Press Comparisons

[Lithographer]

everyone makes a good press and they all can print a good dot. it comes down to the options you're looking for what fits your needs. you said you're looking for a long perfector. I would look hard at a manroland. if you do your homework, you'll see that everyone is copying their technologies, double/double diameter, transferter transfer system, 7 0'clock cylinder geometry, vacuum feedboard and airtracks thoughout the press. they have been using this technology since 1992. what's interesting is that both heidelburg and kba are all copying these features but are advertising it as if it's brand new and that they had just thought of it.
I have ran komoris, heidelburgs and manrolands and the rolands are the easiest and most operator friendly presses. the rolands are now offering the direct dirve machines that will change plates, wash blankets and impressions cylinders all at the same time, on all units!! how much makeready time will that will that save?! no pre-bending of plates like the rest of the manufacturers, too. there's a company in europe somewhere that is saying they ran 169 jobs in 24 hours, on a direct drive long perfector.

back to press testing........ go to each manufacturer with your files in hand, and ship stock to each one as well (yes, this can be expensive, but will give the best results). tell them to leave the stock wrapped until you arrive. this will eliminate any pre-running of stock and the jobs. this will give you the most accurate results based upon a production atmosphere. how many shops get to pre-run thier stock before they run their jobs?
heidelburg is the best at smoke and mirrors. they rehearse everything from what they are going to say to you from the time you walk in the door, 'til the time you leave. anytime you take them out of their comfort zone, that is when you'll really see what their machines are capable of.......also their operators. this goes for all of them.

I've worked for 2 different manufacturers in the past, and following the guidelines above will give you the information you need......without smoke and mirrors. they all do it, some are just better than others.

Heidelberg presses (XL and CD ) have a Venturi air system which allows for a mark free transport of the sheets. The air system allows the sheet to literally "float on a cushion of air. This is far superior to having a guide plate with air hoses blowing a sheet away from the plate that needs to be adjusted manually according to the sheet grammage. The Heidelberg system the Venturi air settings are set automatically when entering the sheet dimensions in the Press Centre.

 

[unbrockster]

Seejay, do you mind giving a quick synopsis of your findings / conclusions?

Thanks

Hi there,

the process that we recently used to test a number of press manufacturers (Heidelberg, KBA, Komori, ManRoland) is as follows:

We selected 5 standard production jobs - 2 sections each, 4x4colour jobs, 1x5colour job. All were on different substrates - satin, gloss and recycled stock, SRa1 to B1 sheet size - which we supplied.
Each vendor was given 1 job in advance, the balance on the day of the test.
The idea was to replicate, as close as possible, a standard production environment to include set-up, make-readies and wash-ups.
The clock started ticking when the first job went on press, it stopped when the final sheet came off press for the final job.
Each vendor was left to decide on colour, all we did was observe and measure (makeready time, number of sheets before good copy, waste, press settings, alchol & fount, etc.).

The results were interesting and varied - from mind-blowing to mind-numbing!!

This was a very good starting point for us.

 

[loopyg66]

Heidelberg presses (XL and CD ) have a Venturi air system which allows for a mark free transport of the sheets. The air system allows the sheet to literally "float on a cushion of air. This is far superior to having a guide plate with air hoses blowing a sheet away from the plate that needs to be adjusted manually according to the sheet grammage. The Heidelberg system the Venturi air settings are set automatically when entering the sheet dimensions in the Press Centre.

The manroland machines use the air pans throught out the press the are controlled with fans, and venturi air fan system in the delivery as well, and were the innovator of this design. they have been setting their air systems through their consoles since day 1 in 1992. the air settings are now set before the job even gets to the console through their offline makeready system, printnet, so the operator doesn't need to.
I'm not sure who uses airhoses to blow the sheet away from the plate, but that does sound like a bad idea.