Violet vs. Thermal

[Prepper]

Question: are all violet plates silver based? Do the photopolymer plates have silver in them also? And are nasty in processors to clean? I thought the photopolymer violet plates didn't have the silver?

I also heard from one supplier violet plates are 120 days order items to start up and 90 day after that? Are they harder to get than thermal?

Trying to decide...
Thanks

 

[marktonk]

Re: Violet vs. Thermal

prepper,

Silver Halide violet plates contain minor amounts of silver, allot less then the same size piece of film. This provides a faster emulsion and require less energy to expose so the laser will last longer. When Violet first came out, they had a 5 mW laser and the only plates you could expose was Silver halide Typically, they are good up to about 350,000 run length, can not be baked and are the higher quality plate.

Photopolymer does not have silver, has a run length of up to 200,000 but can be baked for longer runs. They require more energy to expose and are not as high resolution as the silver halide. Typically, they require a 30 mW or 60 mW laser.

I do not know if you are in the U.S. but we do not have a problem with a quick turn around on violet or thermal plates.

Regards,

Mark Tonkovich
Heidelberg USA
Product Manager, CtP & proofing

 

[Prepper]

Re: Violet vs. Thermal

Hi Mark,

You say the photopolymer doesn't have as good a resolution as the silver halide, but what is that resolution? And no silver means clean processing doesn't it, is it as clean as thermal?

We are a low volume, non-profit inplant basically so the lower entry price, lower maintenance cost, etc. seem to make violet appealing to us. We run a Harris web for all our text, black only, and a Speedmaster 72SP for our covers, newsletters, etc. Top quality design and color on our sheetfed, 4-color photos on 2 pms color vignette backgrounds. We currently print 175 line on the Speedmaster and probably won't be increasing that or going to an FM or hybrid screen anytime soon. Right now we're imaging film on a Herk Pro and burning plates, my thoughts are the violet may not be the highest resolution solution out there but even it would be a step up from where we are with film wouldn't it? First generation and all?

Do you think the violet solution would be a good fit for us?

Thanks,
Terry

 

[marktonk]

Re: Violet vs. Thermal

Hi prepper,

You ask about the plate technology, we choose silver for its higher quality. We run it up to 300 lines with this plate but we can go to 400 with thermal. We have been using it side by side with Thermal for 6 years and do not see a quality difference unless you wanted to exceed 300 line. I asked if you are in the U.S.? I am only speaking for what we do here.

No silver does not necessarily mean a cleaner processor, you do get some sludge from photopolymer which is a different dirty shall we say.. Both processors will require cleaning. For years, we have add a device called Mini ProWash that helps keep the processor cleaner for a longer time.

If you have no desire to exceed the 175 line you image, either plate will work. Photopolymer is sensitive to humidity swings, low humidity will required more energy to get the proper exposure. Check the specs from the manufacture and see if you room is set up to meet it. If not, you will need to add some control to avoid potential problems. If you are in spec, you should be ok. Other factors have to be taken into consideration that will lead to what will work for you. What is your longest run length? If you need over 350,000, silver will not be a solution for you.

You have a Harris web. With any CtP, regardless of laser, when it comes to web presses, you need to look at the clamping on the CtP to see if it clears your bend. and printable area. Some webs have a short distance from edge of plate to begin of print and from edge of plate to end of print. If the CtP plate clamp is larger, it will not be able to expose in that area. What is the bend from leading edge and trailing? What is the begin or print and end of print?

If you are in the U.S., I can have one of our reps review your needs and help determine what may be the best fit for you. If you do decide on our violet Prosetter but decide you want a different plate, the Prosetter has been certified with just about any violet plate that is commercialized, you are not locked into one vendors plate, you have a choice.

PM me if you would like a Rep to contact you. Good luck!

Best regards,

Mark Tonkovich
Heidelberg USA
Product Manager, CtP & proofing

[email protected]

 

[frailer]

Re: Violet vs. Thermal

I can only speak as an end-user, who after about 6 months looking/analysing/field visits; finally went violet. Dec '06. We are high plate output, short run, but higher quality stocks. System we went to is Fuji, partly because pretty good support here in OZ., but mainly the perceived quality of the unit. Been running nearly a year. very happy.
My understanding is that there is a timeline to violet development. Basically the earlier versions of violet, as Mark alludes to, were running only 5mW lasers. DVD technology then enabled the use of the 30+mW lasrs, which then allowed a transition to photopolymer. The bath is alkaline, but quite watery. Doesn't sludge up over time, just gets more pigment in it, mainly. Being alkaline, our EPA allows it to go down the drain, in fact they like it because of its alkalinity. You just have to keep an eye on the pH on a daily basis. No big deal.
The big pluses of "new" violet are speed and low cost of the (single) laser; plus it's longevity. We run 175 lpi. Sometimes 300lpi via Fuji's CoRes screening. No complaints. Press guys love the plates. In deference to Mark, this applies to any of the violets, be they Fuji, kodak...whatever.
There is an article which was syndicated in Nov Australian Printer mag, by Andy Tribute, referring to the development path of processless violet. This will eliminate the whole dev maintenance thing, and flick that variable into oblivion. See if you can track it down. A good read.
we get 20 plate/hour...on cruise control!
Good luck.