Mixing Energy

The mechanical energy for melting and mixing in the RingExtruder does not come from the use of kneading blocks, or other agressive, shear-inducing devices. Instead, it comes form the elongational mixing that occurs in the intermeshing areas between the screws. Unlike existing industry compounding equipment, such as kneaders, single-screw extruders, and twin-screw compounders, this multi-screw ring extruder has the unique capability to deliver superior dispersive and distributive mixing characteristics while managing the total system energy balance to minimize degradation of sensitive resin components.

Elongational Mixing

Elongational mixing occurs as a result of a squeezing action, followed by rapid acceleration and stretching of the resin. Elongational mixing is highly effective in imparting a high degree of particle droplet deformation and breakup necessary to finely disperse additives, modifiers, and fillers without excessive shear or heat generation.

Elongational mixing takes place when the low-energy dispersive mixing of a polymer is enhanced by frequent stretching and recombining of the melt as it is transported from one intermeshing zone to another.

Elongational mixing in these regions is very advantageous, especially over mixing derived from planar shearing devices, such as kneading blocks or other high-shear devices.

As resin enters the intermeshing zone, it is initially compressed and accelerated in an axial direction as it is transferred from the face of one conveying shaft to the adjacent shaft. This is followed by an immediate decompression and acceleration in a radial direction as the resin is deposited on the adjacent upturning shaft.

There are 24 intermeshing zones in the cross section of the RingExtruder, versus two for a typical twin-screw extruder. The key to improved plastics and manufacturing efficiency lies in these 24 zones, where elongational mixing occurs. Elongational mixing is achieved when viscous materials are stretched and dispersed, producing stronger, more consistent plastic components.