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dc.contributor.authorHood, Jonathan Patricken_US
dc.date.accessioned2011-08-06T16:02:46Z
dc.date.available2011-08-06T16:02:46Z
dc.date.issued2004-06-04en_US
dc.identifier.otheretd-08032004-094106en_US
dc.identifier.urihttp://hdl.handle.net/10919/10049
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_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.relation.hasparthood.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectdensityen_US
dc.subjectCompaction Ratioen_US
dc.subjectDarcy's lawen_US
dc.subjectPermeabilityen_US
dc.titleChanges in Oriented Strandboard Permeability During Hot-Pressingen_US
dc.typeThesisen_US
dc.contributor.departmentWood Science and Forest Productsen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineWood Science and Forest Productsen_US
dc.contributor.committeechairKamke, Frederick A.en_US
dc.contributor.committeememberZink-Sharp, Audrey G.en_US
dc.contributor.committeememberLoferski, Joseph R.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-08032004-094106en_US
dc.date.sdate2004-08-03en_US
dc.date.rdate2004-08-05
dc.date.adate2004-08-05en_US


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