Overview
EN ISO 12543-6:2021 (Glass in building - Laminated glass and laminated safety glass - Part 6: Appearance) is a CEN-endorsed ISO standard that defines appearance-related defects and inspection methods for finished laminated glass and laminated safety glass. The standard sets acceptance criteria for visible defects when looking through the glass, with special emphasis on the vision area used in glazing applications. It applies to finished sizes at the time of supply and is part of the ISO 12543 series for laminated glass.
Key topics and technical requirements
- Method of observation: Inspect panes vertically, placed parallel to a matt grey screen, illuminated by diffuse daylight or equivalent. Visual inspection is made perpendicular to the glass at a distance of 2 m.
- Areas to inspect: The standard distinguishes the vision area (main area excluding the edge) and the edge area. For pane sizes less than 5 m² the edge area width is 15 mm; for pane sizes greater than 5 m² it is 20 mm.
- Prohibited defects:
- Vents (sharp fissures running from an edge) are not permitted.
- Creases and streaks are not permitted in the vision area.
- Spot defects: Defects smaller than 0.5 mm are not considered; defects larger than 3 mm are not permitted. The permissible number of spot defects depends on pane area and number of plies (components) in the laminated unit; accumulation rules and adjusted limits apply for multiple plies and thicker interlayers (increase permissible counts by one per interlayer thicker than 2 mm).
- Linear defects: Linear defects shorter than 30 mm are allowed. Longer linear defects are limited by pane area (e.g., not permitted on very small panes; a small number permitted on larger panes).
- Edge area:
- For framed edges, defects ≤ 5 mm diameter are permitted provided total defect area ≤ 5% of the edge area.
- For unframed edges, shelling and bubbles may be acceptable if not visually disturbing; interlayer retractions deeper than 2 mm are not permitted. Edge finishing must comply with ISO 12543-5.
- Thermally treated glass in laminates: Optical distortions and anisotropy from tempering/stress-relief processes may be visible; requirements from thermally treated glass standards also apply.
- Pack inspection (Annex A): Allows observation of jumbos/stock sizes by pack under defined conditions (pack limits such as up to 3 tonnes for jumbos or up to 7 cm thick for other packs).
Applications and users
This standard is essential for:
- Glass manufacturers and laminators for production quality control and acceptance criteria
- Glazing fabricators, façade and curtain wall manufacturers specifying finished glass quality
- Architects, specifiers and consultants writing performance and aesthetic requirements
- Inspectors, testing laboratories and conformity assessment bodies responsible for appearance checks and acceptance on delivery
Keywords: laminated glass, laminated safety glass, appearance, defects, vision area, inspection method, ISO 12543-6, glass in building, spot defects, linear defects, edge area.
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