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TAPPI T 236 Kappa number






Kappa number of pulp


TAPPI T 236 applies to the determination of the relative hardness, bleachability, or degree of delignification of pulp. It may be used for all types and grades of chemical and semichemical, unbleached and semibleached pulps obtained in yields under 60%. This method may also be used for pulps obtained in yields up to 70%, provided the pulp has been well screened. The kappa number is the volume (in milliliters) of 0.1N potassium permanganate solution consumed by one gram of moisture-free pulp under the conditions specified in this method. The results are corrected to 50% consumption of the permanganate added.


The equivalent of 15 grams oven-dried sample is required at a minimum to perform proper testing of the sample. The amount of sample used may need to be increased to ensure that 50% of the permanganate is consumed by the test specimen. Test is run as a single determination, per the method. Duplicate determination can be done at additional cost if requested by the client. If sample is limited, a test can be run via TAPPI UM 246 Micro-Kappa number where the sample size can be limited to three grams.

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IPS cannot sell or otherwise provide standards, specifications, or test procedures to third parties.