Chomerics Elastomer Core Metal EMI Gaskets-html.html

MESH STRIP

with Elastomer Core EMI Gasketing

Contact Information:

Parker Hannifin Corporation

Chomerics Division

77 Dragon Court

Woburn, MA 01801

phone 781 935 4850

fax 781 933 4318

chomailbox@parker.com

www.chomerics.com

www.parker.com/chomerics

Customer Value Proposition:

MESH STRIP gaskets with elastomer

core are cost effective, resilient,

highly conductive, knitted wire over

an elastomer core used to provide

electromagnetic interference (EMI)

shielding, electromagnetic pulse (EMP)

shielding and electrical grounding at the

joints and seams of a variety of enclosure

applications.
The presence of an elastomer core

improves compression set characteristics

as compared to traditional all-mesh

gasket offerings. This results in higher

performance over a longer lifespan,

reducing replacement costs and other

factors associated with the total cost of

gasket ownership.
To reduce application design time,

tooling charges and lead time, MESH

STRIP with elastomer core gaskets

are produced in a variety of standard

cross sectional geometries, wire mesh

alloys and elastomer choices to meet a

wide array of performance criteria. For

unique application requirements, custom

materials and profile geometries are

available upon request.
To ensure quick and easy integration

into any manufacturing environment,

without the need for additional capital

expenditures, material can be provided in

spooled, cut-to-length, or spliced gasket

forms and attached utilizing adhesive

spot-bonding or riveting.

Features:

• Monel, Ferrex* and aluminum are

standard alloy choices, with

customs available upon request

• Standard elastomer choices are

sponge or solid silicone or solid

neoprene, with custom elastomers

available upon request

• Rectangular, round and round with

fin are standard cross sectional

geometries, with customs

available upon request

• High metal content

• Knit construction

• Multiple gasket form-factors and

installation options

• Foreign object debris (FOD) free

version available upon request

Benefits:

• Various metal alloy offerings allow for

optimized performance variables such

as galvanic corrosion, EMI / EMP

attenuation, electrical conductivity and

temperature range

• Various elastomer offerings allow

for optimized performance variables

such as compression set, compressive

force versus deflection, fluid resistance,

temperature range and durability

• Numerous standard geometric offerings

ensure easy gasket integration into

existing applications, thereby eliminating

the need for redesign

• High metal content gaskets are highly

durable, making them an excellent

choice for applications with cut-through

or tear resistance requirements

• Knitted wire construction results in a

light-weight product offering for

applications with weight restriction

requirements.

• Multiple gasket form factors and

attachment methods allow for easy

incorporation into existing

manufacturing installation environments

without the need for capital expenditures

• Encapsulated ends ensure the

elimination of foreign object debris and

associated rework costs

* Ferrex is Parker Chomerics tradename or tin-plated,

copper-clad steel wire per ASTM B-520, ASTM

(QQ-W-343) tin-plated, 2-3% by weight; ASTM B-227

copper-cladding 30-40% by weight; SAE 1010 steel

wire, balance by weight and is the same as Tecknit

Su/Cu/Fe which it replaces.

Metal EMI MESH STRIP

with Elastomer Core - Product Information

Material Type - Wire

MESH STRIP with elastomer core gasketing is

offered in monel, Ferrex and aluminum alloys as

standard offerings, with custom materials being

available upon request. When making a material

selection, a number of variables should be taken into

consideration depending on the specific application.

These criteria include; electrical performance

for EMI/EMP shielding or current carrying

requirements, galvanic compatibility between

the gasket and mating surfaces, overall material

durability and temperature thresholds. Electrical

and galvanic performance are the predominant

driving forces behind the material selection process

and will therefore be focused on in the following text.
MESH STRIP gasketing can provide greater than 60

dB of shielding across a broad range of frequencies,

though specific alloys perform better at specific

frequencies. Depending on deflection percent,

electrical resistance of less than .5 milliohms is also

attainable for lightning grounding applications. For

applications where electrical performance is the

primary concern, it is recommended to evaluate

materials in the following order; monel, Ferrex and

aluminum.
To avoid long-term corrosion rework costs, the

galvanic compatibility between the mating surfaces

of the application with the gasket material of

choice should be evaluated. For applications

where corrosion mitigation against an aluminum

substrate is the primary concern, it is recommended

that aluminum MESH STRIP be utilized, though

electrical performance and physical durability will be

sacrificed.
In summary, monel is the material of choice for

applications with moderate shielding and galvanic

concerns. Ferrex, though good at low-frequency

shielding, should be avoided in applications where

galvanic corrosion is a concern mated to aluminum.

Material Type - Elastomer

MESH STRIP with elastomer core gasketing is offered

with sponge or solid silicone or solid neoprene,

with custom elastomers available upon request.

When making a material selection, similar to wire

selection, a number of variables should be taken into

consideration. These criteria include; compression

characteristics, fluid resistance, overall material

durability and temperature thresholds.
Sponge elastomer materials are typically utilized in

applications where low compression force is necessary.

This is usually because of the following two reasons; a

lack of fasteners causes little force to be generated at

the interface of the gasket and the substrate, resulting

in the inability to deflect solid elastomer gasketing,

or the mating substrate is thin and therefore has a

tendency to bow when force is exerted on it.
Solid elastomer materials are typically utilized in

applications where robust sealing characteristics are

necessary.
Generally, neoprene is a good selection in applications

where physical durability for things such as tensile

strength, abrasion resistance and tear resistance.

Silicone is recommended in applications where

extreme temperature requirements, elongation or

compression set are major design drivers. Fluid

resistance characteristics should also be evaluated on

a case by case basis.

Mounting

There are two main gasket attachment methods to

be considered during the design process. Either

open area mounting or incorporating the gasket

within a groove are options. Groove incorporation

is considered a more conservative selection due to

gasket retention and the ability to obtain more exact

gasket compression and better shielding due to metal

to metal contact between the cover and the flange. For

open area mounting, it is recommended to RTV spot

bond or rivet the material to hold it in place. Pressure

sensitive adhesive is not available with knit mesh

products.
Rectangular and round profiles are typically

recommended for groove applications.

Application Design Information:

Parker Chomerics MESH STRIP with Elastomer

Core gaskets are used to provide EMI/EMP

shielding for a variety of applications. Various

design variables should be considered when

making a product selection to ensure optimal

performance. These variables are expanded upon

in the following text to assist in the design process.

Lastly, aluminum gives great galvanic compatibility

against aluminum housings, but has moderate

shielding capabilities and material durability

limitations.

Metal EMI MESH STRIP

with Elastomer Core - Product Information

Geometric Profile

For MESH STRIP with elastomer core products, round,

rectangular and round with fin are standard profiles.

After the aforementioned mounting criteria are evaluated,

the final decision regarding the geometric gasket profile

to be incorporated into the design is related to size.
Gasket size selection is a balance between available

space in the application, the force available for gasket

deflection and the tolerances associated with the

application.
The larger the gasket, the less effect tolerance variations

have on gasket deflection percentage. This will mitigate

gasket under or over-deflection. Under-deflection

will result is decreased electrical performance. Over-

deflection will result in permanent gasket deformation

and compromised gasket integrity.
Recognizing that larger gaskets incur higher price points,

both for material and the associated machining necessary

in the application, smaller profiles are typically more

appealing to customers. Due to this, it is recommended

to carefully consider tolerance swings and the affects they

will have on the overall performance of the assembly.
See Table 3 for Chomerics standard tolerances.

First, the surface finish must allow for electrical

contact between the gasket and the substrate. If

electric contact is not ensured, gasket performance

will be substantially reduced.
Therefore, non-conductive surface treatments are not

recommended unless masking of the gasket flange

area is possible.
Though non-conductive, chemical conversion coatings

are commonly used in conjunction with MESH STRIP

gaskets. Whenever possible, MIL-DTL-5541 Class 3 is

recommended.
This thinner surface treatment ensures gasket “bite-

through” to the electrically conductive substrate

beneath the finish. Class 1A is thicker and therefore

harder to obtain the same level of electrical continuity

to that of Class 3.
Any form of electrically conductive plating can be

utilized.

Fastener Spacing

Fastener spacing recommendations are a highly

variable situation with many things to be taken into

consideration. As a general rule, spacing should

range between 2.5 and 3.5 inches. In applications

where either extreme forces or thin flange thickness

may be present, flange deformation can occur. This

deformation limits gasket compression at the mid-point

between fasteners. As such, fasterner spacing should

be reduced to 1.5 to 2.5 inches.

Foreign Object Debris (FOD)

Because of the knit wire composition of MESH STRIP

with elastomer core gasketing and the cutting operation

associated with this material, FOD is a potential

concern. To mitigate this risk, Chomerics gives the

option of terminated ends. In post-cutting operations,

a silicone encapsulant is applied to the gasket ends.

This silicone binds any loose debris. Other encapsulant

materials are available to meet your specific application

needs such as temperature and fluid resistance.

Grooves are recommended to be rectangular with the

height being the primary concern.
It is recommended to target gasket compression of 35 +/-

15% when taking into consideration maximum material

condition (MMC) and least material condition (LMC) of

both the gasket and the groove. As a general rule, the

nominal width of the groove should have a target value

that results in the groove being 80 - 90% filled when the

gasket is deflected to the aforementioned amount.
Round with fin profiles are typically recommended

for open area mounting applications. The flat area

associated with this profile type allows for easy

attachment to a substrate. Gasket compression should

be targeted in a similar manner to that of a grooved

design. Open area mounting, however, relies more heavily

on the compressive forces generated by the fasteners

incorporated into the design versus the compression

tendencies of the specific gasket profile selected.

Substrate Surface Preparation

Acknowledging that most applications have a

substrate surface treatment interfacing with MESH

STRIP with elastomer core gasketing, there are a few

variables to evaluate.

Weather Sealing

MESH STRIP with elastomer core gasketing does not

provide a water seal. These gaskets are specifically

designed for electrical properties only. For applications

requiring wire mesh weather sealing performance,

please refer to the Chomerics COMBO GASKET data

sheet.

Note:

These dimensions and tolerances refer to the elastomer core. Outside dimensions or

diameters, including mesh covers, will be approximately 0.031 in. (0.79 mm) greater.

Wall thickness of standard hollow cores is 0.040 in. (1.02 mm)

Metal EMI MESH STRIP

with Elastomer Core - Product Information

Table 2

- Typical Shielding Effectiveness

Materials H-FIELD

100 kHz

E-FIELD

10 MHz

PLANE WAVE

1 GHz 10GHz

Aluminum

130

Ferrex

80+

130+

105

Monel

60+

130

ORDERING PROCEDURE

Continuous Length Gaskets

– Order by part numbers listed in Tables 4 through 8 by replacing

‘X’

with

for Monel,

for

aluminum or

for Ferrex and then specify total length required per part.

Note:

Elastomer Core MESH STRIP gasketing is not easily joined into single-piece gaskets. For this reason, gasketing

should be factory fabricated to customer specifications.

Custom Fabricated Gaskets

– Specify the standard material to be used to manufacture the part by referencing the part

numbers listed in Tables 4 through 8. Submit a fully dimensioned drawing of the required gasket, referencing any splice

locations or terminated ends (when applicable). For design assistance please contact Parker Chomerics Applications

Engineering Department.

STANDARD MATERIAL SPECIFICATIONS

ELASTOMERS

METALS

Gasketing Types

Silicone*

Neoprene*

Aluminum

Ferrex

Monel

Solid

Closed Cell

Sponge

Solid

Closed Cell Sponge

MESH STRIP

(elastomer core)

A-A-59588

Class 2B

Grade 40**

AMS-3195

Mil-R-6855

Class II,

Grade 40

MIL-R-6130

Type II, Grade A,

Condition Medium

Alloy 5056

AMS-4182

***

QQ-N-281

AMS-4730

Nominal Wire

Diameter

.005 in

(0.127mm)

.0045 in

(0.114mm)

.0045 in

(0.114mm)

Table 1

Material Specifications

Table 3

MESH STRIP with Elastomer Core Tolerances

Rectangular Strips

inches (mm)

Up to 0.125; +0.031, -0.015 (Up to 3.18: +0.79, -0.038)

Over 0.125 to 0.375; ±0.031 (3.18 to 9.53: ±0.79)

Over 0.375 to 0.750; ±0.062 (9.53 to 19.05: ±1.57)

Round Strips

inches (mm)

Overall Width Round

Single-Fin

inches (mm)

Up to 0.500; ±0.031, dia.

(Up to 1.27: ±0.79, dia.)

Up to 1.00; ±0.062,

(Up to 25.40: ±1.57)

Over 0.500; ±0.047, dia.

(Over 1.27: ±1.19)

Over 1.00; ±0.120,

(Over 25.40: ±3.05)

* Temperature Ranges:

Silicone, solid,

A-A-59588

, Class 2B, Grade 40. –70° to +500°F (–57° to 260°C).

Silicone, sponge, AMS-3195, –80° to +400°F (–62° to +204°C).

Neoprene, solid, MIL-R-6855, Class II, Grade 40, –45° to +220°F (–43° to +104°C). AMS-3222, –40° to + 255°F (–40° to +107C°).

Neoprene, sponge, MIL-R-6130, Type II, Grade A, –30° to +150°F (–34° to +65°C), meets UL 94HF-1 rating.

** Max tensile strength is 75,000 PSI

***Ferrex is Parker Chomerics tradename for tin-plated, copper-clad steel wire per ASTM B-520, ASTM (QQ-W-343) tin-plated, 2-3% by weight; ASTM B-227

copper-cladding 30-40% by weight; SAE 1010 steel wire, balance by weight.

Table 4

RECTANGULAR CROSS SECTIONS/SPONGE CORE

inches (mm)

Height*

Width*

Part Number

Neoprene Sponge

Silicone Sponge

0.125 (3.18)

0.156 (3.96)

0.188 (4.78)

0.250 (6.35)

01-040X-1845

01-040X-1518

01-040X-1846

01-040X-1847

01-050X-0319

01-050X-0666

01-050X-1320

01-050X-1853

0.188 (4.78)

01-040X-1848

01-050X-1854

0.250 (6.35)

0.375 (9.53)

0.500 (12.70)

01-040X-1564

01-040X-0888

01-040X-1849

01-050X-1855

01-050X-1856

01-050X-1857

0.375 (9.53)

0.500 (12.70)

0.625 (15.88)

01-040X-0328

01-040X-1850

01-050X-1858

01-050X-1859

0.500 (12.70)

0.750 (19.05)

01-040X-1851

01-040X-1852

01-050X-1860

01-050X-1861

Table 6

ROUND CROSS SECTIONS/SPONGE CORE

inches (mm)

Diameter*

Part Number

Neoprene Sponge

Silicone Sponge

0.062 (1.57)

0.125 (3.18)

0.188 (4.78)

0.250 (6.35)

0.312 (7.92)

0.375 (9.53)

0.437 (11.11)

0.500 (12.70)

0.750 (19.05)

01-040X-1890**

01-040X-0541

01-040X-0571

01-040X-0627

01-040X-0626

01-040X-1886

01-040X-0747

01-040X-0845

01-040X-0633

01-050X-1890**

01-050X-1891

01-050X-1892

01-050X-1893

01-050X-1894

01-050X-1895

01-050X-1896

01-050X-1897

01-050X-1898

Table 5

ROUND with FIN CROSS SECTIONS/SPONGE CORE

inches (mm)

Diameter*

Width Overall

Part Number

Neoprene Sponge

Silicone Sponge

0.125 (3.18)

0.500 (12.70)

0.625 (15.88)

0.750 (19.05)

01-040X-1862

01-040X-1863

01-040X-1864

01-050X-0690

01-050X-1877

01-050X-1878

0.188 (4.78)

0.500 (12.70)

0.625 (15.88)

0.750 (19.05)

01-040X-0630

01-040X-1865

01-040X-1866

01-050X-1879

01-050X-1880

01-050X-1881

0.250 (6.35)

0.625 (15.88)

0.750 (19.05)

1.000 (25.40)

01-040X-0819

01-040X-1867

01-040X-1868

01-050X-1882

01-050X-1883

01-050X-1884

0.500 (12.70)

1.000 (25.40)

01-040X-1869

01-050X-1885

0.625 (15.88)

1.375 (34.93)

01-040X-1870

01-050X-0734

Table 7

ROUND CROSS SECTIONS/

HOLLOW SOLID SILICONE CORE

inches (mm)

Diameter*

Part Number

0.188 (4.78)

0.250 (6.35)

0.375 (9.53)

0.500 (12.50)

01-050X-6044

01-050X-6045

01-050X-6112

01-050X-6115

Table 8

SINGLE ROUND with FIN/

HOLLOW SOLID SILICONE CORE

inches (mm)

Diameter*

Width Overall

Part Number

0.188 (4.78)

0.250 (6.35)

0.375 (9.53)

0.500 (12.50)

0.625 (15.88)

0.750 (19.05)

1.000 (25.40)

01-050X-6105

01-050X-6110

01-050X-6113

01-050X-6114

**This size has only one mesh layer.

Metal EMI MESH STRIP

with Elastomer Core - Available Profiles

CHOMERICS is a registered trademarks of Parker Hannifin Corporation. ® 2013 TB 1100 EN April 2016

www.chomerics.com

www.parker.com/chomerics

Note:

Please contact the Parker Chomerics Applications Engineering Department at 781-935-4850 with additional design questions.

Please contact the Parker Chomerics Test Services Department at 781-935-4850 in instances where application specific performance data is necessary.

These dimensions and tolerances refer to the elastomer core. Outside dimensions or

diameters, including mesh covers, will be approximately 0.031 in. (0.79 mm) greater.

Wall thickness of standard hollow cores is 0.040 in. (1.02 mm)

DIA.