Sealing of headlights


To ensure that your innovative vehicle lighting systems can function reliably, we offer you efficient and flexible sealing solutions to meet your individual requirements. Our 2-component sealing foam is installed and compressed in the overall part construction of the vehicle light. This keeps moisture away from the light sources and thus avoids the risk of lighting electronics corroding. The polyurethane based 2-component sealing foams can be applied to a wide range of applications on cars, vans and trucks: front headlights, tail lights, third brake lights, turn signals, rear fog lights, license plate lights and multifunctional lights.

Third brake lights, installed in rear spoilers or on rear windows with 2-dimensional and 3-dimensional geometry are often sealed using the FERMAPOR K31 thixotropic polyurethane foams, because these adapt excellently to the 3D contour. Using the FIPFG process, our dosing equipment applies a small, fine foam bead to the contact surface or in the groove, ensuring reliability under process conditions and stability guaranteed by the high foam viscosity.

FERMAPOR K31 seals are therefore ideally suited for a majority of designs of third brake lights. Although we can produce the sealing material in a variety of colors, the seal in this case is typically red in color and not visible under the red cover of the brake light.


Tailor-made sealing solutions
for headlights


We develop individually for your specific requirements

We offer efficient and flexible sealing solutions to meet your individual requirements for headlights. Our 2-component sealing foam is installed and compressed in the overall part construction of the vehicle light. This keeps moisture away from the light sources and avoids the risk of lighting electronics corroding. 

Even though headlights with xenon, LED and laser light technology now represent state-of-the-art vehicle lighting in many markets, there are still countries where cars are sold with conventional headlight technology. Our customers use FERMAPOR K31 2-component polyurethane foams for sealing these conventional headlights, which are characterized by excellent long-term behavior and very high resilience of the foam structure.

The backcap on the back of the headlight can be opened and closed again at any time, e.g. to change the H7 bulb, without the sealing effect weakening. To compensate for component tolerances, the polyurethane foam can be easily compressed during assembly thanks to a mixed-cell foam structure with low installation forces.


Reference material

    FERMAPOR K31-A-5555-1        FERMAPOR CC-A-5530-2-B

Mixing ratio

  4 : 1   2.3:1

Pot life time

  35 sec   n/a

Tack-free time

  4 Min   16 Min

Viscosity of A component

  55,000 mPas   70,000 mPas

Density of the foam

  0.27 g/cm³   0.31 g/cm³

Hardness (Shore 00)

  54   55

Temperature resistance

  from -40 to + 80 °C   from -40 to +180 °C


  Primer P23 (solvent-based),
P13 (water-based) or plasma
  Primer P23 (solvent-based),
P13 (water-based) or plasma

In addition to the reference products, we develop material systems according to your individual requirements.

Maintenance-friendly processes


The very good resilience of the foam seal allows the components to be opened and reclosed repeatedly for maintenance purposes without the tightness deteriorating. After installation, the headlight is sealed and the sensitive electronics are protected against splashing water and the effects of the weather.

Cross-section of a polyurethane foam bead in the groove without compression.


Cross-section of a polyurethane foam bead in the groove and compressed to approx. 50 %.


DM 402 mixing and dosing system with 3-axis linear robot and a shuttle table for picking parts of the headlight backcaps


The reference configuration shown here for sealing the backcaps of headlights consists of our DM 402 mixing and dosing system with an HE 3-axis linear robot as well as a WT 1-LEVEL shuttle table for picking up parts. The two pick-up plates working in pendulum mode enable the workpieces fixed there to be picked up and processed in one plane. This makes it possible to guarantee continuous operation.

The placement and holding on the shuttle table of the headlight housing to be sealed is performed either by a machine operator, who can also check the parts for quality, or by a Pick & Place Robot. In this case, an optionally installed camera system could carry out the quality control of the parts.


Flexible and fully automatic – according to your requirements

For sealing the headlights, FERMAPOR K31 thixotropic polyurethane sealing foam is applied via the nozzle injector of the CNC-controlled MK 625 mixing head, in a high-precision and fully automatic process, onto the 2D or 3D application surface or into the groove of the component contour. After the dosing cycle, the coupling point of the foam gasket closes almost seamlessly and is thus virtually invisible. Due to the uniform compression in the installed state, a high level of tightness is achieved over the entire contour of the backcaps.

For improved adhesion of the foam gasket to plastics such as PP or PE using plasma, we install an optional plasma application unit on the rear of the CNC Y-axis in addition to the mixing head.

Even with short cycle times and high unit numbers, the material application process using the FIPFG method is carried out with high dosing precision and repeat accuracy. As a result, you achieve foam gaskets of uniformly high quality. This means that your sealed headlights can be processed rapidly, right through to final assembly. This saves time and money.

In addition, our fail-safe mixing and dosing system can be operated easily and intuitively without the need for extensive training. Due to the automatic logging of dosing program data, all process data can be traced and evaluated by the machine operator while production is running.