EMULSIONS

Emulsions for making screen printing screens, covering all current applications.They are emulsions for conventional exposure, with positive film. Their characteristics are described comparatively in the EMULSION CHARACTERISTICS table, presented for each type of emulsion. The method of applying emulsions on the screen, both manually and with dedicated equipment is presented in “Sequence of coated operations”, presented for each type of emulsion. The exposure times of conventional emulsions using positive films are presented for each type of emulsion in the related technical sheet. They are obtained by exposure with a 5000W (5 KW) power lamp at 100 cm distance, after manual coated with a certain number of layers, on the white and yellow screen respectively.

Corrections are applied to them depending on:

- type of lamp 

• 1kW – 5    X time for 5kW lamp

• 2kW – 2.5  X time for 5kW lamp

• 3kW – 1.7  X time for 5kW lamp

• 4kW – 1.25  X time for 5kW lamp

- no. of layers applied 

If the no. of layers applied is changed compared to the no. in the table :

• up 1/1 to 1/2     + 33%

• up 1/1 to 2/2     + 50%

• up 1/1 to 2/3     + 100%

• up 1/2 to 2/2     + 25%

• up 1/2 to 1/1     - 33%

• up 2/3 to 2/2     - 25%

• up 2/3 to 1/2     - 33%

- distance of the screen from the lamp

•  60 cm     0,36

•  80 cm     0.64

•  90 cm     0.81

• 110 cm     1.21

• 120 cm     1.44

• 150 cm     2.25

• 180 cm     3.24

• 200 cm     4

• 250 cm     6.25

- density of the screen

•  140     - 10%

•  165     - 15%

•  180     - 25%

•  90     + 20%

•  77     + 60%

•  43     + 100%

•  32     + 150%

The values ​​in the table are only a starting point for finding the correct time. For a correct exposure time, exposure in steps is indicated.