PEI sheet damaged with first print  

RE: PEI sheet damaged with first print

I am not aware of any ... what material were you printing? Did you remove it from plate while hot? I usually remove plate, wait until it cools down, then bend the sheet back and forth to release.

RE: PEI sheet damaged with first print

Posted by: @pook

So I have a MK3s & MMU2S and just received a mini.  When I removed my first print it took part of the PEI sheet with it.  Are there production problems with PEI sheets that could cause it to crap out after the first print?

Damaged PEI Sheet

Always allow the printing plate to cool down to room temperature, do not apply high forces, possibly use a spatula or bend the plate.

RE: PEI sheet damaged with first print

I had a similar damage to a sheet.  Did you let it cool all the way before removing it?

RE: PEI sheet damaged with first print

Posted by: @pook

So I have a MK3s & MMU2S and just received a mini.  When I removed my first print it took part of the PEI sheet with it.  Are there production problems with PEI sheets that could cause it to crap out after the first print?

Damaged PEI Sheet

This just happened to me 2 days ago. I printed in PETG and I let the printer cool down completely. I did the usual flexing of the sheet to unstick the print. It was really stuck in the middle and when I got it off, it had about a 2mm x 2mm piece of the PEI coating stuck to the bottom of it. I bought this sheet 1 month ago to replace the one I had used for 18 months. That sheet never had an instance where the PEI coating delaminated and I was printing PETG on it 6-8 hours/day for 2 months to print face shields. It certainly caught me by surprise. 

RE: PEI sheet damaged with first print

@ryan-p26

What brand of PETG?

RE: PEI sheet damaged with first print

@charles-h13

PPE orange Prusament PETG

RE: PEI sheet damaged with first print

@ryan-p26

I have used that one, but PETG can really, really stick. I always do a small test and if it over sticks, I use a spray of Windex before printing.  

RE: PEI sheet damaged with first print

@charles-h13

I understand the difficulties with PETG. I’ve printed plenty of it over the past two years. I also printed this very same brand (Prusament) for the last few months. 

RE: PEI sheet damaged with first print

I was printing Black Prusa PETg :/

It wasn't completely room temperature, but close.  I didn't put it in a freezer, maybe I should have?

I bent the plate and that lifted the corners up, then removed it.

RE: PEI sheet damaged with first print

I have a MK3 and two Minis. I was also wondering if there was a differnet in the quality of the sheets as I have already ruined 2 sheets of the mini with PETG.

RE: PEI sheet damaged with first print

Posted by: @pook

So I have a MK3s & MMU2S and just received a mini.  When I removed my first print it took part of the PEI sheet with it.  Are there production problems with PEI sheets that could cause it to crap out after the first print?

Damaged PEI Sheet

That happened to me on one of my first ABS prints on the MK3S.  I did not expect it to stick so well and I lost patience and pried it up with a metal instrument, taking pieces of the PEI with it.  I should have used a release agent and/or let it thoroughly cool.

RE: PEI sheet damaged with first print

@ulrike-b

In order to prevent such events, it may be advisable not to clean the printing plate with isopropanol or to use e.g. Dimafix, Magigoo, the glue supplied by Prusa or similar.
Normally it should be sufficient to let the printing bed cool down to room temperature and then carefully remove the part from the printing plate by bending it.

RE: PEI sheet damaged with first print

@karl-herbert

I am not sure these glues would cause this.  I have them for 2 years without such an event.  

I would limit the use of acetone but it will cause this damage if you do it incorrectly or regular.  I rarely use acetone but when I do it is a quick removal. 

RE: PEI sheet damaged with first print

@charles-h13

Some also say that window cleaner should be good for this purpose. I've never tested it. Other opinions on this topic:

https://forum.prusa3d.com/forum/original-prusa-i3-mk2-s-general-discussion-announcements-and-releases/removing-petg-from-pei-heatbed/

RE: PEI sheet damaged with first print

@karl-herbert

I have used window cleaner when it sticks too much and adhesives when it sticks too much.  The key is a small test print to know which problem you going to have.  I used to spend hours getting things to stick.  I like to test filaments and each filament is difference.  

RE: PEI sheet damaged with first print

@charles-h13

It’s funny you say that because I have used IPA to clean my PEI sheet once a week and acetone less than once a month to refresh the PEI. This is all in accordance with Prusa’s recommendations (First Layer Issues). I just think it’s odd that the PEI coating on my original smooth sheet never delaminated despite regular exposure to IPA, occasionally acetone, glues, and many different materials over it’s almost 2 year lifespan. It also has scars from times when I wasn’t careful with my z-offset and the coating still remains adhered to the sheet. 

So why does my 2 month old sheet experience delamination of the PEI coating under the same pattern of usage, with far less frequency,  as my older one?

RE: PEI sheet damaged with first print

@ryan-p26

Me either, but it is reported.  I wonder is people let it sit on the sheet.  

RE: PEI sheet damaged with first print

@ryan-p26

I think because PEI is not equal to PEI. There are different quality patterns in terms of purity in production.

RE: PEI sheet damaged with first print

I wonder if they have used multiple vendors, with some of them not as good as the others?

I know they have mentioned multiple vendors for the textured sheets, some who did not produce consistently good results.

I have two of the smooth steel sheets, both coded WA-21, and both I consider to be good, other than the user error of f-bomb-ing up the coating on one side of one.  I was, of course, unfamiliar with printing on the thin steel PEI sheets at the time.