Glass has an exciting feature: being in a stable condition; it does not
have the properties of a crystalline substance. This fact is the principal mark
which distinguishes the glass from other liquids.
Glass has several types of classification, for example, according to the
level of transparency. There is less transparent glass, such as tinted,
reflective glass, and mirrors. There is a classic colorless transparent,
"clean" glass. Also, there is an "extra-clean" glass (with
low iron content).
 |
| The "clear" glass and the "extra-clear" glass |
Let's talk some more about the "extra-clean" glass and its differences from the "clean."
Ordinary glass is not as transparent as it seems to us. If you look at it
from the side, you can see that it has a green shade. It isn't usually
noticeable, but it becomes visible with some light. What's the matter? Iron oxide is a component that is widely used in the
manufacture of ordinary glass: it decreases the temperature in the
manufacturing process. Glass gets a green tint as a result of this process.
 |
| The manufacturing process of the low iron glass |
Meanwhile, the new technologies in the production of glass can make the
content of iron oxide lower. As a result, we can get an incredibly clear glass
that transmits the light perfectly. If transparency is vital, you should use
the low iron glass.
When do we use low iron glass? It is possible wherever transparent glass is used: when it is necessary to reduce the ability of the glass to pass the sunrays and at the same time obtain absolute transparency. Glass with low iron content is used in the production of solar photovoltaic modules, solar greenhouses, solar collectors, lampshades.
 |
| A greenhouse made of low iron glass |
What are the technical features of "extra-clear glass"? The luminous incident flux doesn't reflect from the glass but passes through glass. Besides, the light transmission of iron-low glass reaches 99%, which is more than the same rate of ordinary glass (90%). Consequently, the reflectivity of the glass is only 1%. Iron-low glass is called "invisible" for this reason. It is sometimes difficult to understand whether there is glass in front of you. So, it's possible to find the glass only by touching it with your hand.
 |
| The low iron glass railings are "invisible" |
Despite all the advantages, low iron glass has a big minus. It lies in the cost of glass. Extra-clear glass is quite expensive compared to ordinary glass.
