Determination kappa number

The kappa number determination is applicable to all types and grades of semichemical, unbleached, and semi-bleached pulps obtained in yields under 60% and for pulps in yields of up to 70% if the pulp has been well screened prior to the test. Typical values for representative pulps are listed in Table 2.2.7. In... 

Berzins V (1965) A rapid procedure for the determination of kappa number Tappi 48 15-20 Berzins V (1966) Micro-kappa numbers Pulp Pap Mag Can 67 T206-T208 Bethge PO, Gran G, Ohlsson K-E (1952) Determination of lignin in chemical wood pulp I Principles and methods Sven Papperstidn 55 44-48 Bihkova A (1973) Verification of analytical methods for the determination of lignin in water Vodm Hospod 23(2) 44, Abstr Bull Inst Pap Chem 48 1245 Birkett MD, Gambino MJT (1989) Estimation of pulp kappa number with near-infrared spectroscopy Tappi J 72(9) 193-197... 

Srinivasa Rao Y, Shukla RN, Maheshwari S, Kulkarni AY, Jivendra Y (1983) Determination of permanganate and kappa number of pulp with high ash content. IPPTA 20(3) 55-56 Stewart CM, Foster OH, Cohen WE, Leslie RT, Watson AJ (1951) The selection and preparation of a reporducible wood sample for chemical studies. Appita 5 267- 311 Swan B (1965) Isolation of acid-soluble lignin from the Klason lignin determination. Sven Papperstidn 68 791-795... 

Osborne and Fern (1986) have presented detailed band assignments in the near-IR range, and Wetzel (1983) and William and Norris (1987) have summarized the salient points of near-IR spectroscopy. The latter authors emphasize applications for the agricultural and food industries. Birkett et al. (1989) have reported the successful kappa number determination of pulps using spectra in the near-IR range. 

Berzins V (1965) A rapid procedure for the determination of kappa number. Tappi 48 15-20... 

The long warm up period contributes little to the H factor because reaetion kinetics dictate that the rate of delignification more than doubles for every 10°C rise in temperature. The equation is useful as it allows mill operators to determine when to stop the cook even though the operating temperatures have differed from normal, for example because of fluctuations in steam supply to the digesters. Operators merely have to ensure that they cook to a constant H factor (Figure 13.12b), as pulps eooked to the same H factor have essentially the same properties, i.e. yield, lignin eontent (kappa number). Results can be compared provided the initial alkali and sulphidity eoneentrations are the same. 

This experiment was carried out in accord with an established procedure (5). Unbleached softwood kraft pulp (USKP) from Douglas fir was obtained from Pope and Talbot (Halsey, Oregon) and washed with deionized water until the effluent was neutral and colorless. USKP (8.0 g, oven-dried) was autoclaved at 121 °C for 40 min, cooled down at room temperature and then inoculated with 3 mL of P. cinnabarinus spore suspension (ca. 9 x lO spores/mL). The moisture content of the culture was adjusted to 80% and the culture was incubated statically at 30 °C. After a pre-determined incubation time, mycelia were carefully removed fiom pulp. Hie treated pulp was analyzed for kappa number. 

The kappa number was determined in accordance with TAPPI Test Methods (1994-1995) T236 om-85. At least two replicates were performed for each sample. 

By far the most commonly used oxidation method is the corrected permanganate number test (30) in which the number of mL of 0.1 AT KMn04 consumed by 1 g of oven-dried pulp under specified conditions (kappa number) is determined (TAPPI Historical Method T236 hm-85). Typical kappa numbers for representative pulps are shown in Table 3. 

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