S mesh for sim process

[blue moon]

Hi Bimm.

The un matched or complimentary lpi screen angle is connected to moire. You get moire when having to screen angles collide that work against each other.

The mesh (interference) is a different beast often thought of as moire, but is related to the (rule of thumb) connection. This is math. the math determibes the proper (mesh that works well) and has to do wether the mesh threads will be blocking the small dots. That is not morie, but (mesh interference. The two are different beast to tackle. When the mesh nears (too low) those thick mesh threads block small dots causing (interference) and can show that saw toothed jagged halftone at the end of a fade.

Its very easy to mix works and have these terms confused with others. I still do myself sometimes.

There is still yet another term that is similar but I forget what it is at the moment.

I'll add the garment weave interference to this lot. Some garments will create patterns similar to the mesh interference due to the way the fabric is knitted. This generally tends to be spotty throughout the

pierre

[bimmridder]

I guess I always thought that moire was "a pattern within a pattern". If there are dots not printing because of mesh interference, in a pattern, I thought that was moire. My mistake. My ulterior motive in my reply was sometimes you need to test and research. 

[blue moon]

few thoughts here on the subject . . .

we have successfully printed 55lpi thorough the 225S. It did not hold all the dot's, but I think it went down to 5% or so (disclaimer as usual, this is with a calibrated do which is SIGNIFICANTLY SMALLER than stuff printed by RIPs that have not been linearized. It is an equivalent to 65 or possibly even 70lpi on the RIPs straight out of the box).

On the original topic, 330S is our mesh of choice for the high end prints. Daily stuff that does not need as much attention is printed with 305 thread almost without exception. As Dan said, if going on a shirt directly (no ubase), more colors will help saturate the print, but there are options that can be engineered into the print. If the fine detail is needed, we have on few occasions used a spot color bump plate to get more ink where needed or dropped the lpi to 45-50 and used thicker mesh. These are options you can give to your customers and have them decide if better print or lower cost are more important.

As far as printing on an underbase (90% of the sim process jobs), there are no issues with coverage using 305 mesh. The ink is going on top of the white film which is preventing it from soaking into the shirt. I have found that too much ink tends to mushroom out and create soft edges. In our case, 225S on an underbase would not be an option as it would be too much ink.

The total amount of ink deposited on the shirt directly and on the underbase are significantly different. While the white shirt will take 300% deposit (i.e. 3 screens at 100% or 6 screens at 50% for example), only 150% to 180% go on top of an underbase before it starts mushrooming and smearing.  This is obviously all wet on wet and what seems to work for us. I am learning lately that we still have a long way to go when it comes to the proper ink control. . .

pierre

[Dottonedan]

I guess I always thought that moire was "a pattern within a pattern". If there are dots not printing because of mesh interference, in a pattern, I thought that was moire. My mistake. My ulterior motive in my reply was sometimes you need to test and research.

100% correct on that. Test and test, research and research.  You probably just don't run into that problem a lot.   For me, I trouble shoot a lot of shops that run into this and I have to narrow down the exact problem. So I'm probably just more attune to the various causes.

[blue moon]

I guess I always thought that moire was "a pattern within a pattern". If there are dots not printing because of mesh interference, in a pattern, I thought that was moire. My mistake. My ulterior motive in my reply was sometimes you need to test and research.

from what I understand, it is all called moire, it just has different sources. But both of us could be wrong. . .

pierre

[Dottonedan]

They identify the sources (that look like Moire) differently so that you can more accurately and quickly define the true source of the problem. If it were all Moire, you would have to trouble shoot 5-10 options.

[JBLUE]

305 here at 55 LPI. Like Dan I do not care for bigger dots so 45 LPI is done only as on a need be basis. We also run a linearized printer like Pierre. It is a whole other ball game than non linearized films. The dots are a lot smaller since the dot gain of the ink on the film has been adjusted to be accurate. So your dots are like a dot one would see at 65-75 LPI. For us a 230 or 225 will get a moire more often than not. Stepping it up to a 305 s cures that for us.

[Inkworks]

So basically you're saying Murakami needs to come out with a 260-40 that you can tighten to 30 newtons and it's the mesh to end all meshes? :-).  It seems to be too much of a jump anyway between the 225 and 310. Maybe I'm missing a mesh count offering???

http://www.murakamiscreen.com/documents/MeshGuidefromCatalogweb.pdf

[ScreenPrinter123]

Yep. That's what I was looking at - nothing with s mesh in between 225 And 310. Was hoping the 270t may have been a good mesh because it has comparable open area to the 225.

[ScreenPrinter123]

With that said, any of the other s mesh manufacturers make a 260s mesh?

[Inkworks]

Yep. That's what I was looking at - nothing with s mesh in between 225 And 310. Was hoping the 270t may have been a good mesh because it has comparable open area to the 225.

Sorry, I was thrown by them labeling the whole chart as "Smartmesh" at the top. Still the 270 34 micron looks like a viable option even if they don't give it the "S" designation.

[Inkworks]

If you want amazing open area numbers, look at stainless mesh:

http://www.nt-jp.com/en/products/pdf/scr_Micromesh.pdf

[blue moon]

huh, did you see the blade speed on that? 10mm/min? that's 1/3" per min or so!

my understanding is there are issues with the metal mesh so it's a no go.

as far as open area, how's this?

LX Mesh

pierre

[blue moon]

and here's a 230 for comparison

pierre

[Dottonedan]

and here's a 230 for comparison

pierre

This one...  Danny say poo poo for halftone work.       Is this your mesh?


Steel mesh (as far as I can remember) is not great for printing on apparel. The reason being, it's not very elastic. We used it when I worked at the glass factory when we were printing on (hard surfaces) like Coffee mugs.  Even then, as it got hotter and hotter, it would (bag out) or lose it's elasticity. Not real stable on long runs. The more friction and use it got, the more it would distort.


We of course, were printing with hot inks. They were made of a clay like ink material (minerals and such) and you needed to heat them up and melt them in a Bunsen burner of sorts. The metal mesh is all we could use, but after a while (2000 prints or so, you would need a new mesh to maintain an accurate print. They would start to make a round dot egg shaped and elongate your entire print.


Once they do that, they don't ever go back to shape. Same thing I'd bet happens under a flash. As each stroke of the squeegee pulls, after that flash it will elongate your print image causing distortion.