I am debating this with my corrugated supplier right now, based on the attached chart. The chart suggests the curve resulting from ¼” per foot gives a fixed curve (radius of 72.125) and warp allowance is based on this..

This fixed radius changes the warp values such that allowable warp is;

12” = ¼” warp

18” = ½” warp

24” = ¾ “ warp

Etc.

Two problems are arising;

1) The warp calculation of Warp divided by say a 36” sheet converted to a 12” warp number does not match the straight 12” number.

2) Based on the allowed warp using the chart, we are dealing with some serious warp that will cause us to slow down our high speed equipment.

Current process is;

• Measure Length of sheet

• Measure warp deflection

• Divide deflection by length to get warp per 1”

• Multiply by 12 to get warp per 12”

I am working on a full sheet go/no go gage that mimics what the machine sees, i.e. the machine sees the full width sheet, not 12” sections.

I hope you can help clarify what the intended standard is.