EMI Shielded Windows0 pages

Fully laminated (WF Shielding) screened windows

combine the physical strength and optical clarity of

laminated glass or plastic with the shielding

effectiveness of fine wire mesh. They complement

the more cost-effective edge-laminated type (WG

Shielding), which are designed primarily for racks

and large enclosures. Cast plastic style (WC

Shielding), featuring mesh moulded into clear

plastic, complete the W Range.

Copper wire meshes, which form a highly conductive

shielding medium, are available with a conductive

anti-reflective 'blackened' finish which is

non-oxidising and which protects the mesh,

particularly where copper is used for its high degree

of shielding effectiveness. In some instances we can

supply the mesh material in its unlaminated form so

customers can fabricate their own bespoke windows

(WM Shieldng). However, we do not recommend this

to customers inexperienced in handling the fine

mesh, which is easily contaminated or damaged.

Windows with mesh typically have in excess of a

60% open area so provide good light transmission.

Attenuation is a function of conductivity, aperture

sizes and permeability in relation to field strength

and frequency. Conventional mesh materials or

surface coatings in windows do not generally

provide high attenuation at low frequency in the

magnetic field and additional measures should be

taken to supplement the screened window

performance in such applications. Electric field and

plane wave attenuation is, however, normally

excellent and this is the area of activity for most

non-military window applications. Please contact us

for technical advice.

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WINSHIELD | Shielded Windows

W Shielding

Applications:

Our EMI screened windows use glass and polycarbonate as their base

substrate, and can be treated to improve both anti-reflective and

scratch-resistant properties. Glass panels can be etched to provide an

anti-reflective surface. Tinted 'interlayers' can be built into fully

laminated windows to improve their anti-reflective properties

particularly where, for example, non-treated stainless steel mesh is

used.

When specifying the design for a particular application, temperature

cycling, contamination and possible accidental damage should be

taken into account. Glass windows are the most abrasion resistant

but not the best for impact resistance. They are also better for

anti-contamination than plastic. Fully laminated windows have good

properties but are less cost effective than edge-laminated types,

which provide an excellent solution for most applications.

Screened windows are generally mounted within a frame or clamp

system or are bonded onto a fascia or door panel using conductive

adhesive or caulking. Stepped windows (fully laminated only) may

have a front pane protruding through a fascia, with the rear pane

bonded inside the enclosure. The way in which the screen material

inside the window is terminated depends on the type of window -

see the individual series sections for further details. Gaskets are

another important feature that is taken into consideration as shielded

windows are often used where environmental protection is essential.

Bezel mounts can be made to suit most windows. The mounts are

fabricated from aluminium, steel or other suitable metals and can be

hinged or fitted with quick-action fasteners if required.

'Plastic Jnterlayer

'Mesh Gauze

/

Plastic Interlayer

BASIC CONSTRUCTION: FULL LAMINATION - With Plastic Interlayers

Fully Laminated Windows | WF Shielding:

Fully laminated windows in glass or plastic can be produced either

as individual windows or, for smaller size, in sheet form and

machined into segments. All fully laminated windows are

available with or without a step and with or without a silver

painted busbar. Surface treatments for scratch resistance or

anti-reflectance are available and tinted inter-layers for

anti-reflectance or contrast enhancement can be supplied on

request.

Standard terminations for individually produced windows

are flying mesh, foil or silver painted busbar or conductive

gasket. Sheet-cut windows, including stepped types, are

only available with silver busbar and optional gaskets.

Care should be taken with stepped windows, particularly

glass ones, as the pressure exerted by the gasket under

compression can easily overstress even a fully

laminated window. We suggested that stepped

windows should be plastic or a composite where the

glass pane is not under pressure when mounted.

Most gaskets in our range can be used with shielded

windows and the actual type selected will depend

on the degree of shielding and environmental

protection required. Please contact us for

technical advice.

P & P Technology Ltd

1-3 Finch Drive

Springwood Industrial Estate

Braintree CM7 2SF

T:+44(0) 1376 550525

www.p-p-t.co.uk