September 2009最新文献

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Modeling of bagginess due to storage of paper reels with ridges 带脊纸卷储存时的松垮性建模
September 2009 Pub Date : 2009-10-01 DOI: 10.32964/tj8.9.18
C. Land, Lennart Stolpe, L. Beghello
{"title":"Modeling of bagginess due to storage of paper reels with ridges","authors":"C. Land, Lennart Stolpe, L. Beghello","doi":"10.32964/tj8.9.18","DOIUrl":"https://doi.org/10.32964/tj8.9.18","url":null,"abstract":"Paper is subjected to stress relaxation during storage in reels. Ridges in the paper reel subject the paper in the ridge to a higher strain than the paper adjacent to the ridge. The strain difference can become a permanent strain difference, resulting in a baggy web after unwinding. Researchers used a geometrical model based on stress relaxation test results to determine when the bagginess is substantial enough to cause problems. The results showed that runnability problems will appear if the ridge is about 1–2 mm high. This applies for a reel with a diameter of 1.2–1.8 m stored for 1 week.","PeriodicalId":423156,"journal":{"name":"September 2009","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115579976","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: 1
Retention of PCC and GCC fillers on chemical pulp fines surfaces PCC和GCC填料在化学纸浆细表面的保留
September 2009 Pub Date : 2009-10-01 DOI: 10.32964/tj8.9.38
H. Liimatainen, A. Haapala, J. Niinimaki
{"title":"Retention of PCC and GCC fillers on chemical pulp fines surfaces","authors":"H. Liimatainen, A. Haapala, J. Niinimaki","doi":"10.32964/tj8.9.38","DOIUrl":"https://doi.org/10.32964/tj8.9.38","url":null,"abstract":"We studied the retention of precipitated and ground calcium carbonate fillers (PCC and GCC, respectively) on chemical pulp fines surfaces by measuring the amounts of adsorbed fillers on the surfaces of the primary and secondary fines and long fiber fractions of eucalyptus pulp in the presence of a polymeric flocculant \u0000(CPAM). The mechanism of filler particle retention and adsorption on fines surfaces was clarified in more detail by measuring the kinetics of PCC adsorption in the absence of flocculant. The results showed that the primary and secondary fines fractions adsorb more PCC and GCC fillers on their surfaces (per gram of pulp) than the long fiber frac-tion in both the absence and presence of flocculants. In the absence of flocculants the adsorption of PCC both on fines and on the fiber fractions follows Langmuir kinetics, implying that the adsorption is in dynamic equilibrium with filler detachment and the maximum possible amount of filler that can be adsorbed corresponds to the monolayer coverage of particles. At low flocculant doses, i.e., doses that are relevant to papermaking, the fines fractions adsorb significantly more filler than the fiber fractions. In this case, their high surface charge density promotes CPAM adsorption onto fines, which in turn increases the adsorption of fillers to the fines surfaces through polymer bridges.","PeriodicalId":423156,"journal":{"name":"September 2009","volume":"71 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121003704","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: 8
Decreasing specific energy of thermomechanical pulps from reduction of raw materials variability 通过减少原料的可变性来降低热机械纸浆的比能
September 2009 Pub Date : 2009-10-01 DOI: 10.32964/tj8.9.23
E. Dundar, L. Laperrière, F. Ding
{"title":"Decreasing specific energy of thermomechanical pulps from reduction of raw materials variability","authors":"E. Dundar, L. Laperrière, F. Ding","doi":"10.32964/tj8.9.23","DOIUrl":"https://doi.org/10.32964/tj8.9.23","url":null,"abstract":"Wood chip characteristics including species, basic and bulk densities, moisture content, freshness, bark content, and size distribution strongly influence the specific energy consumption (SEC) of thermomechanical pulping. Changes in these characteristics lead to variations in the mass flow rate of the chips fed into the refiner, causing SEC variations. In a typical mill with normal operating conditions, up to 30% of the disturbances in the pulp-ing process can be explained by chip variations. For this paper, researchers used an online measurement system, CMSE (chip management system, extended version), to monitor chip characteristics to study the effect of chip variability on SEC. Models and simulations were built from pilot experiments and results were validated by mill trials.","PeriodicalId":423156,"journal":{"name":"September 2009","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132068414","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: 6
3-D computational simulation of paper handsheet structure and prediction of apparent density 纸质手抄结构三维计算模拟及表观密度预测
September 2009 Pub Date : 2009-10-01 DOI: 10.32964/tj8.9.10
M. Rueff, R. Vincent, C. Voillot
{"title":"3-D computational simulation of paper handsheet structure and prediction of apparent density","authors":"M. Rueff, R. Vincent, C. Voillot","doi":"10.32964/tj8.9.10","DOIUrl":"https://doi.org/10.32964/tj8.9.10","url":null,"abstract":"To obtain a better understanding of the influence of fiber morphology on paper properties, a novel 3-D computational simulator of paper structure was developed and validated by experimental work. Depending on the wood species, the dimensions of the fibers may vary by a factor of two or three, which directly influences paper structure and properties. Using known fiber size distributions, the model creates virtual handsheets made of these pulps that can be visualized, manipulated, and qualitatively and quantitatively compared to real handsheets. For a given basis weight, the model calculates the number of fibers in the sample and the main textural properties: thick-ness, apparent density, porosity, and roughness. It also computes the relative bonded area and the apparent specific surface, which are important factors for assessing mechanical or transport properties. This simulator can be used to predict, in a very short time, the variation of a property as a function of changes in one morphological parameter such as fiber length.\u0000This paper presents the main principles of the simulation and the results for one global textural property, apparent density. A prediction of tensile breaking strength will be presented in a subsequent paper.","PeriodicalId":423156,"journal":{"name":"September 2009","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127645479","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: 5
Pre-extraction of hemicelluloses and subsequent kraft pulping Part II: Acid- and autohydrolysis 半纤维素的预萃取和随后的硫酸盐制浆。第2部分:酸水解和自水解
September 2009 Pub Date : 2009-09-01 DOI: 10.32964/tj8.9.30
W. W. Al-Dajani, U. Tschirner, T. Jensen
{"title":"Pre-extraction of hemicelluloses and subsequent kraft pulping Part II: Acid- and autohydrolysis","authors":"W. W. Al-Dajani, U. Tschirner, T. Jensen","doi":"10.32964/tj8.9.30","DOIUrl":"https://doi.org/10.32964/tj8.9.30","url":null,"abstract":"Aspen wood chip samples were subjected to hot water treatments (autohydrolysis) with and without sulfuric acid to extract hemicelluloses. A liquor-to-wood ratio of 4:1 was used at temperatures from 130° to 210°C \u0000and H2SO4 concentrations in the range from 0% to 1% (w/v), with treatment times up to 4.5 h. Researchers analyzed wood residues and their corresponding hydrolysates, and determined the most suitable conditions for the extraction. Additional information on the suitability of wood residues for pulping purposes is also considered.","PeriodicalId":423156,"journal":{"name":"September 2009","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125504313","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: 53
Breakup mechanisms of brittle deposits in kraft recovery boilers – a fundamental study 硫酸盐回收锅炉脆性沉积物破碎机理的基础研究
September 2009 Pub Date : 2009-09-01 DOI: 10.32964/tj8.9.4
Ameya Pophali, M. Eslamian, A. Kaliazine, M. Bussmann, H. Tran
{"title":"Breakup mechanisms of brittle deposits in kraft recovery boilers – a fundamental study","authors":"Ameya Pophali, M. Eslamian, A. Kaliazine, M. Bussmann, H. Tran","doi":"10.32964/tj8.9.4","DOIUrl":"https://doi.org/10.32964/tj8.9.4","url":null,"abstract":"The breakup mechanism of brittle deposits removed by sootblower jets in kraft recovery boilers was studied in the laboratory by blasting model deposits made of gypsum with an air jet, and documenting the process using high-speed cameras. The results show that thin brittle deposits fail quickly, as an axial crack forms and propagates through the sample. In thicker deposits, the jet first drills a small hole in the deposit. As the hole grows wider and deeper, an axial crack forms, allowing the air jet to penetrate the deposit. This causes the front side of the deposit to split, and subsequently the back side of the deposit to be blown apart. The mechanism implies that in order for a sootblower jet to remove a brittle deposit effectively, it must be able to drill a deep hole and form axial cracks in the deposit within the short blowing time.","PeriodicalId":423156,"journal":{"name":"September 2009","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127621870","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: 7
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