Stacking and Nesting in Molded Pulp Design: The Taper That Pays Twice

Molded pulp parts need 3–5° of draft to release from the mold. That same taper creates nesting, which shrinks in-transit volume and warehouse footprint.

The Scenario: A tray that shipped as air

A food brand's pulp tray was designed with near-vertical walls for maximum pocket depth. Trays could not nest, so 10,000 trays shipped as one-tray-per-level, paying for 8x the volume.

Pain Points

• Vertical walls prevented nesting, inflating freight;
• Warehouse racks held half the trays they should;
• Draft was treated as a design loss, not a logistics win.

The Solution: Taper as a logistics feature

The redesign added 4° of draft, cutting pocket depth slightly and nesting height dramatically:

1. 4° draft for release The taper guarantees mold release and repeatable wall flow.

2. Nesting ratio design Design for 3:1 nesting — three trays stack in the height of one.

3. Anti-jamming nubs Small nubs on the outer wall break vacuum so nested trays separate easily.

The Result: Freight down 62%

The tapered tray nested 3:1, cutting freight volume 62% and doubling warehouse rack density. Pocket depth loss of 2 mm did not affect product fit.