Flammable chemical products with thin viscosities that are
filled into narrow opening bottles, cans and canisters and be filled on either
the Overflow Filling Machine or the Time Gravity Filling Machine. The overflow
filling machine is the filling machine of choice for distilled products filled
in glass and plastic bottles in the liquor industry. The primary reason
for this is that the fill height of the containers are visible to the consumer
and the overflow filling machine guarantees that all bottle fill heights will be
the same within 1/16". This is particularly important in the case of
liquor filled into glass bottles where the manufacturing variances of the glass
can be significant.
Solvents such as acetone and
methanol that are filled in semi translucent bottles are also best filled on
this type of filling machine since the fill height in the bottle is also readily
apparent to the consumer.
Some flammable products
should not be pressurized because the flashpoint of the product may be lowered
to a level that makes it unsafe for commercial filling operations. Also,
continued recirculation of the product in an overflow filling machine could
increase venting of the product to unsafe levels depending on the operator's
control and design of the hazardous location filling area.
(click to enlarge)
|Time Gravity Filling Machine
for Flammable Chemicals
Like the overflow filling
machine for flammables described above, the Time Gravity Filling Machine is also
useful for flammable chemical products with thin viscosities into narrow opening
bottles, cans and canisters. It is also useful for filling large containers of
solvent based chemicals where the top of the container cannot be sealed and
where it is not practical to pressurize or recirculate the product.
there are inherent accuracy issues with time gravity filling machines, they are
relatively cost effective machines and the producers are generally not as
concerned about precision of filling accuracy of these commodity based products.
Also, since these machines are often used for bulk filling applications of
flammable products, the accuracy errors produced by timing errors become
relatively small as a percentage of total fill volume.
Filling Machine for Flammable Chemicals
The most common types of flammable products filled in a
piston filling machine are solvent based coatings and paints into cans and to a
lesser degree, into bottles. Coatings and paints by nature are thicker viscosity
and require a positive displacement delivery system to fill a precise quantity
of product under pressure regardless of viscosity changes. Products like paint
would be too thick to recirculate in an overflow filling machine or flow out of
a time gravity filling machine.
Many piston fillers on the market use
pneumatic only logic control for operation because the piston filling machine
operating system is quite simple; only manual adjustments are made to change the
fill volume. Although piston fillers do have a disadvantage in long setup
times, this is generally not an issue for paint producers since the
generally accepted fill sizes are limited.