problems with delivery and top of pile offset

[joe stag]

my company recently purchased a used Hiedelberg xl-75 6 color with coater and extended delivery. since proper training was not included in the budget we have been winging it as far as air settings for delivery and proper heat management go. I have around 6 years of press experience most of which was on a man roland 300 series. we are using the exact same ink , fountain solution, and substrate on this new press as on the roland. the problem is that most of the time I am having a very difficult time with delivering printed sheets. we usually run 23x29 60# c1s. I have no problems with thicker stock or smaller sheets but our label stock gives me a headache every time. another issue I have is the top of pile offset. on the man roland we run exactly the same stuff without issue but can not figure out why we are offsetting jobs on this press. any advice on air/heat settings in the delivery and some helpful hints for getting this light stock to deliver normally on this press are appreaciated.

 

[aqazi81]

I don't have any experience of XL but as a rule of thumb, always use the minimum air settings when printing lighter or thinner stocks.
If all air settings you believe are ok then also check your delivery gripper settings to make sure all are at same settings.
As far as set-off is concerned, check your ink densities if those are on higher side, use minimum sufficient spray powder to prevent set-off and also check your pile temperature, too much heat can also make an adverse effect on ink and give you set-off problems.
I hope this helps.

 

[joe stag]

Much appreciated. I have gone from light air to heavy air and everything in between. This extended delivery has so many different blast and suction settings that most of the time the sheets are bouncing right over the sheet brakes. For the set off i have tried more heat less heat more powder less powder. I try to keep my pile at around 102 degrees and check with a heat wand regularly. I have even had set off with coating! I am at my wits end with this press. I am actually at work now and pulled in a job with saved settings that ran well last time around but took me 6hrs to adjust the air well enough to deliver at 11000 iph. So frustrating.

 

[aqazi81]

May be you can call a Heidelberg demonstrator and ask him to give you some training on this press.

 

[joe stag]

When we got the press we had one here but only for 2 weeks and in that time we basically spent most of the time fixing broken parts. Now im trying to convince the owner to have another come in.

 

[DeltaE]

I think you can find some instruction to adjust delivery for each kind of stock from Heidelberg operating manual documents or you need some training from Heidelberg guys.
As aqazi8's idea, thin material means less blast air, can try to set speed of sheet brake = 30-40%, suction air of sheet brake = 60-80%, adjust the position of sheet brake. One more thing, does your machine have anti-static device in delivery. You can get some problem if your material is too sensitive to static and make sheets stick each others.

XL75 is very easy to print, you just need to mix dampening solution with right percentage (ex. pH = 5, alcohol = 5-8%,...).

Hope this help you something!

 

[joe stag]

Yes there is anti static. Right now i am running 23x29 60# cis. Sheet brake speed 28-30 cam drop @78% and suction on brake @ 100%. It always seems like the sheets blow rt over the brakes if not @ 100%. I have been successful getting it to deliver @12000iph the last couple nights but it has been a babysitting job and difficult to pull sample sheets without screwing it up. I consulted the manuals and they do provide some "guidlines" but those settings do not work at all. I am beginning to think there are issues w the delivery itself. It shouldn't be this difficult.

 

[DeltaE]

Are you running 60 gsm material? If it is true, you do not need to use 100% suction air of sheet brake.
Please check the suction air of each sheet brake!
I have had this kind of problem with thin material in the past, then I firgured out that there was no suction force from sheet brake.
The electrician forgot to connect electrical cable to suction air motor. The other case was the tear-off suction air hoses of suction air.

 

[joe stag]

Yes i have checked for suction. There is suction there. Yes 60gsm stock. The press is supposed to be fit with 6 sheet brake pods. 2 on each moving unit but only 3 came with the press from the previous owner. Not sure what you mean by tear-off hoses.

 

[DeltaE]

I mean the leakage from broken hoses could cause insufficient suction force of sheet brake.

That's true it should be easy to adjust the XL75 delivery if that is new machine. But your machine is used, so I think its delivery need to be checked by service guys.

Hope you fix your issue soon!
Regards,
DeltaE

 

[joe stag]

Thank you.

 

[LSW]

Can't speak for the XL but on a CD I used to have to make sure a row of fans were pushed back to help blow the sheet down onto the brakes, also we had an issue where the spray powder extraction hood was actually sucking lighter sheets upwards so we had to either turn off powder extraction or limit the amount of extraction suction by adjusting a valve.

 

[jaelliott]

Read all the posts, not sure where you are located but I know a X Heidelberg demo guy, now an independent out of Atlanta that might be able to help, web site is http://www.xl-technical.com/index.html

 

[turbotom1052]

For a smooth delivery I like to slow down the sheet brake, and use the release cam pretty advanced so as to "s t r e t c h" out the sheet before is dropped straight down on the pile with minimum fans or air blast. Also as mentioned your delivery static eliminator should be always on and CLEANED on regular basis. Cleaning off the static eliminator every day would not be too often.