Odd issue with plate

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Re: Odd issue with plate

Postby Gorilla Printer » Fri Jun 12, 2020 2:43 am

lavoie wrote:@Gorilla Printer

We did not use this anilox for any screen printing as we would also run a Pro K most of the time. Screens would run dirty with all of that ink. For block/screen combo plates that were not for process, we used a 600 LPI with 4-4.5 BCM..


Thanks for that lavoie
It looks like for what you use your 600 LPI with 4-4.5 BCM anilox for we use our 500 x 3.2BCM.

Cheers
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Re: Odd issue with plate

Postby longtimefan » Wed Jun 17, 2020 4:28 am

So ran into this issue on a different job. Same customer.diff item and color.

Tried 400 5.2, 360 5.8, 600 4.0

It was on yellow went to The white sticky back. I personally set impress at 300 fpm. Underlaid areas that were missing. I tried a different ink system ...Still no luck

It has to be the plate

I can't attach a picture?
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Re: Odd issue with plate

Postby longtimefan » Wed Jun 17, 2020 12:12 pm

We are ordering new plates for this job..

Had an operator run half the job this way with out making any mention of it
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Re: Odd issue with plate

Postby just Andy » Wed Jun 17, 2020 2:12 pm

Hi longtimefan

Thanks for the update. Let us know how it goes once you receive the new plate.

Just looking at the pic again and that you've set your a kiss impression, there's certainly something uneven for that thick halo to be the result.
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Re: Odd issue with plate

Postby longtimefan » Tue Aug 11, 2020 2:22 pm

Hasn't been ran yet with new plate
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Re: Odd issue with plate

Postby longtimefan » Fri Oct 09, 2020 7:35 am

New plate did the trick I was told.

I didnt see it ran or a sample but was told its good now
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Re: Odd issue with plate

Postby just Andy » Fri Oct 09, 2020 12:59 pm

Hi longtimefan

Thank you very much for the update. I was pretty sure it was just an old, worn plate.

Since this was last discussed, we also replaced a plate that looked a bit old and on it's way out. What I've noticed was that plates that are bounce inducing will have a significantly lower plate life than others. Also plates with no significant bounce but with solids and text together will have a far lower lifespan.

In the above example: I had a plate with a spot red 40% coverage logo on the right and on the left there was fine text with the same red to write the heading of the nutritional information. The first run looks decent but already on the third or fourth run and the plate while still fairly new, looks not that much better than the old plate it had replaced. Though impression is heavy, it is still a decent kiss print but a lot more impression is required to print the front logo.

Cheers
Andy
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Re: Odd issue with plate

Postby lavoie » Sat Oct 10, 2020 6:07 pm

longtimefan wrote:New plate did the trick I was told.

I didnt see it ran or a sample but was told its good now


Just some plate care info:

Clean asap after use. Store in a dark place with moderate temperatures. Light will dry out the plate causing cracking and distort the image over time. We used engineering roll paper in-between each plate (image down), rolled them up and stored them in film cores. DuPont recommends discarding plates after 2 years I think but we got as much as 4 years of moderate use out of some block printing plates. Probably an average of 2 million feet. This was a bonus and never counted on. Our shop was not climate controlled so you can't take anything for granted.

At times when we had bounce issues and the substrate would accommodate, we would mount 25mm bars on both sides to avoid the bounce. Also, many times we made changes to the image stagger. In a pinch, we would cut images into lanes and mount them individually to change the stagger though you need micro dots for each image for anything more complex than the most basic graphics.

I am not a fan of reusing backing. You can get away with it on short runs but over time the cushion will compress and you will have uneven settings causing low and high spots.
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Re: Odd issue with plate

Postby longtimefan » Sun Oct 11, 2020 10:30 am

lavoie wrote:
longtimefan wrote:New plate did the trick I was told.

I didnt see it ran or a sample but was told its good now


Just some plate care info:

Clean asap after use. Store in a dark place with moderate temperatures. Light will dry out the plate causing cracking and distort the image over time. We used engineering roll paper in-between each plate (image down), rolled them up and stored them in film cores. DuPont recommends discarding plates after 2 years I think but we got as much as 4 years of moderate use out of some block printing plates. Probably an average of 2 million feet. This was a bonus and never counted on. Our shop was not climate controlled so you can't take anything for granted.

At times when we had bounce issues and the substrate would accommodate, we would mount 25mm bars on both sides to avoid the bounce. Also, many times we made changes to the image stagger. In a pinch, we would cut images into lanes and mount them individually to change the stagger though you need micro dots for each image for anything more complex than the most basic graphics.

I am not a fan of reusing backing. You can get away with it on short runs but over time the cushion will compress and you will have uneven settings causing low and high spots.





Old regime of mounters didnt clean, and stored however.

We now have a dedicated person and a plate cleaner, they get rollers with tyvek sheets between and in tubes

Cant stagger as its one image across
Attachments
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D0805FAA-F91C-4D30-9D9A-88AD1DB11EC9.png (3.75 MiB) Viewed 98 times
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Re: Odd issue with plate

Postby Gorilla Printer » Wed Oct 14, 2020 9:22 pm

Well, isn't hindsight a bitch?
Welcome to Flexo
Get a new plate made and then see if there is a problem.
I assumed we were dealing with a new plate lol

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Re: Odd issue with plate

Postby Frank Burgos » Thu Oct 15, 2020 8:45 am

On a side note, I advise all of my wide-web clients to store their plates flat and vertical, in snug, flat cardboard boxes. Tubes, while some like that they "pre-curve" plates, occupy multiple times the space as do flat-stored plates. also, storing them flat allows them to be slid out of shelves like books. Stacked tubes make it a challenge to store numerically. If you only have a few customers and jobs, cool. If you have 500-1,000 or more jobs, not so cool.
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Re: Odd issue with plate

Postby just Andy » Fri Oct 16, 2020 5:32 am

@longtimefan
Wow damn that looks really neat and organised. There I am with our workshop making another 2 shelves and all excited that the plates are not stacked all mixed on the spare table. (We've had a time where all small customers were just put on a table because we had limited shelf space).

I agree with Frank. For wide web and large repeats tubes would not be great. Even so it would probably need more than the 6 or 8 inch tubes.

From what I've learnt from multiple places, the best practice is to: wash after use, powder the plates, lay them between foam sheets, place them in an cardboard box and then place them flat on the shelves. Away from sunlight and if applicable, nowhere near the coronatreater exhaust (apparently ozone significantly degrade the plate). If possible climate control is better.

With the above being said, it all boils down to how well the operators and mounters handle the plates. I've seen a place where they the works (as above), dedicated cleaners and also with climate control and getting shelves done to look like a modern kitchen. But all of that and a lot of the plates having poorly made cuts, tears, and bends/folds.
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Re: Odd issue with plate

Postby longtimefan » Fri Oct 16, 2020 5:38 pm

006EE400-B632-4C03-BF66-A7398AAB83AB.jpeg
006EE400-B632-4C03-BF66-A7398AAB83AB.jpeg (411.01 KiB) Viewed 74 times
This is how I wanted to store the wide web but was told no

Take a big sheet cardboard...have it made with score line...fold it like a book and tape edges.

Lay plate down then foam, alter acting until all done. Grab entire foam "book" and Then slide it in the cardboard book and then in rack where you want to put it.
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Re: Odd issue with plate

Postby lavoie » Fri Oct 16, 2020 7:17 pm

For storing wide web plates, I agree that flat is ideal. The issue arises when transporting plates to and from storage. Some jobs required 10 plates with spares. Plates that are 60" or more wide and 30" around are pretty darn heavy. Workplace safety becomes an issue. It is much easier to transport a roll of plates to and from, going up and down steps/ladders. We used cores exactly like the image above. Careless plate cleaners are always going to cause issues with plates getting creased, torn or stored improperly. You have to weigh the pros and cons and what your company is willing to do to accommodate your wants and needs. In my opinion, the mounters should be cleaning the plates. An experienced mounter can tell if a plate is bad and will also take more care when storing the plates as they will be the ones that have to deal with them when it comes time to mount.
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Re: Odd issue with plate

Postby Frank Burgos » Sat Oct 17, 2020 6:51 am

I like Longtime's method, but I have seen boxes made with six sides that stand well on the shelf. Either way, flat and vertical
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