Which photopolymer?

[Maxie]

I want to switch from Diazo to Photopolymer.
Any recommendations?
What do they cost?

[Frog]

There's lots. What brands do you have easy access to?

[Screen Dan]

Murakami Aquasol HV and HV-P have been working out for me for years.  We add diazo.  You don't have to.  DC, WB, plastisol and I don't see why silicone wouldn't work out just great too.

[Frog]

As for cost, here in the States, for various ones I've used over the years, they range from $50 to over $100 a gallon

[alan802]

I always go back to the Murakami Aquasol HV/P.  I try a bunch of different types of emulsion and some work good and some don't, but the HVP I know will work all the time.  Kiwo, Ulano and Murakami make great emulsion and if you can't find anything out of those 3 then I'd say you're doing something way wrong.

[sqslabs]

I've been very happy with HVP as well.  Quick burn times, great detail and solid stencils.

[Rockers]

We like Chroma Blue

[LuckyFlyinROUSH]

Chromablue - 62$ gallon $55 gallon for 6+ gallons

[mimosatexas]

Big fan of sp1400 now, but for non Diaz I really liked the hvp as well. It can be a little sticky and on my expo unit I had issues with delamination on super small details and halftones, but it was way better than the half dozen compel able options I tried.

[Orion]

I want to switch from Diazo to Photopolymer.
Any recommendations?
What do they cost?

Why do you want to switch? Shelf life, fast exposure?

I cannot recommend photpolymer or its cousin dual-cure. Used both for years and now use diazo emulsion. Our diazo emulsions durability and compatibility with different ink systems works very well for us.

As for cost, photopolymers are more expensive.

If you make the switch I hope it works out for you.

[Doug S]

For me it's kiwo discharge all the way.  It has a year shelf life 42% solids and no need to add diazo, it exposes in 1/3 the time of cci wr14 and it has great edge definition.  I will confess though that I haven't tried it for long run waterbased or discharge runs so I can't say much about that.  The longest so far was a 100 piece run of discharge with no troubles.  $69 a gallon from nazdar

[RichardGreaves]

Prescription before diagnosis is malpractice.

I was very pleased to see Orlon write "Why do you want to switch? Shelf life, fast exposure?". Photopolymer isn't an answer in itself.

The weaker your exposure source, the more a photopolymer will be valuable.

Photopolymer reacts and joins quickly like popcorn. Diazo sensitizer takes longer to react and join molecules, so it has more latitude when it comes to a complete cure.

2015 has a fresh new crop of pre-sensitized, 18 month shelf-life photopolymer sensitized emulsions with respectable water resistance like KIWO Polycol Multi-Tex. I have not tested them for halftone resolution, but I like the idea of a faster, universal emulsion for for water-base and 100% solids inks like plastisol.

Diazo dual-cures have always been my go to emulsion because they gave me the best halftones.

[Maxie]

Thanks for the feed back.
I am using Ulano 925 at the moment with fluorescent lamps.
Obviously not the best light source.
I have a great exposure unit that holds 2 screens and don't want to change this.
I recently bought a 300w LED from Saati and this light source will fit into my exposure unit and work well with photopolymer.
Our climate is hot and humid and I understand that photopolymer is not affected by these conditions.
Exposure times will be shorter but this is not a big issue.
I don't know if reclaiming is any different with photopolymer.
Saati have PHU which I intend to test.
Richard are you saying that the Diazo holds more detail?

[inkbrigade]

Another vote for Murakami Aquasol HV.

[RichardGreaves]

I'm sorry Maxie, I didn't notice it was you.

I am using Ulano 925 at the moment with fluorescent lamps.
Obviously not the best light source.

You're using the industry standard water-resistant (WR), diazo emulsion invented in the 1960s. Nothing wrong with 925WR, it's slow to cure but all manufacturers of WR stencils have improved curing speed & reclaim. There are emulsions at any price with better water-based ink resistance & durability for long runs. How long are your average water-based ink print runs?

Fluorescent lamps are the lowest energy UV-A output and your exposure time to cure will be reduced no matter which emulsion you try.

I have a great exposure unit that holds 2 screens and don't want to change this.
I recently bought a 300w LED from Saati and this light source will fit into my exposure unit and work well with photopolymer.

Refitting your equipment with a 405 nanometer Saati LED source will improve your halftone stencils. Fluorescent lamps by their nature diffuse light energy, scatter light and promote under cutting.

Our climate is hot and humid and I understand that photopolymer is not affected by these conditions.
Exposure times will be shorter but this is not a big issue.

All photoemulsions sensitizers are effected by heat over 104 degrees F.

I don't know if reclaiming is any different with photopolymer.

925WR is difficult to remove because of it's water resistance and it's harder to completely cure with your low energy lamps.

Richard are you saying that the Diazo holds more detail?

No. I wrote, "Diazo dual-cures have always been my go to emulsion because they gave me the best halftones."

My favorites are Ulano TLX and KIWO PolyPlus S. I like TLX over it's sister emulsion Ulano RLX because the light teal color exposes 20% faster and is easier to see through for registration.

My next exposure experiments will be with the new KIWO Polycol Multi-Tex when I visit Pierre at Blue Moon later this month.