Rules of Thumb
Vol. 25 #3, Dec. 1998
As we constantly strive for more output, we can and do cause problems in melt quality and rate. Some simple reminders:
- An increase of 1000 psi will increase melt temperature normally from 5 to 30 deg. F.
- Higher pressure will improve mixing.
- Higher pressure will increase die swell.
- Higher pressure may reduce rate per rpm.
- An increase of 10% screw speed will increase melt temperature by approximately 5% and an increase in screw speed will eventually result in poor melting, uneven melt, and surging.
- Mark Sewak, LCI Corp.
See also:
- High motor amps
- Monitor back pressure
- Pressure increases temperature
- Pressure transducers 2
- Profile die design
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