January 2008最新文献

Optimization of ECF bleaching of kraft pulp: Part 1. Optimal bleaching of hardwood pulps made with different alkali charges 硫酸盐浆ECF漂白工艺的优化:第一部分。不同碱用量对硬木纸浆漂白效果的影响

January 2008 Pub Date : 2008-02-01 DOI: 10.32964/tj7.1.4

T. McDonough, S. Uno, A. Rudie, C. Courchene

{"title":"Optimization of ECF bleaching of kraft pulp: Part 1. Optimal bleaching of hardwood pulps made with different alkali charges","authors":"T. McDonough, S. Uno, A. Rudie, C. Courchene","doi":"10.32964/tj7.1.4","DOIUrl":"https://doi.org/10.32964/tj7.1.4","url":null,"abstract":"In an earlier modeling study, we showed that when a hardwood kraft pulp is bleached in the D0(EO)D1ED2 sequence with a D0 stage kappa factor of 0.20, the brightness of the pulp emerging from the D2 stage can be accurately predicted from the brightness of the pulp entering that stage. The entering brightness, in turn, is a well-defined function of the ratio of the D1 stage ClO2 charge to the (EO) stage kappa number. In the present study, we use the results of pulping and bleaching experiments on southern U.S. red oak chips to extend the model to account for the effect of changing the D0 kappa factor and use it to assess the effect of digester alkali charge on pulp bleachability. We also show how this approach can be used to minimize the total ClO2 requirement for any desired final brightness and to optimize the allocation of ClO2 to the three D stages of the D(EO)DED sequence or the two D stages of the D(EO)D sequence. Among the conclusions resulting from application of the model are that the combination of high effective alkali and high D0 kappa factor gives pulp with a higher final brightness ceiling than any other combination, but that for brightness targets of 91 or lower, the combination of low effective alkali and low kappa fac-tor is the most economical.","PeriodicalId":356518,"journal":{"name":"January 2008","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114063100","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: 3

Characteristics of black liquor sprays from gas-assisted atomizers in high-temperature environments 高温环境下气体辅助雾化器黑液喷雾特性研究

January 2008 Pub Date : 2008-02-01 DOI: 10.32964/tj7.1.19

Andrew J. Mackrory, D. Tree, L. Baxter

引用次数: 1

Measurement of wet fiber flexibility of mechanical pulp fibers by confocal laser scanning microscopy 用激光共聚焦扫描显微镜测量机械纸浆纤维的湿纤维柔韧性

January 2008 Pub Date : 2008-02-01 DOI: 10.32964/tj7.1.25

Dongbo Yan, Kecheng Li, Yajun Zhou

引用次数: 2

Application of imaging reflectometry to studies of print mottle on commercially printed coated papers 成像反射法在铜版纸印刷斑纹研究中的应用

January 2008 Pub Date : 2008-02-01 DOI: 10.32964/tj7.1.11

J. Preston, A. G. Hiorns, Nick Elton, G. Strom

{"title":"Application of imaging reflectometry to studies of print mottle on commercially printed coated papers","authors":"J. Preston, A. G. Hiorns, Nick Elton, G. Strom","doi":"10.32964/tj7.1.11","DOIUrl":"https://doi.org/10.32964/tj7.1.11","url":null,"abstract":"It has been well documented that homogeneous coating structures are necessary for obtaining good, mottle-free printed papers. Methods such as mercury intrusion porosimetry are widely used in the paper industry, but will deliver a bulk porosity measure, which contains contributions from both the surface layers and the bulk of the coating. One way of assessing the surface porosity is to measure its effective refractive index (RI) because the RI measured is a combination of the material RI and air.\u0000In this work three papers coated with PCC, kaolin, and GCC were RI mapped using an imaging reflectometer. The data were then treated with a mathematical transform in order to be able to quantify the degree of variation that was taking place at each length scale. These results were then compared to the print mottle, which was evident after both lab scale printing and full scale sheetfed printing of the pilot coated papers. \u0000The commercial mottle was quantified both visually and using image analysis and there was a reasonable correlation between these two methods. In the halftone printed area, the propensity for mottle correlated with the degree of porosity variation of the coating. However, the rankings for the full tone print areas better correlated with the short time water absorbency of the coatings. FFT band-pass analysis confirmed that the same spatial distribution of unevenness occurred in the basepaper, coating layer and printed areas.","PeriodicalId":356518,"journal":{"name":"January 2008","volume":"247 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122120650","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: 24