EVERLAM SATIN WHITE

EVERLAM SATIN WHITE is supplied as a pigmented polyvinyl butyral (PVB) interlayer for laminated safety glass, in roll form with a satin surface texture generated during extrusion rather than by post-embossing. The model designation EVERLAM SATIN WHITE identifies a white, light-diffusing interlayer whose optical effect is produced by an inorganic titanium dioxide (TiO₂) pigment system dispersed in a plasticised PVB matrix. Single-ply gauges of 0.38 mm and 0.76 mm are standard; multi-ply make-ups of 1.52 mm, 2.28 mm, and 3.04 mm are assembled at the lay-up table for enhanced penetration resistance, stiffness, or acoustic mass. The material class is characterised by a density of 1.06–1.08 g/cm³ at 23 °C, and the glass transition temperature by differential scanning calorimetry is normally between 15 °C and 25 °C, depending on plasticiser content and residual moisture.

Tensile properties for pigmented PVB interlayers of this category, measured under ASTM D638-14 or ISO 527-3, commonly show tensile stress at break of 20–28 MPa and elongation at break greater than 180%. The satin surface provides two manufacturing functions: it reduces roll blocking during storage, and it maintains microchannels that allow de-airing during vacuum-bag or nip-roller pre-lamination. The satin finish is not a coating; it is a controlled topography on both surfaces of the film. This topography reduces contact area between adjacent film layers in the roll and provides a network of capillary channels that remains open during the initial stage of vacuum de-airing. After autoclave, the surface texture largely levels into the PVB matrix, producing the satin optical finish rather than a transparent high-gloss layer. Moisture content at lay-up should be maintained in the 0.40–0.60% by mass range, determined by Karl Fischer titration. Exact pigment loading and luminous coordinates for EVERLAM SATIN WHITE are batch-controlled and should be obtained from the manufacturer’s certificate of analysis; published data for this specific configuration is limited.

What Limits Edge De-airing and Autoclave Consistency in Satin White Laminates?

On a production laminating line, the two common failure modes with pigmented PVB are premature edge-closure during de-airing and delayed edge bubble formation after autoclave. The satin surface channels of EVERLAM SATIN WHITE must remain open until the glass edge reaches approximately 60–80 °C during preheating. If the edge seals below this range, residual air is trapped and later expands in the autoclave. Vacuum-bag systems should maintain negative pressure of at least 0.8 bar relative to atmosphere; roller-bag and nip-roller lines should adjust roll-gap force to the glass thickness and interlayer stack. Pre-lamination surface temperatures should be kept between 10 °C and 25 °C. White pigment alters the radiative absorption response compared with clear PVB, so process settings should not be transferred without validation on the actual glass-interlayer make-up.

Water quality on the glass washing line is a controlled variable. A final rinse with deionised water below 20 µS/cm conductivity is typical for architectural PVB lamination because residual salts or surfactants can alter adhesion at the glass-interlayer interface. Glass should be dried immediately before interlayer lay-up, and the glass surface temperature should remain below 30 °C to avoid premature localised adhesion. Autoclave cycles for this interlayer class typically operate at 12–14 bar and 135–140 °C glass-surface temperature, with a hold of 30–60 min after the glass pack reaches setpoint. Heating rate should not exceed 5 °C/min, and forced cooling should remain below 5 °C/min until glass surface temperature falls below 50 °C. For insulating glass laminates or glass thicknesses above 10 mm, the core soak time should be extended because the interlayer is a thermal insulator and the white surface reflects a portion of the radiant energy. Production experience shows that stacked load density in the autoclave also affects uniformity; edge packs may require a slower ramp than centre packs. Batch-to-batch variation in surface roughness and moisture can shift the de-airing window by several degrees, so incoming moisture checks and surface roughness inspection are appropriate controls.

Optical and Solar Performance Across Interlayer Grades

The following table gives representative optical and solar ranges for a 6 mm glass / 0.76 mm interlayer / 6 mm glass make-up using EVERLAM SATIN WHITE, clear PVB, and standard white PVB. Values are representative for this interlayer class and should be verified against the batch certificate for a specific order. Haze is measured according to ASTM D1003; luminous, solar direct, and UV transmittance are evaluated according to ISO 9050.

The practical difference is image obscuration. A satin white interlayer with luminous transmittance below 70% and haze above 70% obscures defined objects while transmitting useful daylight. This distinguishes it from clear PVB, which preserves visual transparency, and from standard white PVB, which may have lower luminous transmittance but lacks the satin surface’s more uniform reflection. The white pigment also suppresses direct solar transmittance, but the exact solar gain depends on the glass selection and the presence of low-emissivity coatings.

Compliance for laminated safety glass fabricated with EVERLAM SATIN WHITE is evaluated at the assembly level, not only on the interlayer film. The interlayer contributes to fragment retention after breakage, but the final classification depends on glass type, thickness, edge work, and framing. Architectural laminated safety glass is commonly tested against EN ISO 12543-2:2021, ANSI Z97.1, and CPSC 16 CFR 1201; the interlayer film is characterised by ASTM D638-14 and ISO 527-3. The compliance matrix below summarises the standard framework.

Because the satin white interlayer is an organic polymer with an inorganic pigment, it is not a fire-rated material. Projects requiring fire-resistant glazing should use a tested fire-rated assembly; EVERLAM SATIN WHITE should not be inserted into a fire-rated make-up without full system testing.

When Satin White Replaces Clear PVB in Spandrel and Baluster Applications

In spandrel glazing, EVERLAM SATIN WHITE can replace clear PVB when the facade design requires a uniform white translucent appearance without a visible backpainted or fritted surface. Because the interlayer is encapsulated between glass plies, the optical layer is protected from abrasion, cleaning chemicals, and environmental degradation. Unlike post-applied films, it cannot be peeled or scratched from the exterior surface. Compared with ceramic frit or backpainted glass, the satin white interlayer retains laminated safety-glass behaviour while allowing diffuse light transmission; it is not a substitute for an opaque spandrel where total concealment of mechanical services is required.

In balustrade and partition systems, the visual separation is accompanied by the viscoelastic response of PVB, which absorbs energy during impact. The inorganic white pigment gives the interlayer better resistance to UV-induced colour shift than organic dyed interlayers, although long-term colour stability should be confirmed by accelerated weathering such as ISO 4892-2. Edge quality and sealant compatibility remain critical: acidic-cure silicone sealants, solvent-based edge paints, and plasticiser-migrating gaskets not approved for PVB should be avoided. Edges should be protected from standing water and highly alkaline cleaning agents during service to prevent edge haze and delamination.

Moisture, Adhesion, and Storage Boundary Conditions

PVB interlayers are hygroscopic. EVERLAM SATIN WHITE should be stored in sealed packaging at 10–25 °C and below 60% relative humidity. Before lay-up, rolls should be conditioned for a minimum of 24 h at 20–25 °C and 25–35% relative humidity. If the laminating room operates above 60% relative humidity, pre-drying of the interlayer is required to reduce moisture content below 0.60% by mass. Moisture above 0.60% increases the risk of edge bubbles and delamination after autoclave; moisture below 0.35% can lower adhesion to glass and reduce the fragmentation retention of the laminated assembly. Adhesion is checked by the pummel test, in which the laminate is chilled to -18 °C for at least 2 h and impacted to expose glass. Typical architectural PVB values are 3–7 on standard cleaned soda-lime glass, depending on glass washing, drying, and interlayer moisture. Values below 3 may indicate inadequate adhesion, while values above 7 may indicate excessive adhesion and reduced impact penetration resistance. For satin white PVB, the same adhesion range is expected, but pigment loading can create slightly higher apparent adhesion on some low-iron glasses; published data for this specific configuration is limited.

When laminating to low-emissivity coated glass, the coating edge deletion must be specified before cutting, and the glass supplier should confirm compatibility of the coating with PVB and autoclave pressure. The product should not be combined with edge tapes, gaskets, or sealants that release plasticiser-migrating oils. Rolls should be stored horizontally and handled with clean, dry gloves. Surface contamination that is invisible at lay-up can become a visible optical defect after lamination and cannot be removed from the encapsulated interlayer.

For applications that require high post-breakage residual strength, such as glass fins, beams, or point-fixed facades, a PVB satin white interlayer is not a direct substitute for a stiffer ionoplast or structural PVB interlayer. The design should be verified by finite-element analysis and full-scale testing under the applicable structural glass standard. Published data for this specific configuration is limited; the interlayer supplier should be consulted for adhesion and stiffness data under the expected service temperature range.

In acoustic applications, standard PVB interlayers provide limited damping. The sound insulation of a laminated glass unit is controlled primarily by glass mass and interlayer thickness; satin white pigmentation is a secondary variable. If a project requires high acoustic performance, a dedicated acoustic PVB interlayer should be considered, and the assembly should be tested according to ISO 10140 or the regional equivalent. The addition of a white satin interlayer can be combined with acoustic interlayers only if the full stack is validated for adhesion and optical compatibility.