No other rubber compound is more versatile then silicone rubber. From
freezing-cold to ultra-hot temperatures, silicone can perform in the
most extreme temperature demands. This leads to its use in most
industries.
Because silicone is maintenance-free and has a longer service life than
other materials, manufacturers are increasingly looking to upgrade from
their current parts to improve performance. Silicone rubber fits
perfectly for this demand. Natural rubber insulators are being replaced
with silicone to improve the weather resistance and give better oil
resistance. Latex is being replaced by low durometer silicone for soft
touch applications to prevent allergic effects and utilize the anti-
microbial composition of silicone. Better ozone resistance, better
insulating and better temperature performance leads to a better rubber
part. This drives the use of silicone in all applications in all
industries.
AEROSPACE
Since its development, silicone has played a key role in the Aerospace
industry because of its wide temperature ranges. With most rubber
compounds maxing out at -40°C, phenyl-based silicone can still stay
flexible down to -100°C. The main silicone specifications for this
industry are AMS 3301 - 3304, A-A-59588 and AMS 3349. Fluorosilicone
is the work-horse for Aerospace applications and provides the extreme
temperature resistance and excellent oil and fuel resistance that this
application demands. Common standards are AMS-R-25988 and AMS 3331.
With a standard post-cure, most silicones and fluorsilicones will also
meet outgassing limits based on ASTM E 595 of historically total mass
loss (TML) of 1.00% and collected volatile condensable material (CVCM)
of 0.10%.
AUTOMOTIVE
The strife for 100,000-mile warranties makes silicone the perfect
replacement material for the automotive industry. Silicone's high
temperature resistance continues to provide long service life as
engines burn hotter to improve emissions. Silicone hoses offer
greatly reduced down time for maintenance issues as they provide
superior resistance to hot ethylene glycol, diesel fumes and engine
cleaning solvents. The low compression set of silicone prevents
retaining clamps from loosening, which can cause leakage and rattles.
Electrical connector seals provide long-term weather ability, even in
extreme temperature ranges, and the self-lubricating property of
silicone provides an excellent choice for multiple-pin connector
seals. Engine mounts and muffler hangers made of silicone make
excellent heat shields and help to control noise and vibrations.
MEDICAL
The simple characteristics of inertness make silicone a great choice
in the medical industries. Silicone can easily pass UPS Class VI and
ISO 10993 Biocompatibility testing. There are three main grades of
silicone; Industrial, Short Term Implant and Long Term Implant grade.
Industrial grades typically have fillers to give better heat and oil
aging which are not recommended for the medical industry. Short Term
Implant materials are typically used for applications that are less
than 29 days. These grades are periodically tested for
biocompatibility and have passed most of the biocompatibility tests.
Implant grades are considered for greater than 29 days. Typically
each lot undergoes a certification test to assure biocompatibility.
The Implant grades are the highest cost, but provide a high degree of
compliance. From catheters, to silicone tube for duct replacements
and micro O-rings for insulin pumps, silicone rubber provides the most
reliable alternative for rubber compounds.
ELECTRONICS
One of the largest consumer groups by volume of silicone is the
electrical industry. Silicone is extruded around cables to provide
and perfect environmental barrier for the cable. With very high
volume resistivity, silicone provides great electrical insulation.
With composite designs using silicone and engineered polymers, ceramic
components are being replaced for higher mechanical strength, greater
design flexibility, reduced weight and lower breakage rates. Special
grades of carbon black and metallic fillers can be used as filler
systems to make the silicones more conductive. These provide EMI/RFI
shielding materials. Housing seals can be created to maintain
conductivity through insulation boxes and covers, and the silicone
seal will maintain its heat, weather and low-temperature resistance.
Due to its flexibility and resilience, silicone keypads are also at a
growing demand. Silicone parts provide for a longer keyboard life and
better sealing. Silicone can easily meet the demands of UL 50 and UL
50E, Enclosures for Electrical Equipment Safety Standard. With low
compression set, weathering, and chemical resistance, silicone rubber
is a great choice for seals in enclosure boxes.
CONSTRUCTION
One of the most visible uses of silicone in the construction
industries can be seen around any window or door. Silicone RTV
provides outstanding adhesion to most constructions materials, while
sealing and providing long-term durability and weather resistance.
Silicone coatings preserve the natural look to building materials and
extend the service life of the product. Silicone expansion joints
provide the ability for construction material to move with thermal
expansion while providing long-term sealing of the joint.
