| HS Code | 487092 |
| Product Name | Saflex QS71 |
| Product Family | Saflex QS series acoustic PVB interlayer |
| Chemical Composition | Polyvinyl butyral (PVB) resin with plasticizer |
| Physical Form | Thin, clear, smooth sheet/film |
| Thickness | 0.76 mm (0.030 inch) nominal |
| Density | 1.07 g/cm³ |
| Refractive Index | 1.48 |
| Glass Transition Temperature | approx. 18 °C |
| Tensile Strength | approx. 25 MPa |
| Elongation At Break | approx. 250% |
| Visible Light Transmittance | >90% for laminated glass construction |
| Haze | <0.5% |
| Ultraviolet Light Transmittance | <0.1% at 380 nm |
| Moisture Absorption | <4% at equilibrium |
| Adhesion To Glass | High, controlled adhesion |
| Acoustic Performance | Enhanced sound damping with typical Rw improvement of up to 5 dB compared with standard PVB |
As an accredited Saflex QS71 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Saflex QS71 is supplied in sealed, moisture-proof foil-lined cartons, each containing one roll. Net weight: 100 kg. |
| Container Loading (20′ FCL) | 20′ FCL: Saflex QS71 palletized, stretch-wrapped, and securely blocked in container to prevent shifting during transit. |
| Shipping | Saflex QS71 is a non-hazardous polyvinyl butyral interlayer supplied in sealed moisture-barrier packaging. Ship at ambient temperature in clean, dry containers, protecting rolls from direct sunlight, moisture, and excessive pressure. No dangerous goods classification applies; standard handling and ventilation are sufficient to preserve material integrity during transit. |
| Storage | Store Saflex QS71 in a cool, dry, well-ventilated area away from direct sunlight, heat, and ignition sources. Keep containers tightly sealed to prevent moisture absorption and contamination. Avoid exposure to high humidity or temperature extremes. Ensure compatibility with surrounding materials and follow all label and safety data sheet instructions for safe handling. |
| Shelf Life | Saflex QS71 has a shelf life of 12 months when stored unopened in original packaging under cool, dry conditions, below 20°C. |
In automotive laminated windshield production, Saflex QS71 is specified as an acoustic PVB interlayer ply rather than a powder formulation; the addition ratio is therefore given as interlayer thickness fraction. A standard OEM build-up places a 0.76 mm QS71 ply between two 2.1 mm soda-lime float plies, producing a nominal 4.96 mm composite with an interlayer thickness fraction of 15.3%. Validation under UN ECE R43 Annex 3-A, FMVSS 205, and ANSI/SAE Z26.1 is required for optical, fragmentation, and penetration performance. In flat laminating lines, glass is dried to 0.3–0.6 wt% moisture before layup; pre-press rollers operate at 68–78°C surface temperature and 0.35–0.55 MPa nip pressure to remove entrapped air. The pre-pressed stack is autoclaved at 12–14 bar and 135–140°C for 60–90 minutes. Production records show that edge bubble density increases when the layup room exceeds 55% RH unless the interlayer is preconditioned at 18±2°C and 30±5% RH for 24–48 hours. The terminal output is the OEM acoustic laminated windshield assembly.
Architectural acoustic glazing under EN ISO 12543-2:2021, EN 14449, and ASTM C1172-18 uses Saflex QS71 in laminates where the outer pane of an insulated glass unit must attenuate low-frequency road noise. A typical build-up is 6 mm float glass / 1.52 mm QS71 / 6 mm float glass, yielding an interlayer thickness fraction of 11.2%. For panels above 2.5 m², the vacuum-bag de-airing stage must reach 0.90–0.95 bar absolute within 4–6 minutes; slower evacuation leaves edge-air channels that become autoclave bubbles at 135°C. The autoclave heat ramp is controlled to 2.5–3°C/min, followed by dwell at 12–14 bar and 135–140°C for 90–120 minutes. Acoustic performance is measured under EN ISO 10140-2 and rated under ISO 717-1; published octave-band data for this specific configuration is limited, so project-level mock-up testing remains necessary. Edge sealants with amine-catalyzed moisture-cure chemistry must be excluded from contact with the QS71 edge because residual amines accelerate plasticizer migration and create a visible opacity ring. Terminal products are laminated outer panes for sound-insulating curtain wall IGUs.
For demountable interior acoustic partitions in commercial buildings, the compliance baseline is CPSC 16 CFR 1201 Category II and ANSI Z97.1. A standard build-up uses 5 mm heat-strengthened float glass / 0.76 mm Saflex QS71 / 5 mm heat-strengthened float glass, giving an interlayer thickness fraction of 7.1%. The layup is performed in a controlled environment at 20±2°C and 30±5% RH, followed by nip-roll de-airing and autoclave curing at 12–14 bar and 135°C for 60 minutes. Terminal products include demountable office partition glass, hotel corridor vision panels, and conference room acoustic glazing.
Security glazing for forced-entry resistance is classified under EN 356:2000 up to P6B and tested under ASTM F1233-08. In this segment, Saflex QS71 is specified in a 5 mm / 1.52 mm / 5 mm heat-strengthened glass build-up, producing an interlayer thickness fraction of 12.2%. Multi-ply security laminates move through a staged vacuum profile instead of a fixed de-airing cycle: 0.6 bar absolute hold for 10 minutes, then 0.95 bar absolute for 30–45 minutes, before autoclave dwell at 14 bar and 140°C for 90–120 minutes. Field audits on security glazing lines show that frame edge bite below 12 mm permits repeated-impact delamination; fabricators therefore add edge trim allowance so the laminate remains fully engaged in the glazing channel. Terminal products are forced-entry-resistant storefront glazing, bank teller screens, and security door inserts.
Coastal fenestration in windborne-debris regions is qualified under ASTM E1996-17 and ASTM E1886-13a, with product approval in Miami-Dade County governed by TAS 201, TAS 202, and TAS 203. The standard large-missile build-up uses 6 mm annealed surface glass / 1.52 mm QS71 / 6 mm inboard glass, equivalent to an interlayer thickness fraction of 11.2%. Before pre-press, interlayer edges are aligned flush within 1.5 mm; edge offset above this threshold creates stress concentrations during cyclic pressure reversal after missile impact. Autoclave curing runs at 13–14 bar and 135–140°C for 90–120 minutes. Following impact, assemblies are subjected to cyclic positive and negative pressure loading as defined in ASTM E1886; the qualification sequence includes 9,000 pressure cycles without tear-out. Terminal products are impact-rated laminated glass door slabs, window units, and storefront assemblies for exterior openings.
Rail vehicle glazing under EN 15152:2019 and, where specified, NFPA 130 uses Saflex QS71 in a 4 mm / 0.76 mm / 4 mm chemically strengthened glass stack, yielding an interlayer thickness fraction of 8.7%. Because chemically strengthened glass loses compressive stress during extended high-temperature exposure, the autoclave cycle is reduced to 12 bar and 130–135°C for 60–90 minutes. The lamination process uses vacuum-bag de-airing at 0.90–0.95 bar absolute, followed by controlled cooling to 40°C before opening the autoclave. After lamination, polyurethane edge encapsulation is applied for vibration isolation and moisture ingress protection; exposed QS71 edges are wiped with isopropanol only, because ketone- or ester-based cleaning agents soften the interlayer and lower edge shear transfer under service vibration. Published data for QS71 in chemically strengthened rail window stacks is limited; operator-specific impact and fire performance tests remain the basis for qualification. Terminal products are side windows and cab door windows for metro and mainline rolling stock.
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Saflex QS71 is supplied as a rolled plasticized polyvinyl butyral interlayer for laminated glass intended to combine safety-glazing retention with sound-transmission-loss control. The QS71 model designation is a supplier-specific grade identifier within the Q-series; the product is commonly specified in nominal thicknesses of 0.76 mm, with multi-ply constructions used for higher acoustic or mechanical demands. It is not a rigid interlayer in the ionoplast class, and specification documents should treat it as an acoustically modified PVB rather than a structural ionoplast. In fabricator practice, incoming rolls are stored in sealed packaging at 10–20°C and 20–35% relative humidity, and the interlayer is allowed to reach 18–22°C before slitting and layup. The laminated glass product is assessed under ISO 12543-2:2021 for safety glazing integrity, while acoustic performance is evaluated under ISO 10140-2:2021 or ASTM E90-09, depending on the market and test laboratory. Where the interlayer is intended for use in a laminated safety glass product, conformity to EN 14449:2005 is verified through initial type testing and factory production control by the glass fabricator. The density of plasticized PVB is typically in the range 1.07–1.08 g/cm³ when measured according to ISO 1183-1:2019; product-specific density figures should be confirmed from the manufacturer’s certificate, because QS71 is a formulated grade and published third-party data for this specific product is limited.
Unmodified PVB interlayers used in architectural laminated glass derive adhesion from hydroxyl groups and a plasticizer distribution that produces a glass transition near 30°C under mechanical test frequencies. QS71 shifts the damping response by modifying the core-phase plasticizer distribution and layer architecture, so that the loss factor in the 100–3150 Hz one-third-octave band is increased relative to a standard PVB of equal thickness. The result is not an increase in mass law transmission loss, but a reduction in coincidence-dip and shear-mode energy transmission through the interlayer. In practice, the improvement depends on glass thickness, air cavity depth, and frame rigidity, and must be measured in the intended insulating glass unit or monolithic laminate. Under ISO 10140-2:2021, reported weighted sound reduction index values are configuration-specific. Published third-party data for all thickness and edge-seal combinations of QS71 is limited, so project acoustic matrices should be supported by laboratory tests using the exact glass build rather than generic interlayer datasheet values. The interlayer still contributes to the safety-glazing performance envelope described by ISO 12543-2:2021, but the acoustic formulation reduces low-frequency shear stiffness relative to stiff interlayers, which has implications for structural calculations.
| Verification category | Standard designation | Control parameter |
|---|---|---|
| Laminated safety glass integrity | ISO 12543-2:2021 | Adhesion and tear energy after impact |
| Airborne sound reduction | ISO 10140-2:2021 | Weighted sound reduction index Rw with C and Ctr |
| PVB tensile properties | ISO 527-1:2019 | Stress at yield, elongation at break |
| Interlayer density | ISO 1183-1:2019 | Immersion or gas pycnometer method |
| Load resistance of laminated glass | ASTM E1300-23 | Uniform lateral load capacity with shear-transfer coefficient |
| Safety glazing classification | ANSI Z97.1-2015 | Impact penetration and fragmentation limits |
Because QS71 is viscoelastic, single-point tensile values do not define design stiffness. Under ISO 527-1:2019 at 23°C and a test speed of 50 mm/min, plasticized PVB typically exhibits a yield stress near 20 MPa and elongation at break above 200%. These are class-typical values, not QS71-specific certification points. Product-specific stress-strain and dynamic shear modulus data are obtained from the manufacturer’s certificate for the production batch because plasticizer level and core-layer thickness vary within the product tolerances. The interlayer is formulated to absorb UV radiation below 380 nm; typical PVB UV transmittance is below 1% across this band. Visible light transmittance depends on the glass substrate and the interlayer water-white grade, and is measured under ISO 9050:2003 or EN 410:2011 for the completed laminate.
Cold interlayer handling below 10°C should be avoided because roll curvature increases and the sheet may embrittle at the cut line. Layup rooms are maintained at 18–22°C and 20–30% relative humidity to limit water adsorption before autoclaving. Glass is washed with deionized water having conductivity below 20 µS/cm, air-knife dried, and inspected under grazing light. The QS71 ply is cut with a tungsten carbide or ceramic blade at 18–25°C, then positioned with a uniform edge gap of 1–2 mm from the glass edge to allow post-autoclave trimming. Vacuum bag de-airing uses a cold vacuum stage below 30 mbar for 15–30 min before heating to 110°C for 60 min; nip-roller lines use preheating to 60–80°C surface temperature followed by an autoclave cycle. Autoclave parameters applied to QS71 laminates on production-scale equipment are commonly 12–14 bar at 130–135°C for 60–120 min, with pressure ramp-up not exceeding 3 bar/min and temperature ramp-up not exceeding 3°C/min to limit glass edge stress. Pressure release is staged below 0.5 bar/min to reduce interlayer expansion and edge delamination. Moisture content in the interlayer should remain below 0.45% by weight; rolls left open at relative humidity above 40% for more than 24 h may require re-drying in a desiccant chamber or at 10–15°C and 10–15% relative humidity before use. Production lines report edge-bubble defects when edge moisture is not controlled before autoclaving, and the defect typically appears as a line of small voids within 5 mm of the glass edge.
On a production line using a vacuum bag system with residual pressure below 30 mbar, the cold de-airing phase is extended to 20–30 min for acoustic interlayers because the lower core viscosity allows air channels to close without preheating. Nip-roller lines set the preheating oven at 60–80°C and maintain nip roller hardness at 60–65 Shore A and line speed at 6–8 m/min. These settings are established for PVB generally; production-scale trials with QS71 should begin at the lower end of the speed range to limit edge waviness. Roll tension at the slitting unit is kept below 100 N/m of web width to prevent interlayer necking, and unwind tension is reduced when the interlayer temperature is above 25°C.
Because the interlayer is viscoelastic, shear transfer to glass declines as the glass surface temperature exceeds 45°C on sun-exposed facades. In curtain-wall cavities, surface temperatures can exceed 60°C, moving the QS71 shear modulus below the value assumed in composite-action calculations. ASTM E1300-23 permits a shear-transfer coefficient that varies with load duration and temperature; for long-duration loads at elevated temperatures, the glass plates behave closer to independent plies. For short-duration wind gusts below 3 s at temperatures below 30°C, partial composite action may be justified only when interlayer shear modulus data are available. Published data for QS71 dynamic shear modulus across the full service temperature range is limited, so design calculations should be based on interlayer-specific testing under the expected load duration and temperature. Point-supported, fin, staircase, or glass-floor applications should not use QS71 as a substitute for stiff ionoplast interlayers or structural PVB grades because the lower shear modulus reduces load-sharing between glass plies. For standard window, curtain-wall, and storefront laminates, the interlayer provides the required safety retention described by ISO 12543-2:2021 and ANSI Z97.1-2015 when processed within the specified moisture and autoclave envelope.
Where noise mitigation sits alongside safety glazing requirements, QS71 is specified in monolithic laminated units and in the laminated component of insulating glass units for hospitals, hotels, transport-facing facades, and office buildings adjacent to roads or rail corridors. It is compatible with standard PVB interlayers and can be used with tinted or coated glass substrates, provided the coated edge deletion is completed before layup. In insulating glass units, the lamination step is completed before the unit is assembled with a dual-seal silicone or polyurethane secondary seal. Edge-seal compatibility must be verified because some silicone sealant formulations contain aminosilane coupling agents that can accelerate edge adhesion loss in PVB interlayers when exposed to water at the edge. Acetic-acid-curing silicones should not be used in direct contact with the interlayer edge. Exposed PVB edges in high-humidity or exterior wetting locations are normally protected by a perimeter gasket or structural silicone cap to prevent water penetration into the interlayer. For projects requiring long-term edge stability under immersion or frequent wetting, edge sealant adhesion tests are run according to the sealant manufacturer’s method, and glazing contractors report that a minimum of 5 mm edge face coverage is used to limit moisture ingress.
Autoclave edge quality is governed less by the acoustic core than by the outer skin temperature and residual moisture during lamination. The glass stack is held at 18–25°C before layup to avoid thermal shock, and the autoclave is loaded with spacing that permits uniform air circulation. Air temperature in the autoclave is ramped to 130–135°C at 2–3°C/min, while pressure is raised to 12–14 bar in a coordinated sequence to prevent premature edge seal formation and trapped air. Holding time is adjusted for glass substrate thickness: 60 min at autoclave temperature is common for monolithic laminates with total glass thickness up to 10 mm, while 90–120 min is used for thick, multi-ply, or heat-strengthened glass stacks. After cooling, the laminate is removed and the interlayer edge is trimmed flush with a razor knife or automated trimming head. The exposed edge is inspected for bubbles, delamination, and insufficient adhesion. Adhesion is commonly controlled by the interlayer moisture content and the glass cleaning chemistry rather than by external primers. Fabricators using automated in-line lamination report that roller nip lines without vacuum require a controlled de-airing temperature profile of 60–80°C at the nip, with roller pressure adjusted to the hardness of the substrate; no additional chemical adhesion promotor is used for standard PVB-to-glass bonding.
Acoustic interlayers achieve increased damping by reducing the glass transition temperature of the core; this also reduces low-frequency shear stiffness at room temperature. In overhead laminated glass, post-breakage retention under long-duration load is dominated by interlayer tensile strength and adhesion, not solely by acoustic loss factor. Saflex QS71 retains safety-glazing classification under ISO 12543-2:2021 for standard impactor tests, but the reduced stiffness compared with ionoplast or structural PVB should not be ignored in finite-element simulations for residual load capacity. Under long-duration dead load after glass fracture at 40°C, some acoustic PVB laminates exhibit lower residual stiffness than identical nominal laminates made with standard PVB; published data for this specific configuration is limited. For point-supported balustrades, blast-resistant assemblies, and horizontal glass floors, a stiff interlayer is normally specified, and QS71 is not considered the primary structural interlayer. Where a project requires both sound reduction and high post-breakage stiffness, a laminate with multiple interlayer types or a rigid ionoplast core may be used, but the acoustic contribution of QS71 must then be re-evaluated because the total laminate damping is not additive in a simple manner. The final selection is governed by the governing glass design standard, including ASTM E1300-23 for load resistance and EN 14449:2005 for product conformity, and the specified interlayer data must be generated on the same glass build and edge condition used in the building.
Solvent contact at the cut edge should be avoided. Ketone and ester solvents extract plasticizer and produce a visible white edge; alcohol-based cleaners, if used, must be evaporated completely before the interlayer is placed. Edge deletion of low-emissivity coatings is performed to a width of 10–15 mm to prevent coating-to-interlayer adhesion failure at the perimeter. In structural glazing with an EPDM gasket, the gasket contact surface is kept free of hydrocarbon lubricants. These compatibility boundaries are standard for PVB and are not unique to QS71, but acoustic core formulations may exhibit more rapid plasticizer movement near the cut edge if exposed to solvent, so edge sealing is specified earlier in high-humidity or solvent-exposed installations.
