Superior Seals, Exceptional Service

3-8159

Robotically Dispensed Gasket Materials

Product
Technology
Duro
Mix Ratio
Description
OEM Specs
3-8159
DFG
55
1:1
2pt, room temperature, self-leveling, 16 PCF density  

 

Dow Corning® 3-8159 RF
Silicone Foam

Two-part, room temperature curing silicone foam system

FEATURES
•Two-part silicone foam system
• Low to medium hardness (Shore 00)
• Reduced flow aids application to inclined surfaces
• User-friendly, easy to handle 1:1 mix ratio
• Fast ambient temperature cure: no need for temporary storage of equipped parts
• Does not require CFCs or other environmentally harmful materials for processing
• Low compression set which is retained at high service temperatures
• Stable and flexible over a wide temperature range

APPLICATIONS
• DOW CORNING 38159 RF Silicone Foam is designed to be dispensed and
cured directly on parts to form an integrated compression gasket.
• Typical applications include automotive parts (e.g. front and rear light units)
and domestic appliance components (e.g. dishwashers).

TYPICAL PROPERTIES


DESCRIPTION
DOW CORNING 38159
RF Silicone
Foam is a reduced-flow medium
hardness product, primarily developed
as a dispensed 'foamed-in-place'
gasket material for the automotive and
domestic appliance industry. When
the A & B liquid components are
thoroughly mixed in a 1:1 ratio by
volume, the product will expand and
cure to a foamed elastomer in
approximately 10 minutes at room
temperature. This foam has a fine cell
structure and functions as a seal or
gasket where long service life,
chemical resistance, good
weatherability and low compression
set are required. The product has been
formulated such that the flow of the
curing material is limited in order to
aid application to inclined surfaces.
The hardness makes the product
suitable for applications with medium
clamping pressure. Furthermore, the
inherent properties of a silicone
elastomer mean that the product can
be used over a broad temperature
range. The material expands without
employing ozone depleting CFCs or
other related blowing agents.

HOW TO USE
Mixing
To ensure a uniform final foam
structure an equal volume of Part A
and Part B should be thoroughly
mixed. The product has been
specifically designed with a
favourable 1:1 mix ratio to suit
robotic application via metermix/
dispense equipment. Mixing can
be achieved either by static or
(preferably) dynamic mixing. The
type and degree of mixing and shear
can significantly affect the cell
structure, cure and density of the final
foam product.

How to apply
The meter/mix equipment can be
attached to a robotic arm/wrist
applicator or on an X-Y-Z table for
automatic dispensing. The mixed
material can be applied into a groove
onto flat surfaces or contoured parts
depending on the specific flow
characteristics.
Cure time
Compared to other foam gasket
systems DOW CORNING 38159 RF
Silicone Foam is a fast reacting
material, thus allowing parts to be
equipped at a high production rate and
avoiding the need for temporary
storage to fully develop the cure. As
supplied and when properly mixed,
DOW CORNING 38159 RF Silicone
Foam has a snap time or working time
of typically 3 minutes (at 23°C) and is
fully cured within about 10 minutes.
Being a highly reactive system, the
cure and snap time are very dependent
upon the temperature of the
components just before and after they
are mixed.

Exposure of the foam material to
elevated temperatures up to 50°C can
shorten the cure time. In order to
eliminate eventual residual surface
tackiness a brief heat treatment for 5-
10 minutes at 60-90°C can be carried
out. Additionally, to optimise
compression set, a post-cure at higher
temperatures (100°C) can be
performed. (see "Typical properties"
table).

Note: See Handling precautions, gas
evolution. Larger pieces of cured
foam should be conditioned for 24
hours at room temperature before
exposure to higher temperatures.

Adhesion
Upon curing DOW CORNING 38159
RF Silicone Foam exhibits
some adhesion to most common
substrates such as glass, steel, wood
and to some plastics. Adhesion to
most substrates can usually be
promoted by use of
DOW CORNING® 1200 Primer.
Substrates to which good adhesion is
not normally obtained include PTFE,
polyethylene, polypropylene and
related materials (contact
Dow Corning for further information).

Good adhesion cannot be expected to
substrates known to inhibit the cure of
DOW CORNING 38159 RF Silicone Foam.

Inhibition of cure
DOW CORNING 38159 RF Silicone
Foam is susceptible to cure inhibition
when in contact with certain materials
and chemicals. This can result in
incomplete cure or a sticky product.
Amines and sulphur containing
materials are strong inhibitors, as are
organo-tin salts as used in
condensation cure silicones. Some
epoxies, amides and related materials
can also cause inhibition, although the
effect is not generally seen with
plastics derived from such materials.
Substrates must be clean, dry and free
of contaminants such as plasticisers or
oils.

To avoid inhibitor contamination of
the A & B liquid components,
dispensing tubes and seals used in
meter/mix equipment must be made
of PTFE rather than conventional
plastic or rubber materials.
In all cases it is recommended that
Dow Corning be consulted in order to
advise on potential inhibition
problems.


TECHNICAL SERVICES
For specific information and technical
service relating to sealing
technologies please refer to the
Dow Corning Sealing & Gasketing
Expertise Team located in Wiesbaden,
Germany.

HANDLING PRECAUTIONS
PRODUCT SAFETY
INFORMATION REQUIRED FOR
SAFE USE IS NOT INCLUDED.
BEFORE HANDLING, READ
PRODUCT AND SAFETY DATA
SHEETS AND CONTAINER
LABELS FOR SAFE USE,
PHYSICAL AND HEALTH
HAZARD INFORMATION. THE
SAFETY DATA SHEET IS
AVAILABLE FROM YOUR LOCAL
DOW CORNING SALES
REPRESENTATIVE.

Gas Evolution
Immediately upon mixing
DOW CORNING 38159
RF Silicone
Foam Part A and Part B, a chemical
reaction takes place that results in the
evolution of flammable hydrogen gas.
APPROPRIATE CAUTION
SHOULD BE EXERCISED!

Keep away from sparks and open
flames. Adequate ventilation must be
provided to prevent localised build-up
of hydrogen gas concentration.
Also on mixing, some exotherm
accompanies the reaction and waste
material must be handled, disposed
and stored with due regard to this
precautionary information, e.g. it
should NOT be sealed in plastic bags
and large quantities should not be
allowed to accumulate.

If Part B of DOW CORNING 38159
RF Silicone Foam comes in contact
with strong acids, bases or oxidising
materials, it could generate hydrogen.
Ensure that containers are properly
closed after use in order to avoid any
contamination of the contents.

USABLE LIFE AND STORAGE
When stored at or below 30°C in the
original unopened containers,
DOW CORNING 38159
RF Silicone Foam has a usable life of 12 months
from the date of production.

PACKAGING
DOW CORNING 38159 RF Silicone
Foam is available as kits in standard
industrial containers sizes suitable for
use in commercially available
meter/mix equipment. For details
please refer to your Dow Corning
sales office.

LIMITATIONS
This product is neither tested nor
represented as suitable for medical or
pharmaceutical uses.

HEALTH AND
ENVIRONMENTAL
INFORMATION

To support customers in their product
safety needs, Dow Corning has an
extensive Product Stewardship
organization and a team of Health,
Environment and Regulatory Affairs
specialists available in each area.
For further information, please
consult your local Dow Corning
representative.

WARRANTY
INFORMATION - PLEASE
READ CAREFULLY

The information contained herein is
offered in good faith and is believed
to be accurate. However, because
conditions and methods of use of our
products are beyond our control, this
information should not be used in
substitution for customer's tests to
ensure that Dow Corning's products
are safe, effective, and fully
satisfactory for the intended end use.
Dow Corning's sole warranty is that
the product will meet the
Dow Corning sales specifications in
effect at the time of shipment. Your
exclusive remedy for breach of such
warranty is limited to refund of
purchase price or replacement of any
product shown to be other than as
warranted. Dow Corning specifically
disclaims any other express or implied
warranty of fitness for a particular
purpose or merchantability. Unless
Dow Corning provides you with a
specific, duly signed endorsement of
fitness for use, Dow Corning
disclaims liability for any incidental
or consequential damages.
Suggestions of use shall not be taken
as inducements to infringe any patent.

Site Information

Sealing Devices Inc.
4400 Walden Ave. Lancaster, NY 14086
Tel: 716.684.7600
Fax: 716.684.0760
E-mail: seals@sealingdevices.com

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