Electrospray atomization to create thin, conformal coatings of polytetrafluoroethylene
The method uses electrospray atomization to create thin, conformal coatings of polytetrafluoroethylene (PTFE)and to determine the optimal processing conditions for creating a thin, conformal film of PTFE on razor blades to alleviate the “first-shave” effect. Thin conformal polymer films for 2D and 3D surfaces have numerous applications. Electrospray atomization is a materials versatile technology and can be used to deposit a range of polymeric materials.
Non line-of-sight deposition: Electrospray can deliver material to 3D surfaces that do not have a direct visual line to the emitting orifice. This is necessary to produce a conformal coating.
Dry Deposition: For sufficient emitter-surface separation distance, the emitted droplets will completely evaporate before reaching the target surface. Dry deposition of the polymer avoids the "coffee ring" phenomena that can occur during solvent evaporation of wet deposits. It also permits deposition at sharp corners (an essential feature for razor blade manufacturing).
Deposit Uniformity: The retained electric charge in the deposited mass acts to produce films with unprecedented uniformity.
Controllable Droplet Size: Droplet size can be controlled via the emitter orifice diameter, solution conductivity, and the magnitude of applied voltage.
Ambient Environment Operation: This technology does not require high temperatures or vacuum conditions. It is operable in an ambient environment.
Small volume deposition: Electrospray deposition emits very small volumetric flow rates. This facilitates the formation of ultra-thin films. The small flow rates used for electrospray are inaccessible using HVLP sprayers.