Heatset web offset - conventional or alcohol dampening?

[Alois Senefelder]

Hello fellow Lithographers,


1) Alcohol Dampening - means the use of Alcohol Enriched Fountain Solution, not a
Dampening System.


2) The use of Alcohol (IPA) in lithographic fountain solutions began in the early 1950's


3) PDFs of various Dampening Systems.


Regards, Alois

[jamfor]

I'm really talking about brush dampning then not conventional. Thanks for enlightning me. I can't think of web presses having a conventional dampning then.

[printerpete]

ive never run webs but out of intrest what is Auto Registration?

[jamfor]

QuadTech RGS V-I Register Guidance System

Here's a link for Auto Registration. Explains it better than I can

[blazini]

ive never run webs but out of intrest what is Auto Registration?

It's a system that uses a camera to find a pattern of dots or marks, each unit prints a mark and the system moves the register motors to align the dots in a pattern. only minor adjustments need to be made once the dots are in their pattern. Auto register is available for sheetfeds too

[blazini]

I'm really talking about brush dampning then not conventional. Thanks for enlightning me. I can't think of web presses having a conventional dampning then.

Older web presses do. going from a narrow to wide web or changing colors the makereadies suck

[printerpete]

It's a system that uses a camera to find a pattern of dots or marks, each unit prints a mark and the system moves the register motors to align the dots in a pattern. only minor adjustments need to be made once the dots are in their pattern. Auto register is available for sheetfeds too

so does the printer not need to get it into fit latrally and circum when making ready only cocking?

[blazini]

so does the printer not need to get it into fit latrally and circum when making ready only cocking?

Yes. Depending on the type of work you do you would ideally want prep to put the marks as close to the gear side of the web/sheet as possible (though they can be anywhere really). The system will align the marks in a perfect pattern (lateral and circ). It's still t up to you to decide on plate cocking, kicking plates, repacking for long circ., or web bustling for fanout.

Say your M is printing slightly long lead to tail, not quite bad enough to repack the plate but you just want to split it up a little. You just tell the system to advance or retard the M say .002" and it will hold those marks 0ff .002". It will bring the lat and circ in when you first start up and hold any moves any moves you make, but it only uses the lat and circ press controls. I've worked on several systems and have never seen one that will use a second set of marks on the operator side and control motorized plate cocking or use the press's phasers