Photo Emulsion

Photo Emulsion is a key material used to make screen plates in screen printing. It is a light-sensitive liquid that can form the desired patterns on a silk screen through exposure and development processes.

Working principle:
Coating: Evenly apply the photosensitive emulsion on the surface of the screen to form a photosensitive film.
Exposure: Cover the patterned transparent film (positive film) over the screen coated with emulsion, and then expose it to ultraviolet light. The emulsion in the exposed area undergoes a photochemical reaction, becoming insoluble in water (curing), while the part covered by the pattern remains in an uncured state.
Development: Rinse the unexposed parts with water. The uncured emulsion is washed away, leaving clear pattern holes.
Drying and printing: After drying, it can be used for printing. The ink is transferred to the substrate through the holes in the pattern.

Common types:
Diazo Photo Emulsion: suitable for most screen printing, low cost, requires mixed use. For example, Diazo-based Water-resistant Emulsion of tianling intelligent technology is suitable for water-based ink printing.
SBQ Photo Emulsion: high ISO, suitable for fine patterns, easy to use. For instance, SBQ-S300 is a one-component, ready-to-use, solvent-resistant photosensitive emulsion, suitable for advertising signs and PCB printing.
Dual Cure Photo Emulsion: Combining the advantages of diazo and SBQ, it is highly durable and suitable for industrial use.

Application features:
High resolution: Suitable for fine pattern printing, it can achieve high-definition images.
Water resistance and solvent resistance: Depending on the specific model, the water resistance and solvent resistance of photosensitive emulsions vary. For instance, the DLS-3303 photosensitive emulsion of Tianling Intelligent Technology is suitable for solvent-based ink printing and features extremely high photosensitivity and excellent solvent resistance.
It is applicable to various industries, including textile printing, advertising signs, PCB printing, etc.

Precautions for Use:
Environmental requirements: When using photosensitive emulsions, operations should be carried out in a yellow light environment to prevent premature exposure of the emulsion.
Wire mesh preparation: Before use, clean the wire mesh with a degreaser and ensure it is completely dry.
Coating method: Use high-quality scrapers for coating. The number of coating times and film thickness should be adjusted according to the requirements of the printing material and pattern.
Exposure time: Adjust the optimal exposure time based on factors such as the mesh size of the screen, the type of exposure lamp, and the distance. For instance, a 150-mesh wire mesh is exposed for approximately 40 seconds under a 3kW high-pressure mercury lamp.
Photosensitive emulsion is an indispensable material in screen printing, and its selection and application directly affect the printing quality and efficiency.