BS ISO 23714:2014 pdf free
BS ISO 23714:2014 pdf free.Pulps一Determination of water retention value (WRV)
From the diluted and well-stirred stock, take samples and carry out WRV determinations at (23±3) °C in duplicate. Carry out all determinations as soon as possible after sampling.
If, for practical reasons, WRV determinations are carried out a day or more after sampling the WRV will be somewhat higher (normally less than 0,03 g/g) than it would have been if the determination had been carried out the same day. Any significant delay in carrying out the WRV tests shall be reported.
Connect the Bichner funnel (6.2) to the suction flask (6.4). Put the glass-fibre filter in the funnel, moisten, and then start the suction. Add to the Bichner funnel a volume of the stock, so chosen that the test pad formed will have an oven-dry grammage of (1 700±100) g/m2, when placed in the test-pad-holding unit (6.5).
For the volume of stock chosen, 100 ml of this volume should be filtered and then the suction stopped. If necessary (if the retention of fines is too low), add this initial filtrate to the remainder of the stock volume to be filtered.
Stop the suction when all the surface water has directly disappeared. The dry-matter content of the test pad should then be between 5 % and 15 %.
Remove the pad from the Buichner funnel and place it in a test-pad holder.
Place the complete test pad-holding unit with the test pad in a centrifuge bucket (see 6.1). Centrifuge at a speed that gives a centrifugal force of (3 000±50) g at the bottom of the pad for 30 min±30 s. This period shall include neither acceleration nor retardation.
The temperature of the test pad during the centrifugation can influence the result, and it is therefore recommended that the centrifuge be able to maintain a working temperature of (23±3) °C. Otherwise,the temperature of centrifugation should be included in the report. If multiple centrifuging tests are to be run, then some time should be allowed for the centrifuge to cool between each run, to be within the proper temperature range.BS ISO 23714 pdf download.
