Science Mini-Spark #1 How Glass is Made

How Glass is Made

5-PS1-4. Conduct an investigation to determine whether the mixing of two or more substances results in new substances.

This process is interesting and a more interesting question is how did humans begin this process in the first place? Watch a video about glass from Mystery Doug and take a few notes as you watch.


What materials are used to make glass?

Glass is made from a mixture of sand, lime and soda. When these ingredients are heated together, they form a liquid glass. This liquid glass is made into sheets by cooling and flattening. To make objects like vases, craftsmen blow into a glob of liquid glass with the help of a long tube.

Plate Glass made by Rolling:

  • Sand, lime and soda are heated together in a furnace to make liquid glass. Rollers are used to flatten glass into sheets, which are first cooled, then cut.

Plate Glass made by Floating:

  • Liquid glass from a furnace is floated and slowly cooled on the surface of liquid tin. After the glass has cooled down, it is cut into pieces.

Handmade Glassware:

  • Vases, ornaments and other intricate glass objects are made by a glass-blower. The glass-blower uses a metal blowpipe which has a glob of hot glass at the end of it. A glass blower then blows the soft glass into shape.

Glass has many uses:

  • Glasses, window panes, mirrors are few of the many things that are made from glass. Glass is not only useful, but can look beautiful too. Windows made of stained glass are works of art.

Additional Information:

  • Other glass-making ingredients can include alumina, lead oxide, salt-petre and zinc oxide which are used to make different types of glass. In the production of plate glass, waste glass from a previous melt is also added, making up 5 to 40 percent of the mixture. Melting takes place in giant furnaces, from where molten glass is floated or rolled into sheets.

Watch this animated step video about glass from Mocomi

Your turn

Draw a picture timeline/use pic collage showing several of the different glass making process. Include at least 3 science words in your visual.


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