Chomerics

Conductive Elastomer EMI Gaskets

Molded and Extruded Materials Selection Guide

ENGINEERING YOUR SUCCESS.

aerospace

climate control

electromechanical

ﬁltration

ﬂuid & gas handling

hydraulics

pneumatics

process control

sealing & shielding

ENGINEERING YOUR SUCCESS.

EMI Materials

INTRODUCTION

CONDUCTIVE ELASTOMER SELECTION GUIDE

Tables 5a and 5b contained herein provide selection guide-

lines for Chomerics’ most general-purpose EMI elastomer

materials. With the exception of certain limitations noted

under “Remarks”, these materials are electrically stable

over time and provide excellent moisture and pressure

sealing. They are all medium-durometer materials and

differ mainly in shielding performance and corrosion resis-

tance. (Nickel-plated aluminum materials are signiﬁcantly

more corrosion-resistant than silver-plated copper, silver-

plated aluminum, and silver-plated nickel ﬁlled materials

against aluminum.)

• Availability

• Design Flexibility

• Cost Effectiveness

• Proven Performance

…just four of the reasons why conductive elastomer gas-

kets are so often the right EMI shielding solution!

Once used mainly to shield critical defense and aerospace

electronic systems, Parker Chomerics conductive elasto-

mers have become the progressive choice for packaging

designers of consumer, telecommunications, business,

industrial equipment, automotive, medical devices and

much more.

Conductive elastomers are reliable over the life of the

equipment. The same gasket is both an EMI shield and an

environmental seal. Elastomer gaskets resist compres-

sion set, accommodate low closure force, and help control

airﬂow. They’re available in corrosion-resistant and ﬂame-

resistant grades. Their aesthetic advantages are obvious.

Almost any elastomer proﬁle can be extruded or custom-

molded with modest tooling costs and short lead times for

either prototypes or large orders. Parker Chomerics can

also take a customer-supplied design and deliver ﬁnished

parts. Parker Chomerics offers hundreds of standard

molded and extruded products. Molded products provide

moisture/pressure sealing and EMI/EMP shielding when

compressed properly in seals, ﬂanges, bulkheads, and

other assemblies. Extrusions provide similar beneﬁts and

are also readily lathe-cut into washers, spliced, bonded,

kiss-cut, or die-cut to reduce installation labor and to con-

serve material, resulting in a cost-effective alternative to

other methods of EMI shielding and environmental sealing.

CHO-SEAL

CONDUCTIVE ELASTOMERS

Over the years, Parker Chomerics has developed and en-

hanced virtually every aspect of conductive elastomer ma-

terials technology, from the earliest silver and silver-plated

copper ﬁlled silicones, to the latest and more cost-effective

nickel-plated aluminum and nickel-plated graphite com-

posites. Today we offer the most comprehensive selection

and highest quality products available.

Each conductive

elastomer consists

of a silicone, ﬂuo-

rosilicone, EPDM

or ﬂuorocarbon-

ﬂuorosilicone

binder with a

ﬁller of pure silver,

silver-plated cop-

per, silver-plated

aluminum, silver-

plated nickel,

silver-plated glass,

nickel-plated

graphite, nickel-

plated aluminum

or unplated graph-

ite particles. The development of these composites is

the result of decades of research and testing, both in

the laboratory and in the ﬁeld. Our proprietary ﬁller

powder technology allows us to carefully control the

composition, size, and morphology of the conductive

particles. Their precise, uniform dispersion within the

resinous binders produces materials with stable and

consistent electrical and physical properties.

Parker Chomerics’ conductive elastomers feature

excellent resistance to compression set over a wide

temperature range, resulting in years of continuous

service. In addition to EMI shielding, these materi-

als can provide an environmental or pressure seal if

required.

For those materials containing silver, both packaging

and storage conditions should be similar to those for

other silver-containing components, such as relays

or switches. They should be stored in sheet plastic,

such as polyester or polyethylene, and kept away from

sulfur-containing materials, such as sulfur-cured neo-

prene, cardboard, etc. To remove dirt, clean the elas-

tomer with water or alcohol containing mild soap (do

not use aromatic or chlorinated solvents). Shelf life of

these conductive elastomers without the presence of

pressure sensitive adhesive (PSA) is indeﬁnite. Shelf

life of the PSA is 12 months from date of manufacture.

Refer to page 30 for Applications detailed guidance on

PSA systems.

Tables 6 and 7 outline the properties and speciﬁcation

limits of Parker Chomerics’ conductive elastomers.

These materials are produced in a virtually unlimited

variety of molded, die-cut and extruded shapes and

sizes. Our Applications Engineering Department is very

accessible, and ready to assist with material selection

and gasket design. We welcome your inquiry.

Chomerics

MATERIAL SELECTION

The Parker Chomerics array of conductive elastomers offers

true ﬂexibility in selecting the appropriate material for a

speciﬁc application on the basis of cost and level of

attenuation required. Price varies directly with shielding

performance.

For some military/aerospace applications, users of

conductive elastomer gaskets consider specifying materials

that meet MIL-DTL-83528 where appropriate but note that

newer materials may not yet be included in that speciﬁcation,

e.g., nickel-plated aluminum ﬁlled elastomers. To avoid the

risk of system EMI or environmental seal failure, any change

in conductive elastomer seal supplier (including

MIL-DTL-83528 QPL suppliers) should be preceded by

thorough system qualiﬁcation testing.

UL 94 V-0 RATED MATERIALS

Chomerics introduced the ﬁrst conductive elastomer gasket

material with a UL 94 V-0 rating.

Since that time, Chomerics now has a selection of UL 94 V-0

rated gasket materials including CHO-SEAL 6370, 6371, 1273,

S6305 and 1310.

CHO-SEAL gasket materials are rated at UL 94 V-0 down to a

thickness of 0.013 Inch (0.33 mm). Actual thickness for each

certiﬁed material, and speciﬁc conditions of use can be found

in UL File #OCDT2.E140244 under Insulating Devices and

Materials – Components. CHO-SEAL materials certiﬁed by

UL for use in Canada can be found in UL File OCDT8.E140244.

For UL Certiﬁcation ﬁles, please visit www.ul.com.

Conductive Elastomer Applications

In general, certain types of Parker’s conductive elastomers

are speciﬁed more often for military/aerospace applications

or for commercial applications. However, there is a

considerable overlap, and our Applications Engineering

department will be pleased to assist you with your product

selection.

ELASTOMER PRODUCT OFFERING

Military and Commercial Products

CHO-SEAL

6502

6503 – Fluorosilicone

1298 – Fluorosilicone

1285

1287 – Fluorosilicone

1215

1217 – Fluorosilicone

S6305

6370 – Extruded only

6371 – Molded only

6308 – Extruded Only

6330 – Molded Only

L6303 – Fluorosilicone

1350

1310 – Molded Only

1273

1270 – Molded Only

Specialty Products

CHO-SEAL

1224 - Molded Only

1221 – Fluorosilicone, Molded Only

S6600 – Molded Only

1401

1239 - Molded Only

1212 – Molded Only

6435 – Molded Only

6307 – Molded Only

6452 – Extruded Only

6460 – EPDM , Molded Only

V6433 – Molded Only

Refer to tables 6 and 7 for speciﬁc material properties

and material guidelines.