Coating technique on low mesh.

[ericheartsu]

same with us.

One thing i Did just find out about though, is that there is a possibility with HSA inks that the PHU and the PHU2 might be absorbing moisture of the ink, causing it to dry out faster.

[mimosatexas]

mostly S mesh with SP-1400 here, with some 280 and 110 standard mesh, and a handful of lower meshes.  Monster max coater.

On everything but the 280 I use 1:1 with a relatively slow stroke.  110 and all of the S mesh has a perfect glisten with just the one stroke.  Cleanup stroke on squeegee side mostly for insurance with possible air bubbles/streaks, and to build the eom a bit.  Don't have a gauge, but I think it is likely higher than many shops.  I can feel the edge of the stencil a bit on every screen after washout.  280 takes 2:1 for glisten etc.

every once in a while I will do a 2:1 on the 110/135S if I am going for a thick ink deposit on a transfer, or weird fabric or one hit whites on a back that is mostly all small text etc.  On the lower specialty meshes I use a different emulsion and those I basically go as thick as possible without drips and irregularities.  I don't have those dialed in at all because of how rare they are used.

Just an aside, what is the logic behind multiple coats on the squeegee side?  I have never seen any benefit to this unless you are compensating for the emulsion not penetrating the mesh to get the glisten you want, or maybe its needed for a really high eom with a super thick emulsion?

[jvanick]

same with us.

One thing i Did just find out about though, is that there is a possibility with HSA inks that the PHU and the PHU2 might be absorbing moisture of the ink, causing it to dry out faster.

We were experiencing this when we weren't post exposing long enough.

I sent a quart of our hsa to saati and they said no problems found.

But I do agree we had something going on.

[Maff]

Hey Colin, What exposure unit are you using? 
We have a 850w MH unit and been using PHU also, but we seem to have a tougher time on our S-mesh getting it to crosslink completely through when we coat them thicker.  I don't have an EOM gauge yet, but just going on our trials and experience.

are you sure it's a crosslinking issue?  What's your symptoms? 

if it's edge breakdown/squeegee wear, it's could be an adhesion issue...

once we started using a mesh abrader (Saati DirectPrep-1) before putting the screen into production the first time (yes I know this flys against all current advice)...  all of our edge breakdown issues went away.

This will totally derail this thread... I'm going to start a new thread on this... I've been meaning to anyways.

[Sbrem]

With a full coater, when coating 81 SDE through 110S, first one coat on the substrate side, then one on squeegee side, I controlled pressure and speed to get the result I wanted. As the coater drained down, I might add a second coat on the squeegee side, but that was my hint to refill the coater. I've always preferred the sharp edge...

Steve

[tonypep]

Interestingly enough EOM recommendations do not take ink rheology and foundation into account. HSA, Acrylic, and waterbase products may  have different requirements for instance

[ScreenFoo]

Or detail requirements, for that matter.

We're lucky though--the substrate is rather forgiving in most textile printing... 

[Itsa Little CrOoked]

I use an AWT with the sharp edge, 2 over 2 (wet on wet) for 305 all the way down to 110, S-Mesh or T-Mesh. For 83, 60, 40 (Mostly all T-mesh in this range) I do one over one. I always start on the shirt side and end up on the squeegee side.

I coat pretty quickly, and don't get along very well with letting anything touch the mesh except the edge. Touching the shoulders as many do doesn't work for me.

I'm NO EXPERT. But that's what I'm currently doing at this point.

[Colin]

Maff:

Start your new thread about exposures etc and I will chime in there.

When exposing S mesh I have definitely seen emulsion behave differently and the details should be put into that thread.