When you need 10 to 50 plastic parts, the choice between vacuum casting and injection molding is critical. This guide breaks down the cost, timeline, and material differences with Sundar Industries.
When a project requires a small batch of plastic parts — typically 10 to 50 units — two processes often come into consideration: vacuum casting and injection molding. Each has distinct advantages based on quantity, timeline, and material requirements. Sundar Industries offers both services, allowing you to start with vacuum casting for your pilot run and transition seamlessly to injection molding for full production.
Vacuum Casting
Process: A silicone mold is made from a master pattern (usually CNC-machined or 3D-printed). Polyurethane resin is cast under vacuum to produce parts.
Tooling Lead Time: 7-10 days.
Tooling Cost: Low.
Per-Part Cost: Moderate for small quantities (10-50 parts).
Materials: Polyurethane resins mimicking ABS, PC, PP, and rubber. Wide color options.
Material Properties: Similar to, but not identical to, true thermoplastics. Good for form/fit and some functional testing.
Ideal For: 10-50 parts, pilot runs, market testing, bridge tooling.
Injection Molding (Production Tooling)
Process: Molten thermoplastic is injected into a hardened steel or aluminum mold under pressure.
Tooling Lead Time: 4-8 weeks.
Tooling Cost: High.
Per-Part Cost: Very low at high volumes.
Materials: True thermoplastics (ABS, PC, Nylon, etc.) with exact mechanical properties.
Material Properties: Identical to final production parts. Excellent consistency.
Ideal For: Volumes above 1,000 parts.
How to Choose with Sundar:
If you need 10-50 parts quickly for testing or market validation, vacuum casting is the cost-effective and fast solution offered by Sundar Industries.
If your design is finalized and you require volumes above 1,000 parts, injection molding becomes the most economical and reliable choice — and Sundar Industries has the in-house capacity to scale with you.
With Sundar Industries as your single manufacturing partner, you can move from prototype pilot runs to full-scale production without the complexity of switching suppliers.
