Emulsion

[3Deep]

Most of you vets already know this, even though I,vie been in this biz for almost 11 years now I,m still learning things.  I was reintroduce to two part emulsion a few months back, reason I stop using it was because I was having a hard time exposing it on my homemade exposure unit so I bought the one part stuff and bang problem solved.  So even after I bought my professional unit I still used one part emulsion thinking the same thing, easy to use quick burn time , but it was hell on burning fine lines and halftones without really having it dial in.  so here come the two part emulsion again I burn a screen, same thing I got years ago washed out screen and emulsion running off.  I moved my exposure time  to 8 mintues and wow I,m now burning 4 color process screens at 50 to 55 lpi with very easy wash outs.  the right emulsion for the right job...so I,d like to who all use what emulsion to burn fine halftone screens, I like the 521 imagemate for fine and the pc 701 for spot color stuff ( thanks Homer for the tip on the 701)

Darryl

[mk162]

I prefer to run 1 emulsion and that's it.  I've been running Image Technology ITX for a long time and love it, the only problem is discharge doesn't work really well.  I am trying out a couple new ones, but I usually end back with ITX.

[Clark]

We used One-coat for standard spot for a couple years and then Ulano LX-680. But I've been getting beautiful screens out of the chromablue the last couple weeks, so may do away with the LX-680.

[Homer]

honestly, I think it's more to do with your exposure unit and knowledge than the emulsion.

[Frog]

honestly, I think it's more to do with your exposure unit and knowledge than the emulsion.

But the basic chemistry choices definitely offer different characteristics.

Pure Photopolymers are extremely long lived both on the shelf and on the screen, neat to use, generally fast, but not the best for extremely fine detail and halftones. For me, they work for 99% of my work, and though not cheap, my favorite is Chromatech PL, though, I am trying to warm up to Xenon Nova.

[bimmridder]

I use a "photopolymer" for most of our stuff...the spot color and half tones under 55. Process work gets a dual cure.

[ebscreen]

Anyone know if it's possible to dope your standard Photopolymer with some diazo
to get a dual cure? I don't like dealing with more products than necessary.

[Frog]

That's SOP for building in more water resistance with the Murakami's you like. I have to assume that it will also affect exposure and resolution.

[squeegee]

Anyone know if it's possible to dope your standard Photopolymer with some diazo
to get a dual cure? I don't like dealing with more products than necessary.

Do it everyday.  I get more detail and resistance to WB/Discharge.  I think the main reason I do it is because of speed and high solids I want for thicker stencils sometimes.

[jsheridan]

I'm using Chromablue polymer as my exposure is black-light. Once I get my Halide I'll switch back to Diazo based as it holds better detail.

[alan802]

Chromablue for mesh counts 137 and up, and Saati PHW red for lower mesh counts and thicker eom's.  I've used several dozen emulsions over the years and I always end up with pure photopolymers.  We don't really have many issues holding 55-65 lpi using the pp emulsion so the need for a dual cure never has really come up.  I guess there are several dozen factors that allow us to get away with that, our light source being like the freaking sun in a metal box and our film must be nice and dense.  Oh and the fact that I'm like a screen ninja

[3Deep]

Thats one of my biggest problem is light source HOMER!! blacklights do a good job , but not really great for the higher counts like 55 up to 65 which I don't try.  Guess I will have to keep it a little longer just replace blanket, the other one went to heaven it was very holely lol tape everywhere.

DArryl

[Denis Kolar]

Hey Darryl. Look online, sites like eBay and Craigslist for used exposure units. I was able to find Nuarc 40-1K Mercury unit for $350 in mint condition. The only issue it had was the shocks for lifting the glass. With 6 months experience, I expose pretty good halftone screens. Using Chromablue emulsion.
The unit has Mercury bulb and not Metal halide, but it works A LOT BETTER than tubes and it is well worth $350. I replaced the bulb and I kept the old one as a back up. I was able to find the new bulb for $45 on eBay.