Source of web breaks: Rollstand, flying paster or infeed.
Problem: Poor Paper Quality
Solution: Try a different position on the jumbo or a different paper altogether.
Comments: Though it is hard to see, when the paper rolls are weak, this will generally show up right away in the beginning of the web press. Check the edges of the roll. Paper defects are common. Sometimes nicks can occur or the slitter at the paper mill was simply dull. Also, hold the paper up to the light and check for pin holes.
Problem: Foreign Material On Idlers
Solution: Clean off idler rollers. Carefully check each one for dents that could cause a raised spot and break through the web.
Comments: Generally a splicer can have two sided tape build up on the idlers. Splice after splice can cause this buildup. Or perhaps a pieces of tape wrapped around the roller to take out wrinkles. Whatever the case, check the idlers carefully for any raised spots on the idlers from buildup or damage.
Problem: Excessive Tension
Solution: Lower tension
Comments: Some papers cannot handle higher tension. Lower your tension as much as possible before it begins to wander. If breaks are happening after the infeed, your screwed. You may have to reject the paper.
I can't find my problem.
Start Over :Web Press Troubleshooting Guide
We have Megtec flying pasters on a newer high speed TKS press. Just recently one specific roll stand (BR4) is experiencing a running break at full speed just a few minutes AFTER the splice on most splices. Its after TWO inches has been run off of the new running rolls full diameter meaning the splice has long been over and the splice has cleared the folder by several minutes. Its always just about exactly after two inches has been run off of the roll diameter.... Any ideas?
ReplyDeleteWow, that's a good one. Sorry, no ideas. Seems to be happening in timing with a cycle related to the splice, but I have no ideas.
DeleteI've been having this weird issue with my press. I've only been a pressman with just under a years experience and two weeks training before they threw me on night shift by myself with zero help....So, when I started, I ran at 900 ft/min @ 40 lbs of tension at the splicer and rewind, someone on day shift did something and now I can only run at 850 ft/min @ 25 lbs of tension. when I start up the web moves over about 1/4 inch and on sht down it moves back over to the left, when I clean my blankets I have to reduce the tension to 15 lbs otherwise my web wrinkles coming through the splicer and generally breaks on the carriage or the auto guide. Currently the pressure on the auto guide is set to 67 for some reason....If I try to run anything over 25 lbs, it wrinkles and breaks my web....I've seen this happen on the slitting machines when the unwind is too unlevel, except it don't break the web, just wanders and wrinkles. My theory is that the splice rollers are work and causing the paper to wander in the back...Really my press needs a good cleaning and overhaul but we neither have the time nor the money to accomplish such a feat. Figured there's gotta be some work around to get past this issue, like a temporary fix or something.
ReplyDelete