Congratulations, you have the same problem I had a few weeks ago. Now, I bit wiser than then, I can tell you the reason.
This part is a Bowden throat. You put your teflon tube inside this part.There are different bowden throats, some of them with teflon inside. Those are the worst kind, and most likely you have one of those inside your 3DPrinter.
"Why?", you may ask, well, between your Teflon tube and the Teflon part inside the Bowden throat there is a gap.
The filament get stuck in that gap after an hour and half, more or less, forming a clog similar to this one.Replace that Bowden throat with one without a Teflon part inside. This simple change fix the problem :)
Congratulations, you have fixed your 3D printer, which should now be able to print whatever you need.
