EXTRUDER OPERATION POINTS

A$)$ Plot the screw characteristic curve $($Q vs Dp$)$ at $40,80$ and $120$ rpm screw speed for a $45$mm square pitch $($f$=17\mathrm{.}65)$ extruder with a channel depth of $4$mm in the metering section and a flight width of $4$ mm$.$ The metering section of the extruder is $5$ turns long. Assume a Newtonian viscosity $=1000$ Pa$.$s and Take Fp$=1$ and Fd$=1.$

B$)$ A slit die is attached to above single$-$screw extruder. It has dimension of $8$ mmX$3$

mm $($WxH$).$ In order to minimize the amount of die swell the die land has to be

long as much as possible. Therefore the die length has been given a size of LD$=40$

mm$.$ Find operating point $($Q and DP$)$ for this extruder$-$slit die combination at $40,$

$80$ and $120$ rpm screw speed.