The precision standard for fluid coating
Slot die coating has become the method of choice for applications where coating precision, process control, and product cleanliness are non-negotiable. A metering pump delivers fluid at a controlled rate into a precision-machined die, which distributes it uniformly across the coating width and deposits it onto a moving web substrate.
What makes slot die fundamentally different is that it is pre-metered. The coat weight is determined by the pump flow rate and line speed rather than by rollers, blade gaps, or other mechanical variables. This gives the operator direct, quantitative control over the amount of material applied.
The closed fluid path from pump through the die body minimizes contamination, reduces solvent evaporation, and prevents skinning. For pharmaceutical, battery electrode, and other formulations where composition drift is unacceptable, this is a significant process benefit.
How the die works
A slot die is a precision-machined body split into upper and lower halves. Inside is a contoured manifold that distributes fluid uniformly to the full coating width. Internal flow surfaces are precision micro-ground and diamond-lapped to mirror finishes, and die body flatness is held to exacting tolerances over the full coating width. The slot opening is set using precision body shims. A die hinge allows the upper half to be opened in place for cleaning.
The complete coating station
IMC slot die stations mount the die on precision servo-positioned carriages. The die is precisely loaded and referenced for repeatable positioning. The backing roll is chrome-plated and ground to matching TIR tolerances. Bead stabilization is engineered into the station for stable coating at speed.
Fluid delivery and coat weight control
Progressive cavity metering pumps deliver smooth, low-pulsation flow. A Coriolis-type mass flow transmitter simultaneously measures flow rate, fluid density, and temperature — enabling true closed-loop coat weight control with automatic compensation for batch-to-batch variation.
Coating configurations
Continuous coating
Uniform layer across the full web. Standard for battery electrodes and barrier films.
Intermittent (patch) coating
Discrete registered zones with clean edges. Used in transdermal patches and pouch cell electrodes.
Stripe coating
Multiple parallel lanes defined by die shim geometry.
Dual-side coating
Two sequential stations, each with its own dryer, for independent control per side.
Applications
- Battery electrode manufacturing
- Medical and transdermal drug delivery
- Functional films and printed electronics
- Display and optical coatings
- Filtration membrane casting
- Emerging thin-film applications including perovskite solar cell coating →