Fully laminated screened windows combine the physical strength and optical clarity of laminated glass or plastic with the EMI shielding effectiveness of fine wire gauze. They complement the more cost-effective edge-laminated type, which are designed primarily for racks and large enclosures. Cast plastic style, featuring mesh gauze moulded into clear plastic, complete the P & P Technology EMI Shielded Window offering.
Wire meshes, which form a highly conductive shielding medium, are available with a conductive anti-reflective finish which is non-oxidising and which protects the gauze, 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. However, we do not recommend this to customers inexperienced in handling the fine gauze, which is easily contaminated or damaged.
EMI shielded windows with a mesh gauze 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 emi shielded 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.
Our EMI shielded windows use glass or 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, a non-treated stainless steel mesh is used.
Temperature cycling, contamination and possible accidental damage should be taken into account when specifying the shielded window design for a particular application. 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.
EMI shielded 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 screening material inside the window is terminated depends on the type of window – see the individual emi shielding product sections for further details. Gaskets are another important feature that is taken into consideration as EMI 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.