Apparatus for applying lubricating materials to metallic substrates

• US 4,221,185 A
• Filed: 01/22/1979
• Issued: 09/09/1980
• Est. Priority Date: 01/22/1979
• Status: Expired due to Term

• Current Assignee: Ball Corporation
• Original Assignee: Ball Corporation
• Inventors: Scholes, Addison B., Dollar, David L.
• Primary Examiner(s): Hoffman, James R.
• Application Number:
  US06/005,084
• Time in Patent Office: 596 Days
• Field of Search: 118/638, 118/634, 427/32
• US Class Current: 118/634
• CPC Class Codes: B05B 5/001 incorporating means for heating or cooling, e.g. the material to be sprayed
• CPC Class Codes: B05B 5/14 specially adapted for coating continuously moving elongated bodies, e.g. wires, strips, pipes

Abstract

Apparatus for generating and substantially uniformly electrostatically dispersing very finely divided lubricating particles onto the surface of an electrically conductive substrate. In this apparatus, lubricant material is atomized into a spray of particles of various sizes. Larger particles are removed from the spray by gravity, airflow and other forces. The remaining cloud of extremely small particles is delivered to a housing. The housing is preferably constructed from electrically non-conductive material and is structured to maintain the cloud of small particles in a substantially quiescent suspension between electrodes spaced from the conductive substrate within the housing. An ionization discharge is maintained by a voltage differential between the electrodes and the substrate to electrically charge the small particles in the cloud for deposition substantially entirely by electrostatic forces.

Claims

1. Apparatus for electrostatically coating metal sheets with a lubricant, comprising a housing having a first wall with an entry opening defined therein, a second laterally spaced wall having an exit opening defined therein, such entry and exit openings being of a size such as to readily accommodate movement of the sheet over a path between said openings through said housing, said housing including a chamber sufficiently remote from said path and providing a sufficient degree of confinement of the atmosphere within said chamber so as to maintain a substantially quiescent atmosphere within said chamber, charging electrode means, a lubricant supply opening into said chamber and spaced from the said charging electorde means a distance such that lubricating particles can be initially confined and dispersed within said chamber without being appreciably affected by electrical ionization from said charging electrode means, lubricant supply means for providing a fluid supply of said lubricant, particle forming means to provide a plurality of lubricating particles into said chamber through said lubricant supply opening, said particle forming means providing lubricant particles having a diameter to weight ratio such that they will remain suspended in the substantially quiescent atmosphere of the chamber, and means for moving quiescently said particles into said chamber and for introducing said particles uniformly within said chamber for charging and deposition on sheets moving over said path.

2. Apparatus for electrostatically dispersing tiny spheroids of lubricating material onto a moving electrically conductive substrate, said apparatus comprising:

means providing a supply of said lubricating material in liquid form;

means forming a cloud of finely divided spheroids from said supply of liquid lubricating material;

means providing a housing through which said conductive substrate is passable longitudinally thereof, said housing forming a chamber sufficiently remote from the moving conductive substrate to maintain a substantially quiescent atmosphere of spheroids of lubricating material within said chamber;

means providing electrodes being spaced from said moving substrate within said chamber and adapted to inhibit the collection of lubricating material thereupon;

means producing an electrical ionization discharge within said chamber by creating a voltage differential between said moving substrate and said electrodes;

means drifting said airborne spheroids into said chamber;

said means drifting including means to maintain substantially all of said spheroids in a substantially quiescent state and to introduce the spheroids into the chamber at a location substantially free of ionization discharge for drifting into said chamber and to permit substantially all of the spheroids to be charged in a substantially quiescent atmosphere and to move toward the substrate surface substantially entirely by the influence of electrostatic forces.

3. Apparatus as in claim 2 wherein said housing portion forming said chamber is electrically non-conductive, said electrodes are wires extending transversely of the chamber and supported only by the electrically non-conductive housing portion forming said chamber.

4. Apparatus as in claim 2 wherein said chamber is several times greater in volume than said means drifting to maintain average spheroid movements of distance per unit time towards and into said chamber which are less than the average substrate movements of distance per unit time through said housing.

5. Apparatus as in claim 4 wherein said means included in said means drifting is adapted to cause average spheroid movements less than approximately one foot per second while said average substrate movements are greater than approximately three feet per second.

6. Apparatus as in claim 2 wherein said means providing a supply of said lubricating material in liquid form and said means forming a cloud comprise:

means providing a substantially closed container housing with an outlet port at the upper portion thereof and including means to liquefy said normally non-fluid lubricating material to comprise said supply of liquid lubricating material and having means to atomize said liquefied lubricating material by compressed air;

said air atomizing means directing a flow of compressed air through an orifice downwardly toward said supply of liquid lubricating material and generally away from said outlet port;

means supplying a stream of said liquefied lubricating material to said air atomizing means to be broken into liquid spheroids of various sizes and propelled downwardly towards said supply of liquid lubricating material and away from said outlet port to remove the larger particles whereby said finely divided spheroids flow out through said outlet port.

7. An apparatus for applying a lubricating material upon a metallic substrate comprising:

means for generating a supply of finely divided particles having an average particle size of less than about 10 microns diameter;

first means associated with said generating means for containing the supply of finely divided particles within a closely confined space;

second means being located adjacent said first means and including an electrically non-conductive housing several times greater in volume than said first means to maintain a substantially quiescent atmosphere of particles and to support an electrode means adapted to inhibit the collection of lubricating material thereupon;

means for impressing a high direct current potential across the substrate and said electrode means situated within said second means, said electrode means extending transversely the width of the substrate and defining one terminus of an electrostatic field; and

means for advancing the substrate through said field.

8. The apparatus as recited in claim 7 wherein the generating means includes a chamber having an atomizer and means in communication with said atomizer for issuing a gas therethrough, and means associated with said chamber for supplying the lubricating material to said atomizer for formation of said particles.

9. The apparatus as recited in claim 8 including means adapted to said chamber for heating the lubricating material.

10. An apparatus for dispersing small lubricating particles substantially uniformly and randomly across at least one surface of a moving conductive substrate, comprising:

means for forming a plurality of particles of a lubricant and

means for separating and providing particles having an average size of less than about ten microns diameter;

a precipitation chamber formed by a housing extending about at least one surface of said substrate;

means for slowly migrating said particles from said separating means into said precipitation chamber, said means including an orifice into said chamber, said precipitation chamber having sufficient depth remote from the moving substrate to maintain said particles in a uniform substantially quiescent cloud distributed throughout and moving randomly within said chamber;

a charging electrode means positioned in said precipitation chamber and adapted to inhibit the collection of lubricant thereon, said orifice through which particles migrate into said chamber being located remote from the charging electrode means; and

means for energizing said charging electrode means to provide an ionization discharge to charge the atmosphere about said electrode means and said randomly moving particles within said chamber and to accelerate said particles onto said moving substrate.

11. The apparatus of claim 10 wherein said lubricant is normally solid at room temperature and wherein said particle forming means further comprises:

means for storing said lubricant;

means for heating said lubricant to liquefy said lubricant in said storing means; and

means to atomize the liquefied lubricant and direct the atomized lubricant in the direction of said storing means to remove the large spray particles;

the remaining particles being urged into said means for slowly migrating said particles through said orifice into said precipitation chamber.

12. Apparatus for electrostatically depositing normally non-fluid lubricating material on a substrate comprising:

a housing having at least one opening and encompassing the substrate on at least one side;

means to move the substrate into and out of the housing along a path;

heating means to liquefy the normally non-fluid material;

means to form the liquefied material into a spray of finely divided particles and to permit the return of the spray of finely divided particles to their normally non-fluid state and to supply said spray to said housing for deposition on the substrate;

electrode means within the housing and spaced from the path of the substrate;

high voltage means connected to said electrode means to create electrostatic charging and deposition of the spray particles on the substrate; and

means to heat said electrode means and prevent an accumulation of non-fluid material on said electrode means.

13. Apparatus as set forth in claim 12 wherein said electrode means includes wires supported with in the housing and said means to heat said electrode wires includes a low voltage means creating a flow of current in the wires.

14. Apparatus for manufacturing a lubricated substrate of electrically conductive material comprising:

a housing of electrically non-conductive material having at least one opening, encompassing the substrate on at least one side and being structured to provide a chamber remote from the substrate and to maintain a substantially quiescent atmosphere within the chamber;

first means to liquefy a normally non-fluid lubricating material;

second means to divide the liquefied lubricating material into a spray, to remove from said spray the larger particles whose weight to diameter ratio is such that they will not remain suspended in substantially quiescent atmosphere, to permit the return of the spray of remaining finely divided particles to their normal non-fluid state and to deliver an airborne suspension of the remaining particles to said housing on said at least one side of the substrate;

electrode means within the housing and spaced from said at least one side of the substrate; and

means to apply voltage to said electrode means of sufficient magnitude to create a charging field to charge and deposit small particles of lubricating material on said substrate from the substantially quiescent atmosphere within the housing.

15. Apparatus for electrostatically depositing normally non-fluid lubricating material on a substrate comprising:

a housing having at least one opening and encompassing the substrate on at least one side;

means to move the substrate into and out of the housing along a path;

heating means to liquefy the normally non-fluid material;

means to form the liquefied material into a spray of finely divided particles and to permit the return of the spray of finely divided particles to their normal non-fluid state and to supply said spray to said housing for deposition on the substrate;

wire electrode means supported within the housing and spaced from the path of the substrate;

high voltage means connected to said electrode means to create electrostatic charging and deposition of the spray particles on the substrate; and

low voltage means to create a flow of current in said wire electrode means to heat said electrode means and prevent an accumulation of non-fluid material on said electrode means.

16. Apparatus for electrostatically dispersing tiny spheroids of lubricating material onto a moving electrically conductive substrate, said apparatus comprising:

means providing a supply of said lubricating material in liquid form;

means forming a cloud of finely divided spheroids from said supply of liquid lubricating material;

means providing a housing through which said conductive substrate is passable longitudinally thereof;

means providing electrodes within said housing, said electrodes being spaced from said moving substrate;

means for heating said electrodes to prevent any accumulation of said lubricating material thereon;

means producing an electrical ionization discharge within said housing by applying a voltage differential between said moving substrate and said electrodes;

means drifting said airborne spheroids into said ionization discharge to permit an electrical charge to accumulate on said spheroids;

said means drifting including means to maintain substantially all of said spheroids in a substantially quiescent state and to permit substantially all of the charged spheroids to move toward the substrate surface substantially entirely by the influence of electrostatic forces.

17. Apparatus for forming a lubricious surface on a moving metallic substrate, comprising:

means for heating a non-fluid lubricating material to provide a liquid supply of lubricating material;

means for forming a plurality of finely divided fluid particles of lubricating material having a diameter to weight ratio such that the particles will remain substantially suspended in atmosphere;

means providing a housing having at least one opening, encompassing the substrate on at least one side and adapted to maintain a substantially quiesent atmosphere within the housing;

means to deliver a substantially quiescent cloud of particles of lubricating material within the housing in their normal non-fluid state;

electrode means within the housing spaced from the path of the substrate and located within the substantially quiescent atmosphere, said electrode means being adapted in size and shape to create an ionization discharge when connected to a source of high voltage and adapted to inhibit the collection of lubricating material thereupon;

means to move the substrate into and out of the housing along a path; and

high voltage means to charge said electrode means to such electrical potential to create an ionization discharge and charging and deposition of the particles of lubricating material on the substrate within the housing.

18. Apparatus for electrostatically dispersing tiny spheroids of lubricating material onto a moving electrically conductive substrate, said apparatus comprising:

means providing a supply of normally non-fluid lubricating material in liquid form and forming a cloud of finely divided spheroids including;

a substantially closed container housing with an outlet port at the upper portion thereof and including means to liquefy said lubricating material and to provide said supply of liquid lubricating material and further including means to atomize said liquefied lubricating material by compressed air, said air-atomizing means directing a flow of compressed air through an orifice downwardly toward said supply of liquid lubricating material and generally away from said outlet port, and

means supplying a stream of said liquefied lubricating material to said air atomizing means to be broken into liquid spheroids of various sizes and propelled downwardly towards said supply of liquid lubricating material and away from said outlet port to remove the larger particles whereby said finely divided spheroids flow out through said outlet port;

means providing a housing through which said conductive substrate is passable longitudinally thereof;

means providing electrodes being spaced from said moving substrate;

means producing an electrical ionization discharge within said housing by creating a voltage differential between said moving substrate and said electrodes;

means drifting said airborne spheroids into said ionization discharge to permit an electrical charge to accumulate on said spheroids;

said means drifting including means to maintain substantially all of said spheroids in a substantially quiescent state and to permit substantially all of the charged spheroids to move toward the substrate surface substantially entirely by the influence of electrostatic forces.

19. Apparatus for manufacturing lubricated substrate comprising

means forming a deposition chamber of electrically non-conductive material;

means to move the substrate into and out of the chamber along a path;

charging electrode means supported by said means forming the deposition chamber within said chamber and spaced apart from the path of the substrate and adapted to create an ionization discharge and to inhibit the collection of lubricating material thereupon;

means to liquefy a normally non-fluid lubricating material, to form a spray of particles from the liquefied lubricating material, to divide from said spray the spray particles whose weight to diameter ratio is such that they will not remain suspended in a substantially quiescent atmosphere and to direct the remaining particles in a substantially quiescent state into the deposition chamber at a location spaced apart from the charging electrode means while permitting their return to their normally non-fluid state; and

means to apply voltage to said electrode means of sufficient magnitude to create an ionization discharge and to charge and deposit particles of lubricating material on the substrate.

20. Apparatus for manufacturing a lubricated substrate comprising

a housing having at least one opening and encompassing the substrate on at least one side;

means to move the substrate into and out of the housing along a path;

means to form a spray of particles from a normally non-fluid lubricating material, to remove from the spray the larger particles whose weight to diameter ratio is such that they will not remain suspended in a substantially quiescent atmosphere, to permit the return of the spray of remaining finely divided particles to their normal non-fluid state, and to deliver an airborne suspension of the remaining particles to said housing in a substantially quiescent state;

electrode means within the housing spaced from the path of the substrate, said electrode means being adapted in size and shape to create an ionization discharge when connected with a source of high voltage and to inhibit the collection of lubricating material thereupon; and

means to apply voltage to said electrode means of sufficient magnitude to create an ionization discharge and to charge and deposit said particles of lubricating material on the substrate.