The Development of New Disperse Dye Ink for Inkjet Textile Printing

The Development of New Disperse
Dye Ink for Inkjet Textile Printing
Hitoshi Morimoto, Yasuhiko Kawashima
Konica Minolta Technology Center, Inc.
Change of apparel production pattern
●Diversification of preference among people
●Difficulty in prediction of fashion modes
Today’s production
Future production
Large batch
Stock
Small batch
Supplementary
with information feedback
from sales
1
Speeding up production time by IJ printing
Traditional
(Screen print)
Inkjet
5days
10days
15days
20days
25days
●Design
●Trace
●Plate making
●Sample proofing
●Print
○Fixing & Finishing
●Design
●Digital image processing
●Sample proofing
●Print
○Fixing & Finishing
30days
35days
40days
45days
50days
55days
60days
2
New Inkjet Textile Printing System for production
High quality & productivity & reliability
3
Features of the new printer
Print speed (max)
Head number
Nassenger Ⅱ
10m2/h
64 nozzle
× 8 head
Head drive frequency
c.a. 2 times
c.a. ¼
Droplet size
Fabric drive
Ink Type
Nassenger V
60m2/h
256 nozzle
× 16 head
Roller drive
Belt drive
Disperse, Reactive Disperse, Reactive
Requirements:
new inks for high speed and small droplets printing
4
Droplets slow down upon intermittent firing
Dry
Wet
condition
condition
Pigment
Ink
Vaporization
Disperse
Ink
Vaporization
+?
What is “?”; what causes the slow down?
5
Features, difficulties and targets
Disperse dye inks:
1- For polyester fabrics
2- Hydrophobic dyes dispersed in an aq. media.
3-High colorants’ conc. for high printing density
Difficulties and targets:
1- High stability for ink storage
NIP19: 2003, International Conference on Digital Printing Technologies, 630-632.
2- High stability for firing
6
Slow down by viscosity thickening
v ∝ f(viscosity, surface tention)
1
1
1
0.8
0.7
0.1
0.6
droplet speed ratio
0.9
η/Pa・s
droplet speed ratio
0.9
0.5
thickening
0.8
0.7
0.6
0.5
0.4
0.01
0.4
0
2
4
fire interval/s
6
1
0
2
4
10 fire interval/s100
Shear Rate/s
6
1000
-1
@ wet condition
7
Flocculation to viscosity thickening
10
1
G''
G', G''/Pa
η/Pa・s
1
0.1
0.1
G'
0.01
0.01
1
10
100
1000
0.001
1
shear rate/s-1
ω/rads
shear
Flocculation
10
100
-1
shear
Agglomeration
8
Dyes cause the flocculation
Dispersants
Independent on dispersants conc.
Dyes
Dependent on dyes
9
Flocculation vs dyes’ hydrophobicity
10
1
8
DyeA
DyeE
DyeC
Yield Stress/Pa
γSP+γSH/mNm
-1
DyeB
6
4
DyeD
0.1
DyeC
DyeB
DyeD
2
DyeE
0
DyeA
0.01
30
35
40
γSD/mNm
45
50
0
-1
2
4
γ SP +γ SH /mNm
6
8
-1
More hydrophobic
more flocculating
10
“?” = flocculation/hydrophobicity
wetting
Air
adsorption
Solvent
Pigment inks Vaporization
Disperse inks Vaporization
+ Flocculation
Hydrophobicity
11
A wetting agent improved rheologic properties
Less flocculating = less hydrophobic
combination with a wetting agent
1
η/Pa・s
Yield Stress/Pa
1
0.1
0.1
0.01
0
2
4
γSP +γSH/mNm
6
-1
8
0.01
1
10
100
Shear Rate/s
1000
-1
12
High stability for intermittent firing
1
droplet speed ratio
0.9
0.8
0.7
0.6
0.5
0.4
0
2
4
6
fire interval/s
Slow down by intermittent firing was improved greatly.
13
Summary
¾ Disperse dye inks showed poorer firing properties
than pigment inks did.
¾ Dyes’ flocculation caused the slow down as well as
vaporization of inks.
¾ Dyes’ hydrophobicity caused the flocculation.
¾ A wetting agent improved the firing properties.
¾ We finally succeeded to develop a highly stable (for
firing & ink & image) and safe disperse inks.
14
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