Applications of EVERLAM QUIET

Laminated glass produced with EVERLAM QUIET is specified in assemblies where acoustic attenuation and glass retention are required in the same construction. The interlayer is a coextruded polyvinyl butyral system in which a lower-glass-transition core is carried between two standard PVB skins. The multilayer structure introduces a constrained-layer damping mechanism; when glass panes vibrate in bending, shear strain is transferred to the core, and mechanical energy is dissipated as heat. This behaviour is not a fixed material constant. It is measured under ISO 16940:2008 as a loss factor across frequency and temperature, and it varies with autoclave time, glass thickness, and edge moisture history. Processing of the interlayer into laminated glass requires the same vacuum de-airing and autoclave sequence used for standard PVB, but the adhesive development is more sensitive to temperature overshoot. Moisture content between 0.35 wt% and 0.55 wt% is controlled before assembly because the acoustic core absorbs atmospheric water faster than the skin layers do.

Automotive acoustic windshields are a primary downstream segment for EVERLAM QUIET. In a typical OEM construction, 2.1 mm annealed float glass is laminated to 1.6 mm glass with a 0.76 mm acoustic PVB interlayer. ECE R43 and ANSI Z26.1 compliance remain the mandatory certification basis for road-use glazing; the acoustic interlayer does not change the fragmentation sequence, but it shifts the pummel adhesion target. Automotive laminating lines reject adhesion values outside 3–7 because low adhesion increases spall risk in headform impact testing, while high adhesion reduces impact energy absorption. On horizontal nip-roll pre-press lines, glass surface temperatures are maintained at 180–220 °C, and the stack is then autoclaved at 12–14 bar and 135–145 °C for 90–120 min. The primary acoustic benefit is suppression of the coincidence dip; for 2.1 mm glass the unfilled coincidence frequency lies near 5000 Hz. The laminated construction reduces the transmission loss dip at that frequency and broadens the damped region. Final acoustic sign-off for automotive windshields is usually performed at vehicle level under wind-noise conditions, not on a bare glass coupon, because frame insertion loss and sealing systems contribute to the in-cabin result. Autoclave temperatures above 145 °C are a known line-side conflict: adhesion to glass increases, but plasticizer redistribution in the acoustic core can reduce constrained-layer damping after long soak.

What Acoustic Loss Factor Is Measured Before Façade Laminates Are Specified?

Architectural noise-control glazing uses EVERLAM QUIET in asymmetric glass build-ups where the source side is thicker than the room side. The interlayer is not a mass barrier; its function is to damp the bending waves that control transmission at and above the coincidence dip. For 6 mm glass, the coincidence frequency is approximately 2000 Hz; for 8 mm, approximately 1500 Hz. The specification pathway begins with ISO 10140-2:2021 laboratory airborne sound insulation, followed by rating to ISO 717-1:2020 Rw(C;Ctr). An acoustic interlayer of this class is specified when a shift of 1–3 dB in Rw is required without increasing glass thickness; published test reports for the exact stack are required because the improvement is not additive and can disappear below 400 Hz or above 4000 Hz depending on leaf thickness and cavity fill. Façade laminates must also pass EN 12600 pendulum impact and EN ISO 12543-4 durability tests. Edge stability in open rebates is an operational boundary: exposed edges must be sealed or covered by a pressure profile because prolonged water entry produces edge delamination. At storage RH above 60 %, pre-conditioning of the interlayer is required before lamination. On production-scale laminating lines, wash water conductivity should remain below 20 μS/cm to avoid alkaline carryover that reduces edge adhesion; this parameter is monitored on the glass washer, not on the interlayer.

Rail vehicle glazing structures combine EVERLAM QUIET with spall containment and fire-smoke requirements that differ from building glass. A typical high-speed train lateral window uses 4 mm heat-strengthened outer glass / 0.76 mm acoustic PVB / 4 mm inner glass, with an edge silicone seal exposed to continuous vibration. The interlayer is selected after loss factor measurement under ISO 16940:2008, but final acceptance is against EN 15152 and EN 45545-2. Fragment-drop criteria following ballast strikes and repeated tunnel pressure pulses are imposed by operators at speeds above 180 km/h. The acoustic core reduces the audible contribution of wheel-rail noise in the 1000–4000 Hz band, where a monolithic glass coincidence dip can reduce transmission loss by 5–10 dB. Rail laminates are processed on vacuum bag or ring-type autoclave lines; edge quality is critical because intermittent moisture and low temperatures to -20 °C expose low-adhesion zones. Pummel adhesion values outside 3–6 have been associated with edge milking under thermal cycling from -20 °C to +50 °C in cyclic weathering chambers, a failure mode observed on batch runs before edge sealing was introduced. No acoustic credit is taken for the interlayer alone; the complete window assembly, including frame and gasket, is tested under ISO 10140-2 or the operator-specific rolling stock acoustic test procedure.

Marine Glazing Damping and Edge Durability Under Saline Exposure

Marine laminated glazing specified with EVERLAM QUIET is used in superstructure windows, wheelhouse glazing, and partition panels on passenger vessels. The marine environment exposes the interlayer edge to saline spray, saturation-level humidity, and cyclic hull flexure. Salt spray testing is conducted to ISO 9227, while window frame test loads follow ISO 12216:2020. The acoustic PVB core remains within its damping temperature window when the wheelhouse is air-conditioned to 20–25 °C; at temperatures above 35 °C, the loss factor falls as the core approaches the transition region of the skin layers. Lamination is therefore validated by sample autoclave runs at 12 bar and 138 °C, followed by 14 days of humidity exposure at 40 °C and 95 % RH. The operational boundary is edge sealant compatibility: polysulfide sealants are preferred over some amine-cured epoxy formulations because the latter can raise local pH and reduce adhesion to the glass surface. Adhesion testing after salt fog uses the same pummel removal method applied in automotive lines, and values below 3 after exposure are treated as edge delamination risk when the edge is properly sealed.

When the Acoustic Interlayer Is Used Inside Ballistic and Forced-Entry Laminates

EVERLAM QUIET is incorporated into multilayer security glass not as a replacement for polycarbonate or structural PVB, but as an inner damping layer behind the ballistic face. A forced-entry laminate may consist of 8 mm glass / 1.52 mm structural PVB / 6 mm glass / 0.76 mm EVERLAM QUIET / 6 mm glass, depending on EN 356 class. The acoustic layer contributes to sound transmission loss in buildings where security and acoustic privacy are required simultaneously, such as street-facing consulates, banks, and courtrooms. Testing is performed to EN 356 for manual attack, EN 1063 for ballistic resistance, and ISO 10140-2 for acoustics; the acoustic damping layer is not a structural add-on and must not be included in load-sharing calculations for bending resistance unless validated by the glass supplier. A processing conflict arises because ballistic laminates require thicker autoclave soak to bond multiple layers, while acoustic cores lose damping if overheated above 150 °C or held above 140 °C for longer than 120 min. On production-scale autoclaves with fan reversal, this conflict is managed by placing a thermocouple between the innermost glass and the last PVB layer and ramping only after the centre reaches 125 °C. Published data for the exact damping contribution in combined ballistic-acoustic laminates is limited; project-specific acoustic testing is therefore specified rather than interpolating from single-function laminates.

Interior glazed partitions in recording studios, broadcast suites, and open-plan offices are fabricated with thick laminated glass in which EVERLAM QUIET is paired with acoustic seals. The acoustic performance of the interlayer is subordinate to frame flanking, mullion transmission, and air leakage; a glazing coupon measured at Rw 40 dB can drop to an installed partition value of Rw 32–35 dB if the surrounding frame is discontinuous. For double-glazed partitions, the acoustic PVB laminate is frequently the room-side leaf, with the cavity width set to 50–200 mm and the cavity edges lined with absorptive material. The interlayer density and modulus are relevant only at bending frequencies; cavity mass-air-mass resonance is controlled by leaf mass and spacing, not by the acoustic PVB. Compliance is verified through ISO 10140-1 and ISO 10140-2, rated with ISO 717-1, and flanking is assessed under ISO 10848-1 for adjacent building elements. On laminating lines, the interlayer is cut oversize by 10–20 mm to account for glass-edge pull-in during pre-press, a dimension confirmed by trial on the same cutting table used for production. No separate acoustic certification of the raw interlayer is accepted; the final laminated glass coupon must be tested after autoclaving.