Process diagram: Glass bottle recycling

The diagram illustrates the process by which used glass bottles are recycled into new ones.

Overall, the process is a cycle of eight stages. Used bottles are collected, cleaned and melted, and they are eventually turned into new bottles, which are sold and then returned to the bottle banks. The first four stages prepare the glass, while the remaining four turn it back into bottles.

The process begins with collection, when used bottles are left in bottle banks by the public. Lorries then transport the glass to a recycling plant, where the bottles are separated according to their colour. After that, the glass is crushed, or broken into small pieces known as cullet.

In the next stage, the cullet is cleaned. Magnets and screens are used to remove any labels and metal. The clean cullet is then mixed with raw materials and melted.

Finally, the molten glass is blown into new bottles, which are filled and sold in shops. Once the bottles have been used, they are again left in bottle banks, so the process starts all over again.