Structural foam molding is unique in the size, strength and versitility it provides. The range of opportunity it brings designers and engineers is just as great.
Along with the Q&As below, we’ve created a Structural Foam Molding Design Guide to help you get the most out of this valuable process.
Because structural foam is a lower pressure process we make tools out of aluminum.
Generally 12-16 weeks after the CAD models are complete and the PO has been issued.
A well built structural foam tool will produce millions of parts.
What are the tooling requirements for structural foam molding vs traditional/high pressure injection molding?
The low pressures used in structural foam molding mean that aluminum tools can often be used. This saves money on tooling costs.
With the very large-sized molds often needed for structural foam molding, the cost savings or aluminum compared to steel molds is also significant.
Low-pressure molding is also less stressful on the tool itself compared to high-pressure molding. This extends the lifetime of the tool and saves money.
Structural foam molding is done using tools that are similar in design to high-pressure molding.
Two-plate molds with two halves and a core plate are commonly used.
Other than generally being much larger in size, there are other differences between structural foam and conventional injection molding tools that must be designed and built into the tool.
The most common differences are:
No Runner Systems
Hot runner systems are often not required with structural foam molding.
Multi-nozzle molding is a beneficial technology that is often used with structural foam molding. Multiple gates and the ideal gate location need to be included in the tool design.
Standard Tool Making
Just as with high-pressure molding, a top-quality tool-maker will serve the manufacturing company well when designing, building and testing your molds.
Important considerations when designing your parts and tools.
Critical considerations when designing a part and tool for any plastic injection molding and special factors for structural foam include the following:
Material options and consequences
Minimizing sink marks
Steel safe areas
Draft angle orientation
Texturing and draft
Scheduling of critical start-up phases
Secondary operations and fixtures
Aluminum tools cost less, and aluminum tools cool faster, allowing for a faster cycle time.
With proper care aluminum tools can last much longer than steel molds used for traditional injection molding. Molds have been known to last 25 years or longer.