How to Guide - Exposing PLUS emulsions and choosing the right exposure system

Washout

When correctly dried and exposed, Capillex stencils are very tough and will withstand extremes of washout conditions. As a rule, Capillex stencils benefit from a 'short, sharp' washout using a strong spray of cold water, predominantly from the print side of the screen.

If the mains water pressure is too low to achieve a strong spray, then a high pressure gun can be used, ideally set with a diffuse spray and held at a minimum distance of 80 cms from the stencil.

Note

As high pressure guns are available in many different powers it is important to test the jet on a non-printing area before processing a production screen.

If the screen is small enough to be handled easily then the ideal washout process is turn the screen during washout so the emulsion from the image areas is rinsed clean from the squeegee side though the bulk of the washout should take place on the print side.

Pre- soak

Although tempting, pre-soaking a small screen prior to washout may cause problems due to the softening effects that soaking can have, especially on thicker stencils that have been under exposed.