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Material sticking to the nozzle and forming blobs / zits

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Hello everyone,

I have been testing a new material called PURA from AprintaPro.

This material has a great texture finish but in my Ultimaker 3 is sticking to the nozzle until it detaches itself and end up in the print in the form or blob / zit. (see pictures attached).

I have been in contact with PrintaPro and they gave me some advise including a Simplify 3d profile tested on the Ultimake 3 in their offices, but the resolt is the same.

I should say that I am using a 3D Solex Hardore printcore with a 0.8mm nozzle.

I have tried all different temperatures, the best one so far has been 190 deg.

this is the link for the material datasheet:




Please help.

I really want to make this work.






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Contact 3dsolex - link to this thread - see if they'll send you a free ICE coated 0.8mm nozzle.  The ice coating is basically teflon - nothing should stick to it.  If you go over 240C it ruins the ice coating and maybe that is what happened to your nozzle?  Or maybe it was never ICE coated.  The ice coated nozzles look a lot like steel.  They are darker and less shiny than uncoated nozzles which are quite shiny (like chrome).


I found that I have to print about 10C to 15C cooler with my 3dsolex 0.8 nozzle than with my UM nozzle because of the RACE technology which has the filament going down two different paths through the nozzle and heating the filament more thoroughly.


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Thank you for your reply.

I don't think it is an ice nozzle, it came with the set of 4 nozzles when you buy the 3d solex print core. (see picture attached).

I don' t know if you remember but I did have allot of problems with my first 3d solex print-core. There was something wrong with it in more than one way.

When I have contacted 3d solex and explain the problems I was having, Carl told me straight away that he was going to send me a new Print-core and to keep the old one.


On top of that he sent me a free Sapphire 0.5mm nozzle.

Even that one sticks with this material.

I will try an ice nozzle and see what happens.

Thank you for your help once again.




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It may just be material-dependent, if the molten material is very sticky like hot-melt glue. I have this on my UM2 too with PET, but far less with PLA. Printing much slower and cooler helped a bit, but did not eliminate the effect in my tests. Especially the slow printing helped, since that gives less pressure in the nozzle, and thus less overextrusion on short lines when the printhead hast to slow down.


PLA melts into a sort of yoghurt-like consistency which is easily deposited on the print, but that particular PET melts into a sticky elastic glue, which retracts into a ball and keeps building-up on the nozzle.


I would suggest: try printing a little test block (e.g. 15mm x 15mm x 15mm), 100% filled, and on the fly adjust printing speed and temp, and keep watching.


For my PET, printing at 25mm/s, 0.1mm layer heigt, and 220°C seems to work best (=at the lower end of the recommended range of 215...250°C).


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