Experimenting with the offset process Ottawa area

[Green Printer]

What is the thinnest ink film on the ink ball that the ITB can effectively transfer? For instance .2mil or .5mil or 1 mil.

 

[Green Printer]

What is the thinnest ink film on the ink ball that the ITB can effectively transfer? For instance .2mil or .5mil or 1 mil.

Green print that is a very good question. I am looking forward to Erik's answer.

 

[Deleted member 16349]

What is the thinnest ink film on the ink ball that the ITB can effectively transfer? For instance .2mil or .5mil or 1 mil.

The ITB concept has the ITB tip metering a consistent amount of ink on the ink fountain roller back to the ink fountain. The amount of ink that is metered back depends on how the tip is designed. The return ink could be equivalent to 0.001" or 0.004" or something else. The ink keys are then zeroed to this amount, what ever it is.

Ink that is metered onto the ink fountain by the ink keys in excess of this zeroed amount is collected at the tip and eventually is fed into the roller train.

The point of the ITB is that it transfers volumes of ink and not necessarily films, so it is hard to answer your question in precise film dimension terms.

There is variation in all things. There is variation in the feed rate of ink by the ink key onto the ink fountain roller. There will be variation of ink being returned by the ITB tip. But by far the largest source of variation in an offset press is the pick up of ink by the ductor because it is affected by so many variables, such as temperature, water press speed, etc.

You can argue the little points that have no major impact but what you really want is "No Change" in how things work. You will never be happy no matter how much is explained and I am not interested in trying to make you happy.

 

[Green Printer]

Erik thank you for the further explanation.

 

[Deleted member 16349]

Erik thank you for the further explanation.

You are welcome. For me the issue is not to make something that is perfect but something that is better. How much better will only be known if it gets to the stage where it would be a product that a press manufacturer sells and results are seen and the market responds. Even good concepts are of no value if they do not get to market.

 

[dabob]

The ITB concept has the ITB tip metering a consistent amount of ink on the ink fountain roller back to the ink fountain. The amount of ink that is metered back depends on how the tip is designed. The return ink could be equivalent to 0.001" or 0.004" or something else. The ink keys are then zeroed to this amount, what ever it is.

Ink that is metered onto the ink fountain by the ink keys in excess of this zeroed amount is collected at the tip and eventually is fed into the roller train.

The point of the ITB is that it transfers volumes of ink and not necessarily films, so it is hard to answer your question in precise film dimension terms.

There is variation in all things. There is variation in the feed rate of ink by the ink key onto the ink fountain roller. There will be variation of ink being returned by the ITB tip. But by far the largest source of variation in an offset press is the pick up of ink by the ductor because it is affected by so many variables, such as temperature, water press speed, etc.

You can argue the little points that have no major impact but what you really want is "No Change" in how things work. You will never be happy no matter how much is explained and I am not interested in trying to make you happy.

Erik . . .

Wouldn't the answer be 0? you could adjust the ITB tip to transfer no ink at their "Zero" setting and then if you increased it thickness it would start to transfer.

Also as a sidebar - if you have no interest in making your potential customers happy . . . I have found that frequently you have no customers

 

[Deleted member 16349]

Erik . . .

Wouldn't the answer be 0? you could adjust the ITB tip to transfer no ink at their "Zero" setting and then if you increased it thickness it would start to transfer.

Also as a sidebar - if you have no interest in making your potential customers happy . . . I have found that frequently you have no customers

Yes, it will go to 0 but I think the question was for a specific non zero value. Can any press operator now say how much ink film thickness they are transferring into the press? Not a very easy thing to do.

Sidebar. I have no customers.

My aim is to interest press manufacturers. Basically engineers who can follow the logic of the technology and their sales force that can see opportunities for increased sales.

Of course there is no guarantee. The offset lithographic process, what will be left of it, can go on for another 100 years without fixing this particular problem.

I give this information to the printplanet forum for their general interest about what can be possible.

In the end, if the ITB or other means that can correct this problem does not get developed, who does it hurt the most? Hurts me a little bit but if you look at what is happening in the industry, there is a strong push to get away from the offset process and its difficult operators who argue about every effort to improve and still expect maybe more respect that they deserve.

There is a large group of operators, which is getting smaller all the time, who will be slowly put out of working running a skill demanding process who might get to work on a lower skill demanding digital printing process that prints more consistently. Owners of printing operations are making their vote on this by buying into digital presses. They have to because no one is giving them big enough reasons to stay with offset.

I can just see an imaginary conversation between a press operator and the print company owner. The owner asks the press operator, "can much be done to improve this process". The press operator says, " no, it really depends on the skill of the operator". The owner thinks to himself. "Time to look at a digital press".

 

[Green Printer]

I have seen the Imer system in action. Printing Automation Systems-I.Mer Co., Ltd-IPC SYSTEM
It is amazing the control it allows.

 

[Alois Senefelder]

Clarification

Clarification

Hello Erik,


IS a preset Zone/Key profile applied onto the Ink Duct Roller Face prior to ITB ???


Regards Alois

 

[Deleted member 16349]

Hello Erik,


IS a preset Zone/Key profile applied onto the Ink Duct Roller Face prior to ITB ???


Regards Alois

Yes, the same way one normally should apply a ink key profile. The more accurate the profile, the better the result.

If the profile preset is accurate, then basically the press could act like a keyless ink feed. One problem is that the industry does not have accurate ink key profiles. But that is another issue.

With jobs that would be repeat jobs such as used often in packaging, saved profiles would work well.

The ITB is only an ink transfer device but one that does it better. Water and contaminated ink will also not go back to the ink fountain. The accuracy of the ink feed depends on the accuracy of the ink metering device, which in most cases is related to the performance of the ink key.

 

[Deleted member 16349]

For those interested in the ITB, here is a video of it running during a test over a year ago. I wasn't sure if it was a good idea to post the video here due to the potential critical comments I tend to get but then I though some people might like to see it. So here it is.

https://www.youtube.com/watch?v=HFzSmEvfGs0&feature=youtu.be

I was not at the test and only got the video about a year after the test was run. I didn't even know they ran metallic ink. I was only told that it would be a long test run (~10,000 sheets).

Right now I am designing a prototype version of the ITB for a Heidelberg SM 52 Press. A printer in the Toronto area was curious about the concept so we are seeing if it is possible to do tests at a reasonable cost.

If it ever gets built and tested, I will try to post another video link.

The interesting thing is that the design is nice and simple and has the potential of being an add on kit for the SM 52 press.

 

[aqazi81]

Hi Erik,

Can you post the video at Dailymotion or email me? Youtube is banned here. :-(

 

[aqazi81]

@Erik....I managed to view the video on my phone, But I could not understand the working principal of the ITB. In the video it looks a blade that is taking off ink from the fountain roller.
Can you explain the ductor roller, is it constantly in contact with the fountain roller or is it moving like normal ductor roller?

 

[Deleted member 16349]

@Erik....I managed to view the video on my phone, But I could not understand the working principal of the ITB. In the video it looks a blade that is taking off ink from the fountain roller.
Can you explain the ductor roller, is it constantly in contact with the fountain roller or is it moving like normal ductor roller?

Asif, you basically have the right idea. The blade does take the required ink off the ink fountain roller but allows a constant amount of ink to return to the fountain. The ink fountain roller turns much slower than with the normal set up.

There is a new pickup roller and it is stationary but does not touch the ink fountain roller. There is a small gap. In this case, the gap was 0.019".

Here is the patent which may or may not help you understand the concept. Patents are not always clear due to the legal wording etc.

Patent US6857366 - Printing press ink transfer mechanism and employment of same - Google Patents

It is simple and low cost but so far the industry does not want such a solution. Some things take time.

 

[aqazi81]

Where does that ink that is taken off by Blade goes? I am sorry I am not an engineer, just a pressman so asking these questions to understand the concept clearly.
What is the function of the pickup roller? I have seen those patent drawings many times but didn't help much. May be an animation can help understand the whole concept.
Anyways Good Luck!

 

[Deleted member 16349]

Where does that ink that is taken off by Blade goes?

It goes into the roller train. The purpose of the ITB is to make the ink transfer from the ink fountain roller to the roller train, independent of variables such as water, temperature and press speed. The ink keys of the ink fountain still do the ink metering.

The ITB only transfers the ink that is metered by the keys in a positive and consistent way. The inconsistent transfer of ink by the existing ductor is at the heart of the ink water balancing problem that is involved with dealing with inconsistent print density.

 

[aqazi81]

Hi Erik!
After 2 hours of extensive reading of the patent link, now I got the basic Idea of your invention. I have a question in mind, The distance between the blade and fountain roller will be fixed or is it going to be operator adjustable?

 

[Deleted member 16349]

Hi Erik!
After 2 hours of extensive reading of the patent link, now I got the basic Idea of your invention. I have a question in mind, The distance between the blade and fountain roller will be fixed or is it going to be operator adjustable?

Hi Asif,

The gap between the blade tip and the ink fountain roller is fixed. It can be in a range of about 0.002" to maybe 0.004" (0.05 mm to 0.10 mm). This depends on what the zero set point is for the ink keys. In the version I am thinking about now, the gap would be maintained by a couple of small projections on the tip of the blade, which would be the only points of contact between the blade and the ink fountain roller.

These projections or bumps, would provide the gap distance. There are other ways to do the same function, which is to have the blade meter the consistent rate of ink, on the ink fountain roller, back to the ink fountain.

 

[aqazi81]

So...lets say, if I am running a job with 50% fountain roller sweep and 30% ink zone opening, will this ITB will effect these settings too or not?
And what about changing the color on that unit, cleaning that ITB will be an issue too.

 

[Deleted member 16349]

So...lets say, if I am running a job with 50% fountain roller sweep and 30% ink zone opening, will this ITB will effect these settings too or not?
And what about changing the color on that unit, cleaning that ITB will be an issue too.

One can think of the ITB arrangement on the press as a pump. The output of this pump is directly related to the speed of the ink fountain roller and the ink key setting. It would be the product of the two. (Ink fountain roller speed) x (ink key setting). The output has to be set to what ever the print requires.

The settings used for the ITB would be different than what you normally use. The ink fountain roller speed must be about 1/3 to 1/4 slower when using the ITB. This related to the continuous feed of the ITB when compared to the intermittent feed of the conventional ductor.

Also the ink key setting is going to be slightly different. The reason for this is that the ink key setting is not consistent on existing systems in order to get the same output. Ink key settings are not directly related to ink feed rate on existing systems due to the inconsistent ink transfer of the ductor. With the ITB, the ink key setting is directly related to the ink feed and therefore can be predictable.


Yes, when changing inks, one has to clean the tip of the blade. This can be done when you clean the ink fountain roller. The ITB blade would easily move to a cleaning position.