Parent Category: Polymer Industry

Polyurethane (PUR) foam simulation:
foaming cup

Polyurethane (PUR) foam simulation can perfectly be performed with our CFD software NOGRID points. Polyurethanes are synthetic materials or resins covering a wide range of stiffness, hardness and densities. They are used as low density foam e.g. in upholstery fabrics and refrigerator insulation and as soft or hard plastic parts ranging from shoes to skateboard wheels to car dashboards to vibration and shock absorbers, to name just a few examples.


Identification of air entrapment by polyurethane (PUR) foam simulation

In most industrial production processes liquid polyurethane (PUR) is injected into a closed mold where it reacts and expands to finally fill out the mold. In this process air bubbles might be entrapped or a structural failure of the hardened but still expanding plastic might occur, resulting in defects, instabilities or unattractive surfaces. Simulation can help to identify these problems in advance.

Polyurethane (PUR) simulation foaming cup

Figure 1: Simulation of foaming polyurethane in a cup

Polyurethane (PUR) simulation reduces need for expensive prototypes

The simulation of the chemical reaction and foaming process of a viscoelastic fluid helps to formulate and verify material models for the different polyurethanes, to analyze the forming of air traps and to optimize the production process by varying the position of the injection vents or other parameters without the need of expensive prototypes.

The meshless CFD software NOGRID points abilities to efficiently handle fast varying fluid surfaces in complex geometries with rapidly changing material properties make it a supreme tool for such simulations.

In figure 1 the PUR foaming process of a cup in an open can, perforated by a small cylinder, is shown. By symmetry only a quarter of the model needs to be simulated. One can see that at the end the mold overflows and forms the typical shape before the reaction finally stops.