powder hose material

Hi everybody,

we are using a R&H Formula1 powder that is very sensitive to contamination. This results in craters in de powder coating film after curing.

We know the contamination comes from hoses made of PVC.  When we remove the hoses, the craters are reduced. What kind of material can be used to transport the powder? The hose should be about 100mm/4" of inner diametre.