Teflon or metal. Teflon spinning bands are used for distillations below 225 °C. Metal bands are used for higher temperature distillations where Teflon would become soft.
All distillations attempt to separate a lower boiling material (A) from a higher boiling material (B). Spinning band distillation uses a spinning band to force the rising vapors into close contact with the descending condensate. This intimate contact between the two phases produces a very good separation of the components.