Glass is a generally bright hard substance. It is composed of silicates and alkalis that fuse at high temperatures.
The glass was already used by the Muslim and Arab peoples. In this way, these people are assigned the use of two concave glasses with magnification to use them as binoculars. Next, and as a summary, we will analyze the characteristics and properties of glass
Characteristics Of Glass
1. Origin and discovery
How is glass made? It is a fluid that is known since the ancient age of man. Although its discovery is not exact, its origin begins when mixing sand and carbonate at high temperatures.
2. History of glass
The glass was already used by the Muslim and Arab peoples. In this way, these people are awarded the use of two concave glasses with magnification to use them as binoculars.
3. Uses of glass
What is the use of glass? Originally its use was strictly ornamental. Then he gave way to the religious sphere. Later, the manufacture of containers and everyday uses began, such as the elaboration of everyday utensils.
Currently its uses are diverse and varied from bottles, hip prostheses, dental, mirrors, windows, etc.
Glass is a type of material that can be recycled more easily than other materials. However, there are some types of glass that, due to their composition, the recycling process is more extensive over time. For example: mirrors, window glass, spotlights and tempered glass.
5. Optical properties
These properties refer to a part of the light is refracted, another absorbed and a third part is transmitted. The optical properties of glass do not change over time.
6. Physical properties
Composition of glass Although there are many ways to make glass, in general, glass is composed of materials of mineral origin fused thermally. Specifically, it contains quartz sand, soda, lime, magnesium oxide and aluminum oxide.
Color. The color is originated by the elements that are added at the moment of their fusion. For example, a bluish-red color will be achieved by the use of cobalt oxide; A yellow color will be achieved by using ferric oxide and a bluish coloration will be achieved by the use of ferrous oxide.
Texture. The texture can vary the brightness of the glass. This depends on the melting process that has taken place.
Malleability. They are malleable when they are in their casting stage. The main methods of molding are:
7. Mechanical properties
- Softening The glass softens at approximately 730 ° C.
- Hardness. It is 470 HK.
- Resistance to compression. It oscillates between 800-100 MPa (megapascal)
- Elasticity of glass It refers to the elastic elongation of a thin glass rod and how resistant this bar is. It has been shown that the glass has a resistance to elasticity of 70,000 MPa.
- Flexural strength. It measures the resistance during the deformation of the glass. According to tests it has been determined that said material has a flexural strength of 45 MPa.
8. Thermal properties
As for the thermal properties, it can be said that the glass reaches a specific heat (temperature) and also that it has a thermal conductivity. In other words, it conducts both heat and cold in the same way.
Temperature for its softening. Certainly glass does not have a defined softening point. Thus, this material passes from a solid state to a plastic state with a pasty appearance. However, modification characteristics can be observed from approximately 600 ° C.
9. Electrical properties
Dielectric constant. Between 5 ° C and 10 ° C. It is a physical constant that explains or describes how an electric field affects (or is affected) by a medium.
Surface electrical resistivity. Under normal conditions the glass has an electrical resistivity of 1020 ohm · cm. This transforms it into one of the best known electrical insulators.
10. Chemical properties
Density. This density depends on the type of materials included in its manufacture. However, in general, the density of the glass is approximately 2500 kg / m3. This gives the flat glass a weight of 2.5 kg / m2 (per each millimeter of thickness).
Viscosity. It is the resistance that a liquid has to flow. Here we are in front of a solid material but we must also refer to the viscosity. However, the glasses are supercooled liquids. It is for this reason that this chemical property of glass must be taken into account.
Corrosion. The glass is very resistant to corrosion. That is why it is frequently used in chemical experiments. Anyway this does not mean that said material is indestructible. In fact there are 4 substances against which the glass breaks:
High concentration phosphoric acid
Alkaline concentrations at high temperatures
Water at high temperature