How glass is produced: an explanation of glass production. Video, glass bending and blowing techniques for the production of bottles and jars. Production of blown glass and plates.
When we talk about glass production we refer to two different production processes based on the product obtained. The glass production process varies in the case of glass or blown glass (glass bending) for the production of bottles, jars and other containers. In both cases glass production can be divided into four phases:
- Preparation of the raw material
- A fusion of silica sand (raw material)
- Glass cooling and processing
- Here is how glass is produced.
Here is how glass is made.
First of all, the processing of the raw materials takes place in large silos or wagons. In this phase the raw material sieve, drying and pre-heating takes place.
The raw material consists of silica sand and other chemical components depending on the quality of glass. These materials, once sieved, dried and pre-heated, are placed on conveyor belts and loaded in batches directly led to the furnace.
Sometimes the raw material for the production of glass consists of fragmented glass derived from differentiated collection with the recycling of glass. In this case the preparation consists of the separation and purification of the “secondary raw materials”.
The types of glass differ in color, quality, purity of raw materials and also from the type of furnace used.
The furnace is fed very slowly. The power supply is controlled by processing systems that also take into account the type of combustion. The industrial furnaces are powered by natural gas or fuel oil and reach a temperature of 2,867 ° F, equivalent to 1575 ° C. In the image below the “mouth” of a furnace is visible.
The size of the glass production furnace is classified according to the production capacity in terms of tons per day.
The glass processing phase differs according to the final shape. It is easy to guess: producing glass sheets sees a simpler method than producing bottles and glass jars!
Raw materials for glass production
Common glass is also called silica glass because we are talking about a material composed almost exclusively of silicon dioxide. Silicon dioxide has a melting point of about 1800 ° C, and for this reason, it is much more expensive (in energy terms) to produce glass starting from silica sand rather than from already fragmented glass obtained from separate collection.
How glass is produced
When it comes to glass bending there are two further production systems. One intended for bottles (or better, “narrow-necked” containers and one for the production of jars and cans (conical open-necked containers).
In both glass production processes a flow of molten glass – at a temperature between 1050 and 1200 ° C – is cut with a cutting blade to form a glass cylinder called “drop”.
Thanks to the high precision cutting blades, the “drop” (glass cylinder) has a predetermined weight, enough to make a bottle.
The drop (the glass cylinder), once cut, falls by gravity from the initial machine and ends up in empty molds which then close on themselves, trapping the drop.
Thanks to a valve, the glass is blown with compressed air. The valve introduces two “puffs” of air. The first gives the draft of the bottle (it already has its shape, complete with a thread intended for the crown cap) and the second puff ends the internal hollow shape. In the end, the valve will give a bottle of its final shape.
What glass is made of
The term glass is commonly used to indicate objects in siliceous oxide (siliceous glasses) used for the production of frames (glass plates and double glass), containers (bottles, jars …) and furniture (vases, table plates …). The technique of working and producing glass is called ialurgia.
Glass, origins, and production
To get an idea of how to explain the production of glass to children, we invite you to read the last paragraph of the article: how to explain recycling to children. Next, the video on the origins and production of glass.