1. The glass production process is somewhat reminiscent of making a cake. The first step is to gather the ingredients: 70% sand (taken from places like the bottom of lakes), 14% sodium, 14% calcium and another 2% chemical components
2. The ingredients are mixed and sent to an industrial oven, which reaches temperatures of up to 1,500ºC! The mixture spends a few hours in the oven until it melts, turning into a semi-liquid material.
3. When it comes out of the oven, the mixture that gives rise to the glass is a viscous, golden goo, reminiscent of honey. It flows through channels towards a set of molds. The dosage for each mold is controlled according to the size of the glass to be created.
4. The first mold serves only to give the initial outline of the object. At this point, the “honey” has a temperature of around 1,200ºC. The primary mold shape leaves an air bubble within the glowing mixture
5. The object then goes to a final mold and a sort of straw is inserted into the bubble. Through the straw, a machine injects air, molding the liquid until it gains the definitive contour – like that of a glass bottle
6. At the end of step 5, the temperature of the glass has already dropped to around 600ºC and the object starts to become rigid and can be removed from the mould. Now only the so-called annealing remains: the glass is left to cool. In the case of a bottle, this only lasts for an hour. After that it is ready to be used.
– Who invented glass?
Did you know
• The physical state of glass almost gained a unique condition, called vitreous. Controversy exists because, although it appears solid, it has the molecular structure of a liquid. Some scientists classify it as an “amorphous solid”, that is, without form
• So-called tempered glass is heat treated to increase its strength. An example of tempered glass is used in cars and bathroom stalls.
• The air puff technique, described in the steps, can also be done by hand. The glasses that serve as sculptures, for example, are blown by the artist himself, with a kind of big straw.
• There are glasses made of sugar! They don’t have any resistance. What are they for then? Mainly to be used in TV or movie footage in scenes where glass objects are broken over the heads of actors and actresses