If you only compare "TPD", you can compare two very different machines. Capacity is the product of three physical variables.
The basic relation
Daily tonnage ≈ trim width (m) × speed (m/min) × grammage (g/m²) × 1.44 × runnability
The constant 1.44 comes from 60 min × 24 h ÷ 1,000,000 (to convert g·m/min to tonnes/day). "Runnability" folds in uptime, broke and consistency (often 0.85–0.95).
Worked example
| Width | Speed | GSM | Theoretical TPD |
|---|---|---|---|
| 3.2 m | 400 m/min | 110 | ≈ 202 |
| 3.2 m | 400 m/min | 90 | ≈ 165 |
| 2.8 m | 350 m/min | 110 | ≈ 148 |
Notice the same 400 m/min machine drops from ~200 TPD to ~165 TPD just by making lighter fluting. That is why a single speed rating means little without GSM.
What this means when buying
- Ask for capacity at your target GSM, not a generic number.
- Speed you can run depends on the dryer section, not just the drive.
- Width you can use depends on your building and pope reel, not just the wire.