Applicator for shear thinning viscous coating materials

摘要

A pneumatic applicator for shear thinning viscous coating materials that includes a nozzle, an air operated system for dispensing viscous material at a steady rate through the nozzle, and an air directing housing defining an air chamber around the nozzle. The air directing housing defines an air outlet opening for the air chamber around the nozzle. Distal surfaces of the housing and nozzle are close to co-planar and the air outlet opening has an area in the range of about 5 to 15 square millimeters. An adjustable system directs air under pressure into the air chamber so that when the viscous material is dispensed through the nozzle at a generally uniform rate, air can be directed into the chamber and out through the air outlet opening around the nozzle and only the amount of air being directed into the chamber need be adjusted to cause viscous material being dispensed from the nozzle to be applied to a surface adjacent the nozzle in coatings of various widths and thicknesses.