Sucker feet marks

[Prepper]

We have been having the problem of getting half circle marks about 3/4 back on sheet from gripper, 19x25 sheet, Heidelberg 72SP, mostly on 2nd unit, cyan, and they tell me its the sucker feet that hold the sheet in place with vacuum and that spray powder on these feet builds up, transfers to blanket and then over time makes a low spot in the blanket and voila, the half circle marks show up. The cure is to change the blanket.

My question is there a way to avoid this or make it longer between changes? Like cleaning those feet when blankets get cleaned or anything like that? They say no cause its just powder that's on the sheets and in the system and it wouldn't help? I've no experience on press and just looking for any info that may be helpful for them.

Thanks

 

[REYES1377]

The powder should not put a low spot on the blanket. it is just building up. The operator needs to cut that spray powder back. Back in the day we would cut some super blue neting and place them over the sucker with a rubber band. This would get us by. How many impressions are they getting off before they have to clean the blankets? Hope this helps.

 

[otherthoughts]

I agree with REYES1377, spray powder should not ordinarily cause a low spot.

Anyways, if you do get a blanket smash for whatever reason, there are two methods that I used to use to repair the smash.

One method was to apply a gel type product to the affected area of the blanket. The product would cause the rubber surface of the blanket to swell up. I think the product was called something like "Blanket Saver or Blanket Swell"? This was not the best remedy because the swelling was not uniform over the area treated. The pattern left by the brush-strokes during application of the product resulted in uneven swelling of the blanket in the same pattern. This uneven swelling could interfere with the smooth printing of screen tints.

Another method was to release the affected blanket at one end and massage the affected area from the underside of the blanket with a lanolin based hand cleaner product. This would cause the canvas backing of the blanket to swell slightly. This type of treatment results in a much more uniform and feathered repair, but it takes longer to perform than the first method. If you are using paper type packing sheets under the blanket? Replace the paper packing sheets with fresh ones, because the paper packing sheets can be smashed too.
​

Best Regards - OT

 

[nhprinter]

I second and third what was said above, but to add......

We have a different type of sucker that we use when we have a problem with powder buildup caused by the forwarding sucker. It has two small suction cups on it and marks a lot less than the disk type.