Bridging Design and Manufacturing
The phrase design-for-manufacture (DFM) gets used often, but in injection moulding, it’s more than a buzzword—it’s a critical practice that determines whether a product succeeds at scale. This article examines a practical case study showing how DFM principles transformed an ambitious concept into a commercially successful product, saving both time and cost.
The Initial Concept
A consumer healthcare company approached an injection moulding specialist with a concept for a new packaging device. The design looked elegant on paper but presented challenges for moulding:
Wall thicknesses varied significantly, risking warpage.
Sharp corners would create stress concentrations.
No draft angles were included, meaning parts would stick in the mould.
Left uncorrected, these flaws would have cost thousands in tool rework and delayed the project.
Applying DFM Principles
The injection moulding partner worked with the client’s design team to refine the concept:
Wall Thickness Uniformity: Adjusted to ensure even flow of molten polymer.
Draft Angles: Incorporated to allow clean ejection.
Radii and Fillets: Sharp corners rounded to improve strength and flow.
Gate Placement: Optimized to prevent weld lines and voids.
Material Selection: Nylon 12 was chosen for its strength and chemical resistance.
The Simulation Stage
Flow simulation software modeled how molten plastic would fill the cavity. This allowed engineers to predict defects before cutting steel for tooling, further reducing risk.
The Outcome
The refined design moved smoothly into tooling, then to pilot runs, and eventually scaled to millions of units. The client saved months of delays and avoided tens of thousands in extra costs.
Lessons Learned
DFM must begin at the concept stage, not after tooling.
Collaboration between designers and moulding engineers ensures manufacturability.
Simulation tools are invaluable for identifying unseen risks.
This case proves that DFM is not optional—it’s a necessity in injection moulding. Products designed with manufacturability in mind scale faster, cost less, and perform more reliably.