Problems with TPU seal
Hello everyone,
I have a problem with the printing of TPU and need your help!It is about the printing of a flexible sealing ring for a field irrigation system.1) What options do I have to make the seam smaller, or preferably make it disappear completely? The inside is the important surface, as this is where the main sealing function is performed2) Why does the seam look so much worse on the inside than on the outside?3) Where do the ‘blobbs’ on the inside of the sealing ring come from? They are always in the same place on the sealing ring! Why is that?
I can provide the .stl file if required.
Thank you very much for your help!
Outer Seam looks good
Inner Seam looks way worse
Where do these blobbs on the inner surface come form?
Thanks alot for your help!
RE: Problems with TPU seal
Make sure you dry the heck out of the TPU and ideally print from a dry box. That should take care of the blobs. The seam. Really no good way to get rid of it. You may want to try the scarf seam option recently introduced into Prusaslicer. I should say though that in my hands it's not something I've been impressed with. I didn't spend hours optimizing parameters but every time I tried it I ended up with two (albeit smaller) seams...
Formerly known on this forum as @fuchsr -- https://foxrun3d.com/
RE: Problems with TPU seal
Does they inner surface seal, or just the faces?
I often create a groove on and surface that I want smooth and then use the seam tool in PS and select the grove. Then all the seams end up in the grove and don't affect my smooth surface.
I agree with drying. You may also increase your retraction. Make sure your printing got enough, around 220, because I've found increasing retraction if your not printing hot enough causes the TPU to act like a spring in the extruder which causes other issues.
RE: Problems with TPU seal
Thanks for the reply!
I already store the TPU in a Drybox at <30% relative humidity. Honestly I don´t believe these blobbs are caused by wet filament, because they´re always ath the same position.
Thanks for the hint with the scarf and the groove, as well as the increased retraction. I´ll definetly try those ones out!