Rauwendaal Extrusion engineering, Inc.
Rauwendaal Extrusion Engineering, Inc. 530.269.1082

A Polymer Process Engineering & Training Company Home of the CRD Mixing Screws

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Features: (From Brochure)
a. CRD
b. VIP
c. HHT



Custom Extruder Screws by Rauwendaal Extrusion Engineering, Inc.

Patented Technologies
REE is a world leader in design and manufacture of custom extruder screws.  We have developed several breakthrough technologies that enable significant improvement in extruder performance.

REE has developed the CRD (Chris Rauwendaal Dispersive) mixing technology that uses strong elongational flow to improve dispersive and distributive mixing.  More recently, the VIP (Vortex Intermeshing Pin) mixing technology was developed to achieve highly efficient distributive mixing.

One of our latest developments is the HHT (high heat transfer) technology to achieved enhanced heat transfer.  An important application of the HHT technology is in tandem foam extrusion where the secondary extruder is used to cool down the gas-laden melt from the primary extruder.

Technical Support
Rauwendaal Extrusion Engineering offers strong technical support.  Not only did we write the book on extrusion we also wrote the book on troubleshooting and know how to solve extrusion problems.  In fact, a substantial part of our engineering services involve analysis and solution of extrusion problems.  REE also offers training programs to improve

Design Tools
REE has a wide range of design tools.  In fact, many suppliers of extruders and screws use the books and papers we have written on extrusion and screw design - no single company has published more in this field.  REE uses a number of analytical and numerical models to analyze and predict extruder performance.  We have developed several new analytical models to calculate extruder performance.  

REE has also developed numerical models for detailed analysis of non-isothermal and non-Newtonian flow.  An example is our CFD software REEflow.  REE works with The Madison Group and the Polymer Processing Group at the University of Madison, Wisconsin on applying the boundary element method (BEMflow) to a variety of extrusion and mixing problems.  REE also cooperates with Compuplast on the use of Flow-2000 in extrusion and similarly with Fluent on the use of POLYFLOW and FLUENT in extrusion and mixing applications.

Types of Extruder Screws
This is a listing of the type of extruder screw we design and manufacture: