Aerosols valves

Valves. The dispensing valve and actuator serve to close the opening through which the product and frequently the propellant entered the container, to retain the pressure within the container and to dispense the product in the precise form and dosage intended by the manufacturer and expected by the consumer. An aerosol valve shown in Figure 4, consists of seven components. Many variations exist both for special purposes and to avoid existing patents. 

There was a small drop in aerosol compounds in 1990 (2.88 biUion units) as compared to 1989 (2.91 biUion units). Aerosol valve and container production remained high. 3.13 biUion valves were produced in 1990. 320 million of the containers shipped in 1990 were aluminum. 

This will give a can pressure of approximately Aerosol Valve ... 

Cutie, A., Burger, J., Clawans, C., Dolinsky, D., Feinstein, W., Gupta, B., Gruene-berg, A., Sciarra, J. Test for reproducibility of metered-dose aerosol valves for pharmaceutical solutions. J Pharm Sci 70 1085-1987 (1981). 

Here the formulation is made up to between a 500 and 1000 L scale in pressurised vessels and then filled into cans through the aerosol valve, precrimped onto the can. Naturally, appropriate safety precautions have to be made for working with large-scale pressurised systems. With increasing scale, there is the move to increasing automation of the filling process. 

Note that in the case of aerosol valves, the effectiveness of the valve system is likely to depend on how the propellants cause swelling (or shrinkage) of the rubber components, i.e. gaskets. Initial loss and steady loss may therefore have to be quantified, with loss usually reducing after the rubber components have expanded. Since all plastics are to some degree permeable to... 

Metal closures are still in wide use, being manufactured from tinplate, aluminium and alloys of aluminium, and these cover screw closures, various forms of lidding, aerosol valves, overseals (e.g. for vials), etc. 

Crimping—shaping, folding and crimping, e.g. collapsible tubes (metal). Aerosol valves for glass bottles. Overseals for injection vials. 

Swaging—to shape with a swage (a die or grooved block for shaping). Aerosol valve in metal cans (1 inch orifice). 

This is usually used in the liquefied gas form as propellants for aerosols. Filling liquefied gas is usually by volume using a specialist high-pressure pump on a time or flow basis, usually filled backwards through the aerosol valve. Alternatively the aerosol container may be open in a highly refrigerated area, where the liquefied gas is dosed by a piston pump then the container is quickly closed. 

The shape of the container, its material and the closure type to be labelled all have a major influence on the choice of labelling machine. Cylindrical containers are the easiest to label, provided that they are clean and parallel sided with no protrusions anywhere on the plane to be labelled. Any other shape increases the difficulty of label placement and wipedown. If the closure of the container is of the dispensing type, e.g. aerosol valve, holding the container by means of top pressure during labelling will actuate the aerosol. 

Kaopolite SF is a fine, dry powder that is inert, insoluble, non-hygroscopic, and will not deteriorate in dry storage. Its fine particle size promotes good suspension in most liquid systems, and allows it to pass easily through aerosol valves. When incorporated into a product, Kaopolite SF s closely controlled water and oil demand properties yield consistent and economical con unds. 

Film is the third largest market followed by consumer products. Key applications include parts for appliances and power tools, caster wheels for furniture, sports equipment such as ski and snowboard bindings and packaging parts such as lighters and aerosol valves. 

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