Our glass production process takes in everything from melting, gob distribution and container forming, to annealing, cold end coating and inspection.
The furnace melts cullet (crushed, recycled glass), sand, soda ash, limestone, and other raw materials together. Molten glass usually ranges in temperature between 2,300 and 2,800°F with furnace control systems monitoring and controlling the ring temperature.
At the end of the furnace, the glass stream is distributed to different forehearths for the respective production line. Molten glass is conditioned in the forehearth and its temperature gradient is equalised to ensure uniform temperature homogeneity. Plungers then intercept the stream of molten glass and cut gobs individually by mechanical shears, before the gob distributor routes the gobs into blank moulds at the I.S Machine.
Gobs of glass are delivered to blank moulds to form a parison. The ring nish and internal bore are created. It is then transferred to a mould side, where compressed air and vacuum are applied, stretching & cooling the parison to exact inner cavity prole of the mould, forming the nal shape of the container.
The glass containers are then submitted through a special type of oven called a Lehr that is designed specially for annealing glass. Glass is heated to the annealing point and then slowly cooled to room temperature. This process relieves the internal stresses, making the glass much more durable.
After annealing, a layer of polyethylene wax, is applied via a water based emulsion. This makes the glass slippery, protecting it from scratching and stopping containers from sticking together when they are moved on a conveyor. The resultant invisible combined-coating gives a virtually unscratchable surface to the glass.
All containers are monitored regularly throughout the production process and the end product is subject to exhaustive computer, laser, electronic, mechanical and manual checks to ensure it passes the most stringent health and safety standard requirements. Typical faults flagged up in this process include small cracks in the glass called checks, foreign inclusions called stones, bubbles in the glass called blisters, and thin glass. Rejected containers are recycled back into the furnace.