Shinohara 52 horizontal banding.

[Lukew]

Re: Shinohara 52 horizontal banding.

update.
Tech has checked the ocilator timming and they are correct,(he is happy to alter the timming to see if the band moves if and when we have time for the press to be down, but is sure that it is purley water roller related banding)
The timming of the ink ducter roller seems out though basically when the ducter roller ducts back across onto the rollers not the ink pan roller the 4th form is about 3 " past the lead edge of the plate where it apparently should be only bout 2" past the lead edge. which means the 1st form is near the tail of the plate, I guess this gives time for the ink to get distributed down to the forms during the cutout in time for the 1st form as it hits the lead edge of the plate.
Apparently that band we have there is nearly as good as it gets when printing full solids on 52 size presses be it shino/heidlberg/ryobi
I find it very hard to beleive that a near million $$ machine can't print a solid without a band, maybee I'm just expecting too much,

I have tightend the nip between the metering roller and the water pan roller but I have noticed ink pilling/picture framing on the plate is a lot worse and my water % during the middle of the day is between 55 and 65 % not sure if this puts undue strain on the little motors,
(How often do you normaly change the metering rollers? I thought every 6 months or so)

Some days you wonder why the hell you would want to be a printer....
Will update when I find out more,,

 

[Bob Peterson]

Re: Shinohara 52 horizontal banding.

Luke,

If the tightening up of the nip reduces the banding but you experience the picture framing and piling I would highly suspect that you may also have a substantial amount of calcium built up in the dampening system.

Calcium Carbonate is the main component used for paper coatings currently. Matte, dull, and satin stocks are by far the worst. If you are a commercial printer and run a lot of these stocks I would suspect this to be a good portion of your culprit. Calcium carbonate leaches off of the paper back into the dampening system and builds up in the micro pours of the rollers and plates. This build up will cause the following problems:

Picture Framing
Roller Stripping
Plate Blinding
Piling
Slow dry times
and the list goes on.

If you haven't already done so I would recommend that you drain and flush your entire dampening system with a blend of hot water and vinegar or a product from a reputable supplier (Prisco, Kelstar, Ect) that they recommend for flushing calcium from the system. I would recommend also that you perform this routine weekly when you drain your tanks.

Others have made comment to the inks. Dryer in the ink will play no roll what so ever in the streaking. However, a weak ink or an overly pigmented ink will definitely over exagerate a mechanical issue and definitely cause streaking to occur. Excessively low tack inks in combination with improperly set ductor roller will cause a streak to occur due to a squeegee effect. However, you would still have this problem even if you turned off the water.

This just my 2 cents for what its worth. Good Luck!

 

[Lukew]

Re: Shinohara 52 horizontal banding.

Bob,
I am very strict when it comes to maintance on the machine.
Every week the entire dampening system gets emptied and flushed, and every second week we use a dampening system cleaner and let it run through the system for at least an 1 hour then flush it out twice with water,
The metering roller gets cleaned with hurst meterung roller cleaner daily and the csrome gets cleaned weekly with chrome roller cleaner.
I run pro calcit on the ink rollers at the end of shift every friday then a deglaze is run once a month.

I have noticed the picture framing happens more with some inks and one very wierd thing I have noticed is that sometimes the picture framing will only start from were that band is 3/4 way down the seet on the cylinders and be on the tail of the cylinders.
When I tried to run zero IPA it was a great failure with not just picture framing but tinting from 3/4 way down the sheet till the tail of the sheet with a perfectly clean top half of the sheet

I am begining to wonder if the polyester plates we use are of low quality, are all poly plates created equal ??? the activator tank is at 30 deg celcius so that should be right

I have noticed though that shinohara runs a much higher shore hardness on its metering rollers between 30-32 and from memory the water form is standard at 26-30 shore harndness.

Has anyone run one of these intergrated for extended periods ie with the bridging roller up ? maybee this might help I'm not sure. I will play with water settings to see if I can get that to work. anytime I've accidently run it intergrated I've ended up with a great emuslified mess....

 

[inky]

Re: Shinohara 52 horizontal banding.

I don't think all Calcium deglazers are created equal, if I use Bottcher EK I get all your problems and more.

It's rollers out and hand clean, and back to something more gentle but regular.

 

[keldrewett]

Re: Shinohara 52 horizontal banding.

Luke, where are you. If you are in Sydney, I may be able to drop in an have a look, or maybe you could ring me. Happy to help..

Edited by: KEL on Jun 9, 2008 6:26 PM

 

[Lukew]

Re: Shinohara 52 horizontal banding.

Kel, you have PM

 

[Ryan H.]

Re: Shinohara 52 horizontal banding.

Luke, What kind of ink are you useing? I'm coming to the conclusion that you may need to change. Like I had mentioned earlier with the banding. We changed ink because we found out that Toyo ink could handle the higher water %. Also, You said the picture framing is less with different inks. This may solve that problem too. I don't fight it, and I can run my water segrigated with this ink which I couldn't do with my previous ink. I never run integrated. Trust me, I'm not an ink salesman. I pulled this ink of my other presses I ran in the past and thought it was absolute garbage. I was the most surprised of anyone to find out this was the ink for our presses. I'd at least give it a shot. Run a test with it and find out. .

 

[Lukew]

Re: Shinohara 52 horizontal banding.

Ryan,
For PMS colours we have used the following (please note, this band occurs on two machines and the tech now says that every single 52 ryobi/heidelberg/shino does the same so I'm at a loss who to believe.)
PMS colour brands.
toyo --- over here toyo mixes constantly didn't match the pms book
hartman
best one
choice inks
flint ink vegetable based ----- flint performs best so far

CMYK inks.
toyo
tokyo cervo 8
best one
K+E novavite 918 bio --- so far we have had best results with this ink as it needs less water then the others to stop scumming and it rarely picture frames.

Ryan do you run poly plates?
I will say though that altering to some of the settings that have been mentioned have made an improvement but I would hate to see what it looks like when the rollers start to age.
Anyway thanks to everyone for your help I will post again after the head aus tech comes to view the machine and the ductor roller timming is changed, when this happens I do not know.
Thanks.

 

[Ryan H.]

Re: Shinohara 52 horizontal banding.

No Luke, I use metal plates. The banding is a common problem on most presses. I've seen it on Mitsubishis and Komoris. It's the water unit that's causeing the problem. I'm certain of it, but you really just have to play with your roller settings. Don't be afraid to turn your water % up and tighten your W. form down. I realize it's not what we're tought, " the less water the better", however it does work. Also, try leveling out your skew. I run mine almost even on all the units. As long as I have no low spots on the ends. Best of luck to you. I hope you get this issue resolved.

 

[Mechanic]

People, i work on Shinos, you are right, the dampening system of the 52 is bad. Change it to Kompac , and it helps. If you run a 4 color though, use PRISCO additive, type 3551 plus2, at 8%. IPA at 8 % , make thin nips, print as low as it can get on damp. Works like a charm.

 

[tmason]

We have three Shinos, 2-66 and one 75. Try testing different blankets and packing and if that doesn't work, have your mechanic tighten up the bearer pressure and see if that helps. We had a similar situation on one of our presses and the bearer pressure fixed it. If you pack a new blanket to .002 over bearer and run a 60lb. sheet and cannot get enough impression squeeze, you probably are light on the bearer.

It sounds like you have tried almost everything in the book. You could also try a different rubber compound for the water form and meter.

Shino dampeners are touchy but they also run well if you pay close attention to them.

good luck

 

[grunter]

Make sure your blanket packing is not going over the trailing edge of the cylinder. Either cut it short or fan it out so that the plate cylnder has an easier transition into the gap.

 

[Dean Graphic Services]

Roller recharge/bounce is caused from the gap made in all plate cylinders. This is why press manufactors make the water form rollers diameter times pie equal half the print image area from gripper. This is based on the page layout of your machine. If you have any knowledge of this, you learn to layout jobs, with this in mind. Shinohara has work on the recharge line by running two different water form diameters. 55 mm even units and 58 mm in odd # UNITS , this to insure two screens do not hit in the same location back to back IE Cyan and magenta. I recommend having the chemistry used in the press tracked and worked on to get the ink and water balance fine tuned this will take time and needs to be charted. Measuring 50 % dots for gain will help you see the difference that 1/2 ounce per gallon changes can make in fountain solutions. Also gumming your chrome roller ever time at the end of your shift if machine is shut down will help with toning and tinting problems. Hope this will help, been doing this for over 17 years now.