TY - JOUR
T1 - Entrance pressure drop studies of corn meal dough during extrusion cooking
AU - Bhattacharya, M.
AU - Seethamraju, K.
AU - Padmanabhan, M.
PY - 1994/8
Y1 - 1994/8
N2 - The entrance pressure drop during extrusion cooking of corn grits was measured using a cylindrical die viscometer attached to a single screw extruder and compared with results obtained using low‐density polyethylene (LDPE). The cylindrical die viscometer had a length to diameter ratio of 40 with half‐entry angles of 30, 37.5, 45 and 90° with the horizontal. The entrance pressure drop at the die was measured as a function of extrusion temperature, product moisture content and the die entry angle. Results indicate that the flow behavior of corn grits and the entrance pressure drop were affected by product moisture content, process temperature and the shear history in the extruder. Entrance pressure drop also increased with wall shear stress for plastic melt, but for food biopolymer, the increase was observed provided shear history effects were minimized. Entrance correction increased with apparent shear rate for LDPE, but the reverse was true for corn meal. Using Cogswell's analysis, corn grits exhibit severe extension thinning behavior in entry flow.
AB - The entrance pressure drop during extrusion cooking of corn grits was measured using a cylindrical die viscometer attached to a single screw extruder and compared with results obtained using low‐density polyethylene (LDPE). The cylindrical die viscometer had a length to diameter ratio of 40 with half‐entry angles of 30, 37.5, 45 and 90° with the horizontal. The entrance pressure drop at the die was measured as a function of extrusion temperature, product moisture content and the die entry angle. Results indicate that the flow behavior of corn grits and the entrance pressure drop were affected by product moisture content, process temperature and the shear history in the extruder. Entrance pressure drop also increased with wall shear stress for plastic melt, but for food biopolymer, the increase was observed provided shear history effects were minimized. Entrance correction increased with apparent shear rate for LDPE, but the reverse was true for corn meal. Using Cogswell's analysis, corn grits exhibit severe extension thinning behavior in entry flow.
UR - http://www.scopus.com/inward/record.url?scp=0028485866&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0028485866&partnerID=8YFLogxK
U2 - 10.1002/pen.760341504
DO - 10.1002/pen.760341504
M3 - Article
AN - SCOPUS:0028485866
SN - 0032-3888
VL - 34
SP - 1187
EP - 1195
JO - Polymer Engineering & Science
JF - Polymer Engineering & Science
IS - 15
ER -