Introduce three types of lotions

Introduce three types of lotions

The working principle of screen printing emulsion is similar to that of plastisol ink. Just as plastisol inks cure when heated, emulsions can also cure when exposed to ultraviolet light. When light shines on the emulsion, the photosensitizer in the emulsion forms a firm bond with the resin of the emulsion, which hardens the emulsion and makes it firmly fixed on the screen. In screen printing, there are three different types of emulsions based on the photosensitizer used. Diazo is called diazo because it contains benzene diazonium. SBQ-based emulsions use styrene-based quaternary ammonium salts; dual-curing emulsions contain both diazonium and SBQ.

Diazo emulsions need to manually mix the photosensitizer with the resin and require a longer exposure time, which may take 15 minutes or more to fully cure. The final template tends to thicken, making diazo emulsions a poor choice for detailed prints or prints that require halftones. Diazo emulsion is the cheapest screen printing emulsion.

SBQ-based emulsion is mixed in one tank without stirring. When exposed to ultraviolet light, they can quickly cure in a few seconds. The finer bonds produced by SBQ-based emulsions make emulsions ideal for detailed work. The emulsion will produce a thinner stencil, but if a thicker stencil is required, it can be applied in multiple layers. SBQ-based emulsions have a shelf life of more than one year, and they tend to be the most expensive types of emulsions.

Dual-curing emulsions combine the characteristics of diazo and SBQ-based emulsions. They require mixing and curing faster than diazo emulsions, but not as fast as pure SBQ-based emulsions. Compared with SBQ-based emulsions, it can produce thicker stencils and is expensive.