Kappa Number → Lignin
Estimate the residual lignin content of a cellulose pulp from the Kappa number, Lignin% ≈ Kappa · 0.15. The Kappa number measures the pulp's permanganate consumption, proportional to the lignin remaining after cooking — the higher the Kappa, the more lignin (dark color, stiffer fibers) remained. It is the main control of delignification, defining the bleaching load needed. Enter the Kappa number.
Result
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Número Kappa → lignina
Depois do cozimento, a polpa ainda contém lignina residual — quanto menos, mais branca e fácil de branquear será. Mas medir lignina diretamente é trabalhoso; a indústria usa um teste rápido e engenhoso: o número Kappa, que mede quanto permanganato de potássio (um oxidante) a polpa consome em condições padronizadas. Como o permanganato reage com a lignina, o consumo é proporcional à lignina presente — e a relação prática é Lignina% ≈ Kappa · 0,15. Um Kappa de 20 indica ~3% de lignina. O número Kappa é o termômetro da deslignificação: define quando parar o cozimento (Kappa muito baixo significa cozinhar demais, degradando as fibras; muito alto, lignina demais para o branqueamento dar conta) e dimensiona a carga de reagentes de branqueamento (cloro, dióxido de cloro, peróxido, ozônio) necessária para chegar à alvura desejada. Polpas para papel kraft de embalagem (sacos, papelão) ficam com Kappa alto (não precisam ser brancas); polpas para papéis de impressão são cozidas e branqueadas a Kappa baixíssimo. Informe o número Kappa.
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The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.