Table 4 Tabulation of physical properties for ISG-1 and ISG-2 in comparison to the original ISG.

Strain Point (Log 14.68, in P)

°C

529

524

533

Annealing Point (Log 13.18, in P)

°C

566

558

566

Softening Point (Log 7.65, in P)

°C

711

707

707

Log 6 (P) viscosity

°C

781

784

Log 5 (P) viscosity

°C

842

852

Log 4 (P) viscosity

°C

927

945

Log 3 (P) viscosity

°C

1024*

1054

1083

Log 2 (P) viscosity

°C

1267

1306

Coefficient of Thermal Expansion

x10^-7 ∙ K^-1

72

69

Density – Archimedes

g∙cm^-3

2.50–2.53*

2.508

2.475

Density - He Pycnometry

g∙cm^-3

2.51–2.53*

2.512 ± 0.001

2.472 ± 0.002

Liquidus

°C

≈830

≈900

Chemical Durability: Base^a (ISO 695)

mg∙dm^-2 (Class)

92.3 ± 9.0 (A2)

77.6 ± 0.7 (A2)

82.2 ± 0.8 (A2)

Chemical Durability: Acid^b (DIN 12116)

mg∙dm^-2 (Class)

565 ± 1 (S4)

497 ± 13 (S4)

Chemical Durability: Water^c (ISO 720)

µg-Na₂O ∙ g-glass^-1

319 ± 4 (HGA2)

273 ± 4 (HGA2)

135 ± 3 (HGA2)

Chemical Durability: 7-day static test (ASTM C1285-21, PCT-B)

g ∙ m^-2

1.145*

0.89 ± 0.09

1.77 ± 0.2