| 1. |
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| 2. |
- Kirabira, J. B., et al.
(författare)
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Properties of super-calendered (SC) paper filled with Mutaka kaolin, Uganda
- 2009
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Ingår i: Paper Technology. - 0306-252X. ; 50:1, s. 11-16
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Tidskriftsartikel (refereegranskat)abstract
- The experts from Makerere University (Mak) and the Royal Institute of Technology (KTH) evaluated three mineral deposits for the production of fireclay refractories in Uganda and found that the Mutaka kaolin deposit in Uganda is of extraordinary quality. Ten tons of raw kaolin was mined at the Mutaka deposit and shipped in a container to STFI-Packforsk, Sweden. The kaolin was first dry sieved in a shaker to remove sand, mica and large particles. The sieved material was mixed with fresh water to a dry content of 15% and hydrocycloned to separate and remove coarse particles. The paper machine trials were carried out at STFI-Packforsk on the EuroFEX paper machine. The results indicate that the potential of exploiting the Mutaka kaolin deposit for paper filling is high. Paper filled with Mutaka clay resulted in a slightly lower opacity, however, with an optimized particles size distribution, this could be improved.
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| 3. |
- Söderberg, Daniel, et al.
(författare)
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Comparison between forming strategies regarding their effect on paper properties
- 2013
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Ingår i: Pap. Conf. Trade Show, PaperCon. - 9781627489669 ; , s. 773-790
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Konferensbidrag (refereegranskat)abstract
- Extensive trials have been performed at the FEX machine at Innventia in Stockholm in order to determine fundamental relations between several process parameters. The goal with these has been to set up a matrix for further research aimed at the formation-retention-strength relations. The trials covered a total of five weeks at the FEX machine. Three of those were aimed at twin-wire forming and two at Fourdrinier forming. The results from these five weeks clearly show the difference between twin-wire and Fourdrinier forming. For the Fourdrinier case there is a linear relation between small-scale (0.3-3 mm) formation and large-scale (3-30 mm) formation, a higher value for the small-scale formation also gives a higher large-scale value. Furthermore, there is a direct relation between formation and retention; an increased retention gives a higher formation value. In addition, it is shown that a better formation gives a higher tensile index value. In comparison, it is shown that twin-wire forming does not have these clear relations. Hence, the twin-wire forming process seems to allow de-coupling of many of these relations.
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| 4. |
- Bäckström, M., et al.
(författare)
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Improved product quality and increased production capacity with impulse technology
- 2009
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Ingår i: Pulp & paper Canada. - 0316-4004. ; 110:2, s. 33-36
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Tidskriftsartikel (refereegranskat)abstract
- Impulse technology is a high-intensity web consolidation technique in which water is removed from a wet paper web by the combined action of mechanical pressure and intense heat. Pilot trials show that impulse technology is a feasible technique for the production of linerboard, paperboard and fine paper. Improved dewatering, combined with enhanced mechanical and surface properties, are benefits that can be obtained.
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| 5. |
- Czerniejewski, P., et al.
(författare)
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Molecular connectedness between self and none self-sustainable populations of Chinese mitten crab (Eriocheir sinensis, H. Milne Edwards, 1853) with focus to the Swedish Lake Vanern and the Oder and Vistula River in Poland
- 2012
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Ingår i: Hereditas. - : Springer Science and Business Media LLC. - 0018-0661. ; 149:2, s. 55-61
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Tidskriftsartikel (refereegranskat)abstract
- The highly invasive Chinese mitten crabs (Eriocheir sinensis) was studied to reveal the genetic relationship between three none self-sustainable population within the Polish Oder and Vistula River and Lake Vanern in Sweden. Crabs from self-sustainable populations were collected from the Elbe River (Germany), San Francisco Bay (USA) and five Asian river estuaries. Both parsimony and maximum likelihood analysis of the nuclear ITS 1 and ITS 2 regions reveal a similar topological pattern. The mitochondrial cytochrome c oxidase subunit I (COI) sequence had too low resolution to be informative. The Oder River haplotypes showed high sequence similarities to both the Elbe population and/or the native spawning areas in China. The Vistula River showed haplotypic similarity to specimens from the Oder River in Poland or the Elbe River. Also high sequence similarities were observed to the specimens from the Swedish Lake Vanern indicating to an origin from the River Elbe. Minor changes in evolutionary interpretation exist depending on how gaps are treated and the analytic method. There is a complex movement involving back and forth transoceanic colonization of the Chinese mitten crab haplotypes. Invasion routes are discussed in relation to ship transfer routes and canal waterways.
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| 6. |
- Drotz, M. K., et al.
(författare)
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Distribution patterns of the Chinese mitten crab (Eriocheir sinensis H. Milne Edwards, 1853) in Lake Vanern, Sweden
- 2012
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Ingår i: Aquatic Invasions. - : Regional Euro-Asian Biological Invasions Centre Oy (REABIC). - 1798-6540 .- 1818-5487. ; 7:2, s. 243-249
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Tidskriftsartikel (refereegranskat)abstract
- The catadromous Chinese mitten crab (CMC), Eriocheir sinensis is well known for its extensive invasion routes across the world. However, little is known about both adult and juvenile behaviour after they arrive to a new region. Particularly if the CMC has utilised freight ship ballast tanks as its invasion vector to new freshwater areas like coastal connected larger lakes. The Swedish Lake Vanern, Europe's third largest freshwater lake, offers a suitable study area since only a handful of CMC had been reported between its first record in 1954 and 2004. Hence, the increased catch of of CMC in the mid 2000s was unexpected and provided a rare opportunity to study the initial phase of a biological invasion. Fortunately local fishermen have traditionally, since the mid 1970s, utilised large stationary fish trap nets, evenly distributed from the inlet to the harbour of Lidkoping outward into the main part of the lake. During the peak occurrence in 2005 the traps captured CMC frequently for 90 days starting on August 10. Daily catch increased from September 19th to October 17th. Thereafter the number decreased until November 7th when the last crab was captured. Only one crab out of the 21 caught in the two traps furthest away from the harbour inlet was caught before September 19th. The number of caught CMC differed significantly between the trap nets. Almost half (48.4 %) of all CMC were caught in the two traps closest to the harbour inlet and 41.9% in the second trap-line, consisting of two traps 6 km from the harbour inlet. The remaining crabs were caught in the traps furthest away. Catch pattern from this unique invasion event is discussed in relation to CMC dispersal/migration, invading sample size, behavioural traits and catch efficiency of traps.
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| 7. |
- Drotz, M.K., et al.
(författare)
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Lake Vänern: A historical outline
- 2014
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Ingår i: Aquatic Ecosystem Health and Management. - : Michigan State University Press. - 1463-4988 .- 1539-4077. ; 17:4, s. 323-330
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Tidskriftsartikel (refereegranskat)abstract
- © 2014, Copyright © AEHMS. Although Lake Vänern is the largest freshwater reservoir in Western Europe, it remains relatively unknown to the scientific community outside of Scandinavia. Therefore, we aim to give a brief outline of the lake and its geological history, in particular the landscape transformation, resource utilization, pollution history, and environmental development of the region. The landscape around Lake Vänern was shaped into its present form during the latest glaciations some 10,000years ago. Large variation exists in its tributaries, with forest in the north and agricultural areas in the south. Human influence on the landscape was relatively small until the mid-18th century. Later, in the mid-19th century, the agriculture, forestry and shipping industries underwent large transformations as the towns around the lake grew and the economy changed. Development of fishing equipment, processes and changes in catching methods industrialized the fishing industry after mid-20th century. In the 1960s the lake was considered to be one of the most heavily mercury-polluted lakes in the world. After the passing of the first national environmental protection law in Sweden the lake turned into a success story: It has been declared to be healthy. However, old pollution still affects the fishing industry. With this new focus on the environment, the scientific community started to be interested in the lake. The lake has also played a very important role as the largest hydropower reservoir in Sweden. Here, too, the environmental question is in focus and the effects of the water regulation are still under debate. The result has been loss of biodiversity and an increased risk of an inflow of invasive species from international shipping. However, still many questions remain to be answered regarding the lake and effect of ongoing climate change on the sustainable development of the lake region.
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| 8. |
- Lindberg, Siv M, et al.
(författare)
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Tactile and instrumental characterization of tissue products
- 2015
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The feeling of softness and smoothness of paper tissue products is an important performance factor in the market place. In a series of panel tests, the relationship between instrumental measurements and perceived softness and smoothness was investigated. Samples of tissue base paper – napkin and toilet paper – were evaluated for surface roughness. The samples were placed on a hard, smooth glass substrate and the respondents used one finger to stroke along the sample surface. Instrumental measurement and characterization were performed using differentinstruments: Emtec TSA and Lena Softness Tester. The results divide the base paper material into product groups, but general mathematical relationships could be found between the test panel and the measurements when normalized in different ways. Measurements using the Lena produced the best correlation with the panel ratings because its principle resembled the method of the test panel most closely. However, a general relationship usingmaterial properties was shown to produce as good an estimator for the surface roughness as the results obtained with the Lena. This relationship consisted of the ratio between the plasticity and the elasticity of the tissue paper (in-plane properties), normalized for thickness. This suggests that those three material properties are fundamental to the perception of surface roughness as evaluated in this study. Using a trained haptic panel to evaluate test samples of similar grammage with variations in furnish and machine operation settings generated a good correlation to the TSA measurement (r=0.9). The panel was more susceptible to variation in furnish than variation in peak pressure, and this was particularly evident for samples evaluated on the Yankee side.
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| 9. |
- Lindblom, A. T., et al.
(författare)
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Improved paperboard properties with impulse technology
- 2006
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Ingår i: Professional Papermaking. - 1612-0485. ; :1, s. 53-57
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Tidskriftsartikel (refereegranskat)abstract
- Impulse technology is a high-intensity web consolidation process in which water is removed from a wet paper web by the combined action of mechanical pressure and high temperature. Pilot scale papermaking trials on STFI-Packforsk's research paper machine showed that impulse technology is a viable consolidation process for production of paperboard. Pilot trials showed significant improvements both in product quality and production efficiency. The surface of impulse pressed paperboard presented lower surface roughness and more uniform surface topographythan a reference board consolidated with wet pressing. This resulted in better print uniformity. The increase in surface smoothness was achieved without loss in total bulk, which preserved stiffness. Thus the relationship between surface roughness and bending stiffness was improved. The outgoing solids content after pressing increased at elevated temperatures, which provides a potential for increases in production capacity.
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| 10. |
- Martin, Andrew R., et al.
(författare)
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Energy analysis of impulse technology : research-scale experimental papermaking trials and simulations of industrial applications
- 2004
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Ingår i: Applied Thermal Engineering. - : Elsevier BV. - 1359-4311 .- 1873-5606. ; 24:16, s. 2411-2425
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Tidskriftsartikel (refereegranskat)abstract
- The impact of impulse technology on a system-wide level has been investigated in this study for non-integrated fine paper and linerboard mills. Impulse unit data were obtained from STFI's EuroFEX research paper machine and correlations were developed in order to predict performance (dewatering, electricity consumption) under commercial operating conditions. Mill analyses were conducted for different configurations (i.e. one or two impulse units with and without web preheating) operating with roll temperatures of 200-320 degreesC. Results show that the ingoing dryness to the dryer section can be increased within a wide span, from 7 to 27 percentage points depending upon the grade and operating parameters. Even though electricity consumption rises dramatically from the inductively heated rolls, overall fuel savings of up to 20% can be achieved with either one or two impulse units operating at 200 degreesC (external power plant efficiency assumed to be 45%). Impulse technology appears to be neutral in terms of production costs since increases in energy costs are expected to be counterbalanced by savings in feedstock materials and enhanced product quality. Estimates show that this technology can lead to substantial reductions in dryer section sizes for new installations or alternatively enhance productivity in existing paper machines.
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