Emulsion in Printing

Coating screen with emulsion is a simple and easy process in screen printing. It can do with scoop coater through with emuslion and coating each side of the mesh which is dried and then exposed.

Types of emulsion

They are two Types of emulsion :
1. PVC Emulsion which is oil based it is a temporary (A1)

2. Dual emulsion : Dual emulsion which is both oil and water based and permanent one for long duration. (cs5 w)

Screen Printing Emulsion

In market ready Emulsions are also Available (Pure Photopolymer). It can be used in halftone screen printing and High Density printing.

Pre Sensitized are pre-mixed emulaion (mix with sensitizer) also available in the market.

Sensitizer : Sensitizer is a liquid form mix that is mixed with emulsion to give the adequate hardnessand better development to the matter
Mixing Ration : Sentitizer need to mixed with the emulsion with the ration of 90 and 10. It might varies from emulsion to emulsion.

Most Common Emulsion used for plastisol and pvc inks are PVC Emulsion.
Emulsion is available in the market solvent base. It has high solid contents, gives fine resolution has fast exposure time is easilty
reclaimable, and gives trouble free screen.

This is a single cure solvent base emulsion can used only in solvent inks
After your screen are coated with emulsion store in a darkroom .

To drying emulsion if have placed in a corner of your screen room with a single fan improperly placed, it can take several hours
for screen dry. If you use screen dryer machine for emuslion coated drying it will take time to dry 30 to 40 mins. It is good for dry the emuslion coated without light .

Decoter is a chemical  used to remove the coated emulsion again you can use that screen.

source : Mahesh babu