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Preventing and Removing Haze

(December 2013) posted on Wed Dec 18, 2013

The products and processes that can streamline your screen-reclaiming efforts.


By Screen Printing's Solution Sourcebook

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When deciding which haze remover will best meet your needs, you want to consider which type of haze is most prevalent in your shop. If it’s ink haze, which ink formulation is the cause? Is it plastisol, UV, solvent, aqueous, conductive, ceramic? And if it’s an emulsion haze, take stock of the emulsions you use. Do you apply an SBQ pure photopolymer emulsion or a diazo, or diazo-photopolymer dual-cure product? Diazo sensitized emulsions generally have a propensity for staining mesh more often than SBQ emulsions. Water-resistant emulsions are prone to staining more often than solvent-resistant emulsions.

If you determine that ink is the only cause of your haze, you may be able to remove it by using a highly effective ink remover, sparing your screens the damage caused by unnecessarily using aggressive and caustic haze removers, thus extending the screens’ useful life. If, on the other hand, you’ve determined that emulsion is the only cause of your haze, you may not need to use a solvent activator with your haze remover in the case where two-part haze removers are used, thereby saving you time and money.

In most cases, however, printers experience haze caused by the ink and the emulsion. Two-component haze removers usually work best here, followed by haze removers that contain a caustic ingredient and some form of solvent. Typical two-component haze removers work most effectively by applying the first component to a dry or nearly dry screen. These systems are less harmful to the mesh, but work slower than caustic systems. For maximum effectiveness, they should be allowed to dry naturally on the screen. Once dry, they are activated by applying a solvent ink wash onto the dried haze remover. This assures us that ink and emulsion stains are treated.


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