Spraying method and device for applying a film to a workpiece

摘要

A spray gun for applying a film to a workpiece has a spray head provided with an annular nozzle designed to discharge material which is to undergo pneumatic atomization. A second annular nozzle surrounds the pneumatic material discharge nozzle and is designed to discharge atomizing air for pneumatic atomization of the material issuing from the pneumatic material discharge nozzle. The spray head is further provided with an additional material discharge nozzle designed to discharge material which is to undergo hydrostatic atomization. The hydrostatic material discharge nozzle is disposed centrally of, and is surrounded by, the pneumatic material discharge nozzle. The hydrostatic material discharge nozzle forms a first spray of hydrostatically atomized material while the annular nozzles form a hollow conical second spray which surrounds the first spray when both sprays are on simultaneously. The spray gun is capable of creating a spray pattern exhibiting the characteristics of a pneumatically generated spray as well as the characteristics of a hydrostatically generated spray. The material supplied to the pneumatic material discharge nozzle may be the same as that supplied to the hydrostatic material discharge nozzle or each of these nozzles may be supplied with a different component of a two-component substance.