Molten plastic at a temperature of 510 °F is augered through
an extruder barrel by a screw occupying 3
5 of the barrel’s volume
(Fig. P5.16). The extruder is 16 ft long and has an inner diameter
of 8 in. The barrel is connected to an adapter having a volume of
0.48 ft3
. The adapter is then connected to a die of equal volume.
The plastic exiting the die is immediately rolled into sheets. The
line is producing 4-ft widths of material at a rate of 30 ft/min
and a gauge thickness of 187 mil. What is the axial velocity,
V1, of the plastic in the barrel? Assume that the plastic density
is constant as it solidifies from a liquid (in the extruder) into a
solid sheet.