single screw extruder design sorted by

relevance

This is a useful approach but it is based on isothermal conditions with purely viscous flow behaviour.

Water acts like a plasticizer by lowering the melting temperature and plasticize the starch polymer.

A vacuum or vent port, installed in a barrel section, that is too close to a die that creates a high die or backpressure has the potential for the polymer to back up at the die and flow out of the vent or vacuum port.

Here the mixing chamber has regions of high shear with some elongation in the close clearance region between the rotors and the casing and in some designs between the two rotors.

2 for the simple case of laminar flow in a pipe.

The increased heat energy generated in the melt film is transferred by thermal conduction and convection to the solid polymer plug, the barrel, and the melt pool.

During the forward movement, the amount of melted component increases, and at one point all of it is melted.

Thermoplastics became increasingly important in the post-World War II period.

Screw design is often still considered to be more of an art than a science.

Since the theory of single screw extrusion is now well-developed, the design of screws for single screw extruders can be based on solid engineering principles.

The gap between the screw tip and the barrel surface is made as narrow as possible• Heat exchange rate from barrel surface to the material is faster and more uniform• In-line static mixing units operate by a redistributive mixing action when used for laminar blending operations.