BC double wall vs AC double wall: side-by-side numbers
AC double wall is 22% thicker than BC double wall (0.344 vs 0.281 in nominal). At the same ECT, the McKee formula rates a AC double wall box 11% stronger in compression; the trade is in size, crush resistance and print surface.
Side by side
AC double wall is 0.063 in thicker than BC double wall. On a 12 × 10 × 8 in box that makes the outside 0.13 in longer and wider and 0.19 in deeper, and at the same ECT the McKee estimate for BC double wall is 90% of the AC double wall figure.
| BC double wall | AC double wall | |
|---|---|---|
| Walls | double | double |
| Nominal caliper, in | 0.2813 | 0.3438 |
| Flutes per foot | — | — |
| OD added to L and W, in | 0.563 | 0.688 |
| OD added to depth, in | 0.844 | 1.031 |
| McKee strength index, same ECT | 53 | 58.6 |
Same box, both boards
| Inside, in | BCT at 44 ECT, BC | BCT at 44 ECT, AC | Boxes per pallet, BC | Boxes per pallet, AC |
|---|---|---|---|---|
| 10 × 8 × 6 | 822 | 909 | 119 | 119 |
| 16 × 12 × 10 | 1,025 | 1,133 | 40 | 32 |
| 24 × 18 × 18 | 1,255 | 1,388 | 6 | 6 |
44 ECT is used on both sides only to isolate thickness; in practice the two boards are made to different grades. Pallet: 48 × 40, loaded to 60 in, column stacked.
Where each fits
BC double wall
- Nearly twice the caliper of C, so much stronger in McKee at the same ECT
- Heavier and bulkier: more board weight and larger outside dimensions
- The B ply on one face gives a better print or wear surface
AC double wall
- Highest McKee estimate of the double walls at the same ECT
- Bulky: outside dimensions grow fastest
- Availability depends on plants running A flute
Sources
- Foster, G. (1997). "Boxes, Corrugated." In Brody & Marsh (eds.), The Wiley Encyclopedia of Packaging Technology, 2nd ed. Wiley. ISBN 0-471-06397-5 (table reproduced in Wikipedia, "Corrugated fiberboard")
- Packaging Corporation of America: Profiles with a purpose
- McKee, Gander & Wachuta (1963), Paperboard Packaging 48(8)
Last reviewed . See all sources and how Packgent computes.