Aerosol containers for foaming and delivering aerosols

An aerosol container for foaming an aerosol composition therein prior to expulsion from the container, and then expelling the resulting foam, comprising, in combination, a pressurizable container having a valve movable between open and closed positions, with a valve stem, a foam-conveying passage therethrough and a delivery port in flow connection therewith;

• bias means for holding the valve in a closed position;
• and means for manipulating the valve against the bias means to an open position, for expulsion of aerosol foamed composition within the container via the valve passage and delivery port;
• means defining at least two separate compartments in the container, of which a first compartment has a volume of at least 0.5 cc and is in direct flow connection with the valve passage, and a second compartment is in flow connection with the valve passage only via the first compartment;
• at least one first liquid tap orifice having a diameter within the range from about 0.012 to about 0.2 cm and communicating the first and another compartment for flow of liquid aerosol composition into the first compartment from the other compartment, and of sufficiently small dimensions to restrict flow of liquid aerosol composition therethrough;
• the ratio of first compartment volume/first orifice diameter being from about 10/x to about 400/x, where x is 1 when the orifice length is less than 1 cm, and 2 when the orifice length is 1 cm or more;
• at least one second gas tap orifice having a total cross-sectional open area within the range from about 4 .times. 10.sup..sup.-5 to about 1.3 .times. 10.sup..sup.-2 cm.sup.2 and communicating the first and second compartments for flow of propellant into the first compartment from the second compartment therethrough, and of sufficiently small dimensions to restrict flow of propellant gas and form bubbles of such gas in liquid aerosol composition across the line of flow thereof to the valve, thereby to foam the aerosol composition upon opening of the valve to atmospheric pressure, and to expel foamed aerosol composition through the open valve.