Fibre separation suspension

The asbestos fibre reference material used in this study was chrysotile (long range) supplied by the NIEHS [10]. 50 mg of this powder was suspended in 5 liters of the prefiltered water and treated by ultrasound probe for 30 minutes at a power of 0.015 in order to obtain a more uniform dispersion and to separate as much as possible the fibres bundles. This suspension was the starting solution used in all experiments. The analyses... 

Paper is made from a suspension of fibres in water. The suspension is drained through a fine mesh so the water drains away and the fibres are retained to form a mat on the mesh. On drying, the fibres stick together and form a sheet of paper. Many paper experts define paper as a material made by a process that involves the separation of fibres into a suspension with subsequent formation into a sheet. 

One unique advantage of pre-formed PECs over in situ PECs is the possibility of controlling their formation and of analysing their structures and colloidal properties before addition to the pulp fibres. Since complex formation occurs in a separate environment, which is more controllable than the paper stock that can vary substantially with time, the PEC formatiOTi can also be made more reliable and robust than if it occurs in the fibre suspension. 

Having shown the principles of ultra-filtration it is now simple to extend the idea to filtration of more conventional suspensions with coarser particle size, and this is the cross-flow filtration in porous pipes. Essentially, the same equipment and types of modules as in ultra-filtration can be used but thicker flow channels or greater-diameter hollow fibres are necessary. It seems, however, that porous pipe systems represent the most practicable approach here. Zhevnovatyi was first to report the use of porous tubes for cross-flow filtration, in his case for separation of hydrated alumina and red bauxite. Dahlheimer et al published an investigation on concentration of kaolin clay... 

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