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dc.contributor.authorGibney IV, Matthew Josephen_US
dc.date.accessioned2014-03-14T20:44:32Z
dc.date.available2014-03-14T20:44:32Z
dc.date.issued2000-06-30en_US
dc.identifier.otheretd-08312000-14550031en_US
dc.identifier.urihttp://hdl.handle.net/10919/34857
dc.description.abstractThreshold leak sizes and leak rates were calculated for a number of liquid food products exhibiting a wide range of surface tension and viscosity values. From this data, one can see that mathematically, under typical pressure differentials generated in food packages (less than or equal to ±34.5 kPa), a leak will never start through a 2 μm defect. The calculated leak rates were compared to calculated evaporation rates. The evaporation rate exceeds the leak rate at lower sized microholes (2, and 5 μm diameter) under typical pressure differentials found in food packages. If the liquid, typically aqueous in food products, is evaporating off faster than the leak itself, then there will be solids left behind that could effectively plug the leak.

The critical leak size is the size micro-defect that allows microbial penetration into the package. The critical leak size of air-filled defects was found to be 7 μm at all pressures tested. This size is considerably important to food packagers because this is when sterility of the package is lost. Previous leak studies have shown that the critical leak size for liquid-filled defects coincide with the threshold leak size and pressure. If this is in fact true, then air-filled defects should exhibit a larger critical leak size than the liquid-filled defects. In this study, air-filled defects were examined. A bioaerosol exposure chamber was used to test micro-defects, nickel microtubes of known diameters 2, 5, 7, 10, 20, and 50 μm hydraulic diameters, against pressure differentials of 0, -6.9, -13.8, and -34.5 kPa.

en_US
dc.publisherVirginia Techen_US
dc.relation.haspartetdgibney.pdfen_US
dc.rightsI hereby grant to Virginia Tech or its agents the right to archive and to make available my thesis or dissertation in whole or in part in the University Libraries in all forms of media, now or hereafter known. I retain all proprietary rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation.en_US
dc.subjectleakersen_US
dc.subjecthermetic sealen_US
dc.subjectmicrobial ingressen_US
dc.subjectpackage sterilityen_US
dc.subjectthreshold leak sizeen_US
dc.titlePredicting Package Defects: Quantification of Critical Leak Sizeen_US
dc.typeThesisen_US
dc.contributor.departmentFood Science and Technologyen_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.disciplineFood Science and Technologyen_US
dc.contributor.committeechairMarcy, Joseph E.en_US
dc.contributor.committeememberHackney, Cameron Rajen_US
dc.contributor.committeememberBlakistone, Barbara A.en_US
dc.contributor.committeememberDavis, Richey M.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-08312000-14550031/en_US
dc.date.sdate2000-08-31en_US
dc.date.rdate2001-09-05
dc.date.adate2000-09-05en_US


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