August 2008 Pub Date : 2008-09-01 DOI: 10.32964/tj7.8.8

M. Carvalho, N. M. V. Carvalho, P. Loureiro

{"title":"Performance of a final hydrogen peroxide stage in the ECF bleaching of Eucalypt D0EOPD1 kraft pulps","authors":"M. Carvalho, N. M. V. Carvalho, P. Loureiro","doi":"10.32964/tj7.8.8","DOIUrl":"https://doi.org/10.32964/tj7.8.8","url":null,"abstract":"The compromise between reaching pulp target brightness and guaranteeing a high-quality bleached pulp is often difficult to manage because of the nature of the last chromophores present. This study reports the performance of either hydrogen peroxide or chlorine dioxide in a final bleaching stage applied to three eucalypt D0EOPD1 kraft pulps to reach a target ISO brightness of 90±0.5%. The D1 pulps had ISO brightness values of 84.7%, 86.9%, and 88.7% (pulps A, B, and C, respectively). The experimental results revealed that while chlorine dioxide charge was linearly correlated with D1 brightness, a much higher hydrogen peroxide charge was needed to bleach pulp A compared with pulps B and C. All P pulps had lower brightness reversion and better beatability than D2 pulps. In addition, we observed better physical and optical papermaking properties in P pulps (except for tear index for pulp A), although these pulps exhibited lower intrinsic viscosity. Therefore, the best choice for completing that particular ECF sequence is to push chlorine-dioxide bleaching action in D1 until at least 87% ISO brightness is reached, with the purpose of degrading phenolic units as much as possible, and then to advance with peroxide to boost brightness at the cost of quinone destruction.","PeriodicalId":179766,"journal":{"name":"August 2008","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114568772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 14

Influence of pulp refining on tissue paper properties 纸浆精制对生活用纸性能的影响

August 2008 Pub Date : 2008-09-01 DOI: 10.32964/tj7.8.27

J. Gigac, M. Fišerová

{"title":"Influence of pulp refining on tissue paper properties","authors":"J. Gigac, M. Fišerová","doi":"10.32964/tj7.8.27","DOIUrl":"https://doi.org/10.32964/tj7.8.27","url":null,"abstract":"We investigated the influence of refining conditions (refiner tackle type and specific edge load) on bulk softness, absorbency, tensile strength, and wet tensile strength of bleached pulp. Commercial elemental chlorine free (ECF) and totally chlorine free (TCF) bleached sulfite and kraft spruce, birch, and eucalypt pulps were used in this investigation. We found that refiner tackle type and specific edge load had a significant influence on the evaluated properties. Higher specific edge load when using a universal tackle increases softness and absorbency of hard-wood kraft pulps. The highest tensile index of bleached hardwood kraft and spruce sulfite pulps was achieved by fibrillation refining at low specific edge load (under 0.70 J/m). The wet tensile strength index of the tested pulps beaten to 30°SR increased 3-4 times. Pulp refining increases wet tensile index and reduces water absorbency of paper. Hardwood kraft pulps are suitable for production of tissue paper with high softness and absorbency. Spruce sulfite pulps are suitable to achieve high bulk softness and low tissue paper absorbency. Birch kraft pulp is a good choice if a higher tensile strength is required in addition to softness and absorbency. To manufacture tissue papers with deep embossing, softwood kraft pulp is required because of its high strength properties.","PeriodicalId":179766,"journal":{"name":"August 2008","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128355765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 28

Application of lipase to reduce ONP flotation rejects. Part 2. Reduction of flotation rejects 脂肪酶在减少ONP浮选废渣中的应用。第2部分。浮选废渣的还原

August 2008 Pub Date : 2008-09-01 DOI: 10.32964/tj7.8.3

Jeong-yong Ryu, B. Song, J. Song

引用次数: 0

Water release from fractionated stock suspension. Part 2. Effects of consistency, flocculants, shear, and order of mixing 从分馏浆料悬浮液中释放水。第2部分。稠度、絮凝剂、剪切和混合顺序的影响

August 2008 Pub Date : 2008-09-01 DOI: 10.32964/tj7.8.14

M. Hubbe, J. Heitmann, Cedric A. Cole

引用次数: 12

Flow dynamics of pulp fiber suspensions 纸浆纤维悬浮液的流动动力学

August 2008 Pub Date : 2008-08-01 DOI: 10.32964/tj7.8.20

Carla A. F. Ventura, F. Garcia, P. Ferreira, M. Rasteiro

引用次数: 24

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