Crimper-propellant fill head

Abstract

In the 'undercap' method of, and closure cap crimper-propellant fill head apparatus for, introducing a charge of volatile propellant in its liquid state into an aerosol container containing product to be dispensed, a significant residual amount of the propellant charge remains in the crimper-propellant fill head bell after the closure cap has been secured in place to seal the container. Not all crimper-propellant head machines are equipped with systems for reclaiming residual propellant, and even when so equipped, it is not always practical to reclaim residual propellant since certain products to be dispensed will foul the reclamation equipment. According to this invention a compressed purge gas is injected into the crimper-propellant fill head bell to purge a substantial portion of the residual propellant into the container before it is sealed by crimping its closure cap on the container mouth. The efficiency of purging with compressed gases is enhanced by providing the crimper-propellant fill head bell with an annular groove on the interior communicating with the purging gas inlet together with a plurality of spaced axial grooves leading from the groove toward the bottom of the bell chamber. Another method of purging residual propellant is to have a sufficient temperature differential between the liquid propellant and the product and a sufficiently low pressure against which the cap can lift so that the residual propellant will be self-purging to a worthwhile extent.