background image
5
ametasolution.com
1 888 452-6382
The principle behind the spray can
The principle behind the spray can is as
simple as it is inspired: using the internal
pressure of the spray can, its contents are
released as an aerosol precisely at the time
you press on the button.
The secret of how it works lies in the mix of
the active ingredient (the actual product) and
the liquid propellant inside the spray can: for
this, one part of the propellant is dissolved
in the active ingredient, and a second part
sits as a gas like a "pressure pad" above the
ingredient-propellant mix. If the button is
depressed, the gas propellant forces the
contents through the valve to the outside. At
that instant, the propellant vaporizes in
fractions of a second, and the active
ingredient that is left behind is distributed
very finely and evenly ­ just the way the
user needs to have his product.
The fineness of these drops is only achieved
using spray cans: the active ingredient is
applied finely, economically and evenly and
dries rapidly. Pump sprays cannot achieve
these unique properties of aerosols, and are
therefore unsuitable for many products.
How a spray can is assembled
The basic component is generally a metal
container: the actual spray can itself, in
tinplate or aluminium. The base of this can
is concave, for two reasons:
· For safety reasons: if overpressure is
generated due to the strong influence of
heat, it allows the base to bend outwards
and thus alleviate the pressure. It means
that the integrity of the spray can is not
compromised despite the overpressure.
· For efficient use of the product: the vertical
feeder tube running down the base against
the inner wall of the can is able to reach the
very last drops of the product when the base
itself is concave.
The valve, the spray head and the protective
cover are located at the top of the metal
container: the valve and spray head are
responsible for "atomising" the product and
for precise dosing. The spray head is
provided with a protective cover. The valve
body is connected to a vertical feeder tube
leading into the inside of the spray can. It
extends down to the base and ensures that
the can is emptied completely and evenly.
The gas phase inside the can also serves as
an expansion space. This ensures that the
filled aerosol can can even withstand
temperatures up to +50 °C.
An essential element in aerosols is the liquid
propellant or propellant gas, since this
generates the pressure needed for spraying.
And ultimately, the even the most
sophisticated design would be nothing
without the product. The active ingredient
which is intended for spraying is similarly in
liquid form and is mixed with the propellant
or propellant gas in the can.
IMPORTANT NOTICE: All information in this brochure is based on our extensive experience, gained over many years, in the manufacture of chemical products and their
application. It is also based on external and internal testing in laboratories and in practical tests conducted in-house.
Due to the variety of the products and their range of possible uses, we recommend that in the specific instance the proposed application is assessed on the basis of
your own operational experience. Technical data sheets and safety data sheets are available for all products, in each case reflecting the latest knowledge and
understanding. Further to this, there are corresponding recommendations on each individual product pack. Due to the range of possible applications, neither the
manufacturer nor the marketing companies domestically or in other countries give a guarantee either expressly or tacitly as to particular outcomes from use of the
product and the durability of same, or for the product lifetimes.
Propellant gas
Active ingredient solution + propellant
Valve
Feed tube
Spray head
Protective cover
Can