posted June 10, 2003 03:29 PM               

You'll need a couple more bits of information, what L/D ratio (longer barrel, more HP), what process.

posted June 11, 2003 09:19 AM               

This will depend on gearbox ratio, screw design, material charachteristics (I'm assuming HMW not MMW), etc., but that is a general guideline.

40HP has been done (again, depending on ratio), however care should be taken because you might break the screw if you aren't careful (you should current-limit the drive to around 75%). 25HP is sufficient in many cases.

posted June 11, 2003 01:40 PM               

The enthalpy of HDPE (at full speed) is typically around 5 to 6 PPH/HP. On the safe side I would plan for 5 PPH/HP. Given a 45mm is capabale of approximately 0.32kgs/hr/rpm of HDPE (or 0.7 PPH/RPM), the anticipated torque requirement is approximately 0.14 HP/RPM (0.7/5). Provided w/ a 14:1 gear reduction (1750 base speed motor) the top screw speed will be 125 RPM. Given this scenario, the necessary HP will be 17.5 HP or a 20 HP motor (0.14 x 125). I would certainly recommend a belt and sheave transmission to provide the greatest flexibility in providing either more or less torque as required.