REVIEW: USE OF OPTICAL BRIGHTENING AGENTS (OBAs) IN THE PRODUCTION OF PAPER CONTAINING HIGH-YIELD PULPS

He, Shi; Liu, Hongbin; Ni, Yonghao; Yuan, Zhenhong; Zou, Xuejun; Zhou, Yajun

doi:10.15376/biores.7.2.2582-2591

Cited by 20 publications

(22 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Holmberg (1999) menciona que diversos alvejantes podem ser oxidados por substâncias oxidantes presentes na polpa. A lignina, por exemplo, tem forte afinidade com radiação UV, o que resulta numa competição com o alvejante (PELISSARI et al, 2003;SHI et al, 2012). O mesmo ocorre com a presença de dióxido de titânio encontrado em pastas de alto rendimento (FERREIRA, 2004;SHI et al, 2012 (HOLMBERG, 1999).…”

Section: Introductionunclassified

Efeitos da sequência de branqueamento na ação de alvejantes óticos em celulose kraft de eucalipto

Manfredi

Colodette

Oliveira

et al. 2014

CERNE

View full text Add to dashboard Cite

RESUMO:Durante o processo de branqueamento a celulose é tratada com reagentes químicos que, ao se tornarem resíduos na polpa, podem interferir na ação dos alvejantes óticos. Diferentes sequências de branqueamento podem produzir polpas com o mesmo grau de alvura, mas com potenciais diferentes para incremento da brancura por meio da aplicação de alvejantes óticos. Neste trabalho, objetivou-se avaliar a influência da sequência de branqueamento da celulose na eficiência de alvejantes óticos dos tipos dissulfonados e tetrassulfonados. Foram utilizadas polpas kraft de eucalipto branqueadas por quatros sequências de branqueamento em três níveis de alvura. Para cada sequência de branqueamento foi gerado um modelo matemático predizendo a brancura final da polpa em função da alvura inicial e carga (quantidade de reagente) de alvejante aplicada. Foi constatado que a presença de resíduos organoclorados na celulose reduz a eficiência dos alvejantes. Sequências que utilizam menor carga de dióxido de cloro possibilitam maiores ganhos na brancura com a aplicação de alvejantes óticos. A substituição de um estágio final de branqueamento com dióxido de cloro por um estágio com peróxido de hidrogênio aumentou a eficiência dos alvejantes.Palavras-chave: alvejante ótico, branqueamento, celulose de eucalipto. EFFECTS OF THE BLEACHING SEQUENCE ON THE OPTICAL BRIGHTENERS ACTION IN EUCALYPTUS KRAFT PULP INTRODUÇÃOAlvura e brancura são propriedades da celulose que expressam o quanto branco a celulose se apresenta. A alvura é calculada baseada na refletância apenas de radiação nos comprimentos de onda próximos à 457nm (faixa do azul), enquanto que a brancura considera a refletância em toda a região do visível, que vai de 400nm à 700nm (JORDAN, 1996).A alvura é muito utilizada pelas indústrias de celulose. Por se tratar de um material amarelado, a celulose absorve radiação violeta e azul-violeta (LEONARDI, 1990). Ao remover os compostos que conferem a coloração amarelada, o processo de branqueamento aumenta a reflexão de radiação na faixa do azul, o que torna a análise de alvura eficiente para o controle do processo de branqueamento (DENCE;REEVE, 1996).As indústrias de papel necessitam de um controle mais rigoroso das características óticas do seu produto. Portanto, utilizam a análise de brancura, que ao avaliar a reflectância em toda a região do visível, expressa um valor para o branco mais coerente com a percepção do olho humano.Para atingir elevado grau de brancura, a celulose pode ser tratada com alvejante ótico. Segundo Pelissari et al. (2003), dependendo da composição da polpa, os alvejantes óticos são responsáveis por 25 a 35 % da brancura final do papel. O branqueamento ótico é considerado como o

show abstract

Section: Introductionunclassified

Efeitos da sequência de branqueamento na ação de alvejantes óticos em celulose kraft de eucalipto

Manfredi

Colodette

Oliveira

et al. 2014

CERNE

View full text Add to dashboard Cite

show abstract

“…The initial fluorescence index of the surface-sized paper was about 49%, and the fluorescence index of the handsheet decreased to 28% only after disintegration, indicating that disintegration led to 41% FWA reduction. This is because a large amount of starch and T-FWA was detached from the surface-sized paper owing to shear force and dissolved into the aqueous phase (Shi et al 2012;Lee et al 2019). However, there was no further FWA reduction when cellulase treatment was performed after disintegration.…”

Section: Fwa Removal From Two Model Papers Using Cellulasementioning

confidence: 99%

Effect of enzyme type on the control of fluorescent whitening agents during recycling

Lee

Kim

et al. 2020

BioRes

View full text Add to dashboard Cite

The goal of this study was to develop an eco-friendly removal technology for fluorescent whitening agents (FWAs) using enzymes suitable for each type of FWA. Internally treated paper with internal FWA (D-FWA) and surface-sized paper with surface-sizing FWA (T-FWA) were made as model papers in a laboratory. The enzymatic treatments were applied to the stock prepared using these model papers by disintegration. Cellulase and (alpha-) amylase treatments were performed at 50 °C under the conditions of pH 3 to 4 and pH 7 to 8, respectively. After disintegration and enzymatic treatments, handsheets were made, and the fluorescence index and FWA reduction of these handsheets were determined for evaluating FWA removal during recycling. Because D-FWA gets strongly attached to cellulosic fibers, it could not be easily separated from the internally treated paper by disintegration. Up to 8.1% of D-FWA was removed by enzymatic treatment with high-activity cellulase. Amylase could not separate D-FWA from cellulosic fibers. In the case of T-FWA, ca. 41% was separated by disintegration, and an additional 24% was detached from surface-sized papers by high-activity amylase treatment. Therefore, cellulase was effective in removing internal FWA (D-FWA), and amylase was required for removing surface-sizing FWA (T-FWA) during recycling.

show abstract

“…This study also illustrates the use of a statistical tool to design the coating experiments and to identify the most important factors to be considered for improving the paper printability. A comparison of HCS and SB coatings was also explored, discussing their influence on the whiteness of paper, given that the interaction between cationic polymers and OBAs, generally anionic, has been pointed out as a major cause of fluorescence quenching (Shi et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Synergetic effect of cationic starch (ether/ester) and Pluronics for improving inkjet printing quality of office papers

et al. 2021

View full text Add to dashboard Cite

Improving the printability of paper is still a relevant challenge, despite the fast development of digital communications.While it is well-known that cationic starches enhance ink density, their commercial paper-grade forms are limited to ethers with low degree of substitution. This work addresses the underexplored potential of highly substituted cationic starch for paper coating and its combination with tri-block polymers, namely Pluronics (P123 and F127), taking advantage of their supramolecular interactions with amylose chains. For that purpose, cationic starch ether and ester (starch betainate), both with a degree of substitution of 0.3, were synthesized by alkaline etherification and by transesterification, respectively. Paper without any surface treatment was subjected to one-side bar coating with suspensions encompassing those products and Pluronics, besides other common components. Black, cyan, yellow and magenta inks were printed on all coated papers through an inkjet printer. Key properties of printing quality such as the gamut area, gamut volume, optical density, print-through, inter-color bleed and circularity were measured in a controlled temperature-humidity environment. For instance, a formulation with cationic starch (ether/ester) and P123 improved the gamut area by 16-18% in comparison to native starch-coated paper sheets. Interestingly, the individual assessment of each component showed that cationic starch ether, starch betainate and P123 only improved the gamut area by 5.6%, 8.9% and 6.8%, respectively. Finally, but not less importantly, starch betainate was found to quench optical brightening agents to a lesser extent than cationic starch ethers.

show abstract

REVIEW: USE OF OPTICAL BRIGHTENING AGENTS (OBAs) IN THE PRODUCTION OF PAPER CONTAINING HIGH-YIELD PULPS

Cited by 20 publications

References 5 publications

Efeitos da sequência de branqueamento na ação de alvejantes óticos em celulose kraft de eucalipto

Efeitos da sequência de branqueamento na ação de alvejantes óticos em celulose kraft de eucalipto

Effect of enzyme type on the control of fluorescent whitening agents during recycling

Synergetic effect of cationic starch (ether/ester) and Pluronics for improving inkjet printing quality of office papers

Contact Info

Product

Resources

About