Reaction Injection Moulding - RIM (cavity foaming)

During Reaction Injection Molding (RIM), cavities are filled with 2K-PUR-Foaming. The initial components are carried by separate circulation pumps that are operated by low pressure and, only right before the application, charged with high pressure. Both materials are mixed in a molding tool before they are precisely applied by the applicator.

The blending of the material components happens during the application. Before that stage, they follow the circuit to the material container of the cell.

The chemical reaction, polyaddition, creates a new substance out of these two components – a polyurethane foam material. Depending on the reaction this substance presents itself as foam or isotope material. In the chemical process following the addition of water, CO2 is created which influences the compactness of the foam.

If the ratio of components is adjusted correctly, there will be no side products. The chemical reaction (R=Reaction) takes place right after the blending in the mixing chamber of the applicator, which means that the applicator applies or injects a mixed material jet (I=Injection). In the mold (M=Mold), the reaction is continued and the polyurethane hardens. PUR-systems that are relevant for the RIM-process show a high reactivity, calling for a fast mixing and application process. The selection of the doser technology, the application pressure and the type of nozzle depends on the output and the viscosity of the processed material.

RIM doser
RIM recirculation system
RIM applicator

Cell technology

The 2K-application system for the RI M area utilizes the ATN doser technology. This tested and proven technology assures accuracy no matter the material output as well as a stable and tailored-to-suite material dosage.
A continuous material flow guarantees that, no matter the type of application, no material standstill occurs and that the optimal prepared material is available at any time.

RIM periphery

Material supply
The material supply of the 2K-applicator system assures a continuous feed of the succeeding modules. The material supply is available in 2 sizes:

  • EFE0200 for 200 liter barrels
  • EFE1000 for 1,000 liter IBC


  • fluid level detection
  • stirrer system
  • air dryer
  • piggyback system

Applicator cleaning
To remove possible stains, ATN offers a fully mechanical operating cleaning station for applicators.

RIM recirculation system

To achieve the necessary properties of the 2K materials, the components need to have precise conditioning. The conditioning and the supply condition of the materials for the succeeding modules is accomplished by the recirculation system (the material is circulating whether or not there is an application). This assures an optimally prepared material for processing.
The circuit system operates with low pressure, thus having a positive effect on noise emission and life expectancy of the equipment.

This module is currently available in two sizes:

  • circuit module with a 50 liter storage (MKS-50-Serie)
  • circuit module with a 280 liter storage (MKS-280-Serie)


  • continuous material circulation
  • integrated heat exchanger for compact design
  • filtration
  • pipe heating


  • fluid level detection
  • stirrer system (for one or both components)
  • air dryer
  • external temperature control
  • redundant design for increase process stability and decreased downtimes
  • encapsulation

RIM doser

The electrical powered volume doser offers the best regulation and dosing properties for the initial materials and additional components and aggregates are not needed.

Because material-carrying part and the power unit are separate maintenance is easy. The applicator is continuously supplied with the initial conditioned materials by the doser unit (PUR applicators with Isocyanate and Polyol).

During the application, the dosers realizes the pressure build-up to up to 200 bar and assure the facilitation of the necessary material quantity. The dosers have a narrow shape which enables them to be placed in close vicinity of the applicators.

Standard volume doser for RIM application

EVD 80

  • material quantity between 5 –120 cm³ 2K-material
  • output per shot max. 50 ccm/s

EVD 155

  • material quantity between 5 –250 cm³ 2K-material
  • output per shot max. 85 ccm/s

EVD 560

  • material quantity between 10 –900 cm³ 2K-material
  • output per shot max. 190 ccm/s

Additional doser sizes are available upon request.

RIM applicator

The RI M applicator is based on the counter-current injection principle with the mixing by turbulent currents. During the material insert, the components are brought together in a small mixing chamber by the nozzles (cross-section between 0.2 and 1.0 mm).

Because of the incurring flow speed of up to 350 m/s, the components hit each other straight on and are mixed homogeneously. During the standstill, the applicator is flushed continuously.

Functions and properties

  • high-pressure mix by utilizing the countercurrent injection principle
  • shot volumes meet industrial conditions and requirements
  • process stable at 10 Gramm
  • dosing deviation < 2%
  • outer nozzle diameter 6 mm
  • weight 3 kg
  • dimensions (L/B/H) 450 x 450 x 2000 mm

Manual application
A handle makes the manual operating of the applicator possible. On the control section, the customer may choose from up to 10,000 saved mixture recipes.
For automated operation, the applicator can be attached to a robot or the manipulator with a flange.

Need more information about product?

We will be glad to assist. Please consult our colleagues, or write to us using the general contact form.

Phone: +49 35936 335-0
Fax: +49 35936 335-2000
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Polyurethane-mixing technique

Our application technology for the foaming can be found in our Initiates file downloadproduct flyer

Industry solutions

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