Research project on Sheetfed offset inks rheology problems

[Print Xpress]

Please suggest me the current problems with offset inks. I will try to solve the same as i am interested in doing research activity

 

[D Ink Man]

The current problem with offset inks is that not nearly enough of them are being used to print the best quality reproductions that man has invented to date.

Further, the offset ink market is mired in a price war as a means of being competitive, rather than the tried and proven methods of quality product, consistency and technical service.

Anything further you need to know, please don't hesitate to ask. D

 

[Ajax]

I'd like to ask if ink companies are using transparent white anymore? Take for instance pms 425. Generally you run more ink to achieve color with heavily diluted inks such as 425. What I've found lately is is that they've almost, if not totally, skipped that part of the mix. The film of ink in my rollers is so thin the tack of it pulls the paper apart. These inks are toyo and van son. I use varnish to thin it out so the ink will lay down and be good.
It's certainly not the way it use to be.

 

[D Ink Man]

Ajax,

It is a matter of color strength. Both TOYO and Van Son have their versions. They need to back off on the black and reflex blue in the formula and add more transparent white.

The book formula means nothing, it is all dependent of the base colorants decided on by each supplier.

This is not your problem however, but one that you can investigate and report the results to a RESPONDING ink supplier.

Check the ink film thickness of your spot color on the vibrator roller, next to the plate form. Ideally ink spot colors should be about .5 - .7 mil thickness. An Interchemical Ink Film Thickness Gauge can help you measure it in a channel of ink coverage on your print form.

The reading must be obtained on the fly, while you're running. I know there are limitations with the guards on most modern sheeters. However, there is a trip device to allow you to run the press with them up.

It is well worth the time and effort to do this. The IFT gauge is a very valuable tool in an offset pressroom.

It is akin to a doctor having a stethoscope as a tool. You need the heartbeat! D

 

[jbeniston]

Years ago we used to use stuff called "reducing" varnish and "thin varnish",
For exactly the same purpose you describe, you're just becoming a retro printer that's all. I don't know if the ink companies still make transparent white or not, but i would think that they are, maybe Toyo call it "extender" instead of transparent white.

 

[D Ink Man]

Years ago we used to use stuff called "reducing" varnish and "thin varnish",
For exactly the same purpose you describe, you're just becoming a retro printer that's all. I don't know if the ink companies still make transparent white or not, but i would think that they are, maybe Toyo call it "extender" instead of transparent white.

All ink companies make transparent white or extender. Both are the same thing, just depends on what they want to call it.

The biggest problem however with this, is that 95% of the ink companies do not put pigment into their transparent white. This is huge, huge mistake from a printability standpont for the printer and final work piece.

D Ink Man

 

[Lukew]

Ink prices have continued to drop over the years which makes you wonder.
Either the ink manufacturers had a healthy profit margin for many years of supply, and had room to drop prices and still remain profitable.
OR
The majority of ink manufacturers are now sourcing cheap inferior raw materials & using production plants with a low cost of labor to enable them to sustain this price war on ink.

I can't speak for other area's in the world, but here in Australia there isn't one ink manufacturer. All the DIC, Flint, Vanson, Toyo, Hostman, T&K Toka, etc etc, are shipped in and on sold.
It's a shame that even the big guys don't have the ability to manufacture or alter an ink to suit a printers needs here.

 

[D Ink Man]

Ink prices have continued to drop over the years which makes you wonder.
Either the ink manufacturers had a healthy profit margin for many years of supply, and had room to drop prices and still remain profitable.
OR
The majority of ink manufacturers are now sourcing cheap inferior raw materials & using production plants with a low cost of labor to enable them to sustain this price war on ink.

I can't speak for other area's in the world, but here in Australia there isn't one ink manufacturer. All the DIC, Flint, Vanson, Toyo, Hostman, T&K Toka, etc etc, are shipped in and on sold.
It's a shame that even the big guys don't have the ability to manufacture or alter an ink to suit a printers needs here.

Excellent points Lukew.
Another huge contributor is the reduction of PEOPLE by the big boy and also the mid size ink companies.

The result is a drying up of all the experienced expertises and as you said, cheap materials and cut throat pricing practices utilized as the primary competitive mechanism. Shameful, absolutely shameful.

D Ink Man