• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.32 no.1
• /
• pp.12-15
• /
• 2022

The effect of SiO₂, Na₂O and CaO on isokom temperatures in soda-lime glass is estimated by comparing calculated isokom temperatures using viscosity model proposed by Lakatos. The isokom temperatures at the viscosity of log η = 12.3, 10, 6.6 and 1 (Pa·s) are lowered by 6, 7, 10 and 24℃, respectively, by the substitution of SiO₂ with Na₂O by 1 mol%. Meanwhile, replacing 1 mol% of SiO₂ with CaO raises the isokom temperatures by 3~4 and 2℃ at the viscosity of log η = 12.3 and 10 (Pa·s), respectively, but lowers the temperatures by 1 and 21℃ at the viscosity of log η = 6.6 and 1(Pa·s), respectively.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.33 no.1
• /
• pp.7-14
• /
• 2023

Forty Viscosity data of glass bottles fabricated in a glass bottle manufacturing plant for 4 years were calculated using Lakatos model. The relationship between the glass bottle compositions and viscosities at log η of 3, 6.6, 10 and 12.3 Pa·s was analyzed. MgO that was a component of the glass bottle showed the maximum coefficient of variation of 0.89, but it gave a very small change in the viscosity. CaO that was another component of the glass bottle lowered the isokom temperature because it tended to reduce the number of non-bridging oxygen at temperature below a softening point.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.32 no.3
• /
• pp.103-106
• /
• 2022

The effect of Al₂O₃ on isokom temperatures in soda-lime glass is estimated by comparing calculated isokom temperatures using viscosity model proposed by Lakatos. Substitution of SiO₂ with Al₂O₃ by 0.5 mol% raises the isokom temperatures by 3.1, 3.3, 3.6 and 7.2℃ at the viscosity of log η = 12.3, 10, 6.6 and 1 (Pa·s), respectively. Meanwhile, replacing 0.5 mol% of CaO with Al₂O₃ raises the isokom temperatures by 1.6, 2.3, 4.1 and 17.7℃ at the viscosity of log η = 12.3, 10, 6.6 and 1 (Pa·s), respectively.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.32 no.6
• /
• pp.246-250
• /
• 2022

An estimation method of glass viscosity using Lakatos model is one of the best way to calculate the viscosity of soda-lime glass. The glass viscosity is obtained by inputting a glass composition consisting of SiO₂, Al₂O₃, Na₂O, K₂O, CaO and MgO to the Lakatos model. A series of composition of glass bottles was obtained once a month for 10 months from a soda-lime glass bottle fabrication line and isokom temperatures at the viscosity of log η = 3, 6.6, 10 and 12.3 were calculated. It was found that the isokom temperature at log η = 3 and log η = 6.6 was closely related to the value of (Si+Al)/O and 1/Na, respectively.