SONDERHOFF FERMAPOR K31
Tailor-made chemistry for growing requirements.
SONDERHOFF FERMAPOR K31 is the two-component polyurethane system to produce soft elastic foam gaskets, which are foamed directly onto the part using FIPFG technology (Formed-In-Place-Foam-Gasket).
They are directly foamed onto the part with the aid of mixing and dispensing systems and FIPFG sealing technology (Formed-In-Place Foam Gasket).

Chemical constituents
The system consists of a basic resin (A-component) and a hardener (B-component), which are mixed with each other in
a predetermined mixing ratio. When foaming up on the part, a soft foam gasket is formed after a few minutes.
After reaction of the material components, the foam gasket is tack-free and can be installed into mating components. According to experience the seal function is achieved with a compression of approx. 30– 60% of the cured foam gasket. The flow behavior, reactivity, degree of hardness and color of the material formulations can be adjusted as required.
Henkel can draw on the variety of more than 1,000 applicationspecific formulations of the SONDERHOFF FERMAPOR K31 family.

Broad range of properties
Mixed-cell SONDERHOFF FERMAPOR K31 polyurethane foam seals have a broad profile of properties, combining the positive sealing qualities of closed-cell systems, e.g. low water uptake, with the low construction forces of open-cell systems. Polyurethane foam seals are used mostly in a temperature range from -40°C to about +80°C, though in the short term temperatures up to +160°C are possible.
Numerous product properties in the SONDERHOFF FERMAPOR K31 family
Depending on customer requirements, SONDERHOFF FERMAPOR K31 can cover many different characteristics. For this, many different SONDERHOFF FERMAPOR K31 family recipes are available; combinations of disparate characteristics within a single recipe are rather exceptional.
Physical and chemical Properties | ||
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Property | SONDERHOFF FERMAPOR K31 | |
Appearance | Black or grey, other colors on request | |
Hardness | From 15 Shore 00 to 40 Shore A achievable | |
Compression load deflection | 5 kPa to 200 kPa (at 25% compression) | |
Density | From 0,1 g/cm³ to 0,6 g/cm³ | |
Temperature resistance | From – 40 °C to + 80 °C (temporary up to + 160 °C) | |
Tensile strength | Up to 2 MPa [N/cm²] | |
Elongation at break | Up to 400 % | |
Resetting ability | Greater than 97 % (depending on test conditions) | |
Water absorption | From 3,5 %, hydrophobic versions available, depending on test conditions | |
Flame retardancy | Up to UL-94 V-2 possible | |
E.g. sliding properties, low fogging, suitable for food packaging, protection class up to IP68 or NEMA 12 (achievable with suitable component design) |

Reliability through FIPFG dispensing technology application
The SONDERHOFF FERMAPOR K31 sealing foams can be efficiently and accurately piped on to parts from the most varied of branches of industry using the FIPFG (Formed-In-Place Foam Gasket) technology and mixing and dispensing systems by Sonderhoff. Depending on the viscosity, they are either freely applied to the surface of the part as a paste or poured in fluid form into a groove.
Only with the exact interplay of the most variable set-up parameters and additional functions of the mixing and dispensing machines, the exact calibration of the part and SONDERHOFF FERMAPOR K31 foam seal within the complete construction and the right material choice, can a truly secure seal of industrial components for the most varied uses against damp, dust and other environmental influences be achieved.
FERMAPOR K31 – the reaction process
SONDERHOFF FERMAPOR K31 sealing foams consist of a liquid to pasty A-component (polyol) and a hardener, the B-component (MDI isocyanate). The chemical reaction of SONDERHOFF FERMAPOR K31 sealing foams is initiated by mixing the A- and B-components. The applied compound foams up to a uniform gasket under room temperature conditions.
SONDERHOFF FERMAPOR – the foaming process | |
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Pot life | The time span from the mixing of the A- and B-components to the beginning of the foaming time (approx. 15 – 60 seconds). It is also referred to a processability time or service life. |
Foaming-up time | The time span in which the SONDERHOFF FERMAPOR K31 foam system expands to form a seal body (after approx. 30 – 180 seconds). |
Tack-free time: | The time from which the sealant surface of SONDERHOFF FERMAPOR K31 foam systems can be touched without causing damage (after approx. 2 – 20 minutes). |
Assembly time: | The chemical reaction has progressed so far that the SONDERHOFF FERMAPOR K31 foam systems can bear loads or the foamed components can be assembled (after approx. 20 minutes – 12 hours). |
THE SONDERHOFF FERMAPOR K31 RANGE SELECTION
The SONDERHOFF FERMAPOR K31 pallet offers effective seal protection for a wide range of application areas and requirements. In the table you will find a selection of foam sealing systems for various industries, from lighting to switch cabinet and automotive construction, to filters, packaging and the household appliance industry.
SONDERHOFF FERMAPOR K31 A-component |
Application area | Viscosity mPas |
Hardness Shore 00 |
Density g/cm3 |
Other properties |
---|---|---|---|---|---|
A-9675-5-VP | Lighting | 1,300 - 1,900 | 20-50 | 0,13-0,24 | UL-50 listed, suitable for moisture-proof luminaires, soft |
A-9675-2-VP | Lighting | 1,000 - 2,500 | 35 - 75 | 0,25 - 0,50 | UL-50 listed, suitable for moisture-proof luminaires |
A-3505-1 | Lighting | 2,000 - 3,800 | 30 - 40 | 0,22 - 0,28 | Product for moisture-proof luminaires, especially self-levelling |
A-4525-1-B-UL | Enclosures | 25,000 - 33,000 | 40 - 50 | 018 - 0,24 | UL-50 listed and good adhesion on lacquer |
A-9021-2-VP1 | Enclosures | 37,000 - 52,000 | 37 - 52 | 0,25 - 0,35 | UL-50 listed |
A-45C2-1-UL-FR | Enclosures | 120,000 - 150,000 | 43 - 53 | 0,23 - 0,29 | UL-50 listed |
A-6045-3-B-UL | Enclosures | 60,000 - 70,000 | 50 - 65 | 0,29 - 0,35 | UL-50 listed, hydrophobic, very good resetting ability (DVR), good adhesion on lacquer |
A-4545-1 | Enclosures | 45,000 - 55,000 | 40 - 50 | 0,27 - 0,36 | High mechanic strength, low friction, optimized against shear stress |
A-4530-3-B | Enclosures | 33,000 - 40,000 | 32 - 42 | 0,19 - 0,23 | UL-50 listed, very good resetting ability (DVR), good adhesion on powder coating, fast assembly |
A-6060-1-B | Enclosures | 55,000 - 65,000 | 50 - 60 | 0,23 - 0,29 | UL-50 listed, hydrophobic, very good resetting ability (DVR), good adhesion on powder coating, fast assembly |
A-9025-2-VP2 | Enclosures | 35,000 - 50,000 | 28 - 42 | 0,15 - 0,30 | Extremely soft, UL-50 listed, good adhesion on lacquer |
A-6045-2-B-MX | Filters | 50,000 - 65,000 | 50 - 60 | 0,24 - 0,30 | Microbial inert adjustable, suitable for ventilation systems |
A-5065-1-G-MX | Filters | 60,000 - 70,000 | 45 - 55 | 0,21 - 0,29 | Microbial inert adjustable |
A-9308-5-VP5-F | Filters | 130,000 - 200,000 | 38 - 62 | 0,18 - 0,27 | For 3D applications, microbial inert adjustable, suitable for ventilation systems |
A.3030-1-MX | Filters | 28,000 - 38,000 | 20 - 30 | 0,17 - 0,23 | Extremely soft, microbial inert adjustable, suitable for ventilation systems |
A-9808 | Filters | 1,000 - 2,000 | 35-65 | 0,17 - 0,35 | For very small groove applications (2 mm) |
A-6501-3 | Automotive | 900 - 1,500 | 56 - 66 | 0,34 - 0,40 | High tightness, hydrophobic, very good resetting ability (DVR) |
A-3565-2 | Automotive | 60,000 - 75,000 | 30 - 45 | 0,13 - 0,16 | Extremely soft, low assembly forces |
A-9308-5-VP5 | Automotive | 120,000 - 160,000 | 35 - 55 | 0,18 - 0,40 | Very high mechanic strength, hydrophobic, for 3D applications |
A-7060-5-B | Automotive | 55,000 - 70,000 | 55 - 65 | 0,30 - 0,36 | Sealing of E-Mobility batteries, fast assembly |
A-5555-1 | Automotive | 50,000 - 65,000 | 50 - 60 | 0,24 - 0,30 | High tightness, hydrophobic, very good resetting ability (DVR) |
A-9199-29-VP3 | Automotive | 45,000 - 60,000 | 20 - 45 | 0,17 - 0,30 | High tightness, low assembly forces and high mechanic strength |
A-9308-5-VP4 | Automotive | 90,000 - 150,000 | 25 - 50 | 0,15 - 0,27 | Very high mechanic strength, for 3D applications |
A-9675-11 | Automotive | 1,000 - 1,500 | 28 - 48 | 0,16 - 0,22 | Hydrophobic, suitable for 2D groove applications, low dens |
A-45C0-1-G-LE | Automotive | 90,000 - 130,000 | 40-50 | 0,18 - 0,24 | Low emissions, meets Daimler DBL5452 and BMW TL 8 350 151_6 design 11 |
A-6501-4-N | Packaging | 1,000 - 1,700 | 62 - 72 | 0,40 - 0,48 | Very elastic, for high tightness requirements, good resetting ability (DVR) |
A-9843-8-VP3H | Packaging | 9,000 - 16,000 | 60 - 75 | 0,31 - 0,37 | Good price-performance ratio, good resetting ability (DVR) |
A-9762-1 | Packaging | 6,000 - 9,000 | 65 - 75 | 0,33 - 0,40 | Approval for food packaging (EU) |
A-6505-1-N-FD | Packaging | 5,000 - 7,500 | 73 - 83 | 0,24 - 0,30 | Approval for food packaging (EU and FDA) |
A-9370-VP5 | Appliances | 58,000 - 80,000 | 10 - 30 | 0,18 - 0,26 | Hyper soft for ceramic stovetops |
10 good reasons for SONDERHOFF FERMAPOR K31
- … is ideally suited for sealing industrial components in practically all shapes and geometries.
- … often achieves particularly good adhesion onto the component through the chemical reaction of
the two material components on the substrate. - … has excellent long-term behavior and shows almost 100% resetting ability even after years of
continuous use. - … is tack-free at room temperature in 2– 20 minutes. A furnace can significantly shorten the reaction
time, but it is not always necessary. - … offers special quick-reacting fast-cure recipes that are tack-free within 120 seconds for higher
production cycle times. - … easily compensates for large component tolerances.
- … forms a cross-linked structure after the reaction, which is extremely resistant to influences
such as moisture, dust and temperature. - … produces foam gaskets with extreme softness.
- … is processed with mixing and dosing systems for two components and can be easily and quickly
changed over to other components, that need to be sealed at any time. - … can be processed profitably even in small production runs.