Parts can be produced
with very low tooling investment.
Molds can be constructed
of plaster of paris, wood, polyester, epoxy, and other nonmetallic
materials. The cost of a mold constructed of such materials
is only a small fraction of the cost of molds for injection-molded
plastics and is cheaper than tooling for other plastic processes.
In packaging, thermoforming
is competitive at the very highest quantity levels. For example,
drinking cups can be thermoformed in multiple-cavity molds at
200 and 300 pieces per minute.
Limitations:
Wall thining takes
place in or adjacent to drawn sections.
Components cannot
be as intricate as those made by molding processes.
Dimensional accuracy
is less than that for molded plastic parts.
