| 1. |
- Ankerfors, Caroline, et al.
(författare)
-
Final Report for the Source-Efficient Paper and Board Making Research Programme Area
- 2018
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This is the final report for the Innventia/RISE Bioeconomy research programme area “Source-Efficient Paper and Board Making”, which was executed 2015-2017.The overall aim of the Source Efficient Paper and Board Making was to improve the resource efficiency in paper and board production. This was achieved by combining paper chemistry, paper physics and process technology. A particular goal was to reduce raw material consumption through the use of stronger materials or creation of bulk, which are needed to maintain bending stiffness and mechanical properties if the grammage is reduced. The work in the project has been carried out in laboratory scale and in pilot scale using the FEX pilot paper machine and the dynamic flow loop.
|
|
| 2. |
- Axelsson, Maria, et al.
(författare)
-
Estimation of the pore volume at the interface between paper web and press felt
- 2006
-
Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 21:3, s. 395-402
-
Tidskriftsartikel (refereegranskat)abstract
- A method for determining the water content at the interface between a press felt and a paper web has been developed. The water content was obtained by subtracting the estimated volume of the indented fibre web from the measured felt surface porosity of the press felt. The felt surface porosity was calculated from a topography map that was imaged with a Confocal Laser Scanning Microscope (CLSM) method. Here, the press felt was compressed against a smooth surface using a stress in the range of 0 to 10 MPa. Artefacts in the CLSM images were reduced using an image analysis method. The indentation of paper webs into the measured felt surface pores at different applied pressures was estimated using another image analysis method, simulating a rolling ball, with different radii of curvature for the different pressures and grammages, rolling over the felt surface. The ball radii were determined for a low and a high grammage web using the STFI-Packforsk Dewatering model. The method was evaluated in a case study with four press felts that had batt fibre diameters in a range between 22 and 78 μm. The indentation was calculated for webs with a low (15 g/m2) and a high grammage (105 g/m2), respectively. The evaluation showed that a considerable amount of porespace is available at the interface between the web and the felt. In most cases, the volume of the water-filled pores accounted for approximately 50% of the total surface porosity of the felt. Assuming a complete water saturation of the web/felt interface, approximately 10 g/m2 of water for the finest felt surface up to 40 g/m2 for the coarsest felt surface, could be located at the interface between the press felt and the paper web at a load of 10 MPa. This implies that a considerable amount of water is available for separation rewetting.
|
|
| 3. |
|
|
| 4. |
- Krochak, Paul, et al.
(författare)
-
The effect of felt-web structure interaction on press dryness variability
- 2019
-
Ingår i: International Paper Physics Conference 2019 : preprint proceedings. - : TAPPI Press. ; , s. 175-180
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Laboratory trials were carried out in order to clarify the interaction between felt and web structure and its impact on dryness variability. Oriented laboratory sheets of 80gsm and consisting of 100% never dried unbleached softwood kraft were prepared using a dynamic sheet former. The sheets were pressed with two different orientations; aligned with the felt aligned in the machine direction or with web aligned in the cross direction. The wet web samples were immediately transferred after pressing to a hot plate and dried under restraint. A bench-scale method was developed using near infrared (NIR) imaging in order to characterise the interaction between felt and web structure during pressing and drying. It was found that the average press dryness had a low dependence on interactions between web and felt structure. Moisture variability in the interaction layer was found to be highly dependent on the web fibre orientation relative to the press felt. High levels of moisture variability on the web surface were observed with large differences in fibre alignment. It was observed that moisture variations in the web surface after pressing continued through the drying process and further increased the total drying time of the paper web.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Landen, Jaren W., et al.
(författare)
-
Ponezumab in mild-to-moderate Alzheimer's disease : Randomized phase II PET-PIB study
- 2017
-
Ingår i: Alzheimer's and Dementia: Translational Research and Clinical Interventions. - : Wiley. - 2352-8737. ; 3:3, s. 393-401
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction The safety, pharmacokinetics, and effect on peripheral and central amyloid β (Aβ) of multiple doses of ponezumab, an anti-Aβ monoclonal antibody, were characterized in subjects with mild-to-moderate Alzheimer's disease treated for 1 year. Methods Subjects were aged ≥50 years with Mini–Mental State Examination scores 16 to 26. Cohort Q was randomized to ponezumab 10 mg/kg (n = 12) or placebo (n = 6) quarterly. Cohort M was randomized to a loading dose of ponezumab 10 mg/kg or placebo, followed by monthly ponezumab 7.5 mg/kg (n = 12) or placebo (n = 6), respectively. Results Ponezumab was generally well tolerated. Plasma concentrations increased dose dependently, but cerebrospinal fluid (CSF) penetration was low. Plasma Aβ increased dose dependently with ponezumab, but CSF biomarkers, brain amyloid burden, cognition, and function were not affected. Conclusions Both ponezumab dosing schedules were generally safe and well tolerated but did not alter CSF biomarkers, brain amyloid burden, or clinical outcomes.
|
|
| 8. |
|
|
| 9. |
- Malmberg, Filip, et al.
(författare)
-
Binarization of phase contrast volume images of fibrous materials
- 2009
-
Ingår i: Proceedings of the 4th International Conference on Computer Vision Theory and Applications. - : INSTICC Press. - 9789898111692 ; , s. 148-153
-
Konferensbidrag (refereegranskat)abstract
- In this paper, we present a method for segmenting phase contrast volume images of fibrous materials into fibre and background. The method is based on graph cut segmentation, and s tested on high resolution X-ray microtomography volume images of wood fibres in paper an composites. The new method produces better results than a standard method based on edge-preserving smoothing and hysteresis thresholding. The most important improvement is that the proposed method handles thick and collapsed fibres more accurately than previous methods.
|
|
| 10. |
|
|
| 11. |
- Malmberg, Filip, et al.
(författare)
-
Measurement of fibre-fibre contact in three-dimensional images of fibrous materials obtained from X-ray synchrotron microtomography
- 2011
-
Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 637:1, s. 143-148
-
Tidskriftsartikel (refereegranskat)abstract
- A series of wood-fibre mats was investigated using high-resolution phase-contrast microtomography at the beamline ID 19 of the European Synchrotron Radiation Facility in Grenoble, France. A method for data reduction to quantify the degree of fibre-fibre contact has been derived. The degree of fibre-fibre contact and bonding plays a fundamental role in the mechanical properties of cellulose-fibre mats, paper materials and cellulose-fibre composites. The proposed computerised automated method consists of two parts. First, fibre lumens are segmented using a watershed based method. This information is then used to identify fibre-fibre contacts in projections along the z-axis of the material. The method is tested on microtomographic images of mats made of wood pulp fibres, and is shown to successfully detect differences in the amount of fibre-fibre contact between samples. The degree of fibre-fibre contact correlates well with measured out-of-plane strength of the fibrous material.
|
|
| 12. |
- Rosén, Fredrik, et al.
(författare)
-
Estimation of fibre segment orientation using steerable filtering
- 2008
-
Ingår i: Paper Conference and Trade Show. - : TAPPI Press. ; , s. 1097-1144
-
Konferensbidrag (refereegranskat)abstract
- This work investigates the combined approach of sheet splitting by heat-seal pouch lamination and fibre segment orientation analysis by steerable filtering to characterize both in-plane and z-directional variations in local fibre orientation. The use of steerable filters allows the orientation of individual fibre segments to be estimated from a series of rotated versions of a two-dimensional fibre template. The performance of steerable filtering is compared to the widely spread method based on local gradients in the image. The results are based on a 60 g/m2 oriented handsheet formed with a dynamic sheet former from decrilled softwood kraft pulp. The sheet was split in 10 z-directional layers and the fibre orientation was estimated on a 10×—10 mm2 sub-area. Despite an observed visual difference in the 2D filter response between the two techniques, the result showed only small differences in the estimated fibre orientation angle and anisotropy. The effect of a decreased signal-to-noise ratio, due to e.g. fines and filler aggregates, was simulated by adding a statistical small-scale noise. The fibre orientation distribution estimated by steerable filtering was more or less unaffected by the introduced noise, whereas the estimation based on gradient filtering showed a decreased anisotropy by 35%. The results indicate that, for routine measurements of local fibre orientation, the more selective properties of steerable filtering do not motivate the more complex computations involved. For most cases, gradient filtering should give similar results. The use of steerable filtering is however recommended as an alternative for non-standard applications, e.g. in the presence of a high "noise" level or to minimize problems related to scanning imperfections. The theoretical possibility to use steerable filtering to determine fibre width distributions is also discussed.
|
|
| 13. |
|
|
| 14. |
- Vomhoff, Hannes, et al.
(författare)
-
Evaluation of the compressibility of kitchen towel
- 2016
-
Ingår i: Tappi Tissue 360 Forum.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The out-of-plane compressibility of kitchen towels is a very important product property in order to achieve a high absorption capacity. A method for the measurement of the compressibility was therefore developed. It allows the compression of a tissue sample by a defined pressure in the range between 0 and 30 kPa. The thickness of the sample is measured. Both single-ply base paper samples and fully converted multi-ply products can be evaluated. The measurement can be performed on both dry or wet samples. Multiple compressions of the samples can also be performed in order to evaluate the difference in plastic deformation as a result of consecutive compressions. Under normal conditions, the applied pressure is gradually increased from 0 to 30 kPa and then decreased back to 0 kPa. This procedure can then be repeated. The compressibility of the sample was evaluated in terms of a bulk versus applied pressure.The compressibility of different tissue grades was evaluated and compared. A clear difference in compressibility between standard DCT and structured tissue samples was observed. The first compression cycle lead to a considerable irreversible, plastic deformation of the sample. The plastic deformation decreased then considerably during the consecutive compression cycles. Wetting the samples lead to a considerable decrease in compressibility. The results allow interesting conclusions in terms of the influence of base sheet production process and the converting processes on the absorption properties.
|
|
| 15. |
- Östlund, Catherine, et al.
(författare)
-
Advanced image based measurement techniques for analysis of process variations
- 2016
-
Ingår i: Paper Conference and Trade Show (PaperCon 2016). - 9781510831193 ; , s. 871-878
-
Konferensbidrag (refereegranskat)abstract
- The Swedish research institute Innventia has taken a look into what the future needs will be for online measurements techniques in paper production. Discussions in a group consisting of experts from industry and academy, of paper and board production, measurement techniques, analysis methods and quality control systems resulted in a roadmap describing tomorrow’s needs of new applications of measurement techniques. The starting point was a vision of a high-resolution, multispectral online analysis of the complete produced area combined with new approaches for interpretation of measurements, to give better and more complete information of the paper production. One approach is to combine modern infrared (IR) imaging systems with data from the existing quality control systems in order to obtain the local grammage variation, to achieve more detailed information for optimisation of the process. The IR camera technique has been studied at the institute for 7 years, both in laboratory studies and at mills. Another online measurement technique that has been developed and studied is the online optical topography system OptiTopo. This gives information of the surface structure variation both in fine-scale and in large-scale. This instrument also gives valuable input in the quality control system. Examples from the two systems are shown.
|
|
| 16. |
- Östlund, Catherine, 1965-
(författare)
-
Analysis of Imaging Spectrometer Data with Lake Environment Applications
- 1999
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis the image processing and analysis aspects of imaging spectrometer (IS) data have been investigated for water and wetland applications. The Compact Airborne Spectrographic Imager (CASI) has been the main instrument in the evaluations. To fully benefit from the high spectral and spatial resolution data in the analysis phase, the preprocessing of data, is important and has been a focus of this thesis. To restore, improve and evaluate the data, the radiometric calibration, wavelength band positioning, noise and other radiometric anomalies, geometric calibration and atmospheric calibration have been studied. Existing methods have been evaluated, and new ones proposed, and the most appropriate methods applied to the data.On the image analysis aspects of hyperspectral data sets, spatial true physical structures in the images were studied using data compression and segmentation methods, and a new technique combining compression and colour transformation. The latter was shown to be a fast and objective method to visualise the spatial structures in a large data set.The usefulness of IS data in water quality applications was evaluated developing statistical relationships between image data and data collected in the field. A comprehensive in situ data set, collected along a transect in Lake Erken, Sweden, during a bloom of the cyanobacteria Gloeotrichia echinulata was used. It was found that a correlation of the image data to chlorophyll a and phaeophytine a could be established, but also that the preprocessing of images is important, and that the dynamic character of water is a complicating factor. Aquatic macrophytes in Lake Mälaren, Sweden, were classified. IS data was found to be powerful for these kinds of applications, but the analysis suffered from poor data.
|
|
| 17. |
|
|
| 18. |
- Östlund, Catherine
(författare)
-
Towards total production monitoring of basis weight and moisture
- 2018
-
Ingår i: PaperCon 2018. - : TAPPI. - 9781595102683 ; , s. 313-316
-
Konferensbidrag (refereegranskat)abstract
- Measurement methods using infrared (IR) camera techniques have been developed and evaluated, both in laboratorystudies, online on the FEX pilot paper machine, and at paper mills. The large advantage with the methods we developedfor applying the high-speed IR cameras on the paper machine is the ability to cover the whole width of the machine toview temperature changes over a longer period of time. The temperature changes can then be correlated to processvariations (i.e. moisture or material distribution) to obtain the local basis weight variation, to achieve more detailedinformation for an optimisation of the process.
|
|
