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Bluecoat - 414 Photo Screen Emulsion
In the process of rotery screen engraving it is the emulsion that forms the link between the image & the screen & playing a vital role. Quality of the image, mechanical resistance to all printing paste, the runability & Photo efficiency are the outstanding features of Bluecoat 414 - PHOTO SCREEN EMULSION. For exposing the screen following procedure is to be followed.
Preparing & Applying
Preparation of Emulsion
Take 1 Kg of Bluecoat 414 Emulsion in a clean vessel & also take 50 ml. of sensitizer. Mix them together for sometime till the colour of Emulsion is changed to light uniform green. Viscosity of the Emulsion can be changed by adding DISTILLED WATER depending upon mesh of the screen & technique of coating - i.e. machine coating or hand coating. Filter this emulsion with bolting cloth & close the vessel for 1 hour in cool dark place so that all the air bubbles are disappeared.
Degreasing & Cleaning the Screen
A completely grease free screen is required in order to achieve good fixing of Emulsion to the screen. Even if the screen is being used for the first time it is required to be degreased with the degreaser, by giving good rinse & immersion in degreaser & subsequent cleaning with pressure of water. Allow it to dry in a dust free area.
Coating of Emulsion
Direct Emulsion Coating requires skill to produce uniform pinhole free coating. Bluecoat 414 Emulsion can be applied to a screen by using circular rubber squeegee. It should be verified that the rubber of the squeegee has constant & correct hardness, elasticity & diameter & even after prolonged use it maintains elasticity & it is not broken or cracked.
There are two methods of coating Photo Emulsion viz. Machine Coating & hand coating.
Machine Coating
In this method Emulsion is applied automatically to screen in single action & one cycle of operation from top to bottom & it forms smooth adhesion between emulsion & screen so that practically no touching is required & pinholes hardly ever occur. Viscosity of the emulsion can be diluted by adding distilled water to suit the machine coating.
Hand Coating
In this type of technique round rings are inserted on both sides of rings & it is placed on floor in upright position & after that emulsion is applied to screen at even speed by using circular rubber squeegee from bottom to top at a even speed & put the screen in dryer. Depending upon the mesh of the screen additional 3 to 4 coats are required by repeating the above procedure.
Conclusion
An engraving is more than just the sum total of film screen & emulsion. Even if each of these product is individually of the highest quality, it is you-person on the job - who contributes the 100% to the ultimate quality of the engraved screen.
Storage
Keep the container closed & away from sunlight.
Shelf Life
12 months, if container is properly closed.
Packing
10 kgs.
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