Pressure Distribution in the Feeding Section of the Single-Screw Extruder.

The author presents mathematical equations derived for the solution of conveying problem in the first (solid) section of the extruder's cylinder. An analytical solution has not so far been offered, and numerical methods meet with difficulties in the marginal conditions. To bring the lead of the flight in the extruder channel into play, it is an advantage to work within helix coordinates. The author explains the structure of an approximation formula for solving this problem. A numerical table shows the values calculated and compares them with the values of a formula for the state of equilibrium in the absence of shear stresses. This formula was used by Schneider in a lecture on the anisotropy of the pressure distribution in bulk goods to calculate the pressures on the walls of a curved channel such as in an extruder.