Screens filling in on press with RipIt plates

[KimPal]

We have a Xante/RipIt Speedsetter x2 running Mitsubishi poly plates on a Hamada 2 color RS34LS2 and an ABD 9970 T-head.

The plates come off the speedsetter looking great -- the dot pattern on the screens look really good with no filling in. However when we get them on press, we have trouble with the screens filling in and trouble cleaning up the plates -- even on short runs.

Could it be the fountain solution mixture? Ink? Rollers? Or is it just the way these plates are? Any advice?

Thanks.

 

[KimSaks]

RipIt Plate Issues

RipIt Plate Issues

My bet is on the fountain solution.
Contact Erick Bristow... [email protected]
He has a solution for this and any other issue you might have with the polyplates and/or any RipIt system.
I'll forward your post to him as well.

 

[Pressman's Pride]

Sample kit

Sample kit

Just ask and I'll give you a sample fountain solution to try and solve the problem, it could be exposure or chemistry and it could be as simple as the solution you are using. Let me know if you'd like to try some known remedies for this type of problem.

Erick
866-319-3334
Pressman's Pride - Chemgon, Commercial Printer Supply, Pressroom Supplies
"We have your solution"

 

[KimPal]

re: screens filling in on RipIt plates

re: screens filling in on RipIt plates

Erick,
Thanks for your reply (and KimSaks, you too). The plates we're using are the new Mitsubishi FRS plates which they sent to us without telling us about the change. We're told the emulsion is different from the old plates (but in all honesty, we had similar issues with the old plates, too). We did the exposure test Mitsubishi recommends and visually it looks good, but as we don't have a densitometer, we're not 100% certain.

We're using various fountain solutions, but certainly are open to trying something different. Currently we're various dilutions of Accel FC1000 and also we're trying Spectra Graphics Super Blue.

What is it you suggest? I'll call you this week. Thanks for your help.

 

[Pressman's Pride]

Polyester issues

Polyester issues

Let me send you some samples of Extreme from Nikken. I think you'll see an improvement right away.Just tell me where to send it and how much solution you think you need to do a valid test. Mix ratio is about 5-7oz per working gallon so if you have a 5G tank I will send a quart, if you think more than that is required let me know.

Erick

 

[BillJ]

You didn't say what fountain solution you are running and at what mixture. It may be as simple as adjusting strength and alcohol/sub.

 

[Pressman's Pride]

You didn't say what fountain solution you are running and at what mixture. It may be as simple as adjusting strength and alcohol/sub.

He did say what he was running.......

We're using various fountain solutions, but certainly are open to trying something different. Currently we're various dilutions of Accel FC1000 and also we're trying Spectra Graphics Super Blue.

 

[Lee Ornati]

Plugging with SDP plates.

Plugging with SDP plates.

Hello KimPal
If the exposure is correct, the most likely cause of screens filling in on your press is that the pressures on the plates are too high. For SDP to do a good job with screens the blanket to plate pressure and the form roller stripes need to be a little lighter then the spec for metal plates. About 3/16 th will work best For the form rollers. If you send me a sample of the test plate that you made for the exposure I can tell you if that is correct. E-mail to get this setup is [email protected]
Thanks Lee
Mitsubishi Imaging

 

[Pressman's Pride]

Frs?

Frs?

Can you explain the "change" to the material code from FRM to FRS? Please be specific for those of us who are not informed of these things...

 

[Lee Ornati]

FRM Change to FRS

FRM Change to FRS

Mitsubishi Paper Mills, the manufacturer of the product does periodic upgrades to the formula for the SDP plate material. They felt this upgrade was a qualitative improvement, and decided that they would change the name to bring attention to the improved product. There is no change to the specs, but the ability to reach the specs varied based on plate making and printing conditions. This release opened up what I call the printing window, in particular ink water balance should be easier. We did quite a bit of testing with this product before its release. We found in many cases there was a considerable improvement in performance. In cases where there was no improvement it was because it was already performing to the full customer’s expectation. However this product still has to be used within the correct processing and printing specs, for instance the on press pressures still need to be correct.

Mitsubishi Imaging (MPM), Inc. - NEW SDP-FRS175

Thanks Lee
Mitsubishi Imaging

 

[KimPal]

Lee, thanks for your response. While we do have our rollers adjusted every six months and they have been adjusted for poly plates (vs. metal), I will make sure it is within the specifications you mentioned.

While I tend to believe that it's not the exposure, I will get in touch with you to setup that test.