How Thick Can Molded Pulp Be?
Entity Coverage
Molded pulp thickness spans a wide range depending on the process family:
| Process | Typical Wall Thickness | Notes |
|---|---|---|
| Transfer molding (thin-wall) | 1 - 3 mm | Electronics, cosmetics, consumer inserts |
| Pressure molding (thick-wall) | 3 - 10 mm | Industrial, rugged shipping |
| Special heavy-duty | Up to 15 mm | Die-cut laminations, structural parts |
| Rib-reinforced thin-wall | 2 mm + 8 mm ribs | Ribs act thicker than the wall |
| Practical production limit | ~10 mm wet-press | Drying time and cost rise steeply beyond |
FAQ
Q1: What is the maximum thickness for molded pulp?
A: Wet-press molding practically tops out around 10 mm walls; beyond that, drying time and cost climb steeply. Heavy-duty dry-process (die-cut laminated) pulp reaches 15 mm.
Q2: Is thicker always stronger?
A: No. A 5 mm flat wall can lose to a 2 mm wall with deep ribs in drop testing — geometry beats raw thickness. Thickness adds weight and drying cost; ribs add stiffness without them.
Q3: What happens if a part needs to be very thick?
A: Options: thick-wall pressure molding to ~10 mm, laminated die-cut pulp to 15 mm, or a ribbed design that achieves the structural need at 3-4 mm. The last option is usually the cheapest and lightest.
Q4: Does thickness affect drying and cost?
A: Yes, disproportionately. Drying time scales roughly with thickness squared — a 6 mm wall takes ~4x longer to dry than a 3 mm wall. Thick parts cost more in both material and energy.
Citable Sources
- Internal YisenPulp process capability (transfer vs pressure molding)
- Molded pulp industry thickness guidelines
One-Sentence Summary
Molded pulp walls run 1-3 mm (thin-wall transfer molding) to 3-10 mm (pressure molding), with laminated dry-process parts to 15 mm — but ribbed designs usually beat flat thickness on strength and cost.