Thermoforming vs Injection Molding
Thermoforming and injection molding are the two main processes for plastic cases. Thermoforming is cheaper for low volumes and large cases. Injection molding is more expensive upfront but cheaper per piece for high volumes and produces more complex parts. This guide compares them.
Feature-by-Feature Comparison
| Feature | Option A | Option B |
|---|---|---|
| Process | Heat plastic sheet, vacuum/pressure form over mold | Inject molten plastic into closed mold |
| Tooling cost | $2,000-10,000 (low) | $20,000-100,000+ (high) |
| Per-piece cost (medium volume) | $20-50 | $5-15 |
| Minimum order | 50-200 pieces (low) | 1,000-10,000 pieces (high) |
| Wall thickness | Uniform 2-6mm | Variable 1-8mm (optimized) |
| Surface finish | Matte to gloss (one side only) | High-gloss, textured, multi-finish |
| Part complexity | Simple shapes (no undercuts) | Complex (undercuts, threads, hinges) |
| Material options | PS, ABS, PP, PE, PET, PVC, PC | All thermoplastics + glass-filled, blends |
| Lead time (tooling) | 2-4 weeks | 8-16 weeks |
| Lead time (production) | 1-2 weeks | 2-4 weeks |
| Best for | Low-volume, large cases, prototypes, simple shapes | High-volume, complex parts, OEM production |
| Common products | Trade show cases, custom cases, low-volume OEM | Pelican, SKB, Nanuk, all major brands |
Our Verdict
Choose thermoforming for: prototyping, low-volume, large cases, simple shapes, fast turnaround. Choose injection molding for: high-volume, complex features, OEM production, best finish. We operate both processes and can recommend the best fit for your volume and design.
Frequently Asked Questions
Is thermoforming cheaper than injection molding?
Yes for low volumes (50-1,000 pieces). Tooling is 10x cheaper ($2,000-10,000 vs $20,000-100,000+). For high volumes (10,000+ pieces), injection molding is cheaper per piece. Break-even is typically 1,000-5,000 pieces.
What is rotational molding?
Rotational molding (roto-molding) is a third process for large plastic cases. The mold is filled with plastic powder and rotated in an oven. Wall thickness is uniform and seamless. Common for cases 50L+. Used for Pelican-style and cooler-style cases. Tooling: $10,000-50,000, lead time 6-12 weeks.
Which is faster to prototype?
Thermoforming. We can produce prototype thermoformed cases in 1-2 weeks (rapid tooling in aluminum or 3D-printed). Injection molding prototypes require steel tooling, taking 4-8 weeks minimum (or 1-2 weeks for soft tooling, which is shorter-lived).
Can you combine thermoforming and injection molding?
Yes. Common pattern: thermoformed main shell + injection molded latches, hinges, and trim. This balances cost (cheap shell) with function (precise hardware). Many OEM cases use this hybrid approach. We offer both processes in-house.
What about 3D printing?
3D printing (FDM, SLA, SLS) is for prototyping and very low-volume production (1-50 pieces). Material properties are different (PLA, ABS, PETG, Nylon). For production cases, 3D printing is 5-10x more expensive than injection molding and limited in size.
Which is more environmentally friendly?
Thermoforming produces less scrap (only trimmed edges, can be recycled). Injection molding has more scrap (sprues, runners) but recycles them. Both are 100% recyclable. Roto-molding is least efficient (waste heat, longer cycle times).
Need a custom quote?
Contact KeXinMaterials for OEM/ODM case manufacturing. 12h quote, 30-day delivery.