{"id":{"repo_id":"purdue-thes","oai_identifier":"oai:docs.lib.purdue.edu:open_access_dissertations-2483"},"canonical_url":"https://search.dev.ndltd.org/etd/purdue-thes/oai:docs.lib.purdue.edu:open_access_dissertations-2483","repository":{"repo_id":"purdue-thes","name":"Purdue University","base_url":"https://docs.lib.purdue.edu/do/oai/"},"display":{"title":"INVESTIGATING RHEOLOGICAL TECHNIQUES TO MODEL AND PREDICT OPERATING CONDITIONS OF A SINGLE SCREW EXTRUDER WITH INTERNAL RESTRICTIONS","abstract":"Understanding rheology of raw materials and the numerous transformations they undergo is an essential aspect of modeling and predicting extrusion conditions. Both off-line capillary rheometry and in-line extruder fed rheometry techniques have been used to model rheology of materials during extrusion. Investigations on use of an off-line capillary rheometer to model apparent viscosity of full fat soy flours revealed inability of the capillary rheometer to handle food/biological materials high in oil content (20%) at high temperature (80C) and low moisture content (15% wet basis). The lack shear degradation in the capillary rheometer also resulted in over-prediction of corn flour viscosities at high temperatures (80 to 120C), shear rates (1 to 100 s-1) and low moisture contents (35 to 40%). A novel two-opening die attached to a small scale extruder operating at 100 to 300 rpm was used to measure in-line viscosities of cornmeal at 32.5 to 37.5% moisture during extrusion. Comparison of off-line versus in-line cornmeal viscosities at similar conditions consistently indicated that for food/biological materials sensitive to shear degradation, in-line viscosities were lower. Pasting property measurement revealed differences in material transformation which could be used to explain differences between techniques. Mechanistic model for the small-scale","abstract_html":"Understanding rheology of raw materials and the numerous transformations they undergo is an essential aspect of modeling and predicting extrusion conditions. Both off-line capillary rheometry and in-line extruder fed rheometry techniques have been used to model rheology of materials during extrusion. Investigations on use of an off-line capillary rheometer to model apparent viscosity of full fat soy flours revealed inability of the capillary rheometer to handle food/biological materials high in oil content (20%) at high temperature (80C) and low moisture content (15% wet basis). The lack shear degradation in the capillary rheometer also resulted in over-prediction of corn flour viscosities at high temperatures (80 to 120C), shear rates (1 to 100 s-1) and low moisture contents (35 to 40%). A novel two-opening die attached to a small scale extruder operating at 100 to 300 rpm was used to measure in-line viscosities of cornmeal at 32.5 to 37.5% moisture during extrusion. Comparison of off-line versus in-line cornmeal viscosities at similar conditions consistently indicated that for food/biological materials sensitive to shear degradation, in-line viscosities were lower. Pasting property measurement revealed differences in material transformation which could be used to explain differences between techniques. Mechanistic model for the small-scale","abstract_has_math":false,"creators":["Ponrajan, Amudhan"],"institution":null,"degree_name":"Doctor of Philosophy (PhD)","degree_level":"Dissertation","degree_discipline":"Agricultural and Biological Engineering","degree_department":null,"school":null,"contributors":["Martin R Okos","Osvaldo H Campanella","Bruce R Hamaker","Ganesan Narsimhan"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-01-01T08:00:00Z","date_published":"2016-01-01T08:00:00Z","updated_at":"2026-07-24T03:54:31Z","subjects":["Extrusion","Grains","Modeling","Rheology"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://docs.lib.purdue.edu/open_access_dissertations/1267","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Martin R Okos","Osvaldo H Campanella","Bruce R Hamaker","Ganesan Narsimhan"]},{"key":"dc:creator","label":"Author","values":["Ponrajan, Amudhan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_discipline","label":"Discipline","values":["Agricultural and Biological Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Extrusion","Grains","Modeling","Rheology"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://docs.lib.purdue.edu/open_access_dissertations/1267"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Understanding rheology of raw materials and the numerous transformations they undergo is an essential aspect of modeling and predicting extrusion conditions. Both off-line capillary rheometry and in-line extruder fed rheometry techniques have been used to model rheology of materials during extrusion. Investigations on use of an off-line capillary rheometer to model apparent viscosity of full fat soy flours revealed inability of the capillary rheometer to handle food/biological materials high in oil content (20%) at high temperature (80C) and low moisture content (15% wet basis). The lack shear degradation in the capillary rheometer also resulted in over-prediction of corn flour viscosities at high temperatures (80 to 120C), shear rates (1 to 100 s-1) and low moisture contents (35 to 40%). A novel two-opening die attached to a small scale extruder operating at 100 to 300 rpm was used to measure in-line viscosities of cornmeal at 32.5 to 37.5% moisture during extrusion. Comparison of off-line versus in-line cornmeal viscosities at similar conditions consistently indicated that for food/biological materials sensitive to shear degradation, in-line viscosities were lower. Pasting property measurement revealed differences in material transformation which could be used to explain differences between techniques. Mechanistic model for the small-scale"]},{"key":"dc:title","label":"Title","values":["INVESTIGATING RHEOLOGICAL TECHNIQUES TO MODEL AND PREDICT OPERATING CONDITIONS OF A SINGLE SCREW EXTRUDER WITH INTERNAL RESTRICTIONS"]}]}],"canonical_facts":{"dc:contributor":["Martin R Okos","Osvaldo H Campanella","Bruce R Hamaker","Ganesan Narsimhan"],"dc:creator":["Ponrajan, Amudhan"],"dc:description.abstract":["Understanding rheology of raw materials and the numerous transformations they undergo is an essential aspect of modeling and predicting extrusion conditions. Both off-line capillary rheometry and in-line extruder fed rheometry techniques have been used to model rheology of materials during extrusion. Investigations on use of an off-line capillary rheometer to model apparent viscosity of full fat soy flours revealed inability of the capillary rheometer to handle food/biological materials high in oil content (20%) at high temperature (80C) and low moisture content (15% wet basis). The lack shear degradation in the capillary rheometer also resulted in over-prediction of corn flour viscosities at high temperatures (80 to 120C), shear rates (1 to 100 s-1) and low moisture contents (35 to 40%). A novel two-opening die attached to a small scale extruder operating at 100 to 300 rpm was used to measure in-line viscosities of cornmeal at 32.5 to 37.5% moisture during extrusion. Comparison of off-line versus in-line cornmeal viscosities at similar conditions consistently indicated that for food/biological materials sensitive to shear degradation, in-line viscosities were lower. Pasting property measurement revealed differences in material transformation which could be used to explain differences between techniques. Mechanistic model for the small-scale"],"dc:identifier":["https://docs.lib.purdue.edu/open_access_dissertations/1267"],"dc:subject":["Extrusion","Grains","Modeling","Rheology"],"dc:title":["INVESTIGATING RHEOLOGICAL TECHNIQUES TO MODEL AND PREDICT OPERATING CONDITIONS OF A SINGLE SCREW EXTRUDER WITH INTERNAL RESTRICTIONS"],"thesis:degree_discipline":["Agricultural and Biological Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-24T03:54:31Z"}