IGen5 - blistering sheets

I am running 8 1/2 X 11 80lb gloss stock on gsm 120. I am printing a 5 1/2 X 8 1/2 booklet which we are sending to the finisher. After about ten sheets I am experiencing a bubbled, blistering of the stock, when this happens where there is image, then the image is broken. I’ve tried other brands of paper and they all react the same.

There seems to be a lot of Fuser oil on the fuser roll.

I’ve tried waiting a few minutes and printing again,which initial works, but by the 10-12 booklet the bubbling is back.

I have been placing another 11 X 17 Uncoated job with around 30 sheet, using the upper tray. Then I now run 8 booklets, in the lower tray and they run fine. So far I’ve had no more bubbling, as long as I run one bigger job on every 8th booklet. This doesn’t work well since the job is 4,000.

Hopefully someone has an idea on why I can not run more than 8 booklets. Thanks again for the advice!

 

if you rotate the paper 180degrees in the feeder, does the problem move to the other side of the sheet?
Does it appear if you run, say 20, in toptray?

 

I e rotated and flip the paper every possible way with no change. I can’t use the upper tray for this job, it is too small, however I’ve used other sheet sizes in the bottom tray with no issues.

 

We shut the machine down for about 45 minutes and were able to run about 40 booklets before it began bubbling again.

 

When's the last time the fuser has been serviced? If you let the machine cool down and had better results i'd like to think it's an overheating fuser.
Sometimes if you see streaks on the fuser roller, it's often mistaken for too much oil - but the opposite can also be true. Both a dry and over oiled roller almost have the same appearance...

 

We put a new fuser in during the time this started happening, we had the tech triple check everything and make sure the fuser was in good shape and set correctly.

I agree that something seems to be causing heat but still no fix.

 

Perhaps the heating lamp within the fuser is defective in someway. Or isnt the right one altogether.
You don't happen to have a second Fuser unit available?

Silly question, but the gsm setting for the stock is correct? I had an operator battle with 100# gloss text (kept sticking and rapping up in the fuser) only to discover he was running it at 300gsm. Woops

 

The bulb idea sound promising. I’ll call the tech to replace it, it’s been in for over 5 million impressions and it’s been close to a year.

Concerning the GSM, we have triple checked it, which is currrntly 120.

Will get back when we try a new bulb.

 

Dang, actually we did have an extra bulb in when we switched fuser rollers and both bulbs acting the same. :/

Still baffled.

 

Is it possible the thermistors are faulty and giving a bad heat reading?

 

Themistor is a good idea. The housing could have separated from where its mounted - causing a constant cool read, thus heating the fuser.
Or its covered in gunk, or simply just not functioning properly anymore.

 

Ok we will work on that! I’ll update as soon as we try. Thanks for the help btw

 

The tech replaced all the thermistors and so far the problem is cured!

Love this Forum and thanks for taking time to check in!!!!

Phylex

 

Aha! Problem solved. (hopefully
Most folks will gripe, but I love the repair and maintenance part of digital printing.
I'm not missing the Igen too much these days, our two NexPRESS's are keeping me busy with tinkering.

Happy printing to ya!

 

I am opposite. Nexpress required way more "tinkering". just too complicated for our needs. GORGEOUS prints compared to Igen though. and learned a LOT.