Small Batch Mold Injection -

Small Batch Mold Injection

Small Batch Mold Injection is a hybrid manufacturing process that uses 3D-printed molds to replace traditional steel molds. These molds are installed on an injection molding machine to produce dozens to hundreds of genuine engineering plastic parts at extremely low cost and lead time.

Upload & Get Quote

More Design Solutions

SLA 3D-printed molds are dense, isotropic, and offer high surface finish and excellent accuracy. Specialized high-temperature resistant resins (such as Rigid 10K) can withstand the high pressure and temperature (up to 200°C and above) of the injection molding process.

Process Considerations

Pressure Control: 3D-printed molds are not as strong as steel molds, so machine parameters must be adjusted to use lower clamping forces and injection pressures.
Temperature Management: Polymer molds have poor thermal conductivity and do not dissipate heat as quickly as metal. Compressed air cooling or designing easily replaceable mold inserts is often used to improve efficiency.
Release Agents: Silicone-based release agents are necessary to prevent plastic parts from sticking to the mold.

Step 1 – Mold Design

CAD drawings optimized for both 3D printing and injection molding.

Step 2 – 3D Print the Mold

Print the mold core/cavity using high-temperature resistant resin.

Step 3 – Assemble the Mold

Mount the printed mold core into a standard mold frame.

Step 4 – Injection Molding

Inject real engineering materials such as ABS, PP, etc., into the injection molding machine.

Step 5 – Eject Finished Parts

Open the mold to obtain parts that are identical to mass-produced components.

Process	Mold Cost	Lead Time	Ideal Quantity	Core Advantage
3D Printing	No mold required	1–3 days	1–10 pcs	Extreme complexity, rapid iteration
Small Batch Injection Molding	low	1–3 weeks	100–500 pcs	Real materials, real performance
Traditional Injection Molding	high	1–2 months	10,000+ pcs	Extremely low unit cost, ideal for mass production

Standard Plastics:

ABS, PP, PE, PS

Engineering Plastics:

PC (Polycarbonate), PA (Nylon), POM (Acetal/Delrin)

Elastomers: TPE, TPU (Soft touch / Flexible)

PC (Polycarbonate), PA (Nylon), POM (Acetal/Delrin)

Pro Tip: Note that mold life varies depending on the material being injected (for example, glass-fiber reinforced materials will cause more wear on the mold).

How accurate are cast vacuum parts?

Vacuum cast parts typically achieve tolerances of ±0.1–0.3mm, depending on part geometry and size. The process offers excellent detail and surface finish, suitable for functional prototypes and end-use parts.

How cost-effective is urethane casting for small batch production?

Urethane casting is a cost-efficient option for runs of 20 to 200+ parts. It avoids the high cost and lead time of hard tooling. Suitable for short runs, bridge production, or early market test.

How does vacuum casting compare to 3D printing?

Vacuum casting offers better surface finish, material strength, and consistency for low-volume production. 3D printing is faster for one-off prototypes but may fall short in appearance or mechanical properties.

How durable are the mold used in vacuucm casting?

Silicone molds typically last for 15–25 castings, depending on part complexity and material used. They’re best for small batches before wear affects precision.