Do you run the Heidelberg SM-52 Anicolor press

[wyagow]

We have a technician from Heidelberg working on the (speedmaster-74) and the sm-52 just went down. They will order the part but not sure how to put it in. How do you take out and change the (1st unit impression jacket on the sm-52 anicolor). we can not get a break on this press.

Its been our experience that Heildelberg will not work on your SM 52 unless you have a work order on it scheduled. The tech guy will most likely tell you that. Having said that I have never changed an impression jacket but have changed transfer jackets as they are easier to access. The operators manual says they can only be changed by Heildelberg tech. Although my press comes with the clamp etc needed to do this ourselves. Our maint guys would want to try this first before calling Heildelberg. If done incorrectly it could cause major damage. I'd be surprised that you would have a spare jacket on hand. I have several transfer jackets on hand but no impression jackets as they rarely go bad. Good luck.

 

[wyagow]

I read your message again and realized that you have Heildelberg ordering the jacket. My manual has instructions in it on how to replace the impression jacket in the last pu. But it mentions that a Heildelberg tech should do the other units. I have changed the impression jacket on a GTO 52 we use to have with success before. You just have to follow the manual to a "T" for instructions.

 

[Ret Heidelberg Instructor]

I would get Heidelberg or someone qualified to change the jacket. WYAGOW is right saying you could really do some damage if you do not know what you are doing. You need a pressing bar and it may not have shipped with the press. I did change one on the last unit of a 4 color SM52 with the aid of a technician, and demonstrated it to the customer. The customer had purchased the Scoring/Slitting option. There were Scoring/Perfing jackets shipped with press and a pressing bar . I also did one on a numbering unit attachment for an SM 52. Once you see it done, you can probably do it yourself. However if Heidelberg does it then the onus is on them if something goes wrong.Transfer jackets are easier to change and the operator or operators should have been instructed on how to do it.

 

[maac]

the parts are on order and Heidelberg will put them in thankyou for your help. you all are the best.

 

[wyagow]

To Michael,
Another thing you may want to do is have your press operator check the amount of packing under the impression blanket. On my press the blanket height should be 0.00 to 0.05mm below bearer. I have found to have the best luck at "0". This should be checked with a packing gauge often as any deviation from this can affect color one way or the other. Just adding or removing 2 thous packing can change your color light or dark especially with magenta. Just another thought.

 

[lazzz]

Maac, thank you sooo much!

We didn't have this heidelberg's paper. And it's very useful one!
For instance, we use 175 lpi and there is written that this particular resolution has conflict with resolution of anilox!
So probably the mottling we have is single-channel moire. I'll try 200 dpi asap.
Off course we use calibration curves. But they can't help much if ink density is unstable. It's the amain issue now. Especially we can't get close to ISO/FOGRA trapping color values. DeltaE is higher than 10.
Very useful chart with density/speed dependence. Our operator currently runs 8000. I guess we have to fix some mechanical issues (e.g. delivery chain tension) and try to increase the speed. Anyway we can't print fast with thick materials like cardboard...

Wyagow, did you mean TVI saying "color"? It makes sense... Heidelberg guys said that packing thickness and type of blanket on form cylinder can impact on solid densities. But they don't know why. Me neither.

Also they said that the temperature of form roller must be always 30 degC. Not less not more. I can't understand the reason...

I agree with you considering ink/water balance issues when ink is too cold or too hot. We definitely should try another ink but first we have to deal with this one. We bought too much of it.

 

[maac]

lazzz thanks:
I am not saying this will work for you but look at my # 57 post on the double cut back this has worked for us!!! and it may work for you on your press. We had to do this because our press has been like this from the beginning. I could never get the right type of calibration curves to work. I think the inks are to dark or the press needs to be reset. In the beginning a Heidelberg color Tech stopped by and was talking about the calibration curves and gave us notes on this type of cut backs for the press. This is what we do (-7% on the Black and Magenta) ( -7 to -9 cyan) and (-12% to -15 on the yellow). make sure you pick up the pdf file to show the layout.

And just make sure your Dot shape elliptical and Preangles required for
Screen family CQS Plus 7.5°

 

[lazzz]

No Title

Sorry, i don't understand what is double cutback. Yes, i saw the attachet pdf...
Is it the same with calibration curve?
There are 8 curves. I guess some of them are linearization curves and other are calibration ones, right?
We use linearization curve for this purpose. See the attached pic.

 

[lazzz]

I can make the curve precise enough for particular ink densities. But when it changes a lot, the curve becomes wrong... Densities change every time! We have to use minimal anilox temperature and it changes with the room temperature. It's hard to keep it the same when we can have -30 in winter and +35 in summer. Sure we should invest in climate control. But right now we can't afford it. And we should do something with what we have.
So dotgain/TVI is not a problem at all. The problem is too much ink (e.g. 2.20 for Black or 1.80 for Cyan). and i'm looking for any kind of work-arounds

 

[wyagow]

Ok after doing a little reseaarch I think I have found that the ink form roller temp can be adjusted on the display monitor of your techno trans unit. My temp is currently set at 77 degrees F or 25 celcius. So Iazzz you could adjust that downward to see if that might improve your ink density issue. 220 black and 180 cyan is extreme. Wonder what your mag and yellow denses at? You can always return to your prev setting if it doesn't work.
We also had trouble with 175 lpi and found that 200 lpi is what is required to be compatible with screen angle on the anilox rollers. The diff between the 2 is tremendous. We had also tried KMS screening. This did not work well in the light screen areas so we returned to 200 lpi.
Not sure what TVI stands for.
On my press the ink form blanket is 1.95mm with self adhesive foil for packing. I do not use a diff thickness blanket or packing but I have manipulated the impression blanket packing to influence color + or -.
Sometimes as with any press you do what you have to do to get a job or jobs printed to customer satisfaction. Pleasing color is what we preach to our customers. Educating them goes a long way.

 

[maac]

No Title

lazzz Hi I would just like to make sure that you are using ( Dot shape elliptical and Screen family CQS Plus 7.5° ) as you may or not know this is the best screen family for the sm-52. And it does make a big difference. And depending on the stock we used (150lpi 175lpi 200lpi) The more porous stock we used 150lpi uncoated stock 175lpi and coated stock up to 200lpi.

Like you we first put togetter a linear set of plates. Then we run a press sheet and put in the printed screen values off the sheet. Then run a set off plates at (10,000 sph) Like most anicolor the color is still too hot. So then we just at the 50% we put in the extra cut back and that will let the press cut back on the ink for the upper midtones and brighten up the lower midtones. then we can run at the (12 to 15sph) and the color will match the proofs and the customer is happy. This works for us.

I am getting the impression that most sm-52 prepress dept. operators do not know of this (Color Mgmt ANICOLOR .ppt) file from Heildelberg to help them set up the calibrations and (Dot shape elliptical and Screen family CQS Plus 7.5° ) for the sm-52 press. So how many used this set up?

 

[wyagow]

Michael you are correct on the lpi. We also use 150 for uncoated 175 matte and 200 coated.

 

[maac]

Michael you are correct on the lpi. We also use 150 for uncoated 175 matte and 200 coated.

But what about: (I am getting the impression that most sm-52 prepress dept. operators do not know of this (Color Mgmt ANICOLOR .ppt) file from Heildelberg to help them set up the calibrations and (Dot shape elliptical and Screen family CQS Plus 7.5° ) for the sm-52 press. So how many used this set up? )

 

[wyagow]

I downloaded and printed your file on that. Looked it over a little. I haven't had a chance to ask prepress if this is what they used to profile press upon installation but I would assume they did or would have to. When time allows I will consult with them. We haven't had any problems for about 3 years now so it has not been something we have had to deal with lately. My expertise is more on the mechanical workings. Only have limited knowledge on tech issues. You seem to have that covered pretty well to me.

 

[lazzz]

Guys, thank you for advises!
We've tried 200 lpi. At first glance it looks much better! Mottling is less visible, it's kinda "finer" than it was. Also the image seems to be lighter. Although it should be darker cause of higher dotgain for higher resolution. But it's to early for any conclusions. I should watch it dynamically. Cause Solid Ink Density isn't stable yet. So now the image seems to look better, but SID is still the issue. It causes poor gray balance and binaries colors, also unstable dotgain. But the higher resolution the less it sensible to ink deviations.
Considering screening method. Now we use chem-free plates Agfa Azura. They have not very good resolution, so i have to use XM screening for highlights. Irrational Screening. Angles are shifted to 7,5° and the dot is smooth elliptical. But i don't understand why the ellipse is better than say round dot...
Wyagow, yes we did changes on technotrans unit. But hiedelberg guys changed it back to 30C last time. Now we set 20C again. Too early to make any deductions, but seems it helped a bit.
As to form roller blanket - which brand do you use? Cause i think that tack, smoothness and hardness of blanket can impact the SID.

 

[maac]

lazzz hi in the Color Management Discussions forum they have a Senior Member named (gordo) he has a great understanding of screen angles and dots elliptical and round and understands why elliptical dot may be better than round dot. but I am not sure if he knows the sm-52 anicolor. Read up on a lot of his post first keep in mind that Heildelberg because of the cells on the anilox rollers we should used (Dot shape elliptical and Screen family CQS Plus 7.5° )

 

[wyagow]

Ink form blanket that I use is from Saphira which is Heildelberg. 4 ply - 077 gauge. Part number in USA is SU 45CN 2001423. You may have a diff set of part numbers. You should have received a parts book or parts CD with the press. I don''t know if your press requres the same style blanket for sure.

 

[lazzz]

Maac, i do know Gordon. He is cool man! That's why i've asked. Cause he suggest the round dot as the best for CtP. Check his blog http://the-print-guide.blogspot.ru/2009/02/am-screening-halftone-dot-shapes.html?m=1
So i wonder if you know why the ellipse is better particullary for anicolor?
As for me, i've tried round dot. It's mostly the same - smooth ellipse is round in highlights and shadows. But probably the rosette is more visible with round dot. I'm not sure.
Wyagow, thanks! I should try different blankets to understand if they impact on SID or not. Currently we use not saphira.
Btw, could somebody send me parts list and any other documentation on SM52 anicolor? I have not everything i need. We bought this machine used. It was first anicolor in Russia, kinda prototype. So machine component scout is for conventional sm52, not anicolor! Now we have to buy some parts, but heidelberg don't want to recognise them by photo... I will ask previous owner, maybe he forget to give us any documents.

 

[wyagow]

Iazzz

Check your operators manual. There should be a Parts CD in the back of it.

 

[lazzz]

There are spare parts for regular SM52, not anicolor((