The effect of coating pore structure on drying efficiency in heatset web offset printing

dc.contributorAalto-yliopistofi
dc.contributorAalto Universityen
dc.contributor.advisorGerstner, Philip
dc.contributor.authorZhang, Hai
dc.contributor.departmentPuunjalostustekniikan laitosfi
dc.contributor.schoolKemian tekniikan korkeakoulufi
dc.contributor.schoolSchool of Chemical Engineeringen
dc.contributor.supervisorGane, Patrick
dc.date.accessioned2020-12-23T13:11:27Z
dc.date.available2020-12-23T13:11:27Z
dc.date.issued2010
dc.description.abstractIn this thesis, drying of offset ink in heatset printing was investigated from a pore level perspective. Specially formed "coating colour tablets" and a mineral oil have been used to represent the role of paper coating and the solvent/diluent of offset ink, respectively. Two representative pigments were employed, one being a monomodal broad size distribution ground calcium carbonate (GCC), the other being an internally porous modified calcium carbonate (MCC), which, when packed as in a coating, displays a discrete bimodal pore size distribution. The weight loss behaviour of offset ink oil saturated coating structures was traced with the help of thermogravimetric analysis (TGA). The experimental method is seen to be applicable to the general problem of drying of porous media. Based on the weight loss curve, the mechanism involved in drying of porous media has been outlined: in the rising rate period, temperature dominates if the internal mass supply can meet the demand of transport of liquid to the evaporating interface. The effect of film flow as being a major internal mass transport mechanism has been confirmed by the experimental results; in the failing rate period, diffusion resistance dominates due to the development of fully dried regions. The link between vapour diffusivity within the porous structure and the liquid permeability has been discussed. Lastly, specific heat of coating colour tablets was measured by differential scanning calorimetry (DSC).en
dc.format.extent88
dc.identifier.urihttps://aaltodoc.aalto.fi/handle/123456789/98998
dc.identifier.urnURN:NBN:fi:aalto-2020122357825
dc.language.isoenen
dc.programme.majorPaperi- ja painatustekniikkafi
dc.programme.mcodePuu-21fi
dc.rights.accesslevelclosedAccess
dc.subject.keywordporous mediaen
dc.subject.keyworddrying mechanismen
dc.subject.keywordTGAen
dc.subject.keywordDSCen
dc.titleThe effect of coating pore structure on drying efficiency in heatset web offset printingen
dc.type.okmG2 Pro gradu, diplomityö
dc.type.ontasotMaster's thesisen
dc.type.ontasotPro gradu -tutkielmafi
dc.type.publicationmasterThesis
local.aalto.digiauthask
local.aalto.digifolderAalto_06708
local.aalto.idinssi41380
local.aalto.openaccessno
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