1.
COATING METHODS – PREMETERED
SLOT DIE COATING TECHNOLOGY

2.
COATING METHODS - PREMETERED

3.
COATING METHODS - PREMETERED
• Pre-metered vs Self-metered
• Pre-metered = amount of liquid applied to the web per unit area is
predetermined by a fluid metering device upstream
• Self-metered = final wet thickness of the coated film is controlled
by the interactions of the fluid flow with the coating applicator
• The average cross-web weight (thickness) is predetermined before
the fluid is applied to the substrate (Pre-metered)

4.
FLUID DELIVERY SYSTEM
• Fluid Delivery and Line Speed
o Coating weight (thickness)
o Ratio
• Fluid Delivery System
o Positive displacement
o Rheology of fluid
o Density
o Particle size
o Shear sensitivity

5.
TECHNIQUE
• Slot Die Coating Technology
• Direct
• Curtain
• Free Span

6.
TECHNIQUE
• Direct coating
o Shim size
o Coating gap
o Attack angle
o Coating window

7.
TECHNIQUE
• Direct coating
o Advantages
 Cross-web uniformity predictable
 Precision surfaces
o Disadvantages
 Narrow gaps
 12 micron coatings or thicker

8.
TECHNIQUE
• Curtain coating
o Balance of liquid momentum and surface tension
o Uniform pressure across fluid flow between edge guides
o If the coating thickness is smaller, then the web velocity
has to be higher
o Sharp lip edge geometry

9.
TECHNIQUE
• Curtain coating
o Advantages
 Large gap (irregular surfaces)
 Increased fluid velocity
 Higher line speed
 Thinner coatings
o Disadvantages
 Air/Vibration
 Minimum line speed & flow rate
 Neck-in

10.
TECHNIQUE
• Tensioned web
o Elasto-hydrodynamic interaction
 Web tension
 Line speed/flow rate
 Wet coating thickness
 Wrap angles
 Lip geometry
 Web penetration

11.
TECHNIQUE
• Tensioned web
o Advantages
 Overcome gap issues
 Follow profile of web
 Thinner coatings
o Disadvantages
 Web dependent (tensions)
 Process dependent (idlers)

12.
SYSTEM
• Slot Die
• Positioner
• Backing roll
• Fluid delivery system
• Substrate

13.
SYSTEM
• Slot Die
o Manifold design
o Manufacturing tolerances
o Lip offset
o Lip geometry
Distribution
chamber
Feed port
Slot gap
Lip land

14.
SYSTEM
• Slot die design
• Rheology
• Manifold
• Body sections
• Fluid flow control

15.
SYSTEM
• Slot Die
o Fixed lip
o Flex lip
o Rotary rod

16.
SYSTEM
• Positioner
o Attack angle
o Position to roll
o Repeatability

17.
SYSTEM
• Backing roll
o Diameter
o TIR
o Cocentricity
o Cylindricity

18.
FLUID DELIVERY SYSTEM
• Fluid Delivery System
o Positive displacement
o Rheology of fluid
o Density
o Particle size
o Shear sensitivity

19.
SYSTEM
• Substrate
o Variation (RTY)
o Surface energy
o Surface treatment
o Vacuum box
o Tension control

20.
COATING METHODS - PREMETERED

21.
PROCESS
• Full width coating
• Lane coating
• Intermittent coating
• Multi-layer coating
• Dual-sided coating

22.
SUMMARY
• Technique
• System
• Process