Mixing Type Screw Designs
There are two types of mixing devices, distributive and dispersive. One example of a distributive mixer is patented under the name "Dray Mixer". Dray mixers divert lower temperature resin from the downstream side of the channel into a groove on the upstream side of the channel, merging the lower temperature resin with the higher temperature resin, bringing the resin temperature to unity. The Spiral "W" mixer is an example of a dispersive	type mixer. Mixing is accomplished by resin flowing through the inlet grooves, over the under cut flight and into the outlet groove. Shear stress is added to any particles smaller than the flight clearance allowing their temperature to come to unity with the surrounding resin. Distributive mixers are designed for high viscosity and filled resins. Dispersive mixers are designed for low viscosity resins.
The Dray Mixing Screw Return to main page