BS ISO 699-2015 pdf download

BS ISO 699-2015 pdf download.Pulps一Determination of alkali resistance. 8 Procedure 8.1 Test portion Weigh, to the nearest 1 mg. about 2,5 g of the test sample. Then immediately weigh two separate test portions for the determination of the dry matter content in accordance with Iso 638. 8.2 Determination Transter the test portion to the beaker (6Jj, add 25 ml o the sodium hydroxide solution (Jj adjusted to (20 ± 0,2) °C (see 5d. Note 1 and Note 2), place the beaker in the constant temperature bath (6S), and allow the pulp to swell for 3 mm. Thoroughly defibre the pulp by stirring and macerating with the stirring rod (ft.2) for at least 3 mm, macerating at a rate of two strokes per second. Add another 25 ml of the sodium hydroxide solution at 20 °C, stir until the suspension is uniform, and dilute by adding 100 ml of the sodium hydroxide solution at 20 °C. Cover the beaker with a watch-glass and leave in the constant temperature bath. 60 minutes after the first addition of the sodium hydroxide solution, stir the fibre suspension again and transfer it to the filtering device (3) fitted on a dry suction flask, adjusted to a temperature of (20 ± 0,2) °C in the constant temperature bath. Apply suction only as long as the fibre mat is still covered with liquid in order that no air is sucked through the mat. Use the filtrate for rinsing the beaker and filter again through the slightly pressed fibre mat in order to collect all fibres. Finally, apply full suction briefly. The time for filtering and washing shall not exceed 20 mm. Compact the fibre mat, especially at the edges, cover with the acetic acid (52) and allow 200 ml to pass through slowly without suction. Drain completely and wash with hot water until the filtrate is free from acid. Cover the filtering device with the hand during the last washing in order that a vacuum is formed above the fibre mat. Then quickly release the vacuum in the suction flask in order to lift the fibre mat. Transfer the fibre mat together with any remaining fibres adhering to the filtering device by means of stainless steel tweezers to the weighing bottle (6A). Place the open weighing bottle together with its lid in a drying oven and dry to constant mass at a temperature of (105 ± 2)...