Material systems for stainless steel control cabinets –
also with ATEX suitability


Stainless steel control cabinets are sealed for indoor and outdoor use with suitable polyurethane sealing foams from the FERMAPOR K31 product family.

In accordance with the European Union’s ATEX directives, explosion-proof control cabinets used in mining, chemical or oil industries are sealed with are sealed with FERMASIL temperature-resistant silicone foams. We fulfill the IEC 60079 standard for electrotechnical equipment with explosion protection and your requirements for the ATEX approval of explosion-proof control cabinets. Good adhesion to stainless steel surfaces is achieved by pretreatment with primer.

Paste-like (thixotropic) sealing foam consisting of polyurethane or silicone is applied to the control cabinet parts with contour accuracy using our fully automatic DM 502 mixing and dosing machine. Due to its high viscosity, the applied foam remains stable on the flat surface of the control cabinet panels and doors. After final assembly, the control cabinet is seamlessly sealed in accordance with DIN EN 61439 (IEC 61439) and its overall construction is impervious.

If you are interested in a 3E dosing cell for the application of silicone foam gaskets, we will be pleased to offer this to you as well.

Animation of sealing process of control cabinet panels with Sonderhoff DM 50x and shuttle table on two levels. 


Material systems for stainless steel control cabinets –
also with ATEX suitability


We develop customized solutions for your specific requirements

Our polyurethane and silicone foam gaskets fulfill the types of protection up to IP 68 or NEMA 4 and 12, as well as NEMA 4x for stainless steel cabinets (depending on the component design and foam system).

The very fast-reacting Fast-Cure foam gaskets made of polyurethane for indoor and outdoor use have very short installation and tack-free times, which allow the rapid processing of the control cabinet parts up to their final assembly. This will save time and money.

With more than 30 years of practical experience of control cabinet construction, the foam gasket (tested according to DIN EN ISO 1856) shows very good recovery behavior (DVR) even after years of use. The resilience of polyurethane foam is > 95 % (DVR < 5%) and that of silicone foam > 97 % (DVR <  3%). This enables the frequent opening and locking of the control cabinet door while maintaining a consistently high level of impermeability.


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


Reference material


Stainless Steel
Indoor / Outdoor

  Stainless Steel
Special Requirements (ATEX Cleanroom)
    FERMAPOR K31-A-6060-4-B          FERMASIL A-93-1-VP3-GREY      
Mixing ratio   4.8 : 1   1 : 1
Pot life time   26 sec.   40 sec.
Tack-free time   3.5 min.   8.0 min.

Viscosity of the A component

  60,000 mPas   110,000 mPas
Density of foam   0.25 g/cm³   0.36 g/cm³
Hardness (Shore 00)   56   62
Temperature resistance   from -40 to + 80 °C   from -60 to+180 °C

P23 (solvent-based) or           
P13 (water-based) primer

  Primer P8 or TEROSON SB450

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.

Frequent opening and reclosing of control cabinet, while remaining sealing effect

The very good resilience of the foam seal allows the control cabinet to be opened and closed again for maintenance purposes without the tightness deteriorating. After the door is closed, the housing is tight and the sensitive electronic parts are protected against splashing water and the effects of the weather.

The video shows the silicone foam seal FERMASIL in cross section - first in the uncompressed state, then 30 % compressed, so that the sealing function of the seal is given.

Cross-section of a silicone foam bead – unpressed


Cross-section of a silicone foam bead with approx. 30 % compression

DM 502 mixing and dosing system with 3-axis linear robot and a conveyor belt for the feeding of parts


Flexible and fully automatic –
fully in line with your requirements

Through our combination of individual material systems, customer-specific mixing and dosing machines and skilled process expertise, you receive solutions from us to meet your technical and commercial requirements.

For the construction of your control cabinets, we as process experts offer you individual consulting for the optimal integration of fully automated material application processes with the Formed-In-Place Foam Gasket (FIPFG) technology into your production. You can select different configuration and equipment options for semi-automatic or fully automatic production systems.

In the illustrated reference configuration of our DM 502 mixing and dosing system, the control cabinet parts are fed to the dosing station on a transfer belt at the cycle rate specified for your production, where they pass under the 3-axis linear robot.

The components with plastic surfaces are pretreated with plasma, whereas the components with powder-coated or stainless steel surfaces are pretreated with primer.

The 3-axis linear robot takes over the CNC-controlled movement of the precision mixing head above the component with contour accuracy. The primer or plasma is applied at the same time. This results in the improved adhesion of the foam gasket. We also offer the use of a primer exhaust station depending on the primer to ensure professional air cleaning on the machine.

For the sealing of the control cabinet parts and electrical distribution boxes, the CNC-controlled MK 800 PRO precision mixing head applies sealing foam to the preprogrammed contour. This process is fully automatic with a high level of dosing and repeat accuracy. The seal closes seamlessly with an almost invisible coupling point. The applied material foams and forms an elastic soft gasket with the desired foam hardness at room temperature.

Elevator Supply Tap Mixing head 825 PRO Control cabinet Dosing machine cabinet


Optional: Automatic ELEVATOR drum refilling station for the A-component with pneumatic lift and agitator

More information to our refilling stations

Supply Tap

Optional: Automatic SUPPLY TAP drum refilling station for low-viscosity products, e.g. isocyanate (B-component)

More information to our refilling stations

Mixing head 825 PRO

MK 800 PRO precision mixing head with high-pressure water rinsing or alternative component rinsing system

More information to our mixing heads

Control cabinet

The control electronics, safety engineering and industrial PC are installed in the control cabinet.

More information to our control cabinets

Dosing machine cabinet

The dosing machine cabinet contains the components of the dosing periphery, e.g. the dosing pumps.

More information to our dosing machine cabinets


The basic solution for standard applications

Dosing cell for easy handling and high process stability

The reference configuration of the 3E dosing cell shown is a low-pressure mixing and dosing system for two components for the partially and fully-automatic application of sealing foams.

The 3E dosing cell takes up little space due to its compact design, and as a CE-compliant cell, it does not require additional safety fences or light barriers.

This is a pre-programmed Plug & Work version that is delivered pre-assembled in a container. As soon as electricity, water and compressed air are connected and the material is prepared in the material pressure vessels, production can begin. The costs of installation and training courses can therefore be kept to a minimum. 

The 3E dosing cell can process liquid, medium- and high-viscosity material systems based on polyurethane or silicone. The application rate is adjustable from 0.5 to 5.0 g/s. Experience shows that this is the range that can be used to represent 90 % of control cabinet applications. 

The optional shuttle table enables the processing of components of different sizes in one plane. Continuous operation is guaranteed by the two shuttle tables that can be moved manually in pendulum mode. For larger parts such as the control cabinet panels and doors, the two shuttle tables can be connected to form one large sliding table.

The CNC-controlled MK 825 BASIC precision mixing head for two material components applies paste-like polyurethane sealing foam with repeatable accuracy to the control cabinet parts that have a powder coating or consist of stainless steel. If stainless steel control cabinet parts should receive a primer application to improve adhesion, this can be prepared manually or with auxiliary equipment outside the dispensing system.

In the case of electrical distribution boxes, our dosing technology ensures a very precise dosing application into the very narrow grooves in the housing contour.

With the CE-compliant 3E dosing cell, an immediate, safe start to production is possible, as well as efficiency-enhancing space and cost savings.