Distortion of Flexography Photopolymer Plate

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In this blog, we are going to learn about what is Distortion & How to calculate it theoretically.

First of all, What is the term distortion?

Distortion means deformation of original shape and size of an object when it is twisted, stretched, or wrapped.

In the case of the Flexography Photopolymer plate. when it is mounted over the plate cylinder, It changes their thickness as well as length in the mounting direction. 

We need to prepare the plate smaller in length from the circumference of the plate cylinder. So, it finally matches the length after being mounted on it known as the Distortion of the flexography photopolymer plate.  

Some defects arise due to improper distortion such as a distorted image. improper mounting.

Now, the Formula for the calculation of distortion of flexography Photopolymer plate.

Distortion constant = 

2 X 3.14 (Plate Thickness - Polyester Backing Thickness)

Soft part thickness =

Plate Thickness - Polyester Backing Thickness

Plate Size = 

Plate cylinder Teeth X 3.175 mm – Distortion Constant.

Note: Put all the values in mm.

Polyester Backing thickness.

• 0.127 mm for 1.7 mm plate Thickness.

• 0.178 mm for 1.14 mm plate Thickness.

For Example: 

Let us consider 

Cylinder Teeth is 92 T.

Plate Thickness is 1.14 mm. 

Polyester Backing Thickness is 0.178 mm.

Distortion Constant = 2 x 3.14 (1.14 - 0.178) mm.

                                = 6.041 mm

So, we need the Perfect Plate Size for 

92T (292.1 mm) is 6.041 mm smaller in length

ie ; 286.058 mm.

Note: After Preparation of Imposition layout select the whole layout and change the length 292.1 mm to 286.058 mm in Adobe illustrator, Then, Send to next process.

Hope you get some knowledge from this blog.

Note : I am trying to give you my best. It might be some mistake happen. Please comment if any suggestions.