Compare / Thermally toughened glass, enamelled vs Float glass (annealed)

Thermally toughened glass, enamelled vs Float glass (annealed)

Europe EN 12150-1 · Glass

Thermally toughened glass, enamelled

Toughened glass with fired enamel (ceramic frit) on the surface: fb,k 75 MPa on the enamelled face.

Europe EN 572-1/-2 · Glass

Float glass (annealed)

Ordinary annealed soda-lime float glass: fg,k 45 MPa, E 70 GPa, 2 500 kg/m³.

Mechanical

PropertyConditionThermally toughened glass, enamelledFloat glass (annealed)Difference
Modulus of elasticity E—70 000MPa270 000MPa2same
Shear modulus G—29 166MPa229 166MPa2same
Poisson's ratio ν—0.220.22same
Knoop hardness HK—6GPa26GPa2same

Design values

PropertyConditionThermally toughened glass, enamelledFloat glass (annealed)Difference
Modification factor for load duration kmodinstantaneous load · wind gust, 3 s1111same
medium-term load · snow on heated buildings, 5 days0.4910.491same
permanent load · 15 years0.3210.321same
Partial factor for the material γMannealed glass part, γM;A1.811.81same
surface prestress part, γM;v1.21—

Physical

PropertyConditionThermally toughened glass, enamelledFloat glass (annealed)Difference
Density ρat +18 °C2 500kg/m³32 500kg/m³3same

Thermal

PropertyConditionThermally toughened glass, enamelledFloat glass (annealed)Difference
Coefficient of thermal expansion α20–300 °C9×10⁻⁶ /K29×10⁻⁶ /K2same
Specific heat capacity cp—720J/(kg·K)2720J/(kg·K)2same
Softening temperature Tso—725°C1725°C1same
Resistance to temperature difference ΔT—40K140K1same
Thermal conductivity λ—1W/(m·K)11W/(m·K)1same

Optical

PropertyConditionThermally toughened glass, enamelledFloat glass (annealed)Difference
Refractive index nvisible light, 589.3 nm1.511.51same
Emissivity εcorrected (for U-value calculation), uncoated0.83710.8371same

Electrical and magnetic

PropertyConditionThermally toughened glass, enamelledFloat glass (annealed)Difference
Electrical resistivity ρeat +25 °C · 1 000 Hz5 × 10⁷Ω·m15 × 10⁷Ω·m1same

Rows are matched by condition (thickness band, temperature, product form). A dash means the grade has no sourced value for that condition. Differences are Float glass (annealed) relative to Thermally toughened glass, enamelled; for ranges the lower bound is compared.