It is important to carefully consider
all the factors that weaken the stacking strength of a box before
products are packed and put into the distribution cycle. A target
compression value can be determined by answering the questions
on this worksheet. Remember the bottom box must support the top
load over a period of time in which it may be exposed to fluctuations
in temperature and humidity as well as other factors that impact
performance such as excessive handling, pallet patterns, pallet
deck-board spacing and box overhang. Enter the appropriate values
from the table into the fields below. Enter 1.0 as the multiplier
if the pallet pattern is columnar and aligned, if there is no box
overhang on the pallet, if there is proper deck-board spacing on
the pallet, if there is no excessive handling and if there is no
head space in the box. A multiplier of 1.0 indicates that stacking
strength is not weakened by this factor. The provided loss variables
help determine a recommended safety factor. This safety factor
is the mulitplied by the top load that the bottom box is supporting
and a target compression value is calculated. Knowing the target
compression strength will help your box designer determine the
proper board to use for your box.
Using the given table of multipliers, complete the form below,
then click 'Calculate' for your Target Compression values:
| |
Compression Loss |
Multipliers |
|
| Storage time under load: |
10 days - 37 percent loss |
.63 |
|
| 30 days - 40 percent loss |
.6 |
|
| 90 days - 45 percent loss |
.55 |
|
| 180 days - 50 percent loss |
.5 |
|
| |
| Relative humidity,
under load (cyclical RH variation further increase compressive
loss): |
50 percent - 0 percent loss |
1 |
|
| 60 percent - 10 percent loss |
.9 |
|
| 70 percent - 20 percent loss |
.8 |
|
| 80 percent - 32 percent loss |
.68 |
|
| 90 percent - 52 percent loss |
.48 |
|
| 100 percent - 85 percent loss |
.15 |
|
| |
| Pallet Patterns |
|
Best Case |
Worst Case |
| |
Columnar, aligned |
0 percent loss |
|
|
| |
Columnar, misaligned |
10-15 percent loss |
.9 |
.85 |
| |
Interlocked |
40-60 percent loss |
.6 |
.4 |
| Overhang |
20-40 percent loss |
.8 |
.6 |
| Pallet deck-board gap |
10-25 percent loss |
.9 |
.75 |
| Excessive handling |
10-40 percent loss |
.9 |
.6 |
| Head space in container |
10-20 percent loss |
.9 |
.8 |
| (Top-to-bottom fit) |
|
|
|
|
