Export engineering
Rubberwood plywood and container weight: the export arithmetic
Plywood containers hit the weighbridge limit long before they run out of space. Core density decides how many sheets you actually ship — here is the working.
The problem: you weigh out before you cube out
Every container has two limits: cubic capacity and payload. For plywood, payload wins every time. The practical numbers:
| Container / route | Practical payload | What sets it |
|---|---|---|
| 20ft, general | ~28.2 t | CSC plate / shipping-line practice |
| 40ft, general | ~26.7 t | Payload cap; tare eats into max gross |
| 40ft into Israel | ~24.5 t | Destination road-weight rules |
| US-bound (highway) | ~20 t | 80,000 lb gross vehicle limit incl. truck & chassis |
Check the cube side: a 40ft container holds about 67 m³ internally. 1,150 sheets of 12mm plywood occupy roughly 41 m³ (1,150 × 2.97 m² × 0.012 m). The box is 60% full by volume when the scale says stop. Sheet count is a weight problem, not a space problem — and the working rule is always load to the lowest of the container plate, the line’s limit, and the destination road cap.
Core density: where the weight comes from
The face veneer — Okoume or Gurjan — is a thin skin. The core species sets the panel weight. Kerala rubberwood and eucalyptus cores run light; dense-hardwood cores run heavy.
| Panel construction | Finished density (approx.) |
|---|---|
| Rubberwood-core MR panel (Kerala) | ~600–680 kg/m³ |
| Gurjan / dense-hardwood core panel | ~750–800 kg/m³ |
A real datapoint: our calibrated 16mm Okoume-faced panel weighs 32 kg per 8×4 sheet. Working: 8ft × 4ft = 2.97 m²; 2.97 × 0.016 m = 0.0476 m³; 32 kg ÷ 0.0476 m³ ≈ 672 kg/m³. Squarely in the rubberwood band.
Sheet weights: 8×4 ft rubberwood panels
At ~650 kg/m³ finished density. Weight = 2.97 m² × thickness × density. All figures approximate and panel-spec dependent — confirm against your construction before fixing a stuffing plan.
| Thickness | Weight per 8×4 sheet (approx.) |
|---|---|
| 6mm | ~11.6 kg |
| 8mm | ~15.5 kg |
| 10mm | ~19.4 kg |
| 12mm | ~23.2 kg |
| 15mm | ~29.0 kg |
| 16mm | ~31.0 kg |
| 18mm | ~34.9 kg |
The container arithmetic, worked honestly
Take 12mm packing plywood. Rubberwood core: ~23.2 kg/sheet. Dense-hardwood core at 800 kg/m³: 2.97 × 0.012 × 800 ≈ 28.6 kg/sheet. Divide the payload cap by the sheet weight:
| Route / payload cap | Rubberwood core (~23.2 kg) | Dense hardwood (~28.6 kg) | Extra sheets |
|---|---|---|---|
| 40ft, 26.7 t | ~1,150 sheets | ~930 sheets | ~220 |
| 40ft into Israel, 24.5 t | ~1,050 sheets | ~855 sheets | ~195 |
| US-bound, 20 t | ~860 sheets | ~695 sheets | ~165 |
That is roughly 24% more usable sheets per container at equal thickness, rounding conservatively. Same box, same ocean freight, same customs clearance — the freight cost per sheet drops in proportion. For a packing-case maker buying by the container, core density is a landed-cost line item, not a spec footnote. Indicative panel pricing sits in our plywood price guide — ex-factory Perumbavoor, GST & freight extra; confirm current rates before ordering.
MR or BWR for the voyage
Bond grade should match the exposure, not the brochure. MR (moisture-resistant, urea-formaldehyde) handles most containerised dry-cargo voyages: the case rides inside a sealed box, sees container sweat at worst, and is broken up on arrival. Specify BWR (boiling-water-resistant, phenolic) when the route earns it: long humid legs with monsoon-season transshipment, open-yard storage at destination, deck-stowed breakbulk, or crates and pallets built for multiple return trips. If the case will stand in rain or be hosed down, BWR. If it lives inside a container and dies at the receiving dock, MR does the job at lower cost.
ISPM-15: what needs treatment, what doesn’t
Plywood is processed wood. The heat, pressure and adhesive of manufacture kill quarantine pests, so plywood panels are exempt under ISPM-15 — no treatment, no stamp needed on the panel itself. The solid-wood members of a crate are a different matter: runners, battens, skids and load-bearing lumber must be heat-treated (56°C core temperature, 30 minutes) and carry the IPPC mark. A mixed crate passes inspection on the strength of its stamped solid members. We ship ISPM-15 compliant packing: exempt plywood panels, HT-treated and stamped hardwood runners.
Run the numbers on your next container
Send us the thickness, sheet size and destination. We will return the stuffing plan — sheets per container against the correct payload cap for your route — alongside the quote. Export loadings to the UAE, Israel, Sri Lanka and beyond ship from Kochi.