Home page Site map Ελληνικά
The glass manufacturing process
Glass containers manufacturing appears to have been produced as far back as 5000 BC.
According to the Roman historian Pliny glass was 'discovered by accident' when Phoenician sailors, resting on a sandy beach in Syria, created fire to cook their food; they laid their cooking pots on nitrate blocks they were carrying as cargo. The combination of the nitrate blocks that melted and the beach sand resulted in an 'opaque liquid' that is, glass.
Glass blowing has probably started approximately 2000 years ago, in the greater Mesopotamia area. The craftsmen used a long thin tube to blow the molten glass. However, due to the time-consuming process and the difficulty and 'secrecy' of the trade glass containers represented a luxury rather than a necessity.
Automization of glass production started circa 1905, when the first completely automatic glass bottle machine was manufactured in the USA.
Amazingly enough, the basis of glass manufacturing process is not significantly different today. To produce a glass article (whether bottle, jar or tableware) we mix the following raw materials: sand (59%), soda ash (19%), limestone (13%), dolomite (5%) and in smaller quantities feldspar and salt cake. The furnace melts them in a temperature around 1600οC; molten glass is soft, and almost liquid, thus very flexible.
The molten glass is cut into uniform gobs, and then sent to a forming machine that forces the molten gobs into the desired mould shape. The shaped glass leaves the forming machines, and enters a cooling plate, so that it cools off to a solid form.
Manufactured glass articles go through a series of quality control instruments and personnel, that test them for flows or technical non-conformities (bubbles, or scratches that might have been created during the production process and hinder the product's strength and durability).
Glass products are then packaged and stored or shipped to the end-user.
Modern technology, materials and equipment have made it possible to constantly ameliorate earlier drawbacks of glass containers, such as durability, heat and cold resistance, elimination of process variations, weight of final products. In other words, a typically traditional product is currently made in a high-technology environment.




 
 F.A.Q.