| HS Code | 276769 |
| Product Name | S-LEC Sound Acoustic Film |
| Material | Polyvinyl butyral (PVB) |
| Application | Interlayer for laminated glass |
| Thickness | 0.38 mm, 0.76 mm, 1.14 mm |
| Sound Insulation Performance | High sound transmission loss, providing up to 5-10 dB improvement over standard PVB interlayers |
| Light Transmittance | Greater than 89% |
| Haze | Less than 1% |
| Uv Absorption | Blocks over 99% of ultraviolet radiation |
| Adhesion To Glass | Excellent adhesion to glass after autoclave lamination |
| Impact Resistance | High impact strength and penetration resistance for laminated glass |
| Flexibility | Flexible and formable at low temperatures |
| Tensile Strength | Approximately 20-40 MPa depending on formulation |
| Elongation At Break | Approximately 200-400% |
| Glass Transition Temperature | Optimized for room-temperature acoustic damping |
As an accredited S-LEC Sound Acoustic Film factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | S-LEC Sound Acoustic Film is supplied in rolls of 100 meters, individually wrapped and packed in moisture-protective cartons. |
| Container Loading (20′ FCL) | S-LEC Sound Acoustic Film is loaded in a 20-foot FCL, palletized, wrapped, and securely braced for safe transport. |
| Shipping | S-LEC Sound Acoustic Film ships as rolled interlayers on protective cores, wrapped in moisture-barrier packaging with desiccant. Ensure dry, temperature-controlled transport to prevent blocking or deformation. Handle with care, avoid sharp impacts, and store in clean, flat orientation until use. |
| Storage | Store S-LEC Sound Acoustic Film in its original packaging in a cool, dry, well-ventilated area away from direct sunlight, heat sources, and moisture. Keep rolls flat or upright as recommended to avoid deformation. Maintain moderate humidity and avoid contact with solvents. Handle carefully to prevent scratches or contamination. |
| Shelf Life | Shelf life is typically 12 months from manufacture when stored sealed, cool, and dry, avoiding moisture, heat, and sunlight. |
In OEM windshield lamination, S-LEC Sound Acoustic Film is positioned between two 2.0 mm to 2.3 mm soda-lime float glass plies that have already been sag-bent as a matched pair; the interlayer thickness is typically 0.76 mm, giving an interlayer thickness share of 14–16 % for a total stack of 4.76–5.36 mm. The compliance framework for the finished windshield includes ECE R43 for fragmentation, optical, and impact requirements; JIS R3211 where Japanese OEM validation applies; ANSI/SAE Z26.1 for North American test conditions; and ISO 16940 for mechanical impedance and loss factor of the laminated glass. On a continuous windshield laminating line, the bent glass pair is washed, rinsed with deionized water at 45–55 °C, dried with ionized-air knives, and transferred to a layup room maintained at 18–22 °C and 20–30 % RH. The PVB interlayer is cut from roll stock with 0.5–1.0 mm oversize allowance for edge flow, placed between the glass plies, and de-aired through a pre-press calender at 60–80 °C and 0.4–0.8 MPa roll pressure or through a vacuum-bag station at −80 kPa to −100 kPa for 10–20 min. The pre-pressed assembly is then moved into a horizontal autoclave and consolidated at 130–140 °C and 1.2–1.4 MPa for 60–90 min; pressure is maintained during cooling until the edge temperature falls below 40 °C to prevent interlayer creep and optical distortion. A known production failure mode is edge sealing collapse when the pre-press nip pressure falls below 0.4 MPa or when room humidity exceeds 30 %, producing trapped air pockets that become visible as edge bubbles after autoclave. The terminal product is an OEM acoustic windshield; transmitted noise in the coincidence-dip region is measured by third-octave sound reduction under ISO 10140-2, and damping is expressed as loss factor under ISO 16940.
Acoustic side lite lamination with S-LEC Sound Acoustic Film uses a lighter stack than windshield glazing; a frequent production layup is 1.8 mm outer glass / 0.76 mm acoustic PVB / 1.4 mm inner glass, which places the interlayer at 19.2 % of total stack thickness and demands tighter process control because the glass is press-bent rather than sag-bent in many side-lite plants. The applicable type-approval and validation set includes ECE R43 for impact and fracture behavior, GB 9656 for China-market glazing, 49 CFR 571.205 under FMVSS 205 for North America, and ISO 16940 for acoustic damping verification. On the production line, the outer and inner glass plies are printed with ceramic ink, dried, and press-bent to the door-glass curvature; after washing, the pair enters a layup room held at 18–22 °C and 20–30 % RH to prevent moisture uptake by the PVB interlayer. The interlayer is cut with minimal excess, placed onto the lower glass, and covered with the upper glass; vacuum-bag de-airing at −85 kPa to −95 kPa or roll nip pre-pressing at 55–70 °C removes trapped air. Autoclave consolidation is performed at 125–135 °C and 1.0–1.2 MPa for 45–75 min, followed by controlled cooling to 35–40 °C before unloading. Optical distortion in side lites is checked with a zebra-board or collimated-light inspection against the OEM specification; a common defect arises when the inner glass edge is not uniformly pressed during pre-lamination, causing local interlayer thinning near the perimeter. The terminal product is a laminated side door window that reduces wind and traffic noise transmission while retaining ejection-mitigation and theft-resistance performance required by side-glazing standards.
Flat architectural lamination with S-LEC Sound Acoustic Film is specified for facades where high weighted sound reduction must coexist with impact-safety glazing. A representative acoustic curtain-wall stack is 6 mm clear float glass / 0.76 mm acoustic PVB / 6 mm clear float glass, giving an interlayer thickness share of 5.9 % in the 12.76 mm laminated lite; when the lite is assembled into an insulating glass unit, it is typically combined with a 12–16 mm argon-filled spacer and a solar-control low-emissivity lite. The compliance path includes EN ISO 12543-2 for laminated glass requirements, EN 14449 for laminated safety glass used in buildings, EN 12600 for impact performance, and acoustic testing under ISO 10140-2 with rating under ISO 717-1:2020. The production process in a flat-glass lamination plant begins with cut-to-size float glass washed by oscillating brushes and rinsed with deionized water at 45–55 °C, then dried with high-velocity air knives. The PVB interlayer is positioned on the lower glass, and the upper glass is lowered in a layup room maintained at 20–25 °C and 20–30 % RH; the assembly is de-aired by a pre-press calender or vacuum-bag line at 70–90 °C roller temperature and 0.5–0.8 MPa nip pressure. Autoclave consolidation uses 135–145 °C and 1.0–1.3 MPa for 90–150 min, with slow cooling to 30–35 °C to minimize optical waviness. The terminal product is a building facade lite for high-noise districts, commonly installed as the inner or outer lite of an insulating glass unit; the table below lists the mandatory acoustic and safety evaluations applied before project release.
| Evaluation | Standard designation | Parameter |
|---|---|---|
| Airborne sound reduction laboratory test | ISO 10140-2 | R, dB, 100–5000 Hz third-octave |
| Weighted sound reduction rating | ISO 717-1:2020 | Rw + Ctr |
| Mechanical impedance and loss factor | ISO 16940 | loss factor, equivalent bending rigidity |
| Laminated glass safety and durability | EN ISO 12543-2 | impact resistance, optical quality |
For demountable office partition systems and hotel room divider walls, S-LEC Sound Acoustic Film is supplied as a 0.38 mm or 0.76 mm film placed between two 5 mm tempered glass panes, yielding a total thickness of 10.38 mm or 10.76 mm and an interlayer thickness share of 3.7 % or 7.1 %. The compliance set for the laminated partition panel includes ANSI Z97.1 for safety glazing used in buildings, 16 CFR 1201 Category II for impact resistance in architectural application, EN 12600 for pendulum impact classification, and ISO 10140-4 for in-situ airborne sound insulation of the assembled partition. In production, the tempered glass is cut to size before tempering, then washed and transferred to a dry-room layup station; the PVB interlayer is centered with edge offset held below 1.0 mm, and the stack is placed in a vacuum bag where de-airing is maintained at −85 kPa to −90 kPa for 15–25 min before autoclave. Autoclave consolidation for these interior laminates uses 125–135 °C and 0.95–1.15 MPa for 60–90 min; after cooling, edges are inspected for interlayer squeeze-out and trimmed with a warm knife if required. The terminal product is a frameless or aluminum-framed interior partition panel, sliding door, or meeting-room glass wall that combines acoustic damping with the retained-particle safety behavior of laminated tempered glass.
Specifying S-LEC Sound Acoustic Film for a rail side window introduces a requirement set that differs from both automotive and architectural use because the laminate must remain in place under the thermal load defined by fire safety regulations. A representative high-speed rail sidelite stack uses 4 mm chemically strengthened glass / 0.76 mm acoustic PVB / 4 mm chemically strengthened glass, giving an interlayer thickness share of 8.7 %; some multilaminate configurations add a second PVB layer to increase installed robustness. The relevant compliance framework includes EN 15152 for railway vehicle glazing, EN 45545-2 for fire behavior of materials and components, EN 12600 for impact classification, and ISO 16940 for loss factor and equivalent bending rigidity. Production of rail sidelites typically begins with precision-cut and edge-worked chemically strengthened glass; the plies are washed, dried, and placed in a dry-room at 20–24 °C and 25–30 % RH. The interlayer is laid onto the lower glass, the upper glass is positioned, and vacuum-bag de-airing at −90 kPa is performed for 20–30 min before autoclave. Autoclave consolidation is run at 130–140 °C and 1.1–1.3 MPa for 75–135 min, followed by a slow cooling ramp to 30–35 °C to minimize edge stress around drilled or cut-out features. Because rail glazing systems often include integrated frames, heating elements, or gaskets, published data for this exact stack configuration is limited; system-level validation under the rail operator’s approved glazing specification is required rather than reliance on standalone interlayer data. The terminal product is a laminated rail side window that provides noise damping, passenger retention, and optical quality in high-speed and intercity rolling stock.
In commercial bus and coach side window lamination, S-LEC Sound Acoustic Film is used in a thicker stack than passenger-car side lites; a frequent production specification is 4 mm outer glass / 0.76 mm acoustic PVB / 3 mm inner glass, giving an interlayer thickness share of 9.8 % in the 7.76 mm laminate. The finished window is certified under ECE R43 for large-vehicle glazing, ECE R118 for burning behavior of interior materials in motor vehicles, and ISO 16940 for loss factor; where the window is adhesive-bonded to the coach frame, the edge zone is pumice-ground and treated with a silane primer qualified under ISO 4587 for adhesive peel strength. The production route follows autoclave lamination with 130–140 °C and 1.0–1.2 MPa for 60–90 min; before lamination the bent glass pair is washed and dried in a humidity-controlled room below 30 % RH, and the PVB interlayer is cut to a controlled oversize of 1.0–2.0 mm to allow edge flow without excessive squeeze-out. The terminal product is a bonded or gasket-mounted side window for intercity coaches and transit buses, suppressing engine and road noise transmission while maintaining the emergency exit and passenger-retention performance required by vehicle type approval.
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S-LEC Sound Acoustic Film is manufactured by Sekisui Chemical as a polyvinyl acetal-based interlayer for laminated glass in which airborne sound transmission loss must be improved in the coincidence frequency region. The product is identified as S-LEC Sound Acoustic Film within the S-LEC interlayer family and is supplied as a co-extruded film with PVB-based skin layers and a sound-damping core layer. The skin layers retain adhesion and safety behaviour typical of standard PVB, while the core contributes frequency-dependent mechanical loss measurable under ISO 16940:2008. The film is available in standard interlayer thicknesses such as 0.76 mm and 1.52 mm; final film selection is determined by the safety classification required for the finished laminate under EN 12600:2002, ANSI Z97.1, or ECE R43.
Unlike standard PVB, this acoustic grade is intended for glazing assemblies tested for airborne sound reduction according to ISO 10140-2:2021 and rated under ISO 717-1:2020. The interlayer contribution is not evaluated as a standalone film property but as part of a laminated glass build. The product is not a substitute for increasing glass mass or using asymmetric glass configurations at low frequencies, and published data for specific glass/film combinations is limited to controlled laboratory configurations or manufacturer bulletins.
Laminated glass transmits sound through mass-law behaviour at low frequency, through shear and bending waves at mid frequencies, and through coincidence effects where the wavelength of incident sound matches the bending wavelength of the glass. The acoustic core of S-LEC Sound Acoustic Film is formulated to raise the laminate loss factor η measured in accordance with ISO 16940:2008. The effect is strongest in the coincidence region of the glass build, frequently located between 1600 Hz and 4000 Hz for monolithic glass thicknesses of 4 mm to 6 mm. Under laboratory conditions, an acoustic PVB interlayer may improve the sound reduction index by 1–3 dB in this region compared with standard PVB of the same nominal thickness, but the exact improvement depends on glass thickness, interlayer thickness, laminate size, edge clamping, and temperature. Product-specific values for S-LEC Sound Acoustic Film should be obtained from the manufacturer’s technical bulletin for the exact build instead of extrapolating from generic acoustic PVB literature.
At room temperature, the acoustic core has a lower shear modulus than the skin layers, which promotes shear deformation and energy dissipation. Damping performance is temperature-sensitive. Below approximately 10 °C, the loss factor of acoustic PVB generally decreases; above approximately 40 °C, the interlayer softens further and the acoustic benefit may shift. The product is therefore primarily specified for service environments between 10 °C and 35 °C. Where glazing is exposed to sustained high-temperature environments, the acoustic film should not be selected without evaluating the expected service temperature against the manufacturer’s published damping-temperature curve.
Automotive acoustic glazing with S-LEC Sound Acoustic Film is commonly used for windshields and front side glazing where aerodynamic noise is concentrated between 2000 Hz and 4000 Hz. In vehicle testing, the reduction in interior sound pressure level at the driver’s ear is not predicted solely by the interlayer; it depends on glass sealing, body cavity absorption, and powertrain noise spectrum. Automotive laminated glass using acoustic PVB must satisfy the safety requirements of ECE R43, including the impact tests applicable to windscreens and side windows. Published data for specific vehicle models is limited outside OEM validation programmes.
Production-scale lamination with acoustic PVB requires a modified edge-seal procedure compared with standard PVB. The sound-damping core reduces melt viscosity at autoclave temperature, so premature edge sealing during calender nip-roll de-airing can trap air and produce edge flow lines. Laminating lines with infrared pre-heating typically set the calender roll gap 0.3 mm to 0.5 mm larger than the total glass-plus-interlayer thickness; standard PVB often tolerates a tighter gap, but acoustic film responds differently because of its lower flow resistance. Autoclave cycles for PVB-based laminates commonly operate between 125 °C and 145 °C with pressure from 1.0 MPa to 1.5 MPa; for acoustic PVB the lower temperature segment is preferred on many laminating lines to avoid excessive edge squeeze-out and residual stress. When vacuum-bag de-airing is used instead of nip rollers, the cold vacuum stage should be extended until the edge seal is continuous. Moisture control is critical: PVB film is hygroscopic, and exposure to relative humidity above 60% may require reconditioning or drying before lamination to prevent bubble formation and adhesion loss at the glass interface.
S-LEC Sound Acoustic Film differs from standard PVB mainly in the acoustic core formulation and its effect on the temperature-dependent loss factor. Standard PVB provides safety, adhesion, and some damping but does not place the same deliberate mechanical loss into the coincidence frequency range. Ionoplast interlayers are significantly stiffer and provide higher post-breakage residual strength, but their acoustic loss factor at typical service temperatures is lower than that of acoustic PVB. The choice between these interlayers is therefore not governed solely by sound control; it is determined by the combination of safety category, structural demand, optical quality, and lamination process capability.
| Interlayer type | Primary function | Acoustic loss factor at service temperature | Typical processing condition |
|---|---|---|---|
| Standard PVB | Safety and adhesion | Moderate; not optimised for coincidence region | Autoclave 125–145 °C, 1.0–1.5 MPa |
| S-LEC Sound Acoustic Film | Safety and frequency-dependent sound damping | Higher at 20–30 °C in coincidence region; measured per ISO 16940:2008 | PVB-type cycle with wider calender gap and controlled edge seal |
| Ionoplast | Structural stiffness and post-breakage strength | Lower ambient-temperature loss factor | Higher temperature cycle; moisture-insensitive handling required |
Because the acoustic grade remains a PVB-based interlayer, it is compatible with standard PVB glass washing and storage equipment. However, laminators should not infer that one autoclave recipe is valid for all acoustic PVB products. Batch-to-batch variation in film moisture, roll age, and glass surface cleanliness can shift the acceptable temperature window by several degrees; the manufacturer’s certificate and technical bulletin provide the specific maximum soak temperature and cooling rate for the current production lot.
Architectural facade use of S-LEC Sound Acoustic Film is generally considered when the exterior noise spectrum is dominated by road traffic or rail sources. The acoustic film is incorporated into a laminated glass build that may also include coated glass for solar control or low-emissivity functions. The sound reduction of the complete insulating glass unit is tested according to ISO 10140-2:2021, and the final Rw + Ctr value may be improved by using the acoustic interlayer, but the improvement is not uniform across all frequency bands. For railway noise, the low-frequency dominance means the acoustic interlayer alone may not control the A-weighted level unless the glass build also has sufficient mass.
Incoming film inspection should include roll hardness, thickness profile, haze, and moisture. Thickness profile is measured with a contact micrometer according to ISO 4593; roll width and core alignment are checked against the order specification. Because the acoustic core is co-extruded, total film thickness and core centring are process variables that can influence damping behaviour. Laminators should request the manufacturer’s quality certificate for each production lot and retain it with the batch record for compliance audits.
S-LEC Sound Acoustic Film should be stored in its sealed moisture-barrier packaging at 5 °C to 25 °C. Open rolls should be re-sealed immediately and conditioned to processing temperature before lamination. If the film is exposed to relative humidity above 60%, moisture uptake can promote bubble formation during autoclave and lower glass adhesion. Edge stability in service is influenced by the finished laminate edge detail. Exposed PVB edges should not be allowed to stand in water; glazing rebates should be drained and the edge should be isolated from sealants containing ketones, esters, or high levels of migratory plasticisers. Compatibility testing with the specified sealant system should be performed before installation because published data for all sealant combinations with this specific acoustic film is limited.
Long-term optical quality depends on the edge moisture barrier and the cleanliness of glass surfaces after washing. In laminated glass production, glass surfaces are washed with demineralised water and inspected for contact angle or surface contamination before assembly. The acoustic core may show different haze behaviour under ASTM D1003-21 compared with standard PVB, so incoming film quality should be verified using a haze meter and the manufacturer’s acceptance values. For automotive applications, visible defects are evaluated under the rearview mirror zone criteria of the applicable vehicle manufacturer or the methods referenced in ECE R43.
The following methods are commonly required when acoustic laminated glass is specified. They are not alternative product certifications; each applies to a specific property of the finished laminate or interlayer.
| Property | Method/standard | Typical report output |
|---|---|---|
| Mechanical impedance and loss factor of laminated glass | ISO 16940:2008 | Loss factor η and equivalent bending rigidity |
| Airborne sound insulation in laboratory | ISO 10140-2:2021 | Sound reduction index R in one-third-octave bands |
| Weighted sound reduction rating | ISO 717-1:2020 | Rw, C, Ctr |
| Impact performance of architectural laminated glass | EN 12600:2002 | Classification such as 2B2 or 1B1 depending on build |
| Automotive safety glazing approval | ECE R43 | Component or vehicle approval |
| Haze and luminous transmittance | ASTM D1003-21 | Percent haze and transmittance |
In each case, the standard applies to the assembled laminate rather than the interlayer alone. Acoustic film does not independently confer a safety rating or a sound insulation class; the glass thickness, interlayer build, frame conditions, and installation details determine the final performance. For that reason, the film should be specified by a build definition, not by a single product code.
