DOUBLE WALL GLASS
The double-walled glass is basically a glass within a glass. The air between the two glasses is sucked out when it is made, creating a vacuum. Instead of having a heating or cooling element to keep drinks hot or cold, it is designed to keep beverages at the correct temperature by not allowing heat to escape or enter.
This “vacuum” is the best insulator because there is no air to transfer the heat into. According to a study that was conducted over six hours, normal glasses are terrible at insulating liquids. In contrast, double-walled glasses and cups did a great job at keeping the beverage at the desired temperature.
Typically made of high-quality borosilicate glass, double-walled glasses can generally accommodate hot and cold drinks alike. Because of the extra wall of glass, double-walled glasses are able to keep your drink insulated for a longer period of time, so your coffee won’t get too cold (or warm) as you continue to work or read the daily news. These double-walled glasses are typically pretty sturdy.
Although the technology and thought behind the double-walled glass isn’t a new idea. According to “The Legend of Bohemian Glass: A Thousand Years of Glassmaking in the Heart of Europe,” by Antonin Langhamer, the double-walled glass was created in the early 1700s in North Bohemia. They were formed “by two glasses that fit precisely, one into the other.” The surface of the smaller one was painted or coated with gold or silver leaf. These glasses were more decorative in nature.
Perhaps the closes thing to the double-walled glass in the thermos. Thermoses were invented in 1892 by Sir James Dewar who was a scientist at Oxford University. The “vacuum flask” wasn’t made for commercial use for about 12 more years when two glass blowers formed the Termos GmbH. The word thermos comes from the Greek word “Therme,” meaning “hot.”
Double-walled glasses have a rich history, including the invention of the double-walled Pyrex glass dish that was created in 1928 and the Coffee Butler, a vacuum insulated glass carafe created in 1985.
Not only are these glasses better for keeping your drink hot or cold, they are also very durable.
REGULAR GLASSES
These cups are generally made from glass, which is produced by cooling molten so the internal arrangement of atoms remains in a random or disordered state, according to the Encyclopedia.
Although glass can be found in nature in the form of obsidian, which is made when the heat from volcanoes melts rocks like granite to make them glassy when they cool, most glass used in the production of glass cups is man-made.
Man-made glass is often formed into cups, plates, vases, and more by glassblowing. Glassblowing involves a metal rod or pipe being used to pick up molten glass and act as a pipe. The glassblower could blow into the molten glass to help shape it into whatever they needed. Today, the art is still recognized and can be used to make glasses. Glasses like these can also be made with machinery.
When making glass cups or wine glasses, it begins with design. What will it look like, and what will the dimensions be? After that is decided, the glasses go into production. First, a craftsman picks up a glob of molten glass. He then takes it over to a mold where it is shaped. If the glass has a stem, they are generally hand crafted. After that, the glasses go through quality control. Some machines have been created to help this process along without the need of highly-skilled craftsmen.
In short, while regular glasses can be beautiful, they are often thin and break easily. They also do not provide much insulation to keep a drink hot or cold.