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.