Type of nip on wide web ci

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Type of nip on wide web ci

Postby longtimefan » Tue Jul 21, 2020 11:44 am

We have a register issue on my press. We can see it drifting ahead and back..

We are bringing in a tech in to work on the computer part of the servo motors.

I've tried tensions..nip pressure...between color dryer flows... Webbing film differently..It only seems like its a servo motor or a mandrel issue

But was wondering the durometer of your nips?
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Re: Type of nip on wide web ci

Postby Gorilla Printer » Tue Jul 21, 2020 10:19 pm

Probably best to go with manufacturers specs.
Regarding registration problem -would need more details to help

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Re: Type of nip on wide web ci

Postby longtimefan » Wed Jul 22, 2020 4:59 am

When they bought this press the registration always moved..not side to side but ahead and back.

It would look good then 1000 feet later it moves. Doesn't matter what film..or tensions. Speed does help some
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Re: Type of nip on wide web ci

Postby Fuzz » Wed Jul 22, 2020 9:39 am

While looking at the nips, also check the diameter of the pacing rolls. Make sure they are not worn and under sized.
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Re: Type of nip on wide web ci

Postby longtimefan » Wed Jul 22, 2020 11:49 am

Fuzz wrote:While looking at the nips, also check the diameter of the pacing rolls. Make sure they are not worn and under sized.

Pacing rolls?

Same as tension setting rollers?
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Re: Type of nip on wide web ci

Postby Fuzz » Wed Jul 22, 2020 2:33 pm

The roller you are nipping the web against.
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Re: Type of nip on wide web ci

Postby longtimefan » Wed Jul 22, 2020 9:29 pm

Fuzz wrote:While looking at the nips, also check the diameter of the pacing rolls. Make sure they are not worn and under sized.


Should thru be same diameter of nip roller?
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Re: Type of nip on wide web ci

Postby just Andy » Fri Jul 24, 2020 9:06 am

Hi longtimefan

Ours 65 Shore A.
I know another persons press specified for 70 A (running paper mostly).
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Re: Type of nip on wide web ci

Postby lavoie » Sat Jul 25, 2020 5:51 pm

I would like to see an example of the registration issue. Without seeing it I can only speculate.
1. Make sure your plate sleeves and anilox sleeves are spinning at a synchronized speed or it will cause slurring. May be an issue with incremental increase as speed increases.
2. CI nip roller bearings. You may loose tension if there is play in them.
3. CI nip material hard and dried out. Though this would effect the print all of the time.
4. In between driers pulling film.

These are just some things off the top of my head. Pictures could help.
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Re: Type of nip on wide web ci

Postby lavoie » Sat Jul 25, 2020 5:54 pm

I should mention that always my first go to is cleaning the nip and drum. An obvious place to start but you would be surprised how many operators avoid it like the plague.
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Re: Type of nip on wide web ci

Postby Gorilla Printer » Sat Jul 25, 2020 9:48 pm

longtimefan wrote:When they bought this press the registration always moved..not side to side but ahead and back.

It would look good then 1000 feet later it moves. Doesn't matter what film..or tensions. Speed does help some


Is it all the stations, a particular station. a couple of stations. Does #1 move as well? Is it gearless?
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Re: Type of nip on wide web ci

Postby Gorilla Printer » Sat Jul 25, 2020 10:27 pm

lavoie wrote:I would like to see an example of the registration issue. Without seeing it I can only speculate.
1. Make sure your plate sleeves and anilox sleeves are spinning at a synchronized speed or it will cause slurring. May be an issue with incremental increase as speed increases.
2. CI nip roller bearings. You may loose tension if there is play in them.
3. CI nip material hard and dried out. Though this would effect the print all of the time.
4. In between driers pulling film.

These are just some things off the top of my head. Pictures could help.


Agreed. The worse thing a Printshop can do is bring in a contractor to find out something basic is the cause of the issue. Everything needs to be checked that they are working properly and within spec beforehand.
Before cleaning any nip roller I'll have it un nipped and check for play. Then have it nipped and do the "paper test"If both are OK I'll clean it. If it looks like cleaning will take over 10 minutes, that thing is coming out.
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Re: Type of nip on wide web ci

Postby longtimefan » Sun Jul 26, 2020 10:48 am

So we had a tech come in and worked on the servo settings and it may have helped on one deck but he wasn’t able work on rest.

Another tech from diff company came and said he didn’t see issue in computer settings of servo.

Nip is clean and drum is clean. I have tried adjusting deck dryers flow and can move the actual dryer away from drum.. it does help some.

I have decks listed that are worse than others.

I can’t post video says mob extension not allowed
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Re: Type of nip on wide web ci

Postby Gorilla Printer » Sun Jul 26, 2020 7:34 pm

longtimefan wrote:
I can’t post video says mob extension not allowed


Maybe have a video elsewhere and post the link
Is the press gearless?
Name the press and model. Someone here might have had the same experience with the press and know the answer.
We have a PCMC vision press and tensions have to be set in different modes for it to work best.
I notice you said before that it can run 1000ft good. Does that mean register is moving less or no it's holding?
How about posting up your list of stations and movement.I'm expecting the worst to be the back stations as is usually the case.

Cheers
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Re: Type of nip on wide web ci

Postby longtimefan » Sun Jul 26, 2020 10:29 pm

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