Method and machine for coating a surface of a hollow body made of glass

1. A coating machine for coating a surface ( 2 ) of a hollow body ( 1 ) made of glass and constituting a container designed to receive one of food products, pharmaceutical products or cosmetic products, said coating machine including a support ( 7 ) designed to receive said hollow body ( 1 ) and a spray device ( 9 ) designed to spray at least one coating material onto said surface ( 2 ) of said hollow body ( 1 ), said support ( 7 ) and said spray device ( 9 ) being designed to have relative movement imparted to them, said coating machine being characterized in that it is designed so that said relative movement includes rotation of said support ( 7 ) taking place at a velocity that varies as a function of the distance (d) between said spray device ( 9 ) and said surface ( 2 ), while the spray device ( 9 ) is spraying said at least one coating material.

2. A coating machine according to claim 1 , characterized in that it includes servo-control means for servo-controlling the relative velocity to said distance (d) between the spray device ( 9 ) and said surface ( 2 ).

3. A coating machine according to claim 1 , characterized in that it includes a brushless motor designed to adjust the relative velocity while the spray device ( 9 ) is spraying said at least one coating material.

4. A coating machine according to claim 3 , characterized in that said motor is mounted on said support ( 7 ) and/or on said spray device ( 9 ), and is designed to move in rotation and/or in translation at least one of the elements constituted by said support ( 7 ) and by said spray device ( 9 ).

5. A coating machine according to claim 1 , characterized in that said spray device ( 9 ) includes a spray nozzle ( 10 ) designed to be moved in rotation and/or in translation at a relative velocity that varies.

6. A coating machine according to claim 1 , characterized in that said support ( 7 ) includes a fitting ( 7 A) having an axis of rotation (XX′) that is substantially vertical, and designed to be moved in rotation and/or in translation at a relative velocity that varies.

7. A coating machine according to claim 1 , characterized in that said spray device ( 9 ) sprays said material to the form of a spray beam ( 20 ) that is substantially conical in shape.

8. A coating machine according to claim 1 , characterized in that it constitutes a coating machine for coating at least a fraction of the inside wall ( 1 B) of a glass bottle ( 1 ).

9. A coating machine according to claim 1 , characterized in that it constitutes a machine for decorating said surface ( 2 ) with at least one decoration material.

10. A coating machine according to claim 9 characterized in that it constitutes a machine for decorating a glass bottle ( 1 ).

11. A method of coating a surface ( 2 ) of a hollow body ( 1 ) made of glass and constituting a container designed to receive one of food products, pharmaceutical products or cosmetic products, said method comprising:

a step of positioning said hollow body ( 1 ) on a support ( 7 ) designed to receive said hollow body ( 1 ); and

a step of spraying at least one coating material onto said surface ( 2 ) of said hollow body ( 1 ) by means of a spray device ( 9 ), relative movement being imparted to said support ( 7 ) and to said spray device ( 9 );

said coating method being characterized in that said relative movement includes rotation of said support ( 7 ) taking place at a velocity that varies as a function of the distance (d) between the spray device ( 9 ) and said surface ( 2 ).

12. A coating method according to claim 11 , characterized in that said velocity increases when the distance ( 2 ) between the spray device ( 9 ) and said surface ( 2 ) decreases.

13. A coating method according to claim 11 , characterized in that said velocity decreases when the distance ( 2 ) between the spray device ( 9 ) and said surface ( 2 ) increases.

14. A coating method according claim 11 , characterized in that said relative movement includes rotation of said spray device ( 9 ).

15. A coating method according to claim 11 , characterized in that said relative movement includes movement in translation of said spray device ( 9 ) and/or of said support ( 7 ) at a velocity in translation that varies.

16. A coating method according to claim 11 , characterized in that, during the spraying step, said coating material is sprayed in the form of a spray beam ( 20 ) that is substantially conical in shape.

17. A coating method according to claim 11 , characterized in that said relative movement includes a downward movement of said spray device ( 9 ) into said hollow body ( 1 ) and/or an upward movement of said support ( 7 ), in such a manner as to enable at least a fraction of the inside wall ( 1 B) of said hollow body ( 1 ) to be coated.

18. A coating method according to claim 11 , characterized in that said relative movement includes movement in rotation of said support ( 7 ) and movement in translation of said spray device ( 9 ) inside said hollow body ( 1 ), in a manner such as to enable at least a fraction of the inside wall ( 1 B) of said hollow body ( 1 ) to be coated.

19. A coating method according to claim 11 , characterized in that said at least one coating material is chosen from among at least one of the following coating materials: lacquer, sol-gel solution, metal solution, solutions constituted by organometallic resins, varnish, and paint.

20. A coating method according to claim 11 , characterized in that said hollow body ( 1 ) is a bottle ( 1 ).

21. A coating method according to claim 20 , characterized in that said bottle ( 1 ) is designed to contain a pharmaceutical, a care cosmetic, or a perfume.

22. A coating method according to claim 11 , characterized in that said hollow body ( 1 ) is a glass bottle ( 1 ).

23. A coating method according to claim 11 , characterized in that the method is performed to decorate said surface ( 2 ) with at least one decoration material.

24. A coating method according to claim 23 , characterized in that the method is performed to decorate a glass bottle ( 1 ).