
| Title: |
Formulas for Plate Distortions |
| Submitted By: |
Catherine Haynes, APR Director of Training |
| Date Submitted: |
09/06/05 |
Formulas for Plate Distortions
We are often asked for the formulas to determine plate distortions. Below are these formulas.
The plate cylinder repeat must be known for both distortion formulas. If the K-Factor is known than you can determine both the distorted repeat and the distortion percentage. The distorted repeat is simply the plate cylinder repeat minus the K-Factor. The distortion percentage can then be calculated as the distorted repeat divided by the plate cylinder repeat times 100 (to convert to a percentage).
Formula for Distorted Repeat
cyl. - K = distorted repeat
Formula for Distortion Percentage
(cyl. - K) / cyl. x 100 = % distortion
To determine the K-Factor, subtract 0.005 from the plate thickness. Multiply the resulting number by 3.142 times 2.
Formula for K-Factor
(Thickness - 0.005) x 3.142 x 2 = K
Following are K-Factors for some common plate thicknesses.
K-Factors
0.030 = 0.16
0.045 = 0.25
0.067 = 0.39
0.107 = 0.64
0.112 = 0.67
0.187 = 1.14
0.250 = 1.54
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