TAPPI TIP 0809-01 PDF

Scope:

Drainage of water through a pulp pad is affected by many factors such as fiber flexibility, amount of fibrillation, fiber length, and amount of debris present. Because the relative importance of these factors varies in the different methods for measuring freeness or drainage, there is no conversion table which will apply to all pulps.

The following tables are based on the results of 1500 measurements for freeness and drainage made on 50 samples of stock. These 50 samples consist of 10 samples of stone groundwood, four samples of refiner groundwood, and 36 samples obtained by beating five types of bleached chemical wood pulp for various lengths of time. Both hardwood and softwood pulps were used.