extruder clogged in the printing and it continue running above model (UM 3)

[leizhuo 0]

Problem Description:

I found my extruder is running above model with nozzle clogged when I return office after 3 hours start printing. Several material drippings are found on the model sections.

 

1.  It is single material printing – PVA material. CURA setting is shown in the attachment.

 

2.  Before start printing, I set print core temperature to 200 ℃ and try hot pull several times for nozzle clean. Meanwhile, I cleaned extended extruder suite feeder for filament importing easily. In the start, the material exporting is fluent and boundary line is broad; everything seems perform in a regular routine.

 

3.  I tried two times for printing, but they failed in the same way. It seems this case happens randomly.

 

How to fix this case?