Rheology and Slot Die Coating Technology by Coating Tech Slot Dies
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View this presentation on Rheology and Slot Die Coating Technology given by Mark Miller. This is the presentation from AIMCAL TV's live webinar February 6, 2019.
Rheology and Slot Die Coating Technology by Coating Tech Slot Dies
- 1. RHEOLOGY & SLOT DIE COATING TECHNOLOGY
- 2. SLOT DIE COATING TECHNOLOGY Background System Technique Process Summary
- 3. BACKGROUND Slot die basics Closed system Distribute fluid uniformly Define coat width Maintain temperature
- 4. BACKGROUND Slot die applications Viscosity versus shear rate % Solids Coating thickness Particle size Coating width Line speed Operating temperature
- 5. BACKGROUND Slot die design Rheology Manifold Body sections Fluid flow control
- 6. BACKGROUND RHEOLOGY Viscosity Shear Rate (Stress) o 1-10,000 1/sec
- 7. RHEOLOGY Test methods o ASTM D4440 Parallel plate Cone and Plate Cup and Bob Capillary
- 8. GEOMETRIES BOB and CUP CONE and PLATE PARALLEL PLATE DMA Rotational/Oscillatory Rotational/Oscillatory Rotational/Oscillatory Oscillatory, Creep Very low to medium viscosity Low to high viscosity, constant shear rate across the sample Low viscosity to soft solids, curing studies, dispersions Solids, thermo- mechanical analysis, curing, Tg, Relatively large volume, inertia limitations in oscillatory test Very small volume, measure of normal stresses (elasticity) Very small volume, relatively large gap Stress is force over sample cross section
- 9. BACKGROUND RHEOLOGY Newtonian Polymeric o Shear thinning o Shear thickening 侶 粒 . 侶 粒 . 侶 粒 . 侶 粒 . 侶 粒 .
- 10. BACKGROUND RHEOLOGY Process Knowledge o G (storage) o G (loss) o tan 隆
- 11. SYSTEM Slot Die Positioner Backing roll Fluid delivery system Substrate
- 12. SYSTEM Slot Die o Manifold design o Manufacturing tolerances o Lip offset o Lip geometry
- 13. SYSTEM Slot Die o Manifold design o Slot dimensions Slot height Slot length o Pressure o Velocity o Deckling Distribution chamber Feed port Slot gap Lip land
- 14. SYSTEM Slot Die o Manifold design Infinite cavity (Newtonian) Coat hanger (Polymeric) o Goal = uniform volumetric flow rate and pressure across coat width o Range of viscosity (families)
- 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. 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. SYSTEM Vacuum System Vacmin = (12袖VLD)/dD 3 * ((dD/2)-h)) minimum vacuum required for coating thickness h (LD and dD are downstream lip length and slot die to substrate gap)
- 21. TECHNIQUE
- 23. TECHNIQUE Tensioned web o Elasto-hydrodynamic interaction Web tension Line speed/flow rate Wet coating thickness Wrap angles Lip geometry Web penetration
- 24. TECHNIQUE Curtain coating o Advantages Large gap (irregular surfaces) Reduced lines and streaks Increased fluid velocity (hydrodynamic assist) Higher line speed o Disadvantages Air Vibration Minimum line speed & flow rate
- 25. PROCESS Full width coating
- 26. PROCESS Lane coating o Deckling o Body shim o Lip shims o Spreading (experimentation)
- 27. PROCESS Intermittent coating o Continuous o Discrete panel o IP o Process limitations Head Tail Line speed Start/stop phenomenon
- 28. PROCESS Multi-layer coating o 2-3 layers in typical slot die design o 際際滷 die design accommodates more layers o Separate fluid delivery system for each layer o Combined outside the slot exit top < bottom (surface energy stability)
- 30. SUMMARY System Technique Process