how is glass made?

Question

how do glasses differ from each other

Answer 1

Glass is any solid which was melted and cooled before the disordered liquid atomic structure could form a solid and regular crystal structure. There is a fair amount of thermodynamics, kinetics, and chemistry that goes into this description but suffice it to say a glass consists of elements falling into three groups.

First, you need a glass former (Silica, Boron, Vanadium, Telerium, Selinium...) which forms the basis of the solid disordered structure. Because of their high melt temperatures (something like 2200 C), most glassformers like silica (sand) require the addition of a second group of elements known as Network Modifiers. This group consists of elements like Sodium, Potassium, Lithium... and they work to break up the network and reduce the melt temperature. The third group is an Intermediate like Calcium or Magnesium, which changes physical properties such as chemical durability. The range of chemical compounds can be used to engineer a glass with very specific properties.

On the commercial level glass is seperated at the batch house, mixed, and sent to the melt tank where it is melted by liquid fuel (often OxyFuel or Oxygen Natural gas combo) flames. Sometimes elctrical boosting is employed to help the melt process. It is important all the batch be melted and compositionally alike (homogenious). The glass is then fined, which means the bubbles created by batch decomposiotion are allowed to rise and burst as dictated by the Stokes equation. From there the glass is carefully cooled and formed. Some glasses need to be annealed which means they are heated after cooling to some temperature below the melt temperature (near the glass transistion temperature) to allow for atomic relaxation but not recrystallization. This prevents shattering due to thermal stresses incurred from rapid cooling.

Some exotic glasses include metals melted and rapidly quenched in liquid nitrogen fed roolers and organics dried over long periods of time at room temperatures (call the sol or sol gel process)

Glasses vary as widely as their compositions and as such they are truely an engineering material... they can be tailored to most any need.

Answer 2

By melting together SiO2 with other metal and nonmetal oxides. Brorosilicate has B2O3 in addition to SiO2. It is resistant to shattering on extreme temperature changes. Leaded glass has PbO. That's good for drinking goblets. Because of the high nonmetal oxide content, which are acidanhydrides, it'sbest not to wash glass with ammonia, which is a base. That's why alot of glass cleaners say, "Contains no ammonia."

Answer 3

By melting sand. You can add other elements, like aluminum, to make it stronger, or colored. You can heat it differently. It's a science and art that would fill an encyclopedia -

Answer 4

i'm sure you can find all the info on the net on how it is made, but i do know that glass is made of sand..good luck..