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dc.contributor.authorHood, Jonathan Patricken
dc.date.accessioned2011-08-06T16:02:46Zen
dc.date.available2011-08-06T16:02:46Zen
dc.date.issued2004-06-04en
dc.identifier.otheretd-08032004-094106en
dc.identifier.urihttp://hdl.handle.net/10919/10049en
dc.description.abstractConvective heat transfer during hot pressing in wood-based composite panel manufacturing is widely accepted as the most important means of heat transport for resin curing. The rate of convective heat transfer to the panel core is controlled by its permeability. Permeability in the plane of the panel also controls the flow of vapor to the panel edges, thereby influencing the potential for panel "blowing". This research considers how flake thickness, flake alignment and changing mat density during hot-pressing influences OSB mat permeability, through its thickness and in the plane of the panel. Some previous research exists but it fails to address the affects of horizontal and vertical density gradients as well as flake alignment. An apparatus was designed to allow cold pressing of aligned flakes to desired densities while enabling permeability measurements through the mat thickness. An additional apparatus was designed to allow the measuring of permeability in the plane of the mat. These designs permitted permeability measurements in mats that had no vertical density gradient, allowing for the direct study of permeability versus density (compaction ratio). Superficial permeability was determined using Darcy's law and for each sample, multiple readings were made at five different pressure differentials. Permeability through the mat thickness was highly dependent on compaction ratio and to a lesser extent flake thickness. As the compaction ratio is increased, the initial reduction in permeability is severe, once higher compaction ratios are achieved the reduction in permeability is less pronounced. Permeability decreased with decreasing flake thickness. Permeability in the plane of the mat decreases with increasing compaction ratio but in a less severe manner than through the mat thickness. In this case, the permeability-compaction ratio relationship appears linear in nature. Again, permeability decreases with decreasing flake thickness.en
dc.format.mediumETDen
dc.publisherVirginia Techen
dc.relation.hasparthood.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectdensityen
dc.subjectCompaction Ratioen
dc.subjectDarcy's lawen
dc.subjectPermeabilityen
dc.titleChanges in Oriented Strandboard Permeability During Hot-Pressingen
dc.typeThesisen
dc.contributor.departmentWood Science and Forest Productsen
dc.description.degreeMaster of Scienceen
thesis.degree.nameMaster of Scienceen
thesis.degree.levelmastersen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.disciplineWood Science and Forest Productsen
dc.contributor.committeechairKamke, Frederick A.en
dc.contributor.committeememberZink-Sharp, Audrey G.en
dc.contributor.committeememberLoferski, Joseph R.en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-08032004-094106en
dc.date.sdate2004-08-03en
dc.date.rdate2004-08-05en
dc.date.adate2004-08-05en


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