Process diagram: Brick manufacturing

The diagram shows how bricks are made in a factory, in a process that consists of eight stages.

Overall, the process is linear. Clay is dug up, shaped into bricks and hardened by drying and firing, and the finished bricks are then delivered to building sites. The first three stages prepare the clay, the next four shape and harden the bricks, and the final stage delivers them.

First, clay is extracted from a quarry. Large lumps are then broken up by crushing, and the clay is mixed with water and sand. Next, the mixture is pressed into moulds so that it is shaped into bricks.

In the middle of the process, the bricks are dried in warm air for two days. They are then baked in a kiln at 1,000°C, so the bricks are strengthened gradually.

In the final two stages, the bricks are cooled slowly so that cracking is avoided. Slow cooling is therefore an important final step. Finally, they are stacked and taken to building sites, which completes the process.