Target Compression Formula

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)      

  * = required field
*Load on Bottom Box: lbs.
*Storage Time Under Load:
*Relative Humidity:
*Pallet Patterns:
*Pallet deck-board gap:
*Excessive Handling:
*Head Space in Container: