63 | Glass Manufacturing Methods, Forming Methods, and Processing Methods 1

Hello everyone 🎵

Glass Oyaji's blog has been going on for over a year now, with stories about the history of glass, domestic and international glass factories and manufacturers, and along the way, the history and challenges of Kimoto Glass. Oyaji is happy to hear that many people look forward to each post.

From this time, I'd like to start talking about the basics of glass manufacturing methods, forming methods, and processing methods. I will try my best to explain it in a way that is easy for beginners to understand, but if anything is unclear or you don't understand a certain word, please feel free to leave a comment.

Thank you in advance.

First, when I talk about glass, there's something I always ask everyone.

Is glass a gas, a liquid, or a solid?

It's not a gas, is it? It's not a solid either; it's a liquid.

Although it appears solid at room temperature, it becomes liquid when heated, like syrup. It's soft when warm and hardens as it cools.

I will talk about the composition of glass again, but since it is inorganic and transparent, it is basically transparent and quite hard. Depending on the type, the Mohs hardness (Mohs hardness is "the resistance to scratching when scratched with something") of a human nail is about 2.5, glass is about 5, and a knife blade is about 5.5. It is hard, resistant to chemicals (strong against acids, weak against alkalis), has a smooth surface, and is easy to clean. It is widely used not only for glasses but also for car window glass, building window glass, mirrors, lenses, and ornaments in daily life and industrial fields. Also, "enamel," which is a glassy film on a metal surface, and the smooth part of pottery's surface are, in a sense, similar to glass in their properties.

Physically, its density is 2.5 times that of water. It is a poor conductor of electricity and is used as an insulator, similar to rubber and ceramics. However, it has the mysterious property of decreasing electrical resistance as the temperature increases. Its tensile strength is 1/10 that of steel, but it is about the same as a leather belt or wood.

The broader category of glass, encompassing not only familiar beer bottles but also optical fibers, cathode ray tubes, hard disks, LCD/plasma displays, and mobile phone parts, is used in various aspects of our daily lives.

Next time, I will talk about glasses among these, so please look forward to it.