A rotary atomizing electrostatic coating apparatus includes a plurality of paint nozzles and a solvent nozzle. Each paint nozzle communicates uniquely with a respective paint source separate by respective paint passages which are pathwise separate from each other. In each paint passage, a respective paint valve is installed. When changing a painting color according to the present invention, the paint filling the operating paint nozzle and the paint passage connected thereto is not washed out by a washing solvent, so that the amount of paint wasted when changing the painting color is decreased to substantially zero and the working time period for changing the painting color is also shortened. A corresponding method of use of such an apparatus is also disclosed which reduces the amount of paint wasted and the amount of solvent used during a step of switching from a first paint to a second paint.

The present invention includes a device and a method of applying a coating to a web. The preferred device comprises a feed nozzle coupled to a stiffener coupled to a spring coupled to a position/force adjuster. The feed nozzle comprises a fluid reservoir, a feed pipe, a metering surface, end seals and a back seal. The stiffener spring, as the frame deflects and polymer covered rolls deform, permits the rotation of the feed nozzle so a proper geometry is maintained, permitting increased control and a wider film thickness control range for a specific nozzle shape. This device permits greater film thickness control, ability to process at much higher speeds than currently achievable, and a wider range of film thickness. This device permits coatings to be applied at much wider ranges of rheological characteristics. Coatings can be applied at higher percent solids with improved characteristics. Multiple feed nozzles provide rapid product changeover for greater equipment utilization and higher productivity.

The present invention includes a device and a method of applying a coating to a web. The preferred device comprises a feed nozzle coupled to a stiffener coupled to a spring coupled to a position/force adjuster. The feed nozzle comprises a fluid reservoir, a feed pipe, a metering surface, end seals and a back seal. The stiffener spring, as the frame deflects and polymer covered rolls deform, permits the rotation of the feed nozzle so a proper geometry is maintained, permitting increased control and a wider film thickness control range for a specific nozzle shape. This device permits greater film thickness control, ability to process at much higher speeds than currently achievable, and a wider range of film thickness. This device permits coatings to be applied at much wider ranges of rheological characteristics. Coatings can be applied at higher percent solids with improved characteristics. Multiple feed nozzles provide rapid product changeover for greater equipment utilization and higher productivity.

Two embodiments of end seal design are described, each having preferably three seal lips, one of which differs in the center of its radius of curvature from the center of radius of curvature for the other two seal lips. The end seal is gently spring loaded. In this way the end seal provides a good seal and minimizes spray, spatter, and slinging, and can accommodate various plunge depths and can accommodate various angles of attack of a nozzle upon an application surface such as a web or applicator roll. The nozzle is able to have any of various user-determined angles of attack upon the application surface.

A voltage block comprises first and second reservoirs and a switching device including an inlet port, an outlet port, a first reservoir port and a second reservoir port. The switching device is mounted in a third reservoir for movement between a first position and a second position. The third reservoir includes an electrically non-conductive fluid medium in which at least a portion of the switching device is immersed.