Plastic Molding & Forming
Pressure Forming is a sophisticated
version of the vacuum forming process utilizing
air pressure as a forming aid to increase
the detail on the mold side. Features that
could not be achieved by vacuum alone can
be molded with pressure forming. The result
is a product with the look and feel of an
injection or structural foam molded part
at a price close to a vacuum-formed one.
The mold makers start
by creating a pattern based upon drawings
and specifications of the custom part.
From the pattern, these craftsmen produce
either a hardwood or aluminum mold. A
wooden mold is used mainly for a customer
required prototype or a very low volume
production run. The aluminum mold is used
for a full production run and when the
pressure forming process is necessary.
The pressure forming
technique provides for forming heavier
sheet from 0.093" thick up to 0.375" thick.
The technique is accomplished by forcing
a hot sheet against a mold, usually female,
by introducing compressed air to the back
side of the heated sheet. This method
will provide as much as 75 psi working
on the sheet surface as compared to the
14 psi in vacuum forming.