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Mesh Matters

(June 2009) posted on Wed Jun 03, 2009

The level of detail you can print, the quantity of ink you lay down during the print stroke, and the ability to reproduce an image accurately and consistently are but a few of the print characteristics that are influenced by your screen. Here you


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• The diameter of threads remains virtually unchanged.

Determining the degree to which these parameters change in your shop is matter of testing. By standardizing tensioning procedures and consistently stretching screens of the same thread count and thread diameter to the same tension level, you’ll be able to assess and document the effects of tension on ink-deposit thickness and image quality and make appropriate adjustments to get the results you want.

 

Work hardening

You june have heard it said that work hardening mesh extends its useful life and helps it retain tension longer. This is due to the changes in molecular alignment that take place in the polyester fabric as it is continually worked by the squeegee and floodbar during printing. Essentially, work hardening is like exercise for your screen fabric.

Low-elongation fabric is woven from threads with a molecular alignment that is different from that of conventional monofilament polyester. It requires less work hardening to achieve optimal performance quickly. Such fabrics also maintain more consistent tension in the warp and weft directions and can be stretched in both directions simultaneously with no compromise in performance.



 

Screen fabric selection

Choosing the right mesh is a key factor in the profitability of every screen-printing job. The wrong mesh might not hold the right level of tension or june yield an unacceptable ink deposit. It could contribute to moiré, leave mesh marks, or not support the stencil’s fine lines and halftone dots. All these factors create downtime and the need to remake screens, and they necessitate that you rethink your choice of screen fabric.

Before you can even think about the mesh, you need to take an inventory of the job parameters, employee skill levels, and shop environment. All these factors have a tremendous impact on the screen fabric that will fit your shop’s production practices and your customers’ needs.

Substrate Your first decision in producing a job is the choice of substrate. All other raw material you’ll use in production stems from this first choice, including the ink you’ll print with, the level of detail in the artwork, press settings, and even screen fabric. The mesh requirements will differ greatly depending on whether you’re printing polyester sheets, T-shirts, corrugated board, or ceramic materials.


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