Two-component, room-temperature cross-linking silicone systems for sealing, gluing and potting
Tailor-made chemistry for the most demanding requirements.
FERMASIL® is the trade name for the two component silicone system from Sonderhoff Chemicals for manufacturing of fl exible silicone elastomers and silicone foam sealings, which are applied directly onto the
part by using FIPFG (formed-in-place foam gasket) technology.
The systems consist of an A-component and a crosslinking B-component, which are processed in a given mixing ratio. After mixing the components most systems react by their own at room temperature and generate
a soft and fl exible silicone foam sealing or permanently flexible silicone elastomers.
FERMASIL® systems are processed using 2- component low pressure mixing and dosing machines. Suited for the mixture are dynamic mixing systems as well as static mixers. Sonderhoff recommends dynamic mixing systems for material friendly processing.
Sonderhoff FERMASIL® Systems can be used by a constant temperature from -60°C to +180°C and temporary up to +350°C but they keep always their softness and flexibility. Due to their closed cell structure they
do not absorb water and are suitable for the use in tropic or damp rooms. They are also highly resistant to other chemicals (e.g. cleaning agents, alcohols, lubricants, hydrochloric acid, nitric acid, brake fl uids, cooling agents and ammonia gases).
2D application on a level surface
2D application in a groove
3D application on a surface
3D application in a groove
Thixotropic (pasty) sealing systems are preferentially used which, depending on the degree of viscosity, form a seal body with a height/width ratio from 1 : 2,5 to 1 : 1,5.
Fluid sealing systems, which are self-levelling over joints, are usually used in this case. This allows smooth seamless seals to be created.
Thixotropic (pasty) sealing systems are preferentially used which, depending on the degree of viscosity, form a seal body with a height/width ratio from 1 : 2,5 to 1 : 1,5. Use is possible even with extreme slopes up to vertical application.
Thixotropic (pasty) sealing systems are used most often in this case. Seal application is also possible even with extreme slopes.
10 good reasons for using FERMASIL® :
- FERMASIL® systems can be used by a constant temperature up to +180°C (special types up to 250°C)
and temporary up to +350°C.
- FERMASIL® systems is closed-cell and therefore do not absorb water.
- FERMASIL® systems are highly resistant to many chemicals.
- FERMASIL® systems are hydrolysis stable and therefore suitable for the use in tropic or damp rooms.
- FERMASIL® systems keep greatest possible fl exibility even down to -60°C.
- FERMASIL® systems are tack free in 2 - 30 minutes which depends on the thermal condition. An oven can reduce the reaction time considerably, but it is not a necessity in all cases.
- FERMASIL® systems are processed using two component metering units and can be adapted anytime flexibly and quickly to other components to be sealed.
- FERMASIL® systems develop a cross-linked structure which is extremely resistant to environmental effects such as humidity, dust and temperature.
- FERMASIL® systems possess exceptional long-term behaviour and have almost 100% resetting ability, even after many years of continual use.
- FERMASIL® systems are suitable for direct contact with food in some cases.
FERMASIL® - The technology
The reaction of FERMASIL® foam sealants is initiated by mixing the A and B components. This results in a chemical reaction which proceeds steadily at room temperature. The applied mass foams equally in all dimensions to form the gasket.
FERMASIL® - The foaming process
- Mixing time: the time period in which the A and B components are mixed.
- Reaction time: the time period in which the FERMASIL® foam system begins to react
(after approx. 15 - 60 seconds *)
- Rise time: the time period in which the FERMASIL® foam system expands to form the seal body (after
approx. 60 - 180 seconds *)
- Tack-free time: the time after which the seal surface of FERMASIL® foam systems is tack free at room
temperature and can be touched without causing damage (after approx. 2 - 30 minutes *)
oder im Ofen klebfrei ist und ohne Beschädigung berührt werden kann (nach ca. 2 – 30 Min.*)
- Assembly time: is the time point after which FERMASIL® foam systems can bear loads or the sealed components
can be assembled (after approx. 20 minutes - 12 hours *)
* depends on the temperature conditions
FERMASIL® silicone systems are processed using two component mixing and metering machines. The recommended processing temperature is +23 +– 5 °C. Most of the FERMASIL® components can be stored in the original packaging and for at least 6 months.
PHYSICAL AND CHEMICAL PROPERTIES
white, grey or black, other colours upon request (also transparent)
gel-like up to 80 Shore A feasible
Compression load defl ection
20 to 150 kPa (at 25% compression)
from 0,3 g/cm³ to 2 g/cm³
from –60° C to +180° C (short time up to +350° C)
up to 4,5 MPa [N/cm²]
Elongation at break
up to 600 %
> 97 % (depending on test conditions)
< 1 %
up to UL-94 V-0 possible
Viskosity of the A component
from 1.000 mPas (liquid) to 500.000 mPas (highly pasty)
UL50 conformity, UV resistant, low fogging, good chemical resistance, if requested IP 69K ingress protection class and Nema 4-6p protection class are possible.
The FERMASIL® range
2C addition curing
Slightly foamed, liquid silicone system,
Highly viscous, stable, medium hardness, curing possible without heat treatment
Liquid, good fl ow, curing possible without heat
very good dielectric properties, good fl ow rating, color and reactivity are adaptable to costumers’ wishes, by changing the mixing ratio also able to process gel-like.
Soft elastomer seal with good mechanical properties
Use in contact with food is possible, fast curing, good mechanical properties
Liquid, PTB approved in electric enclosure applications
Thixotropic, stable, standard material with medium hardness, UL50E listed
UL50E listed, thixotropic, stable, curing possible without heat treatment
2C condensation curing
alkoxy cross linking, no corrosive fi ssion products while curing, very soft foam seal