Fig. 5.

(a) Processing operator exchanges collection bag containing ∼7 kg of thermally treated CNF product in the vicinity of Position C in Fig. 1. The bag was purged with an inert atmosphere during filling. Tamping product and subsequent closing of bag resulted in significant CNF release (Event I in Fig. 4). (b) An empty collection drum adjacent to the dryer base. Once the drying cycle was complete, dumping of dried CNFs from the dryer above into the bag-lined collection drum below resulted in the largest transient increase in respirable mass concentration observed (Event III in Fig. 4). A canvas flange can be observed at the base of the dryer to assist in reducing the gap between dryer base and drum. This may not have been performing adequately for this operation.