• Excellent Heat Transfer Characteristics:

  In conventional polymer processing, a thermal gradient is something that has to be mixed out of the polymer prior to extrusion. In reactive processing, thermal gradients at any point in the extruder can give a variable rate reaction or even promote the wrong reaction. Our counter-rotating, non-intermeshing twin screw design provides excellent distributive mixing along the entire witted length of the screws. The mixing is the result of a flow pattern that provides multiple reorientations of the melt. This pattern provides a low shear continuous homogenization of the melt that effectively minimizes the magnitude of thermal gradients.
  
  In high viscosity fluids, the temperature of the fluid rises as shear is applied to the fluid.
  
  Removing the heat through conductive cooling may be ineffective and will introduce thermal gradients in the polymer. To overcome this problem, NFM/Welding Engineers applies direct inert fluid contact technology. This technology was developed for our proprietary emulsion finishing process in order to provide extensive cooling capability. This technique avoids thermal gradients that accompany any conductive cooling mechanism. Inert fluid rates in each stage of the process can be as high as five times the polymer throughput rate without reducing polymer throughput rate. Precise temperature control is accomplished by regulating the stage pressure if the inert fluid is boiling and by regulating the flow rate and temperature of the inert fluid if it is not boiling.

• Excellent Mass Transfer Characteristics:

  Mass transfer in highly viscous fluids is often rate-limiting in a reaction. NFM/Welding Engineers has the experience to establish rapid intimate contact of the reactants, regardless of whether the mass transfer is between a melt and a liquid, a melt and a vapor, two melt streams, or a crumb and a liquid or vapor. Our devolatilization technology can be readily applied to polycondensation reactions or any melt vapor mass transfer operation. Our mixing processing technology promotes contact between co-continuous insoluble phases. The continuous reorientation mechanism provides excellent distributive mixing of multiple melt phases.

• Excellent Residence Time Characteristics:

  Insufficient residence time is a common cause for failure of reactive extrusion process development. A residence time limitation will make the throughput capacity insufficient to justify commercialization. Our non-intermeshing twin screw design allows us to operate at higher throughput or longer residence time than competitive designs.

• Grafting Reactions
  • Acrylic Acid, Methacrylic Acid, Maleic Anhydride Grafting to Polyolefins, EP Rubber Vinylsiloxane Grafting to SEBS Block Copolymer
• Dynamic Vulcanization
  • Polyethylene (silane crosslinking)
• Imidization of Acrylics
• And Many Other Proprietary Reactions

Capabilities for larger machines available upon request.
Specifications are subject to change without notice.

• For more information on reaction or any other processes made possible by an NFM/Welding Engineers' system, please contact us. We would be glad to provide additional data or technical support at any stage of your project.