Tips/Tricks - Flexographic Mastery.

Ask or answer questions related to the flexo pressroom environment

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iteachflexo
Posts: 47
Joined: Thu Aug 02, 2018 11:20 am

Re: Tips/Tricks - Flexographic Mastery.

Post by iteachflexo »

Some companies make a paper liner for trays for mark andy presses
DIP is the company that manufactures paper and plastic ink trays for various presses. I've used them at work and at school. Helps reduce clean up time.
iteachflexo
Posts: 47
Joined: Thu Aug 02, 2018 11:20 am

Re: Tips/Tricks - Flexographic Mastery.

Post by iteachflexo »

Line drip trays with a Vaseline.
Instead of using Vaseline which is clear, try using a red grease from Walmart. Easier to see when you apply. I use the red grease on the journals of anilox and metering roll for easier clean up.
Fuzz
Posts: 354
Joined: Mon Jan 19, 2009 4:37 pm

Re: Tips/Tricks - Flexographic Mastery.

Post by Fuzz »

@ Gorilla Printer KECO Engineered Coatings works great if you don't want to use disposable pans. Well worth it IMO.
Gorilla Printer
Posts: 282
Joined: Wed Oct 06, 2010 1:13 pm

Re: Tips/Tricks - Flexographic Mastery.

Post by Gorilla Printer »

Keep ink flow to bare minimum.
It took me years to figure this out, as no one in my shop was taught it.
Actually, when I started experimenting with the practice, people would complain because it wasn't the norm. They wanted to see "good flow"(tap open about half way). What is good flow?
So long as you have enough to print good and not cause a dry out , that's all that's needed.
All shifts on my press minimise flow now, because they have learnt from experience.

Remember, flow x speed = more pressure in the chamber. So less flow = fewer leaks, chamber blow outs and minimises mess. Seals aren't being compromised, so chambers last the week. Including the white, which is practically running 24/7.

When first experimenting, yes you will have dry out or two or the pneumatic pump will stop from lack of flow. No worries, persevere, and you will teach yourself where the sweet spot is. The reward is immense.

Easier Printing Everybody!

Gorilla.
Gorilla Printer
Posts: 282
Joined: Wed Oct 06, 2010 1:13 pm

Re: Tips/Tricks - Flexographic Mastery.

Post by Gorilla Printer »

Hi All
In my shop, white is usually the first lay down.
Guys like to set inkers /impression for the other colours with it on.
I understand, it's easier to see with a white background

The problem is the risk of picking white off onto the plate you are setting. Especially with screens. With no background there is nothing to pick off or cause build up.

Get used to setting colours individually first and then bring them on to register.
I suppose people could achieve the same, setting print from last station to first

You use less make ready roll while maintaining clean plates because you can do this at low speed. Which makes it easier to set registration and Kiss impression, before fine-tuning down at the scanner

Cheers

Gorilla
Gorilla Printer
Posts: 282
Joined: Wed Oct 06, 2010 1:13 pm

Re: Tips/Tricks - Flexographic Mastery.

Post by Gorilla Printer »

If you are coming on to a long run, set up by the last shift, reset the print. Then you'll "know" if there are any print quality problems -Kiss impression has been sorted.
When all settings have been achieved (tensions, taper, heaters etc...) save file.
Last edited by Gorilla Printer on Thu Feb 24, 2022 5:42 pm, edited 1 time in total.
just Andy
Posts: 80
Joined: Sun Sep 15, 2019 8:11 am

Re: Tips/Tricks - Flexographic Mastery.

Post by just Andy »

On the topic of long-runs: the best for efficiency is (super obvious statement coming up), less stops. So prior to a long run all preparations are made: blades and seals that are still 30-40% life left, get changed preemptively. Also during the run operators and assistants co-ordinate knowing what to do during a planned stop. E.g.: one washes the process plates, second person changes some blades and seals, and third person cleans the nip rollers/helps with the other two. So during a stop, more preemptive work goes in; and less likely to have frequent unplanned stops.

Regarding cylinders: if it is less the number of maximum stations or you have spare cylinders: prepare the mounting tape beforehand. When you see the impression is starting to look poor on a particular station(s); stop and re-mount the plate on fresh tape. It's only a 5 minute stop if the tape is already prepared. It's even faster if it's only a cylinder change because you have spare plates (which for a long run is definitely beneficial, as a few days planned run can be easily disrupted due to an accident/mishandling).
Gorilla Printer
Posts: 282
Joined: Wed Oct 06, 2010 1:13 pm

Re: Tips/Tricks - Flexographic Mastery.

Post by Gorilla Printer »

This is for those that don't have automatic wash units
When rinsing any station, have the anilox turning for two minutes tops.
Leave rinsing with the anilox off if necessary.
AliceInFlexoland
Posts: 3
Joined: Sat Sep 26, 2020 9:24 am

Re: Tips/Tricks - Flexographic Mastery.

Post by AliceInFlexoland »

Hi Gorilla, have you received the 3 blade doctor chambers yet?

I tested them few times but don't see any help with the ghosting.
Gorilla Printer
Posts: 282
Joined: Wed Oct 06, 2010 1:13 pm

Re: Tips/Tricks - Flexographic Mastery.

Post by Gorilla Printer »

AliceInFlexoland wrote: Tue Jul 26, 2022 4:11 am Hi Gorilla, have you received the 3 blade doctor chambers yet?

I tested them few times but don't see any help with the ghosting.
Hi AliceinFlexoland
Sorry, I didn't. The boss was happy with results we got using some interventions, so buying a 3 bladed chamber was canned.
We were practically copying what another division does when printing big solids on laminates. Using soft mounting tape, digicap plates, with a GTT roller got a run rate they were prepared to live with. Our main problem was bounce.
just Andy
Posts: 80
Joined: Sun Sep 15, 2019 8:11 am

Re: Tips/Tricks - Flexographic Mastery.

Post by just Andy »

Hi all

On the topic of bounce, we had an interesting case last month. We had a job that was bouncing significantly (you could hear it was that job just by the sound and frequency of the bounce, and intensely feel the floor vibrating as well).

The plate had multiple horizontal bands and thus design wasn't possible to stagger an offset pattern. However we thought if we could make wider bearer bars on both sides, it would at least alleviate the problem but from what we could see was that there was no change at all.

The original design was about 1/8" (3mm) and we increased it to 1/4" (6mm) and solid print. With that we thought we would get at least a small increase of speed but it turned out to not have any affect. There was no difference in the vibration/maximum speed we could achieve.
longtimefan
Posts: 351
Joined: Sat Jun 13, 2015 1:10 pm

Re: Tips/Tricks - Flexographic Mastery.

Post by longtimefan »

just Andy wrote: Mon Aug 01, 2022 2:47 am Hi all

On the topic of bounce, we had an interesting case last month. We had a job that was bouncing significantly (you could hear it was that job just by the sound and frequency of the bounce, and intensely feel the floor vibrating as well).

The plate had multiple horizontal bands and thus design wasn't possible to stagger an offset pattern. However we thought if we could make wider bearer bars on both sides, it would at least alleviate the problem but from what we could see was that there was no change at all.

The original design was about 1/8" (3mm) and we increased it to 1/4" (6mm) and solid print. With that we thought we would get at least a small increase of speed but it turned out to not have any affect. There was no difference in the vibration/maximum speed we could achieve.
Digicap plates are needed
Gorilla Printer
Posts: 282
Joined: Wed Oct 06, 2010 1:13 pm

Re: Tips/Tricks - Flexographic Mastery.

Post by Gorilla Printer »

just Andy wrote: Mon Aug 01, 2022 2:47 am Hi all

On the topic of bounce, we had an interesting case last month. We had a job that was bouncing significantly (you could hear it was that job just by the sound and frequency of the bounce, and intensely feel the floor vibrating as well).

The plate had multiple horizontal bands and thus design wasn't possible to stagger an offset pattern. However we thought if we could make wider bearer bars on both sides, it would at least alleviate the problem but from what we could see was that there was no change at all.

The original design was about 1/8" (3mm) and we increased it to 1/4" (6mm) and solid print. With that we thought we would get at least a small increase of speed but it turned out to not have any affect. There was no difference in the vibration/maximum speed we could achieve.
Hey Andy!
Sorry I missed your post
This could be a stupid question
Are you just mentioning an incident ?Or are you also looking for solutions as well?
Cheers

Goriila
just Andy
Posts: 80
Joined: Sun Sep 15, 2019 8:11 am

Re: Tips/Tricks - Flexographic Mastery.

Post by just Andy »

Hi longtimefan

We don't normally work with Kodak plates, but I Googled it and it seems to mainly be for screens. This particular design is full solids.

Hi Gorilla

Well I'm always open to suggestions that we can reasonably trial the next time this order comes through. But I added it just as a note.
I thought that making the bearer bars a lot wider than standard would make it at least 5%-10% faster, but from what we could achieve, it made no difference.

The next idea I had was to put hard tape under the bearers and soft tape under the print. This job we print is quite a nice case because it runs so slowly and so anything we try we will really be able to see incremental gains.

Cheers
Andy
Gorilla Printer
Posts: 282
Joined: Wed Oct 06, 2010 1:13 pm

Re: Tips/Tricks - Flexographic Mastery.

Post by Gorilla Printer »

just Andy wrote: Sat Aug 13, 2022 6:24 am
We don't normally work with Kodak plates, but I Googled it and it seems to mainly be for screens. This particular design is full solids.
Hey Andy

Kodak Plates are for big solids. They are more expensive, but worth it. The difference in using them is like night and day. When you get them made, there are like about 9 different patterns they can use. I'm sure with some communication provider will know what's best.Now the thing is because of the patterning the solid can be printed with less pressure. Which equates to less bounce. We use pink 3m mounting tape (the softest in our shop). Using normal hard tape defeats the purpose. The actual plate is harder , any ding in it from gels etc can't really be taken out with a heat gun. Minimised maybe, but not eliminated.Well, that's what I've found.

The rest of your plates for the job can be normal.

So a Kodak plate, with light medium density tape and a new chamber should word wonders. You can minimise bounce even more if you can increase image count and use a bigger cylinder. I think using a GTT roller helps a bit as well, but that could be due to personal preference. Colour has more "pop" I feel. But that can be looked into later maybe

To minimise inkers/impression, I speed up in 5-10 m/min increments and adjust accordingly. You know the drill, absolute kiss impression. These sets I find are more challenging than process work. Because management want them running at the highest speed possible due to them being our biggest rolls.

No kidding , when I first experienced setting a Kodak plate it blew my mind how the ink laid down. Akin to witnessing witchcraft, lol

Try it, you'll like it. You can get an increase of 30 -100 m/min in the speed you are running currently

Good Luck and give us an update should your shop try it.

All our Biggest solids are Kodak digcap plates now

Gorilla
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