December 2008最新文献

Surface Mechanical Treatment of TMP Pulp Fibers Using Grit Material 磨粒材料对TMP纸浆纤维的表面机械处理

December 2008 Pub Date : 2009-01-01 DOI: 10.32964/tj7.12.4

P. Somboon, H. Paulapuro

{"title":"Surface Mechanical Treatment of TMP Pulp Fibers Using Grit Material","authors":"P. Somboon, H. Paulapuro","doi":"10.32964/tj7.12.4","DOIUrl":"https://doi.org/10.32964/tj7.12.4","url":null,"abstract":"The authors studied surface mechanical treatments of thermomechanical pulp fibers using a grit material after first-stage refining and the treatment’s impact on second-stage refining. The surface mechanical treatment was performed using an ultra-fine friction grinder. The grit size of the grinding stone, the intensity of treatment and the rotational speed were optimized to accomplish rapid development and minimization of pulp fiber shorten-ing. The second stage of refining was carried out using a wing defibrator operated under typical TMP refining conditions. Surface mechanical treatment using a grinding stone with a grit diameter of 297-420 µm, operated at a contact point of the stones and a high rotational speed of 1500 rpm, provided an efficient disruption of pulp fibers with minimized cutting. A promising degree of fiber cell wall fracture was obtained when the energy applied during disruption was approximately 20% of the total refiner energy consumption. During second stage refining the disrupted pulp developed freeness more quickly while requiring 37% less energy. Laboratory sheets showed no significant differences in properties between the disrupted and non-disrupted pulps at a given freeness.","PeriodicalId":308567,"journal":{"name":"December 2008","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125998401","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

Examining interrelationships between caliper, bending, and tensile stiffness of paper in testing validation 在测试验证中检查卡尺，弯曲和纸张拉伸刚度之间的相互关系

December 2008 Pub Date : 2009-01-01 DOI: 10.32964/tj7.12.17

C. Carson, R. Popil

引用次数: 7

Measuring the Bonding Ability Distribution of Fibers in Mechanical Pulps 机械纸浆中纤维粘结能力分布的测定

December 2008 Pub Date : 2009-01-01 DOI: 10.32964/tj7.12.26

S. Reyier, O. Ferritsius, O. Shagaev

{"title":"Measuring the Bonding Ability Distribution of Fibers in Mechanical Pulps","authors":"S. Reyier, O. Ferritsius, O. Shagaev","doi":"10.32964/tj7.12.26","DOIUrl":"https://doi.org/10.32964/tj7.12.26","url":null,"abstract":"Currently, the pulp and paper industry mainly uses average values of mechanical pulp properties to characterize fibers, while printing paper grammages keep decreasing, making every fiber more important for strength, surface, and structure properties. Because fibers are inhomogeneous, average values of the whole pulp may not be enough for proper fiber characterization. This paper reports results from the development of a method to measure the distribution of fiber bonding ability in mechanical pulps.\u0000 Fibers from two commercial TMPs were fractionated into five hydrocyclone streams, using a four-stage hydrocy-clone system. The fiber bonding ability of Bauer McNett fractions R16, P16/R30 and P30/R50 collected from each stream was analyzed. Five different methods of evaluating fiber bonding ability all showed that fibers were separat-ed in the hydrocyclones according to their bonding ability. \u0000 Long fiber handsheets of the highest bonding fibers had up to 2.5 times higher tensile strength for the P16/R30 fraction than handsheets from the lowest bonding fibers. We also found that both the degree of fibrillation and col-lapse resistance index (CRI) of the fibers obtained from optical measurements are sufficient to predict quite accu-rately the tensile strength of handsheets made from fiber fractions. Further, we propose how to describe the distri-bution in fiber bonding ability for mechanical pulps, by combining some of these five different methods. A method to calculate fracture toughness of long fiber handsheets based on acoustic emission is also illustrated. \u0000 A more rapid way to characterize fibers in mechanical pulps with respect to their bonding ability distribution needs to be developed in the future. It appears that it is time to move on from characterizing pulp suspensions and handsheet properties using conventional approaches based on average values.","PeriodicalId":308567,"journal":{"name":"December 2008","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129376593","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: 10

Influence of mechanical pulp fines on clay retention 机械浆细粒对粘土保留率的影响

December 2008 Pub Date : 2009-01-01 DOI: 10.32964/tj7.12.10

H. Liimatainen, T. Taipale, A. Haapala, J. Niinimäki

{"title":"Influence of mechanical pulp fines on clay retention","authors":"H. Liimatainen, T. Taipale, A. Haapala, J. Niinimäki","doi":"10.32964/tj7.12.10","DOIUrl":"https://doi.org/10.32964/tj7.12.10","url":null,"abstract":"We investigated deposition of clay filler on fibrillar and flake-like fines and long fibers of mechanical pulp to study the effects of the fines on filler retention. The role of different retention mechanisms was illustrated by comparing clay retention in deposition and filtration experiments. The amount of clay deposited varied significantly between the pulp fractions in the presence of polymeric flocculants. Cationic polyacrylamide (CPAM) promoted filler deposition on fines, especially flake-like fines, more than on long fibers. Presumably, this was due to the high surface area and surface charge density of fines, which increase their bonding strength with polymer chains. Polyethylene oxide (PEO) slightly increased the deposition of clay on fines but started to disperse the clay, and especially the fines, as the polymer dose increased. PEO releases small particles from the fines that exist as bundles or entanglements in the suspension. When the deposition-based retention mechanism and the filtration-based mechanism were compared, mechanical attachment of clay in the filter cake had a significant effect on its retention. Also, long fibers are better able to form a filter layer on the screen than fines, which in turn adsorb more filler through chemical interactions.","PeriodicalId":308567,"journal":{"name":"December 2008","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133641679","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: 2