Sealing dirt traps in dishwashers


The reference material presented here, FERMAPOR K31-A 9675-2-VP and B-4 (B-component), is a room-temperature-curing 2- component polyurethane foam for the sealing of dirt traps in dishwashers and has already proven itself in many years of use by leading appliance manufacturers.

The polyurethane sealing foam is applied directly to the component using FIPFG (Formed-In-Place-Foam-Gasket) technology and our fully automated dosing machines – very precisely, safely and efficiently.


Bespoke sealing solutions for the dishwasher

Polyurethane foam gaskets for sealing dirt traps in dishwashers

If desired, we can also customize our polyurethane sealing foams to meet your specific component requirements. Influencing factors include pot life until start of foaming, curing time, and the viscosity, hardness and adhesion properties.

Thanks to a mixed-cell foam structure, the closing forces when installing the foam gasket are low. FERMAPOR K31 compensates for component tolerances when sealing and has a very high temperature resistance from -40 to +80 °C.



The different reaction phases of the sealing foam in the chronological sequence


Reference material

    Sealing dirt traps
in dishwashers
    FERMAPOR K31-A-9675-2-VP       
    FERMAPOR K31-B-4 
Mixing ratio   4 : 1
Pot life time   38 sec.
Tack-free time   3.5 min.

Viscosity of the A component

  1,800 mPas
Density of the foam   0.34 g/cm³
Hardness (Shore 00)   64
Temperature resistance   from -40 to + 80 °C
Pretreatment   Plasma / Korona / Primer

In addition to the reference products, we develop material systems according to your individual requirements. Influencing factors include pot life until start of foaming, curing time, and the viscosity, hardness and adhesion properties.


Repeated installation and removal of dishwasher dirt trap for cleaning while maintaining the sealing effect

The good resetting ability of the FERMAPOR K31 polyurethane foam gasket allow frequent removal and reinstallation of the dirt trap for cleaning purposes while maintaining the sealing effect of the foam gasket. It exhibits excellent long-term behavior even after years of continuous use.

The video shows the polyurethane foam seal FERMAPOR K31 in a cross section in a groove - first in the uncompressed state, then about 50% compressed, so that the sealing function of the seal is given and the component is tight.

Cross-section of a polyurethane foam bead in the groove – unpressed


Cross-section of a polyurethane foam bead in the groove with approx. 50 % compression

DM 502 mixing and dosing system with 3-axis linear robot for the sealing of dirt traps with polyurethane foam


Flexible and fully automatic – fully in line with your requirements

The reference configuration shown here for true-to-contour application of FERMAPOR K31 2-component polyurethane sealing foam in the groove contour of the dirt trap components for dishwashers consists of the DM 502 mixing and dosing system with a 3-axis linear robot and the WT 1-LEVEL shuttle table.

Parts are picked up and processed in continuous shuttle mode in one plane. Alternatively, we can offer the WT 2-LEVEL shuttle table with pick-up plates in two planes situated one above the other in shuttle mode.

The highly dynamic LR-HD 3-axis linear robot used or, alternatively, the highly efficient LR-HE plus ensures that the MK 800 PRO precision mixing head is guided over the component true to contour. At the same time, the mixing head applies the polyurethane foam to the pre-programmed contour fully automatically with high dosing accuracy.

After the dosing cycle, the coupling point of the foam gasket closes seamlessly and is thus almost invisible. The applied material foams, expanding to several times its original volume, and forms an elastic soft foam gasket with the desired foam hardness at room temperature. Due to the chemical reaction of the FERMAPOR K31 material components, good adhesion to the component is usually achieved. A cross-linked structure is formed afterwards, which is extremely resistant to moisture and temperature effects.

Our mixing and dosing machines can be operated easily and intuitively without requiring much training. Thanks to the automatic logging of dosing program data, all process data can be traced and evaluated by the machine operator via the CONTROL 2 operating panel while production is running.

In all solutions, our main focus is on extremely reliable plant engineering, minimized maintenance times and consistent dosing quality. As process experts, we support you with tailored advice for the automation of your manufacturing processes.