Hot-Press Drying in Molded Pulp: The 150–200°C Window and Moisture Targets

After forming, a molded pulp part is roughly 60–70% water, and drying removes it under heat and pressure. Hot-press drying commonly operates at temperatures around 150–200°C to reach target moisture (TAPPI technical information papers). The press does double duty: it dries the part and, through heat and pressure, sets its surface smoothness and density.

The Scenario: Drying that shapes the surface

Drying control faces three challenges:

Pain Points

• Under-dried parts retain moisture that feeds mold and weakens the structure;
• Over-dried parts risk scorching, brittleness, and wasted energy;
• Press temperature and pressure jointly set surface finish — one without the other is incomplete.

The Solution: Three drying solutions

Three practices master the drying step:

1. Hold the 150–200°C window Operate hot-press drying in the common 150–200°C range to reach moisture targets efficiently (TAPPI reference).

2. Target final moisture Dry to the specified final moisture so parts are dimensionally stable and mold-safe.

3. Press-finish coupling Coordinate heat and pressure so the surface sets smooth and dense in the same step.

The Result: Dry, smooth, stable parts

Parts leave the press at target moisture with set, smooth surfaces — stable and ready for the next step.