Overview
Choosing between injection molding and 3D printing is one of the most important decisions you'll make in product development. Each technology has distinct advantages depending on your volume, timeline, and design requirements.
3D Printing Explained
3D printing, or additive manufacturing, builds parts layer by layer from digital files. Common technologies include:
- **SLA (Stereolithography):** High detail, smooth surfaces
- **SLS (Selective Laser Sintering):** Strong functional parts
- **FDM (Fused Deposition Modeling):** Cost-effective prototypes
Injection Molding Explained
Injection molding injects molten plastic into a mold cavity. Once cooled, the part is ejected and the cycle repeats.
Best for: High volumes (1,000+ units), consistent quality, lower per-unit cost at scale.
Side-by-Side Comparison
| Factor | 3D Printing | Injection Molding |
|--------|-------------|-------------------|
| Setup Cost | Low ($0-500) | High ($3,000-$100,000+) |
| Per-Unit Cost | High ($5-100+) | Low ($0.10-$5) |
| Lead Time | 1-5 days | 3-8 weeks |
| Design Freedom | Very High | Moderate |
| Surface Finish | Good | Excellent |
| Material Options | Limited | Extensive |
Decision Guide
Choose 3D Printing when:
- You need 1-500 units
- Design is still evolving
- Complex internal geometries
- Speed is critical
- You need 1,000+ units
- Design is finalized
- Consistent quality is essential
- Per-unit cost matters
Many projects use both: 3D printing for prototyping and validation, then injection molding for production.