A Correlation between the kappa number and the Ventorim index in the bleaching process

Vitor Hideyoshi Hayashida Ribeiro; Evelyn Eduarda Gil dos Santos; Fabiana Clara Cezar Alves; Marianne Vitória Gil dos Santos; Higor Rogério Favarim; Gustavo Ventorim

doi:10.53661/1806-9088202549263846

A Correlation between the kappa number and the Ventorim index in the bleaching process

Authors

Vitor Hideyoshi Hayashida Ribeiro Universidade Estadual Paulista “Julio de Mesquita Filho”, Graduando em Engenharia Industrial - Madeira, Itapeva, São Paulo, Brasil https://orcid.org/0009-0006-6553-9447
Evelyn Eduarda Gil dos Santos ETEC Dr. Demétrio Azevedo Junior, Técnico em Química, Itapeva, São Paulo, Brasil https://orcid.org/0009-0006-7413-5495
Fabiana Clara Cezar Alves ETEC Dr. Demétrio Azevedo Junior, Técnico em Química, Itapeva, São Paulo, Brasil https://orcid.org/0009-0007-4910-7684
Marianne Vitória Gil dos Santos ETEC Dr. Demétrio Azevedo Junior, Técnico em Química, Itapeva, São Paulo, Brasil https://orcid.org/0009-0009-7772-0528
Higor Rogério Favarim Universidade Estadual Paulista “Julio de Mesquita Filho”, Departamento de Ciências e Tecnologia, Instituto de Ciências e Engenharia, Itapeva, São Paulo, Brasil https://orcid.org/0000-0002-8936-9319
Gustavo Ventorim Universidade Estadual Paulista “Julio de Mesquita Filho”, Departamento de Ciências e Tecnologia, Instituto de Ciências e Engenharia, Itapeva, São Paulo, Brasil https://orcid.org/0000-0001-9238-4141

DOI:

https://doi.org/10.53661/1806-9088202549263846

Keywords:

Bleaching, Kappa number, Ventorim bleaching index

Abstract

The determination of the kappa number in the bleaching process is typically conducted with a pulp quantity between 3 and 4 grams, allowing for the calculation of values above four. However, after the oxidative extraction stage with hydrogen peroxide, the pulp presents a kappa number lower than this value. Therefore, the present study proposes a new method for determining the kappa number by creating the Ventorim bleaching index, which avoids the inconveniences associated with traditional kappa number analysis. For this study, industrial oxygen-delignified pulp was used. Four different ECF bleaching sequences were performed: OD(E+P)DD, OAD(E+P)DP, OADEDP, and OAEDP, along with the determination of the kappa number and the Ventorim bleaching index. The Ventorim index was based on the four chlorine-free bleaching sequences (ECF), all of which achieved a final brightness of 90% ISO, with very similar R² values and linear regressions. Consequently, a single equation was generated using all the data: Y=0.7202x+0.1464. This unified approach simplifies the analysis and broadens the applicability of the Ventorim bleaching index in the pulp and paper industry.

Keywords: Bleaching; Kappa number; Ventorim bleaching index

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Published

2025-02-06

How to Cite

Ribeiro, V. H. H., Santos, E. E. G. dos, Alves, F. C. C., Santos, M. V. G. dos, Favarim, H. R., & Ventorim, G. (2025). A Correlation between the kappa number and the Ventorim index in the bleaching process. Revista Árvore, 49(1). https://doi.org/10.53661/1806-9088202549263846

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Issue

Revista Árvore, Viçosa-MG, v.49, 2025

Section

Wood Technology and Utilization of Forest Products

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All authors agreed to submit the work to Revista Árvore and granted the exclusive license to publish the article. The authors affirm that it is an original work and has not been previously published elsewhere. The scientific content and opinions expressed in the article are the sole responsibility of the authors and reflect their opinions, not necessarily representing the opinions of the editorial board of Revista Árvore or of the Society of Forest Investigations (SIF).