Problems with support material

[stoccarda 0]

I currently have problems with support material in a UM3 and Cura 4.6.0

1. UM PVA

I had used this material in the past and it worked well with the standard settings (NFC).

But in the last prints there is almost no flow and prints look like this:

When loading the PVA it is flowing out of the BB 0.4 and even a brim is printed , but not entirely.
Printing temperatur is 215°C. Standby temerature in the material setting 175 °C, but 100 °C in the printing profile (?).
The PVA has become mostly white after printing.

The PVA is now 15 months old, most time store in a vaccum bag and dried before storing.
Could it be an aging problem?

 

2. Formfutura Atlas
I started using it, raising printing temperature to 220 °C. The prints were satisfactory, but now, I have smilar problems. There is also a problem feeding the filament through the Bowden tube: It looks like there is too much friction of the rougher Atlas . Even when pushing by hand it is almost impossible now to move it through the tube.
May be the inner diameter of the tube being too small ? The diameter of the was Atlas in tolerance. The roughness of the filament is higher compared to the UM PVA.
Loading the Atlas works with some flow. There is always some material below the feeder.

 

The nozzle has been cleaned.

 

Thanks for any suggestions !

[SandervG 1,521]

On 4/30/2020 at 7:08 PM, stoccarda said:

 

The PVA is now 15 months old, most time store in a vaccum bag and dried before storing.
Could it be an aging problem?

 

 

 

I think that is quite likely. 15 months is pretty old. Is it brittle when you try to bend it?

 

On 4/30/2020 at 7:08 PM, stoccarda said:

2. Formfutura Atlas

 

On 4/30/2020 at 7:08 PM, stoccarda said:

May be the inner diameter of the tube being too small ?

I am not familiar with this material, but if this would be the case I think it would be more accurate to say the filament would be too thick. 

 

Besides keeping filament in a vaccuum bag, do you also keep silica bags in the same bag? 

[stoccarda 0]

The part of the PVA which has passed the feeder was brittle, but the filament before was not brittle.

 

The Atlas has a diameter of 2.86 mm, PVA 2.88 mm.

I see the main diference that the PVA has a smoother (less rough) surface, especially after running through the feeder

 

I am using a unit  with a vaccum pump and hot sealing, as you use it before deep-freezing food.
Hence I did not use silica bags, or do have I?