? Best Means To Create Equal Ink Dwell Time with a Printing Machine ?

[Deleted member 16349]

Dabbing ink on the rollers of a moving press is not only dangerous as you say but the colour variation would be horrendous.

I don't recommend it but it was an interesting comment on an old method. The colour variation does not have to be horrendous if the old timers put the ink to the side of the low coverage area and let the oscillation feed the ink from the sides. I think that technique was done mainly when the press was stopped and allowed to run a bit first before printing. Since the presses were much slower in the past and people took more time, these kinds of tricks could work. Today is a different situation. For me it was an interesting comment since it showed how press operators knew how the press dynamics worked for this kind of problem.

 

[D Ink Man]

This can help in some situations but IMO it is not a good solution with respect to press design. Controlling low coverage and avoiding over inking are important issues for control and the reduction of waste and there are press design concepts that can greatly help. I won't go into them here since it has no practical benefit for those with existing press designs.

The weakness of the above approach is that one can have very low coverage on one side of the plate (gear side) and high coverage on the other side (operator side). The interrupter method probably will have problems supplying the high coverage side with enough ink.

If the interrupter method on a press was able to supply enough ink to the high coverage also, then there might be an issue with the density of the high coverage having a bit more variation due to the less often supply of higher amounts of ink from the ink fountain and ductor. High coverage requires a more continuos ink feed because it is being taken out of the press so fast, while low coverage can have ink fed on a much more non continuous basis since the ink goes out of the press so slowly.

I have been told that in the old days, press operators sometimes turned the ink fountain off and just applied some ink occasionally to the roller train with an ink knife for images that had very low coverage all the way across the plate. Not recommended while the press is running due to being a dangerous thing to do.

Oscillation should help move excess ink from regions of low coverage but oscillation does not move ink laterally on press very effectively. It does help smooth out ink differences in local areas.

Aren't take off bars a good method to allieviate the unequal coverage that can occur on particular forms as you mentioned across the width of the press? Providing you have cutoof room; me understands sometimes you don't.

D

 

[aqazi81]

I have been told that in the old days, press operators sometimes turned the ink fountain off and just applied some ink occasionally to the roller train with an ink knife for images that had very low coverage all the way across the plate. Not recommended while the press is running due to being a dangerous thing to do.

The trick that I have used for this problem was to turn off the ductor roller for sometime and re engage it, it works well but one needs to be very careful, if you forgot to turn on the ductor you can ruin the job. Sometimes we use the paper strips where too much ink is deposited in the rollers during paper feeding stoppages.

 

[Cornishpastythighs]

The trick that I have used for this problem was to turn off the ductor roller for sometime and re engage it, it works well

An early form of ductor interupter.

 

[D Ink Man]

A strength adjusted process ink system I believe is still a concept that could be researched, developed to provide constant ink dwell from barrel to substrate, regardless of the coverage. Take off bars could be utilized for those forms with the lightest of coverage's and where a bias of unequal coverage is present across the width of the press with a particular form.

We put a man on the moon almost 50 years ago; nano ink particles fused onto a substrate will continue to be an environmental nightmare if ever developed to produce sellable work in the end of the print pieces' life cycle (also mention lack of quality print), but this my friends what I mention is a true, non-fallible concept that could lift lithography exponentially to never seen before consistencies.

D Ink Man

 

[Schnitzel]

nano ink particles fused onto a substrate will continue to be an environmental nightmare... (also mention lack of quality print)

How do you know that?

 

[D Ink Man]

Because I'm smarter than the average Schnitzel.

I know the mountains, valleys, plateaus and deserts that are blocking your way.

Throwing M O N E Y at it shall not clear the path of obstacles. But trudge on...my friend(s').

 

[Schnitzel]

So, you've never been to the factory, never seen a single print, don't know how the machines and the process work, never seen the deinking score the prints received, but you somehow "know" everything.

Maybe you are not as smart as you present yourself with such arrogant authority. You are just guessing. Trudge on.

 

[D Ink Man]

Where is the productivity (#1) off these marvelous printing contraptions that were so highly touted going on about a half decade now? I expect Drupa 2016 to be another dog and pony show with more capital capturing executed by Benny and the jets.

Don't get me wrong, I am actually rooting for you. However with that said, I do not want the planet for our successors to be crawling with an amoeba like goo in our oceans as the by product from the ink stuffs that do not decompose with time. The same thing that you all are promoting about the armor like printed ink film and it's ability to print on any substrate turns around to be a horror for the environment when the printed piece has reached it's end of life.

The mechanical aspect of your workings is most likely a lesser challenge to why there is no printing or presses installed for ROI, like Komori, for one instance. It is the ink man, and I know it.

D Ink Man

 

[Green Printer]

So, you've never been to the factory, never seen a single print, don't know how the machines and the process work, never seen the deinking score the prints received, but you somehow "know" everything.
.

Mr.Schnitzel were the deinking test performed by INGEDE?

 

[D Ink Man]

Where does Landa nano stand on the scale??

 

[D Ink Man]

All’s Quiet on the Eastern Front

 

[Alois Senefelder]

Hello fellow Lithographers,

Perhaps, "de-inking" and other environmental issues are the "Achilles heel" of Inkjet and Toner based

Imaging Systems.?


Regards, Alois

 

[Schnitzel]

All’s Quiet on the Eastern Front

Come on, be serious. Do you honestly think I can give you the numbers before they've been published officially? I'm signed under the most strict NDA. A few posts ago you claimed to be smarter than the average Schnitzel - at least pretend.

 

[D Ink Man]

Thank you for answering the question Schnitzel; you just did in case you didn't know. We all know now.

D

 

[Green Printer]

So, you've never been to the factory, never seen a single print, don't know how the machines and the process work, never seen the deinking score the prints received, but you somehow "know" everything.

Maybe you are not as smart as you present yourself with such arrogant authority. You are just guessing. Trudge on.

Sometimes the quickest way to find an answer is to ask INGEDE directly. So I emailed them and received the following response from Axel Fischer of INGEDE.


Dear ?????

Probably Schnitzel (who is from Rehovot, Israel, according to his profile) hasn’t seen the deinking scores either? You almost could read that as well?

We did not perform any tests yet, we were not given any samples yet, we offered cooperation and early tests under NDA already at Drupa 2012 and many times after but Landa did not come back on that offer.

So I assume that the Landa technology will be a thinner Indigo film, some plastic film transferred from a carrier to the paper? There seem to be no nano ink particles but they together form a layer that needs a certain grade of cohesion to be transferrable from the carrier to the paper?

So if all these assumptions are right, there are chances that we will have similar problems as with Indigo (which is currently the digital printing technology causing by far the biggest problems in paper recycling): large, thin, flexible chunks of plastic that are difficult to remove from the recycled pulp in the deinking process. A lamination rather than a printing technology. And despite all of HP’s greenwashing, it is NOT deinkable.

And I think if it was different, the Landa folks would have come up to us and given us samples to have this feature clear. I thought Benny Landa was smart enough not to run into the same trouble that Indigo has now, but that has been developed in times when sustainability was not an issue.

Feel free to use all this when commenting!

Best regards
Axel.

 

[D Ink Man]

Well, DO TELL! Bless your pea picking heart sir.

Litho ON gentlemen, no trudging necessary.

D

 

[Schnitzel]

Sorry, you seem to have mistaken me for someone who actually cares whether you believe him or not.

You can believe anything you want, including the fanciful speculations of Mr. Fischer from INGEDE. After all, everyone is entitled to their own opinions, as evident on this forum. Luckily, not everyone is entitled to their own facts, to paraphrase Moynihan. Keeping my job is more important to me than satisfying the curiosity of strangers on the internet, so forgive me for not falling for that childish bait.

I apologize for making this post so belligerent, I don't fight over the internet - it's pointless. It's the constant mosquito bites from D Ink Man that got the better of me.

 

[aqazi81]

Keeping my job is more important to me than satisfying the curiosity of strangers on the internet, so forgive me for not falling for that childish bait.

Then I think you should quit this forum because all of us (strangers on the internet) here are for sharing knowledge and experiences with each other.

 

[Schnitzel]

I happily share knowledge that I have. They want confidential information that I'm not allowed to share. I'd rather quit this thread than this forum.