KM Pro 951 - self adhesive labels - corners creasing intermittently

[Ynot_UK]

Does anyone have any thoughts on this?

The stock is standard self adhesive office grade laser labels, fed face up from Tray 4 on the PF-706 deck and output face up on the FS-532 for the straightest path.

The scenario is as below and happens regularly with this repeat job.

• Requested 10 sets offset (job saved in a Public Box)
• Circa copy #585 I pressed the FS-532 pause button to take off sets 1-6 to start boxing up
  • Pause correctly initiated after #600
  • Sets 1-6 taken off the FS-532 (all stacked perfect with no corner creasing)
  • Job resumed at FS-532
• The photos are of the remaining four sets
  • Set 7 was messy
  • Set 8 was perfect
  • Set 9 was good, except for two copies
  • Set 10 was messy
• There were no jams experienced throughout the job

I'm aware the CED mentions the machine does not officially support label stock, however in practice I would imagine it supports them no more or less than the KM office grade machines (454e / 554e) which we have successfully run labels on for years, before getting the Pro951. One issue we used to have when running labels on the 554e was fluid seepage and curling, because of the higher fuser temperature. The Pro951 fixes that issue. If we can fix the intermittent problem of the corners catching on whatever and creasing, the job would be perfect - the image quality is great and the stacking spot on.

 

[pippip]

Strange that the first sets all went well. Mostly those types of office labels are designed long grain, so are recommended narrow edge first, might be a work around if your image area is ok at the edges.

Presumably these are out of boxes of 100sheets, maybe a discrepancy between boxes?

 

[Ynot_UK]

Strange that the first sets all went well. Mostly those types of office labels are designed long grain, so are recommended narrow edge first, might be a work around if your image area is ok at the edges.

Presumably these are out of boxes of 100sheets, maybe a discrepancy between boxes?

Thanks @pippip - interesting thought re. the grain - I'll try running it narrow edge... and Yes, they are boxed 100s, we don't break the shrink wrap on the boxes until immediately before using them.

 

[Puch]

Some glue might get out from the stock (because of the heat), sticking to some rollers. The contamination then cause the sheets to stick intermittently to rollers, eventually cleaning itself away. When another sheet with loose glue enters the machine, the circle starts again.

 

[Ynot_UK]

Some glue might get out from the stock (because of the heat), sticking to some rollers. The contamination then cause the sheets to stick intermittently to rollers, eventually cleaning itself away. When another sheet with loose glue enters the machine, the circle starts again.

Thanks @Puch - this all makes sense, since the corner folding issue does manifest on 80GSM paper jobs run immediately after a labels job. After a few hundred copies it goes away.

What shall also be interesting, is the after effect of @pippip 's suggestion of running short edge (210mm) then going back to running paper at 297mm or 320mm, as any glue residue on rollers should be confined to a lesser area to the centre of the output - hopefully minimising/eliminating the problem on paper jobs immediately after label jobs.

We can also try different label stock, from another supplier.

 

[Puch]

There are adhesive stocks designed for digital, where there is a small 'stay-away' area around the sheet perimeter (1-2 mm) without glue. Of course they're a bit more expensive. Another workaround might be to lower the fusing temperature.

 

[leecott]

Strange that the first sets all went well. Mostly those types of office labels are designed long grain, so are recommended narrow edge first, might be a work around if your image area is ok at the edges.

Presumably these are out of boxes of 100sheets, maybe a discrepancy between boxes?

We run a lot of labels through our 1060 and initially had similar problems with curling and corners creasing. Grain direction as mentioned was 100% the issue for us. If you are feeding from draw 1 or 2 we would recommend having the labels face down. You may find the creasing is coming from the initial feeding as the labels can curl slightly even without any ink. We also slightly reduced the fuser temp.

One final thing you could try is cleaning the separation claw. Hard toner can build up underneath it which means the paper is not sitting flat on the roller. You can usually scratch of the toner with your nail. I doubt this is the issue but worth a clean. Fixed our issues feeding NCR paper.