Mica Glass Tape Insulation

Glass Cloth as the Reinforcing Layer

Mica glass tape insulation combines mica paper with glass cloth to bring electrical insulation and mechanical reinforcement into one tape construction. In the supplied product information, glass-fibre-backed phlogopite mica tape is used for fire-resistant cables, while glass-fabric-reinforced mica tape is also offered for VPI insulation systems. The reinforcement is applied to one side of the mica paper in the described standard construction.

The technical data provides 145 ± 8 g/m² phlogopite mica, 32 ± 2 g/m² fibreglass, and 25 ± 3 g/m² binder for the 0.15 mm glass-fibre-backed tape. Tensile strength is greater than 120 N/cm, water absorption is less than 0.5%, and the total weight is 202 ± 20 g/m². Each layer has a dielectric withstand of more than 1.5 kV.

Mechanical Support During Application

The role of the glass reinforcement becomes especially relevant when the tape is wrapped around conductors or electrical coils. The supplied information describes the glass-fibre backing as providing mechanical strength, while the mica supplies the high-temperature electrical insulation. For fire-resistant cable production, the tape may be installed in one or more layers with a 20–50% overlap. The glass backing also makes the described construction non-combustible during flame propagation testing.

Glass-Reinforced VPI Options

Mica glass tape insulation is also available in low-resin VPI constructions. The standard glass-fabric-reinforced VPI tape has a nominal thickness of 0.10–0.18 mm, glass fabric content of 33 g/m² and resin binder content of 10–12 g/m².Air porosity is greater than 1,600–2,500 s/100 ml, dielectric strength is between 15 and 25 kV/mm, and tensile strength is at least 150 N/cm. 155°C Class F and 180°C Class H are the specified temperature classifications.Therefore, this design is appropriate for situations where the mica layer requires more mechanical support without sacrificing the properties needed for high-temperature service and electrical insulation.