Glass Melamine Laminates — Sheet & Rod

Glass melamine is a family of woven-glass-fabric/melamine-resin thermoset laminates defined by NEMA LI-1. These composites are manufactured by impregnating woven glass cloth with melamine resin and curing under heat and pressure, producing rigid phenolic sheet and structural stock with exceptional arc and track resistance. Ready Plastics stocks the G-5/G-9 grade within this family — the standard designation for glass melamine in switchgear and motor insulation applications.

Glass melamine laminates are distinguished from other thermoset grades by their melamine resin system, which inherently resists surface tracking under high voltage — a critical property in bus bar insulators, motor slot liners, and panel boards where arcing or carbon tracking along the insulation surface could cause failure. The material combines strong mechanical performance (up to 70,000 psi tensile strength for G-9), UL 94 V-0 flame retardance, and low moisture absorption to serve demanding electrical environments reliably. Compared to glass melamine epoxy grades, melamine provides enhanced rigidity and better arc resistance at its operating temperature range.

Standards and performance context. Glass melamine grades meet NEMA LI-1 and are tested per ASTM D709. G-9 carries a UL 94 V-0 classification. These materials operate continuously up to 120°C (248°F). Applications requiring higher temperatures should consider glass epoxy grades G-11 or FR-5 (up to 180°C) or glass silicone Grade G-7 (up to 220°C).

Related families. Ready Plastics carries a full range of thermoset laminates: glass phenolic for general electrical insulation, glass epoxy for high-strength and moisture-resistant insulation, and glass silicone for extreme-temperature service. All are part of the broader thermoset laminates and phenolics lineup.