A dispensing head for air assisted and airless application of a material to a surface includes a cylindrical barrel having a supply passage therein for the material to flow from a source to a nozzle. The barrel includes at one end a nozzle seat that slideably receives a nozzle body. The nozzle body has a bore that opens at one end to the barrel passageway, and at another end has a nozzle tip with an orifice through which material is dispensed. The nozzle body has a groove formed therein that receives a seal. When the nozzle body is inserted into the nozzle seat, the seal is compressed between the nozzle groove wall and a wall of the nozzle seat to hold the nozzle within the nozzle seat during further assembly of the dispensing head. The seal is preferably captured and isolated from a set of air jets that are formed in the nozzle body, thereby preventing the seal for blocking the air jets.
A method of applying liquid adhesive to surfaces of components of an electrochemical cell employing a needle valve applicator. The liquid adhesive is applied by dispensing it through a tubular tip connected to a pneumatically actuated needle valve applicator. The method is effective in applying adhesive to narrow width or difficult to reach surfaces of cell components in a precise, consistent and reproducible manner. In a specific application the adhesive can be applied to the narrow recessed step surrounding the terminal portion of the cathode casing of a zinc/air button cell. In such application the cathode casing may typically be rotated at speeds of between about 50 and 1000 revolutions per minute as adhesive is applied thereto from the applicator. The adhesive provides a tight seal between the cathode casing and cathode assembly, thereby preventing leakage of electrolyte from the cell.
