miun.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Holmvall, Martin
Publications (10 of 12) Show all publications
Uesaka, T., Wiklund, H. & Holmvall, M. (2012). Fluid-Structure Interactions in Random Fibre Networks. Paper presented at ECCOMAS (European Congress of Computational Methods for Applied Sciences).
Open this publication in new window or tab >>Fluid-Structure Interactions in Random Fibre Networks
2012 (English)Conference paper, Oral presentation with published abstract (Refereed)
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:miun:diva-18026 (URN)
Conference
ECCOMAS (European Congress of Computational Methods for Applied Sciences)
Available from: 2012-12-20 Created: 2012-12-20 Last updated: 2013-01-16Bibliographically approved
Holmvall, M., Drolet, F., Uesaka, T. & Lindström, S. (2011). Micro-fluidics in printing nip - Liquid transfer on random fibre network surface. In: Progress in Paper Physics Seminar. Paper presented at Progress in Paper Physics Seminar in Graz, Austria. Graz, Austria: Verlag der Technischen Universität Graz
Open this publication in new window or tab >>Micro-fluidics in printing nip - Liquid transfer on random fibre network surface
2011 (English)In: Progress in Paper Physics Seminar, Graz, Austria: Verlag der Technischen Universität Graz , 2011Conference paper, Published paper (Other academic)
Place, publisher, year, edition, pages
Graz, Austria: Verlag der Technischen Universität Graz, 2011
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:miun:diva-15451 (URN)
Conference
Progress in Paper Physics Seminar in Graz, Austria
Available from: 2011-12-19 Created: 2011-12-19 Last updated: 2011-12-20Bibliographically approved
Holmvall, M., Lindström, S. & Uesaka, T. (2011). Simulation of two-phase flow with moving immersed boundaries. International Journal for Numerical Methods in Fluids, 67(12), 2062-2080
Open this publication in new window or tab >>Simulation of two-phase flow with moving immersed boundaries
2011 (English)In: International Journal for Numerical Methods in Fluids, ISSN 0271-2091, E-ISSN 1097-0363, Vol. 67, no 12, p. 2062-2080Article in journal (Refereed) Published
Abstract [en]

A two-dimensional model for immiscible binary fluid flow including moving immersed objects is presented. The fluid motion is described by the incompressible Navier-Stokes equation coupled with a phase-field model based on van der Waals’ free energy density and the Cahn-Hilliard equation. The immersed boundary method has been utilised to handle moving immersed objects and the phase-field boundary conditions have been adapted accordingly. Numerical stability and execution time was significantly improved by the use of a new boundary condition which implements minimisation of the free energy in a direct way. Convergence toward the analytical solution was demonstrated for equilibrium contact angle, the Lucas-Washburn theory and Stefan’s problem. The proposed model may be used for two-phase flow problems with moving boundaries of complex geometry, such as the penetration of fluid into a deformable, porous medium.

Keywords
fluid-structure interaction, immersed boundary, moving boundary, two-phase flow
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-10571 (URN)10.1002/fld.2484 (DOI)000297736100018 ()2-s2.0-83255186838 (Scopus ID)
Projects
Nip Mechanics and Hydrodynamics in Flexo Post-Printing and Print Quality
Available from: 2009-12-07 Created: 2009-12-07 Last updated: 2017-12-12Bibliographically approved
Holmvall, M., Uesaka, T., Drolet, F. & Lindström, S. (2011). Transfer of a microfluid to a stochastic fibre network. Journal of Fluids and Structures, 27(7), 937-946
Open this publication in new window or tab >>Transfer of a microfluid to a stochastic fibre network
2011 (English)In: Journal of Fluids and Structures, ISSN 0889-9746, E-ISSN 1095-8622, Vol. 27, no 7, p. 937-946Article in journal (Refereed) Published
Abstract [en]

The transfer of a microscopic fluid droplet from a flat surface to a deformable stochastic fibre network is investigated. Fibre networks are generated with different levels of surface roughness, and a two-dimensional, two-phase fluid-structure model is used to simulate the fluid transfer. In simulations, the Navier-Stokes equations and the Cahn-Hilliard phase-field equations are coupled to explicitly include contact line dynamics and free surface dynamics. The compressing fibre network is modelled as moving immersed boundaries. The simulations show that the amount of transferred fluid is approximately proportional to the contact area between the fluid and the fibre network. However, areas where the fluid bridges and never actually makes contact with the substrate must be subtracted.

Keywords
fibre network, flexo, fluid-structure interaction, fluid transfer, moving boundaries, two-phase flow
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-11295 (URN)10.1016/j.jfluidstructs.2011.06.003 (DOI)000295300900004 ()2-s2.0-80052260413 (Scopus ID)
Projects
Nip mechanics and hydrodynamics of flexo post printing and print quality
Available from: 2010-02-19 Created: 2010-02-19 Last updated: 2017-12-12Bibliographically approved
Holmvall, M. (2010). Nip Mechanics, Hydrodynamics and Print Quality in Flexo Post-Printing. (Doctoral dissertation). Sundsvall: Kopieringen
Open this publication in new window or tab >>Nip Mechanics, Hydrodynamics and Print Quality in Flexo Post-Printing
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Place, publisher, year, edition, pages
Sundsvall: Kopieringen, 2010
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-11347 (URN)
Public defence
(English)
Supervisors
Projects
Nip Mechanics and Hydrodynamics of Flexo Post-Printing and Print Quality
Available from: 2011-01-14 Created: 2010-03-05 Last updated: 2011-01-14Bibliographically approved
Holmvall, M. & Uesaka, T. (2008). Print Uniformity of Corrugated Board in Flexo Printing: Effects of Corrugated Board and Halftone Dot Deformations.. Packaging technology & science, 21(7), 385-394
Open this publication in new window or tab >>Print Uniformity of Corrugated Board in Flexo Printing: Effects of Corrugated Board and Halftone Dot Deformations.
2008 (English)In: Packaging technology & science, ISSN 0894-3214, E-ISSN 1099-1522, Vol. 21, no 7, p. 385-394Article in journal (Refereed) Published
Abstract [en]

Print non-uniformity problems are a major concern for flexo post-printers. Many of these non-uniformities are suspected to be caused by the corrugated board structure itself. Striping is the most obvious one, but also other print quality problems might be structure-related. This work focuses on how deformations of the board might lead to print non-uniformities, and if the deformation of halftone dots is the mechanism behind striping in halftone flexo post-printing. The problems were analysed by using finite element models to simulate deformed board and halftone dot compression in the printing nip. Distortions of the board due to non-uniform hygro-thermal strains were shown to be a potential cause of print non-uniformities. Striping in halftone prints was found to be caused by differences in dot gain between ridge and valley areas above the flute structure.

Keywords
corrugated board, dot gain, flexo, halftone, striping, warp
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-313 (URN)10.1002/pts.816 (DOI)000260649100002 ()2-s2.0-55649096951 (Scopus ID)5139 (Local ID)5139 (Archive number)5139 (OAI)
Projects
Nip Mechanics and Hydrodynamics of Flexo Post-Printing and Print Quality
Available from: 2008-12-11 Created: 2008-12-11 Last updated: 2017-12-13Bibliographically approved
Holmvall, M. & Uesaka, T. (2008). Striping of Corrugated Board in Full-tone Flexo Post-Printing. Appita journal, 61(1), 35-40
Open this publication in new window or tab >>Striping of Corrugated Board in Full-tone Flexo Post-Printing
2008 (English)In: Appita journal, ISSN 1038-6807, Vol. 61, no 1, p. 35-40Article in journal (Refereed) Published
Abstract [en]

Striping is a print defect that is often seen in flexo post-printing on corrugated board. It appears as lines parallel to the flutes of the corrugated medium (fluting). These lines are generally thought to be print density and/or print gloss variations. The objective of this Paper is to obtain fundamental understanding of the striping mechanism. Print density and print gloss have been determined as a function of printing pressure. Typical printing pressure variations have also been determined by a non-linear finite element method. A 2D reflectance mapping has been performed for printed corrugated boards. The results showed that striping is dominated by print density variations for uncoated board, and the print density variations are, in turn, caused by the printing pressure variations. The extent to which the pressure variations appear as print density variations depends on the ink transfer characteristics of the liner board.

National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-312 (URN)000252686700007 ()2-s2.0-38349104629 (Scopus ID)5138 (Local ID)5138 (Archive number)5138 (OAI)
Projects
Nip Mechanics and Hydrodynamics of Flexo Post-Printing and Print Quality
Note
VR-ChemistryAvailable from: 2008-12-10 Created: 2008-12-02 Last updated: 2017-12-13Bibliographically approved
Holmvall, M. & Uesaka, T. (2007). Nip Mechanics of Flexo Post-Printing on Corrugated Board.. Journal of composite materials, 41(17), 2129-2145
Open this publication in new window or tab >>Nip Mechanics of Flexo Post-Printing on Corrugated Board.
2007 (English)In: Journal of composite materials, ISSN 0021-9983, E-ISSN 1530-793X, Vol. 41, no 17, p. 2129-2145Article in journal (Refereed) Published
Abstract [en]

A finite element model of a flexo printing press has been developed and the material and geometrical properties of the sustem has been investigated. The results showed that it is the photopolymer and the top liner that have the biggest impact on the printing pressure variations.

Keywords
Flexo, Striping, Corrugated Board
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-311 (URN)10.1177/0021998307074135 (DOI)000249099200007 ()2-s2.0-34547522828 (Scopus ID)
Available from: 2008-12-11 Created: 2008-12-11 Last updated: 2017-12-13Bibliographically approved
Holmvall, M. & Uesaka, T. (2007). Striping of Corrugated Board in Halftone Flexo Post-printing. In: 61st Appita annual conference and exhibition, Gold Coast, Australia, 6-9 May 2007, 2007 International paper physics conference, 6pp: .
Open this publication in new window or tab >>Striping of Corrugated Board in Halftone Flexo Post-printing
2007 (English)In: 61st Appita annual conference and exhibition, Gold Coast, Australia, 6-9 May 2007, 2007 International paper physics conference, 6pp, 2007Conference paper, Published paper (Other academic)
Abstract [en]

A fintie element model has been used to simulate how halftone dots deform during printing. Another finite element model has also been used for simulating how the pressure distribution in the nip changes when the corrugated board is deformed before printing by e.g. moisture induced warp. The simulations showed that striping in halftone prints can be explained by the deformation of halftone dots leading to more "dot gain" above flute ridges than between. When the corrugated board is deformed over a few flutes, the pressure distribution is affected which might cause print non-uniformities.

Keywords
striping, halftone, corrugated board, flexo
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-4266 (URN)5037 (Local ID)5037 (Archive number)5037 (OAI)
Projects
Nip Mechanics and Hydrodynamics of Flexo Post-Printing and Print Quality
Available from: 2008-12-11 Created: 2008-12-10 Last updated: 2009-06-08Bibliographically approved
Holmvall, M. (2007). Striping on flexo post-printed corrugated board. (Licentiate dissertation). Sundsvall: Mittuniversitetet
Open this publication in new window or tab >>Striping on flexo post-printed corrugated board
2007 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Striping is the most common print non-uniformity on corrugated board. It is defined as periodic print density and/or print gloss variations parallel to the flutes. Corrugated boards are mainly printed with flexography, making striping a major concern for the flexographic post-printing industry. In spite of its long history, the basic mechanisms of striping have not been fully understood, and no concrete solution has been provided. The objective of this thesis is to obtain an understanding of the fundamental mechanisms behind and a solution to striping. Both experimental and numerical approaches have been taken in thiswork. Nonlinear finite element models have been constructed in both corrugated board and halftone dot scales to determine the pressure distributions in the printing nip. Ink transfer experiments have been performed to determine the print density vs. pressure relations. Parametric studies have been done for the effects of printing system variables and deformations. The results showed that striping is predominantly print density variations caused by pressure variations in the printing nip. The pressure variations are inherent to the corrugated board structure. Washboarding was shown to play a minor part in causing print density variations, but might contribute to gloss striping. A new printing plate design has been proposed to eliminate the pressure variations and hence the print density striping.

Place, publisher, year, edition, pages
Sundsvall: Mittuniversitetet, 2007
Series
Mid Sweden University licentiate thesis, ISSN 1652-8948 ; 26
Keywords
Kemiteknik
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-111 (URN)5136 (Local ID)978-91-85317-63-9 (ISBN)5136 (Archive number)5136 (OAI)
Presentation
2007-10-25, 102, M, Holmgatan 10, Sundsvall, 10:00 (English)
Opponent
Supervisors
Available from: 2008-02-18 Created: 2008-02-18 Last updated: 2009-06-08Bibliographically approved
Organisations

Search in DiVA

Show all publications