The Mind-Boggling Theory Behind Why Does Glass Break When Heated

The science behind why does glass breaks when heated is actually straightforward and concise but explaining it and understanding it takes time.

Glass can actually be heated to mold it into any shape possible, and it might not break, but this only happens when the heat is applied to it to a certain degree, but too much heat causes stress marks to appear on the glass, and it cracks.

Everyone has seen glass at least once in their lifetime. It can be considered an exceptional material because of its multiple properties.

While some think of glass as just some material that can be seen through, others are fascinated by its property to be cast into any shape.

As a result, many things are made of glass and are used by almost everyone, whether it is the windscreen of their car or beautiful earrings.

All can be crafted from heated glass. But this heat can also be the reason why it’s so hard to work in the glass industry.

This passage answers many questions about glass, so you should read on. But before we answer any question, let us explain what glass is and how it contributes to the daily lives of humans.

What Exactly Is Glass?

Why Does Glass Break When Heated

Glass falls under the category of solids formed by rapid melt quelching to get desired properties. Glass is a non-crystalline amorphous material with a wide range of practical and ornamental applications.

Glass is used in a variety of things such as construction and decoration. Most humans also use it in their day-to-day lives in the form of optical glasses or tableware glasses that act as containers for consumable liquids.

Although everyone uses glass, making it requires extensive work. Glass work goes hand to hand with heating as glass can only give desired shapes when molten; thus, heat does not always crack the glass. However, this phenomenon still occurs under certain conditions.

Let me tell you how and why glass breaks when heated and how to prevent it from happening.

What follows is factual information about the science behind glass formations and breaking, so keep up.

What Does It Take to Make Glass?

Glass has many interesting properties which make it stand out from most other materials. Glass is made from liquified sand, and all that is required is to heat the sand so that it melts and then can be molded into any shape.

The melted sand can be taken from any beach as all are fundamentally the same and contain the same molecular buildup.

How it exactly works Is relatively easy, and melting glass only has a few requirements. These conditions must be met to make glass or anything relating to it:

  • One of the two main methods of making glass is the Float Glass method. The glass produced by this method takes the shape of straight panels which are extremely flat and contained the desired thickness.
  • The process was invented in the 1950s by a British glass manufacturer named Pilkington, which is why this process is also called the Pilkington process. This type of glass is passed over a bed of molten metal such as tin, and as it floats over it, it forms the shape that is commonly used in windows and doors.
  • The second glass production method is called Glassblowing and is a bit more interesting. This method can be tricky as it requires more handling as compared to the Pilkington process. This way of making glass products dates back to the middle of the first century where it became quite popular.
  • A glassblower blows air through a blowpipe into molten glass to inflate it and then bends the inflated glass into the preferred shape. The molten glass can also be blown into a container to obtain a desired shape. this method is called Mold-Blowing.

How Technology Is Involved!

Now you see it, and now you don’t. Glass is a puzzle. It is tough enough to keep us safe, but it shatters with astonishing simplicity. Even though it is built of opaque sand, it is fully transparent.

And, perhaps most strangely, it behaves like a solid material. Still, it is actually a strange liquid! Glass can be found almost anywhere: most rooms in your house will have a glass window, and if not, a glass mirror or a glass light bulb. Glass is one of the oldest and most versatile materials ever made by humans. Let us learn more about it.

There are also other multiple ways in which glass products can be made as technology has come a long way, and everything has been automated.

Many factories around the world use machines to make glass bottles and other glass-made containers. The machines used in these factories vary greatly because glass-forming contains many different processes.

The scientific and technical revolution in all sectors has resulted in massive advances in the science of glass and glass-making technologies in recent decades. Thermal, acoustic, and electrical insulation are all provided by the glass and its layers.

New materials are known as fiberglasses, in which glass fiber and glass layers are mixed with various organic matter binders, which have a lot of potentials.

Fiberglass is used to construct boats, ships, vehicle bodies, cisterns, and other structures. The fragility of glass is its greatest drawback.

However, great progress has been made in strengthening the strength of the glass in recent years.

It is feasible to increase the glass’s resistance to static bending using thermochemical toughening techniques. Glass containers for the food sector are now widely manufactured.

The presence of quartz sand alone is insufficient to make glass goods that meet all of the demands of the most discerning customers. As a result, the technical department of a glass-making company steps in.

The recipe for the mixture of components used in the melting of glass is created by professionals in this sector.

The high-grade glass mass is obtained when the proportions of the elements are suitably chosen.

Why Does Glass Break When Heated? What Is The Process Called?

This is a fascinating topic. Glass expands as it heats up and contracts as it cools, just like most other materials.

It has a low thermal conductivity as well. It is also tough but fragile. These three facts explain why glass can break when heated rapidly.

Assume you hold a heated, thick piece of glass in your hand. It is uniformly heated, which means it is uniformly expanded thermally.

Put it in an ice bath; the surface will chill nearly instantaneously, but the middle will have to wait for the heat to dissipate before it can cool. This results in an uneven thermal profile, with the outside being cold and the center being hot.

As a result, the surface shrinks or attempts to shrink. The surface glass does not shrink due to the hot interior glass.

This puts a lot of strain on the glass because the surface is attempting to shrink but is unable to do so; therefore, it is driven into tension. The hot core is attempting to maintain its volume, but the surface squeezes it in, causing the core to compress.

The compressive strength of glass is considerable. And any enclosed solid that is subjected to stress is nearly indestructible.

Surprisingly, glass also has a high tensile strength; in fact, under regulated conditions, glass is much stronger than metal. However, real-world situations are uncontrollable, and we all know how brittle glass is.

As a result, in our hot-glass-in-ice-water example, the surface is attempting to shrink but failing, putting it under tension. In addition, by opposing shrinkage, the core is compressed.

It is not difficult to figure out which portion of glass wins the tug of war: the surface. And a crack appears as a result of a minute fault, expanding and spreading until the stress is eased or the glass is completely shattered through. That is why glass breaks when heated.

Glass cracks for a variety of reasons, including temperature, the rate at which the glass is heated, and the distribution of heat play a big role in deciding how much glass expands and contracts, resulting in shattering and cracks.

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Uses Of Glass

Glass is a clear, hard, produced solid that is used for a multitude of applications, including spectacles, bottles, windows, and even certain types of furniture. Glass coffee tables, for example, are widely used to embellish living rooms, and it can even be shaped into decorative works of art.

When ordering glass from a local or online retailer, you will have a variety of options. You may choose to select thin glass or a higher-quality, more durable glass; you can usually customize the thickness of the glass when ordering through a specialty retailer.

You can get this Meihua Glass Coffee Table for Living Room from Amazon to experience a good coffee table made out of robust and sturdy glass.

To get some glass bottles, look no further than Epica 18-Oz. Glass Beverage Bottles. Most water and juice bottles are difficult to fill and clean, but their wide mouth makes filling and cleaning a breeze. They are also airtight and environmentally friendly.

You can also get a soundproof glass, which functions as a sound-deadener and is particularly useful for your apartment’s outside windows. Tempered glass is more resistant to shattering and is more robust, which is another option.

This type of glass is utilized in circumstances where safety is critical. It is up to five times stronger than conventional glass and is also heat-resistant due to its treatment throughout the production process.

Because tempered glass is so useful and durable, It is in more demand, especially for exterior windows of public buildings.

How To Prevent Glass From Breaking

While glass is aesthetically diverse and performs admirably, it does require certain unique considerations when working with it.

This is especially true in commercial design, where huge glass panels are frequently specified to produce a dramatic impression. One such issue is the breaking of glass under heat.

Some factors that can affect the glass and its durability are:

  • Type Of Glass: Glass comes in a variety of colors, ranging from ultra-clear to the darkest gray tinge. Solar radiation is absorbed and heated by tinted and spectrally selective glasses. Because of this absorption, colored glasses are more likely to break due to being heated instead of clear glass.
  • Type Of Coating: Low-e and reflective coatings both reflect and absorb solar radiation, and depending on their surface location, they can increase the amount of heat absorbed.

Use Tempered Glass

The glass that has been heat-treated to make it tougher and safer is known as tempered glass. “Toughened” or “completely tempered” glass is another name for tempered glass.

It has a minimum surface compression of 10,000 pounds per square inch and a minimum edge compression of 9,700 pounds per square inch. Tempered glass has a surface that is roughly four times stronger than standard annealed (non-safety) glass of the same thickness.

Tempered glass is extremely difficult to break, but if it does, it shatters into little, comparatively harmless fragments. This unique “dice” breaking pattern reduces the danger of major damage.

You can get this Farberware - 78624-10 Farberware Glass Utility Cutting Board. It is heat resistant, break-resistant, stain-resistant and will protect the counter and other surfaces from heat, dampness, and scratches.


Now you know the mind-boggling theory behind why does glass breaks when heated and the uses of glass and prevention methods that can be employed to stop glass from breaking.