Flight Radii Size

The size of flight radii on the screw channel is important for the proper performance of a single-screw extruder. The specifications of the flight radii are commonly made using a combination of personal experience and guidelines [16] from the Society of the Plastics Industry, Inc. (SPl). These guidelines state unless otherwise specified the root radius will not be less than one-half of the flight depth up to 

Screw Section Flight Radii to Channel Depth Ratio 

Transition Blend radii sizes from the soiids-conveying section to the metering section 

---

Figure 5.27 The effect of flight radii size on solids conveying rates for a barrel temperature of 75 °C, a screw temperature of 50 °C, and a screw speed of 50 rpm...

Spalding, M. A., Dooley, J., and Hyun, K. S., The Effect of Flight Radii Size on the Performance of Single-Screw Extruders, SPEANTEC Tech. Papers, 45, 190 (1999)... 

According to the random-flight theory, the size of a molecule increases in proportion to N -, where size means either the average end-to-end distance (r-) = Nh or the most probable radius Rq = 2Nb /3. We showed on pages... 

---