Learn more about intermittent coating, a method of slot die coating. This type of coating is particularly useful in pharmaceutical/medical and energy storage products industries.

1. INTERMITTENT
COATING

2. BACKGROUND
• We.ng
– Surface
energy
modifica=on
• Pump
Control
– Valve
control
(=ming)
– Physical
movement
(=ming)
• Physical
Posi=on
– Liquid
(vapor)
adsorp=on
• Distance
• Roughness
• Concentra=on

3. INTRODUCTION
• Con=nuous
• Discrete
Panel
• Process
limita=ons
– Head
– Tail
– Line
speed
– Start/stop
phenomenon

4. PATENTS
• US
4,938,994
– Edward
Choinski
(1990)
• Flow
control
• Mechanical
movement

5. PATENTS
• US
5,360,629
– Thomas
Milbourn
and
Jerry
Barth
(1994)
• Con=nuous
web
• 3-­‐way
valve
– Time
limita=on
• Mul=ple
sta=ons

6. PATENTS
• US
5,824,156
– Watanabe
et
al
(1998)
• Con=nuous
web
• Internal
shut-­‐off
bar

7. SPECIFICATIONS
• Coat
width
=
340
mm
• Coat
length
=
680
mm
• Intermibent
coa=ng
capability
required
up
to
10
mpm
(30
mpm
in
further
study)
with
maximum
3
mm
tail
allowed
• Crossweb
varia=on
tolerance
based
off
weight
(5
+/-­‐0.15
mg/cm2).
• Required
coa=ng
speed:
at
least
10
mpm
for
a
slurry
with
loading
of
6
mg/cm2
and
50
solid
%
• Coa=ng
edge
quality
to
match
crossweb
coa=ng
varia=on
capability
• Tension
control
improvement
to
match
downweb
coa=ng
varia=on
capability
based
off
weight
(5
+/-­‐0.15
mg/cm2)

8. SPECIFICATIONS
• Head
&
Tail
development
– Crossweb
caliper
control
– Velocity
gradient
– Pressure
gradient
– Volumetric
flow
• Edge
effects
– Surface
tension
– Film
stretching
– Die
swell
• Patch
control
– Computer
control
and
programming
(die
posi=oner,
valve
and
web
control)
– Electrical
response
(valve
and
physical
movement)

9. EXPERIMENTAL
• Anode
– Water-­‐based
(shear
thinning)
– Copper
substrate
• Cathode
– NMP-­‐based
(shear
thinning)
– Aluminum
substrate

10. EXPERIMENTAL
• Slot
die
setup
– Offset
=
0
– Lip
face
(upstream
and
downstream)
=
762
micron
(0.030
inch)
– Shim
thickness
=
500
micron
(20
mil)
– Coa=ng
gap
=
25
micron
(1
mil)
– Coa=ng
width
=
340
mm
(13.38
inch)

11. RESULTS
• Simula=on
feedback
– Pressure
– Velocity
– Volumetric
flow
– Mass
flow
• Tension
and
compression
– Flow
stability
– Stagna=on
zones
– Die
swell

12. RESULTS
• Line
speed
increase
– Parallellism
worsens
• We.ng
• Reac=on
=me
• Pressure
increase
– Fluid
velocity
increase
– Measure
and
balance
around
valve
• Edge
effects
– Stresses
(surface
tension,
film
stretching
or
die
swell)
– Draw
ra=o
(substrate
speed/fluid
speed)
– Slot
die
design
and
simula=on
• Air
– Excessive
fluid
flow

13. CONCLUSION
• 10
mpm
acceptable
applica=on
speed
• Best
setup
(reduced
head/tail,
reduced
edge
bead
and
improved
parallel
edge)
– Flow
control
– Mechanical
movement
• FUTURE
– Increased
line
speed
(30
mpm
+)
– Alterna=ve
technologies
– Mul=ple
sta=ons
– Surface
modifica=on
effect
– Vacuum
effect