Raw glass it is so called ready sheet annealed glass that wasn’t exposed to toughening or thermostrengthening.
Annealing is a regulated cooling of a glass sheet, allowing to remove residual voltage in the glass. This operation is an integral part on the production process of float-glass.
There are two modes of glass sheet production: horizontal one on the melt metal (float-glass, thermally polished glass) and vertical pulling (drawn glass). The technology consists in making the glass ribbon on the surface of the melt tin.
Float glass (polished glass) of M1-M2 types is remarkable for its glance surface, high transparency (89-90%) and wonderful optic features, excluding image distortion. This kind of «usual» window glass can be used in multi-layer glazing and is the base for production of wide range of modern improved glasses and glass units. The sheets of 3-18 mm thick can be used in the building. The sheets of 8 mm thick are called the «plate glass». The glass manufactured in this way has a uniform thickness, almost perfect polished surface and no optic defects.
The raw glass can be exposed to cutting, mechanic treatment, drilling, edge machining and polishing.