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| Posted on 4/6/08 at 07:40 PM | |
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Hello Laura, If you want to take the guess work out of exposure times you might want to invest in a 21 step gray scale. If your plate supplier does not sell them then Google the scale and you will find a supplier. You can place this on a piece of plate material (you can cut a plate into 1” strips so you are not using many plates for testing). Expose the scale do not use the screen then wash out (make sure the wash out fluid is around 80 degrees F). If the scale washes out to the 13th step then your exposure is correct. If you wash out above 13 then you need to decrees exposure time. Below 13 increase exposure time. If you now take your film and expose it for the same time on a piece of the plate (do not use the screen) then wash it out. If it washes out to the same depth as step 13 (all of the way to the base material) you film is dense enough. If you do not wash out as deep then you need film that is denser. You can use a piece of the black bag the plates come in but you it will take more testing. What you are trying to achieve is the shortest first exposure time to wash out the plate to the base material without leaving the top surface of the plate still exposable. If you can still expose the top surface you will burn the screen into the non image area and you will run a dirty plate. TPR ink can be thinned to 20% I would start at 15% and it still runs rather fast. Make sure that the temperature of the room, machine, ink, pad, and items you are printing are around 70 degrees F. Pad Printing Clean Up procedure To clean up your pad printer you will need the following items At 1 gallon paint thinner or ink cleaner 1 gallon plastic pale or equivalent 1” wide inexpensive paint brush paper towels trash can lined with a plastic bag. Plastic jug or equivalent I like to use the wind shield washer bottles Plastic gloves Take the plastic jug and cut the top off. Turn the top upside down and place it in the bottom and staple it in place. Pour the pad cleaner in the plastic pale ( not the jug) Using two pales with ½ gallon cleaner works best Take the ink cup and the plate out of the machine. Turn the plate and cup upside down(so the ink will stay in the cup.) Put on gloves if you have not done so already. Pull the plate off of the cup. Put the cup upside down in the jug top to drain. Wipe ink off of he plate with the paper towels and clean off with in the ink cleaner After the cup has drained awhile Wipe the cup out with the paper towel as best as you can. Place the cup in the cleaner and clean out with the brush. This is where it is best to have two pales with cleaner Because you can put the cup in the second pale to clean it farther Remove the thinner cap and clean out the threads. Remove the cup and wipe dry. Hope this helps Frank | ||
 
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