BS ISO 699:2015 pdf free.Pulps – Determination of alkali resistance.
BS ISO 699 specifies a method for the determination of the alkali-insoluble fraction of puips using sodium hydroxide solution of fixed concentration. The sodium hydroxide concentrations most frequently used are 18, 10, and 5 % (rn/rn).
The method is applicable to all kinds of pulp.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 638, Paper, board and puips — Determination of dry matter content — Oven-drying method ISO 4793, Laboratory sintered (fritted)fiIters — Porosity grading, classification and designation
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1 R-value alkali resistance; the insoluble fraction expressed as a percentage by mass of the oven-dry pulp
3.2 R18, R10, R5, orR R-values in which the indices 18, 10, 5, or c refer to the chosen concentration in grams of sodium
hydroxide per 100 g of solution
4 Principle
Defibreing of the pulp under specified conditions in sodium hydroxide solution of chosen concentration. Filtering of the insoluble fraction, washing with sodium hydroxide solution of the same concentration, and temperature as that used for defibreing and acidification, washing, drying, and weighing.
5 Reagents
Use only reagents of recognized analytical grade and only distilled water or water of equivalent purity.
5.1 Sodium hydroxide, solution of known concentration containing less than I g of sodium carbonate per litre (see the notes), for example.
5.2 Acetic acid, 1,7 moth solution, corresponding to 100 ml of CH3COO[l (P20 = 1,055 to 1,058 gfml) per litre.
6 Apparatus
6.1 Beaker, of capacity 250 ml, flat-bottomed, made of alkali-resistant material.
6.2 Stirring rod, of diameter 15 mm, with a flat end, made of a non-brittle alkali-resistant material, preferably hard plastics.
6.3 Filtering device, of capacity 80 to 100 ml, internal diameter about 30 mm, with a bottom made of sintered glass, of porosity grade P 250 (porosity 0) in accordance with ISO 4793.
6.4 Weighing bottle, with a lid.
6.5 Constant temperature bath, capable of maintaining a temperature of (20 ± 0,2) °C.
7 Preparation of the test sample
If the pulp is in slush form, remove the water by suction taking precautions to avoid the loss of fine fibres, press between blotters, and dry at a maximum temperature of 60 °C.
If the pulp is in the form of wet sheets or rolls, dry the sample at a maximum temperature of 60 °C.
Tear the sample into pieces of size approximately 5 mm x 5 mm. lithe pulp is difficult to defibre, split the sample by means of tweezers (see Note 1).
Check that the pulp contains not more than 0,1 % ash (see Note 2). Before weighing, condition, the sample for not less than 20 mm in the atmosphere near the balance.BS ISO 699 pdf free download.