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| Posted on 8/29/07 at 07:21 AM | |
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The emulsion can't be bad if it stays in the mesh. Stencils are easy. If it is hard to wash out, it was exposed to heat or UV energy and has started to cross link. If it washes out, it wasn't exposed to enough UV-A energy. Unexposed stencil should wash out easily. Do a couple of experiments - Coat a very small amount of emulsion and let it dry, then take it to the sink and wash it out. It should melt out of the mesh because it has not been exposed to UV energy or heat. Test to see if your positive is blocking UV light. The next time you expose a stencil, attach a dime to the stencil which will not let any light pass. It some UV light leaks through the the positive, it can prevent the stencil from washing out in the image area. You can test your setup with a failure test. Print a 10" x 1" solid black line and do a step test of 1 minute per inch. If segments of the image don't wash out, UV-A energy leaked through and cross linked your stencil so it wouldn't dissolve with water and wash down the drain. Properly exposed, any un-exposed stencil should dissolve with simple city water pressure and shouldn't require a pressure gun. EPSON Dye Printer at 1440 dpi If you are using the discontinued EPSON 3000 or 1280, you are lucky. The EPSON driver has a media setting for Back Light Ink Jet Film, that increases ink deposit. This the the setting that started the popularity of the EPSON 3000. Without a RIP to increase ink deposit, EPSON dye or pigment ink rarely goes above 1.6 UV density. You have to learn how to make an exposure test so you don't under or over expose your stencil. There is a 2 minute video on how to make an exposure step test on the Ulano site: http://www.ulano.com/support/supportmenu.htm [Edited on 8/29/07 by richardgreaves] ____________________ Richard Greaves, ASPT Ulano Corp. New York Technical Services 718-943-1338 direct | |
  
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