Process comparison
Thermoforming vs Blow molding
Blow molding inflates a molten tube (parison) inside a mould to make hollow containers; thermoforming shapes a sheet into open parts. Twin-sheet thermoforming can make hollow parts too, which is where they overlap.
Thermoforming vs Blow molding — side by side
| Thermoforming | Blow molding | |
|---|---|---|
| Part type | Open shells, trays, panels (twin-sheet: hollow) | Hollow bottles, containers, tanks |
| Neck / opening | Fully open | Small controlled opening |
| Tooling cost | Low | Moderate to high |
| Best volume | Low to medium-high | High (packaging) |
| Wall uniformity | Engineered by plug/draw | Varies around the blow |
Choose Thermoforming when…
- Open covers, trays and panels
- Hollow double-wall parts via twin-sheet forming
- Low-to-medium volume, fast tooling
Choose Blow molding when…
- Bottles, jerricans and closed containers with necks
- Very high-volume packaging
- Thin, light hollow vessels
The verdict: For open parts — or hollow double-wall parts via twin-sheet — thermoforming is the flexible, low-tooling choice. For necked bottles and high-volume hollow packaging, blow molding is purpose-built.
Frequently asked
Can thermoforming make hollow parts?
Yes — twin-sheet thermoforming forms and fuses two sheets into a hollow, double-walled part, useful for pallets, ducts and cases.
Which is better for bottles?
Blow molding — it is designed for necked hollow containers at high volume.
Not sure which fits?
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