xc-540 and white ink

[petepaz]

got our new soljet a couple of weeks ago ...love it thing has got flames shooting out from the pinch wheels it's so fast

we are set up to print white and we have been doing some samples printing on .010 polycarbonate and i am still trying to master this
but one problem i have noticed is if you print cmyk mirror image and then flood with white the areas that are white and not a flood coat on the cmyk pull away or crack
i can print the white alone..fine
cmyk alone..fine
solid colors with flood white...fine
but when i print cmyk with clear areas then flood white i get seperation and cracking ..see pics (these pics are of the worst case i had 2 over prints of white to get more opacity but it also happened with just a single print)

 

[artbot]

can you get in a little closer or cut out a piece and scan it? it's a bit hard to tell... is it doing some kind of "crackle finish" (like the craft paints where the white is designed to shrink and not entirely stick whilst shrinking, thus drying in a cracked form)?

is it taking the color with it, or cracking over the color. it looks like the color is cracking with the white.

... and i've not seen cracking like this printing white. sometimes some very tiny cracklike structures only seen up close.

 

[petepaz]

sorry about the pics had to take them with my phone
but the cracking starts where the color and white meet but it is worse the more overprints i do so on the normal print it is not as bad but it still does it
but yes it does start to pull the color away also

i have try some samples with different temp settings i also have the vender i got the machine from working on it also but figured i check if anyone else had some similar issues
i have to do some clear vinyl decals so i can do some tests with that also

 

[artbot]

you can turn the heat way up for the poly carb and it will stick really well. the only problem is solvent ink goes on really thinly and has a tension to it. when you are laying down the white, it is allowing for that tension to break. i've noticed this when printing on veneer. the ink can crack with some top coats. from the pic, it looks like you are putting down a ton of white. try letting your color layer dry and relax for much longer and see if that helps, or print simultaneously so that the colors are dry at the same time (not sure if it will help, just throwing out some stuff).

 

[petepaz]

thanks for the input
i will give it a try

 

[DRamm76]

Pete, After the testing we did here, the heat is def the issue. I agree with Artbot. Letting the first layer dry for a bit before printing the second is def key. When we printed the tests with the heat off it cracked like crazy. After making adjustments on the heat, we had much better results. Letting it sit before running the second layer will make all the difference. Call me with any questions. I'll be up next week.