TDI and MDI describe different polyurethane chemistry routes, but the names alone do not define finished-cover performance. Formulation, hardness, cure control, machining and operating conditions also matter.
When TDI is the practical starting point
TDI is often suitable for routine volume, established replacement plans and applications where planned cover changes do not create excessive production cost.
When to evaluate MDI
Consider MDI when cycle volume is higher, changeover downtime is expensive, or correctly operated current covers still fall short of the planned interval. Compare total cost per operating period rather than purchase price alone.
Rule out machine and application problems first
Strong one-sided wear, damage in a fixed position or repeated seam failure requires checks of alignment, pressure, die condition, locking and cover rotation. A material upgrade cannot correct a mechanical cause.
Useful selection data
- Cycles per shift, current change interval and downtime.
- Board type, cutting pressure and normal die condition.
- Current material, hardness and primary failure mode.
- Machine, dimensions and locking structure.
TDI supports a stable routine-production route. MDI targets a longer replacement interval. Both depend on correct fit, pressure and machine condition.
