Method for applying lubricating materials to metallic substrates

A method for electrostatically dispersing tiny spheroids of lubricating material onto a moving electrically conductive substrate, said method comprising the steps of:

• providing a supply of lubricating material in a liquid phase;
• forming a mist of finely divided spheroids from said supply of liquid lubricating material, a majority of said spheroids having an average diameter less than 10 microns in size such that said mist is airborne and substantially independent of gravity forces;
• providing a housing through which said conductive substrate is passable longitudinally thereof, the housing having electrodes extending therewithin, said electrodes being spaced from said moving substrate;
• producing an electrical corona discharge within said housing by applying a voltage differential between said moving substrate and said electrodes to thereby produce a plasma therewithin of electrically charged ambient gaseous molecules electrically charged to the same polarity as the electrical polarity existing on said electrodes;
• drifting said airborne mist into said plasma to produce multiple collisions between said charged ambient gaseous molecules and said relatively larger spheroids, thereby accumulating a like electrical charge on said spheroids;
• said drifting step being carried forth so as to cause substantially all of said spheroids to attain a substantially uniform maximum charged state whereupon substantially only electrostatic forces cause substantially all of the thusly charged spheroids to move toward the oppositely charged substrate surface and to substantially uniformly disperse thereover whereby substantially all the spheroids drifted into said plasma are eventually uniformly dispersed onto the substrate surface to produce a uniform steady state percentage coverage of the substrate that is defined primarily only by the steady state quantity of spheroids drifted into the plasma and by the steady state speed of the substrate moving through said housing.

A method for applying a lubricating material upon a metallic substrate comprising:

• forming a mist of finely divided particles of said lubricating material from a plurality of mist sources, the particles of said material having an average size of less than 10 microns diameter;
• passing the particles from said plurality of mist sources into a first containing means extending along the width of said metallic substrate and having a substantially quiescent atmosphere therein and permitting said particles from the different sources to diffuse together therein and form a substantially uniformly distributed mist of said particles along the entire width of the substrate;
• passing the particles from said first containing means into a second containing means having an electrostatic field therewithin while maintaining the particles within a closely confined space within the electrostatic field whereby said particles are charged therein;
• and
• conveying the metallic substrate through said second containing means while establishing an attracting electrical field between said confined charged particles and said metallic substrate so as to electrostatically deposit the lubricating material upon said substrate.

A method of dispensing small lubricating particles substantially uniformly and randomly across at least one surface of a moving conductive substrate comprising the steps of:

• forming in an atomizer a plurality of droplets of a lubricant,
• filtering said droplets to form a mist of finely divided droplets having an average size of less than about ten microns diameter,
• slowly migrating said droplets into a nonconductive precipitating chamber,
• distributing said droplets substantially uniformly about said chamber,
• moving said droplets substantially randomly within said chamber,
• moving a conductive substrate through said chamber, and
• continually charging said droplets with respect to said conductive substrate until said droplets are accelerated toward said substrate to form a substantially uniform and random distribution of said droplets on at least one surface of said substrate.