Electrostatic spray coating methods

Claim 1

A method of electrostatic spray coating an article comprising the steps of continuously generating a mist of particles of less than 10 microns in size by aspirating coating material from a supply with a downwardly directed gas stream so that the aspirated particles are directed in a downward direction, the heavier particles returning to the supply and the lighter particles flowing upwardly through an outlet port, establishing an electrostatic field having an average gradient less than 10 kilovolts per centimeter between said mist generator outlet port as one electrode and the article to be coated as a second electrode; maintaining a quiescent zone in the atmosphere adjacent the article to be coated, the distance of the article from the output of the mist generator being sufficient to permit substantial dispersion of the spray particles that pass through said outlet port; accelerating said particles under influence of said electrostatic field For deposit on the surface to be coated, said electrostatic field carrying said particles through said quiescent atmosphere so that a substantial portion of the mist particles which would not otherwise have been deposited on said article are deposited on said article, and effecting continuous relative movement between said mist generator and the article surface transverse to the general direction of mist particle movement during particle deposition.

Claim 2

A method of electrostatic spray coating an article comprising the steps of continuously generating a mist of particles of less than 10 microns in size by aspirating coating material from a supply with a downwardly directed gas stream so that the aspirated particles are directed in a downward direction, the heavier particles returning to the supply and the lighter particles flowing upwardly through an outlet port, establishing an electrostatic field having an average gradient less than 10 kilovolts per centimeter between said mist generator outlet port as one electrode and the article to be coated as a second electrode; maintaining a quiescent zone in the atmosphere adjacent the article to be coated, the distance of the article from the output of the mist generator being sufficient to permit substantial dispersion of the spray particles that pass through said outlet port; accelerating said particles under influence of said electrostatic field For deposit on the surface to be coated, said electrostatic field carrying said particles through said quiescent atmosphere so that a substantial portion of the mist particles which would not otherwise have been deposited on said article are deposited on said article, and effecting continuous relative movement between said mist generator and the article surface transverse to the general direction of mist particle movement during particle deposition.

Claim 6

The method of applying a shave facilitating coating to razor blades which comprises the steps of: disposing a multiplicity of razor blades in a stack with their sharpened edges aligned parallel with one another, said edges together defining a plane; providing a dispersion of coating material; continuously generating a mist of particles of less than 10 microns in size from said dispersion of coating material by aspirating material from said dispersion with a downwardly directed gas stream so that the aspirated particles are directed in a downward direction, the heavier particles returning to said dispersion and the lighter particles flowing upwardly through an outlet port, said outlet port facing said plane; establishing an electrostatic field having an average gradient in the range of 4-9 kilovolts per centimeter between said mist generator outlet port as one electrode and said stack of razor blades as a second electrode; maintaining a quiescent zone in the atmosphere adjacent said stack, the distance of said stack from the output of the mist generator being sufficient to permit substantial dispersion of the spray particles; accelerating said particles under the influence of said electrostatic field for deposit on the edges of said blades, said said electrostatic field carrying said particles through said quiescent atmosphere so that a substantial portion of the mist particles which would not otherwise have been deposited on said blade edges are deposited thereon; and effecting continuous relative movement between said mist generator and said blade stack transverse to the general direction of mist particle movement during particle deposition.

Claim 7

The method of applying a shave facilitating coating to razor blades which comprises the steps of: disposing a multiplicity of razor blades in a stack with their sharpened edges aligned parallel with one another, said edges together defining a plane; providing a dispersion of coating material; continuously generating a mist of particles of less than 10 microns in size from said dispersion of coating material by aspirating material from said dispersion with a downwardly directed gas stream so that the aspirated particles are directed in a downward direction, the heavier particles returning to said dispersion and the lighter particles flowing upwardly through an outlet port, said outlet port facing said plane; establishing an electrostatic field having an average gradient in the range of 4-9 kilovolts per centimeter between said mist generator outlet port as one electrode and said stack of razor blades as a second electrode; maintaining a quiescent zone in the atmosphere adjacent said stack, the distance of said stack from the output of the mist generator being sufficient to permit substantial dispersion of the spray particles; accelerating said particles under the influence of said electrostatic field for deposit on the edges of said blades, said said electrostatic field carrying said particles through said quiescent atmosphere so that a substantial portion of the mist particles which would not otherwise have been deposited on said blade edges are deposited thereon; and effecting continuous relative movement between said mist generator and said blade stack transverse to the general direction of mist particle movement during particle deposition.