WRV is an empirical measurement to evaluate the hold-water capacity of cellulose [Eq. (5.2)]. During pulp disintegration, the WRV value increases due to an increase of cellulose surface area. Therefore, WRV measurements (adopted from TAPPI UM 256 standard) can be used as an indication of CNF degree of fibrillation.Different conditions were used to determine the WRV,After centrifugation, the supernatant was removed and the wet sediment was weighed and oven dried at 105C until reaching a constantweight.