Minimum print repeat for given plate thickness?

Ask or answer questions related to the flexo pressroom environment

Moderator: Frank Burgos

Minimum print repeat for given plate thickness?

Postby darebn » Fri Sep 29, 2017 11:03 am

Hello guys,

I have on one machine inline flexo print unit with one color for some basic prints, currently running with 210mm (8.27") print repeat with 2.84mm (0.112") plate. I know it is too small diameter but it works well, we use good quality duplofl and it sticks pretty good.

Now we need to change dimension to 170mm (6.7") print repeat, so we need to make custom roller. I was wondering is there some limitation for print repeat for 2.84 mm plates? Or I need 340mm roller, because 170mm print repeat roller might be too small diamter for this plate thickness...

I will be thankfull for any help :)
Thanks in advance.
darebn
 
Posts: 3
Joined: Fri Sep 29, 2017 5:08 am

Re: Minimum print repeat for given plate thickness?

Postby richflexo » Fri Sep 29, 2017 1:41 pm

Hi,

You will just have to secure the plate down and give some serious distortion, approx. 89%. If you're printing circles, you don't want them to come out as ovals!

If you take a .112" plate and try to drape it, there wont be much give. If you were able to go to .067" you will have a better drape around the cylinder and only distort it by about 94%.

You'll have to consider the sticky back to with that kind of outside diameter.

RF
richflexo
 
Posts: 62
Joined: Fri Jun 01, 2012 3:01 pm

Re: Minimum print repeat for given plate thickness?

Postby guy de cafmeyer » Mon Oct 02, 2017 2:31 am

Another thing to consider is if the press can physically take such a small cylinder ... apart from distorting correctly ..
guy de cafmeyer
 
Posts: 37
Joined: Tue Apr 14, 2015 3:13 am

Re: Minimum print repeat for given plate thickness?

Postby darebn » Fri Oct 06, 2017 4:08 am

Yup, I measured, it can fit so small flexo plate roller,

Distroting factor will be incalculated in plate height.
I'm not aware too much about distorting, since it is basic one color in line print, no halftones just text, logo and some patterns will be printed.

Biggest problem might be self seperating of printing plate from a cylinder during press run due to samll diameter of cylinder...
Maybe longer flexo plate washout in process of making plates will be helpful to increase depth of printing pattern and decrease base thickness so plate will be more elastic and easier to wrap over cylinder.

I will probbably give it a try very soon, I hope for good results. :)
darebn
 
Posts: 3
Joined: Fri Sep 29, 2017 5:08 am

Re: Minimum print repeat for given plate thickness?

Postby dkelley » Fri Oct 06, 2017 3:20 pm

If you are using a forced air dryer to dry the plate you can roll the plate up into a small tube and place it in the dryer for an hour. This will pre-curl the plate and help with any lifting from the stickyback.
dkelley
 
Posts: 227
Joined: Fri Jan 08, 2010 12:26 pm

Re: Minimum print repeat for given plate thickness?

Postby darebn » Fri Oct 06, 2017 3:28 pm

Thanks dkelley for a nice tip,

Honestly, I would never tought about that - so obvious, simple and logic solution :)

Thanks!
darebn
 
Posts: 3
Joined: Fri Sep 29, 2017 5:08 am


Return to Pressroom

Who is online

Users browsing this forum: Bing [Bot] and 4 guests