672
1737
1932
0
500
1000
1500
2000
2500 Kelvar
no
additive
HALS
UV
absorber
UV
absorber+HALS
UV
absorber+HALS
+Antioxidant
UV Protection Factor
Before exposure 100 h exposure
200 h exposure
Kevlar based samples

26. Conclusion
1. The contact angle of the films were significantly decreased and after plasma treatment
2. The crosslinker content of PU adhesive was optimized (2.5-3%)
3. The peel strength of different double layered joints was increased
4. All the laminates performed better in terms of gas barrier and weather resistance properties