When faced with depositing a low viscosity liquid film on a wire, process engineers usually rely on wire coating by withdrawal. This process is referred to technically as Free-Meniscus Coating or more simply “dip coating.” The dip coating process offers the following advantages
- Superior wall uniformity (+/- 10 percent)
- Coating thickness controlled by the liquid viscosity, surface tension, solids content, and wire speed
- The process is effective with the liquid viscosity ranging from 1 to 250 cps
- For a liquid viscosity greater than 500 cps, the use of enameling dies is recommended
We offer the schematic below of the major components required for implementing the dip coating process using our MWS units. Our process allows a multi-pass system to be implemented in a small form factor (and thus less liquid dispersion to be used as part of the process).
Some implementations of the wire dip coating process immerse the whole roller system into the dispersion liquid. There are several disadvantages to this process which include the following:
- Larger lot size of dispersion/liquid required
- It is more difficult to prevent contamination of the material (larger open surface area)
- Cleaning of the tank/rollers takes longer
- Since the surface area is larger, material evaporation will be larger
