Study: Additive Manufacturing Can Compete With Injection Molding for Mass Customization

Additive manufacturing can compete economically with injection molding in low-volume, high-mix production, according to a peer-reviewed study published in the International Journal of Precision Engineering and Manufacturing-Green Technology by researchers at Sungkyunkwan University's School of Mechanical Engineering.

The research evaluates whether 3D printing technologies can bridge mass production and mass customization through measurable gains in throughput, cost control, and production flexibility.

The Study

Researchers assessed five process categories defined under ISO/ASTM 52900:

• Material Extrusion (MEX)
• Vat Photopolymerization (VPP)
• Powder Bed Fusion (PBF)
• Binder Jetting (BJ)
• Directed Energy Deposition (DED)

Each process was evaluated using representative industrial systems including the Stratasys F3300, 3D Systems Figure 4 Modular, Desktop Metal P-50, and Stratasys H350.

Key Findings

Benchmark testing used a 30mm × 30mm × 30mm solid cube (27 cm³ volume) to compare productivity. Injection molding, assuming an eight-cavity mold with a 15-second cycle time, achieved 1,920 parts per hour.

Additive systems showed significantly lower single-batch throughput but improved in continuous production scenarios:

Effective Parts Per Hour (EPPH)

Researchers introduced a metric called Effective Parts Per Hour (EPPH), which accounts for preprocessing, printing, and mandatory post-processing. For metal systems such as the Desktop Metal P-50, printing may take approximately four hours, but sintering, cooling, and depowdering can require up to 36 additional hours.

Polymer systems such as the Figure 4 Modular require shorter post-processing steps, including washing and UV curing, typically completed within several hours.

What It Means

The study confirms that AM is most competitive with injection molding in low-volume, high-mix scenarios where the upfront cost of injection molding tooling ($10,000-$100,000+) cannot be justified. This aligns with the growing trend of on-demand, distributed manufacturing.

For mass customization applications — where each part may be unique — AM offers clear advantages in flexibility without requiring expensive mold changes or inventory.