TPE won't stick to Printbed...  

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christian.ho
(@christian-ho)
Active Member

Hi,

I bought some Fillamentum Flexfill TPE 90A.

It is my first print with flex. So far I had almost 10 failed attempts printing the benchy ship. Everytime, the print comes loose. Sometimes sooner, sometimes later.

Print Settings: 240°C / 50°C, 0.15mm, slow (0.8mm³/s max), 1.1 extrusion multiplier. The Filament was sealed until this morning and I am printing directly from a dry box.

What I tried so far:

- Smooth sheet, textured sheet, cleanded with ethanol.

- Painter's Tape, adhesive tape, glue stick (the one delivered by prusa and pritt as well)

- Remove the text on the bottom of the benchy so there is a solid fist layer

- add skirt

Now I'm starting to run out of ideas. It is like printing on teflon! Any suggestions?

 

Best regards

Christian

Posted : 25/10/2020 2:20 pm
RH_Dreambox
(@rh_dreambox)
Prominent Member

Be careful when printing with Flexfill, especially on the smooth plate. Flexfill bites incredibly well and can be difficult to remove.
So I think your problems are due to a too high Z level. Check that the first layer is tight without any cracks.

You may also need to wash the bed with detergent and warm water. Also keep in mind that the smooth plate and the textured one must be calibrated to different Z-levels.

Bear MK3 with Bondtech extruder...
Posted : 25/10/2020 3:04 pm
christian.ho
(@christian-ho)
Active Member

I switched the z offset presets when switching the sheets. Also I did a calibration of the first layer height after another print failed.

The fist layer does not have any cracks or gaps. Judging from the looks of the first layer, I guess - if at all- the first layer is too low.

What do you mean by bite? Just how well it sticks? Or something else?

 

Usually I print PETG (85%) or PLA (15%). The line in front, where the extruder is being primed is usually quite hard to remove, while the bed is still hot. For the Flexfill, I virtually need no force to pull it off. And it looks really well squished down.

Maybe I made another mistake: Is setting the volumetric speed in the filament settings to 0,8mm³/s enough? or do I also have to reduce the linear speeds in the print settings? Right now, I reduced the speed to 28% on the printer. If that fails, too, I will try cleaning detergent next.

Posted : 25/10/2020 3:24 pm
--
 -2
(@-2)
Illustrious Member

TPU sticks better than anything else I have printed. It requires a release agent before printing. The last part I printed a few days ago I had to stick in the freezer for 30 minutes to freeze the sheet and the part in order to remove the part. Even then I worried about damage to the PEI.

Something is preventing the TPE in this case from actually touching the sheet. Have you washed the plate in soap and hot water?

Try printing something small using the standard Generic PLA settings.  It's a bit fast for a flex product but worked for a couple of medium parts I've made (70 mm base). The Generic Flex profile was too hot, and much too slow for me, but also worth trying. A profile without user tweaks gives a baseline.

In one case in nearly three years I've received a spool of bad filament. It had something on the surface layers of the spool that absolutely prevented adhesion. Once I had used up 1/4 the spool, it started sticking. But that filament (from Prusa) was never 'right' ... so you might have a bad spool. Contact the manufacturer and ask about the issue.

ps: TPE is not a urethane, so TPU experience probably doesn't apply.

This post was modified 1 month ago by --
It is always wise to get more than one opinion... as for trusting Prusa? No way man....
Posted : 25/10/2020 4:18 pm
RH_Dreambox
(@rh_dreambox)
Prominent Member

Bite = stick, translation error 🙂
Christian-ho, I have never changed the parameters you mention. The filament profiles are calibrated with the correct values, so if you change them, there is a risk that they will impair the print quality.
The right Z level and a clean bed are very important for trouble-free printing.

Bear MK3 with Bondtech extruder...
Posted : 25/10/2020 4:27 pm
christian.ho
(@christian-ho)
Active Member

I attached my wall of shame...

Usually the print fails after the first few layers. The best results so far were with adhesive tape. This is what i am currently trying (tape is additionally roughened with sand paper). Then I will wash the sheet. However, I am not hopefull. I clean it often and especially the sooth one I hardly used so far.

so you might have a bad spool. Contact the manufacturer and ask about the issue.

I will try that if I don't have success in a few days.

 

Posted by: @rhdreambox

I have never changed the parameters you mention. The filament profiles are calibrated with the correct values, so if you change them, there is a risk that they will impair the print quality.

The problem is that there is no profile for this filament. At least I was not able to find one. I started with the Filamentum Flexfill 92A and adjusted it according to the recommendations from Fillamentum that are on the provided datasheet.

As you can see in the pictures, I tried various Z settings from too low to too high. Always the same result, does not stick.

 

Maybe a more proper comparison is: It is like printing teflon. That stuff is REALLY smooth.

 

Posted : 25/10/2020 5:12 pm
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 -2
(@-2)
Illustrious Member

For reference, it really looks like that top center boat is severely underextruder on layer 1. The boat right of center looks acceptable, I'd expect it to stick if the bed is clean.

The TPE 90A is an olefin ... that places it in the same family as Delrin, if I'm not confusing things. Quite slippery.  You may need to use something like glass or even bare steel to print it. Though, you'd think tape would work, but maybe you tape has a coating. Another reason to ask the mfg questions.

It is always wise to get more than one opinion... as for trusting Prusa? No way man....
Posted : 25/10/2020 6:02 pm
christian.ho
(@christian-ho)
Active Member

For reference, it really looks like that top center boat is severely underextruder on layer 1

I certainly agree. Just wanted to show what I tried so far.

 

Update: The sanded adhesive tape workes quite ok so far. Did not come off yet. 44% done, 2h30 remaining...

I don't think I will want to have the mess with the tape each time I print. Can I use just any steel sheet to print on it? Certainly I would make all corners smooth before using it to not damage the heatbed.

 

 

 

Posted : 25/10/2020 6:20 pm
--
 -2
(@-2)
Illustrious Member

I found a steel flex sheet off Amazon - I have NOT used it yet - just got it a week ago, haven't even taken it out of the box (intent is trials of printing Carbon Fiber Acrylic). It comes with a sheet of PEI to stick on it. It is supposed to be thicker than Prusa's sheet, and be a better more accurate surface flatness. But, since it comes bare steel, sans PEI applied, it should work well enough, if steel is tacky enough for your filament. The other thing is you can probably sand or grind the steel to roughen it up, and the effect is permanent. Plus, this sheet is pretty cost effective at only $25.

https://www.amazon.com/gp/product/B07LBQ57WV

Another thought is the textured car vinyl appliques (similar to what they use to armor cars with signs). Bob has printed on that stuff and says it seems to work pretty well as a print surface.

 

It is always wise to get more than one opinion... as for trusting Prusa? No way man....
Posted : 25/10/2020 6:58 pm
christian.ho
(@christian-ho)
Active Member

Short update: The print succeeded!

Thanks for all hints and discussion. I will post pictures and details on settings later today.

Posted : 26/10/2020 6:19 am
towlerg
(@towlerg)
Honorable Member

Obviously the posters on this thread have a great deal of experience but here's my 2 cents.

Brim is your friend, overall it costs nothing even for a big brim (I use a 5mm brim no skirt by default)

I guess your trying to overcome some under extrusion problem but 1.1 extrusion multiplier seems excessive.

If you do not have experience with flexible materials, is it possible to try something that has a profile in PrusaSlicer?

Posted : 26/10/2020 11:40 am
jonathan-lin
(@jonathan-lin)
Eminent Member

Check the manufacturer's Fillamentum Flexfill TPE 90A 3D printing guide PDF on their website under https://fillamentum.com/pages/data-sheets for what printbed surface and adhesives to use.

Posted : 26/10/2020 3:24 pm
--
 -2
(@-2)
Illustrious Member

Interesting - and not surprising based on this thread - the Mfgr recommends MagiGoo Pro for Polypropylene, and they recommend a 1.1 multiplier for top and bottom layers.

This post was modified 1 month ago by --
It is always wise to get more than one opinion... as for trusting Prusa? No way man....
Posted : 26/10/2020 5:15 pm
christian.ho
(@christian-ho)
Active Member

Thanks for all the replies!

Here are my results:

 

I think it is quite ok and I am happy with it like that. The stringing is expected for flex. What do you think?

Interestingly, it sticks extremely well to this type of tape. So well, that I can't get it off anymore.

Here you can see where the hotend moved onto the tape (bottom right). Already there it sticks really well to the tape, while the slightest touch would remove it from the PEI sheet.

Brim is your friend, overall it costs nothing even for a big brim (I use a 5mm brim no skirt by default)

I used 3mm brim. For any other surface, even printing the brim did not work properly.

I guess your trying to overcome some under extrusion problem but 1.1 extrusion multiplier seems excessive.

I was pretty sure to have seen this as general recommendation for this filament somewhere. In fact, the preset in prusa slicer is 1.15 for the 92A filament, which I would expect to be less critical, as it is less soft.

If you do not have experience with flexible materials, is it possible to try something that has a profile in PrusaSlicer?

My purhcase was a compromise between price, requrements (skin contact safe), availability, and reputation of the brand. However, I didn't expect the print to be soo difficult. If I had known, I certainly would have chosen differently.

 

Check the manufacturer's ... printing guide

...

the Mfgr recommends MagiGoo Pro for Polypropylene

When I purchased this printer (it is my first), I was like: Yay! A print sheet to rule them all!!

(Then I found that there are 2 different sheets and I still was like: Ok. Two sheets to rule them all...)

Anyway, I was not expecting so many problems. I still hope that a plain steel sheet will also give good adhesion. I guess I will make some trials with the failed prints and a hot air gun...

 

Is there anybody who ever printet with this exact filament?

Posted : 26/10/2020 6:38 pm
Nikolai
(@nikolai-3)
Noble Member

TPU/TPE can be easily removed from any tape/sheet with IPA.

Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram...
Posted : 26/10/2020 9:27 pm
christian.ho
(@christian-ho)
Active Member

Hi everyone,

I have a reply from filamentum. They say the filament is based on polypropylene and therefore it is very different from TPU and it is really difficult to get adhesion. They again recommended Magigoo PP.

Recently I printed the flexible part of a valve. It is a disk of 2 printed layers with 34mm diameter. In the middle is a tip with 3mm diameter and 3mm height. So the part is basically only brim.

The print succeeded, however, I needed virtually no force to remove it from the bed after the print was done. I didn't even need to wait until it cooled down. So I really think it is not worth trying larger prints with just brim for increaed adhesion.

TPU/TPE can be easily removed from any tape/sheet with IPA.

I succeeded to remove the glue part of the tape. However, I was still not able to remove the tape from the printed TPE. If I need a surface that has no tape on it, I guess I will have to buy the magigoo.

 

Posted : 10/11/2020 5:08 pm
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