Edco Industries Inc. prides itself on its ability to assist
our customers with their structural plastics product design utilizing our fully staffed engineering department. Edco has proven
success with molded plastics projects from concept to reality project management.
The key element in structural foam molding is low pressure. Unlike conventional injection
molding, which utilizes extremely high pressures to force materials into a mold's cavity, structural foam molding takes advantage
of a part's configuration, its generally thick wall sections (that act as runners), and the foaming action (supplied by either
chemical reaction within the resin blend, or the introduction of a compressed, inert gas into the mold), to allow the molten
resin to flow much further, and with far lower pressure, than the typical injection molding process would allow.
But why is low pressure and structural foam molding desirable?
First, low cavity
pressure suggests that tooling can be produced from materials that have lower yield strengths and are softer (and lighter)
than tool grade steels. Typical structural foam molds are produced in aluminum, which can be machined up to three times faster
than tool steel, creating large savings in the tool cost, especially when considering the size of many structural foam molds
and parts. In addition, aluminum tools will weigh approximately one third the weight of an equivalent steel tool, making lifting
and handling less difficult and time consuming.