How LEGO® bricks are made

Lorries arrive

It all starts with tiny plastic chunks called granules which come in a bunch of different colours. Lorries filled with granules drive up to one of the LEGO® factories all around the world, where giant hoses suck up the granules and then dump them into three-story high metal silos. There are 14 silos and each one can hold up to 33 tonnes of granules. From the silos, the plastic granules are fed down pipes to the moulding machines.
 

We turn up the heat

Inside the moulding machines, the granules are superheated to a temperature of about 450 degrees Fahrenheit (230°C). This melted plastic goo is fed into moulds, little metal containers shaped like hollow LEGO® bricks. Think of these as very complicated versions of the ice cube trays you keep in your own freezer. The moulding machine applies hundreds of tonnes of pressure to make sure the bricks are shaped with perfect accuracy. Then they are cooled and ejected, which only takes about 10 seconds.
 

Robots lend a hand

Because of the dangerous conditions and high precision required, the moulding process is almost completely automated. Finished pieces roll down conveyor belts into boxes. When a box is full, the moulding machine sends a radio signal to one of the robot trucks that patrol the hall. The robot trucks are guided by grooves in the factory floor. They pick up full boxes and place them onto another conveyor belt that takes them onto the next step of the manufacturing process.
 

Time to decorate

What would our bricks be without lots of cool details and decorations? The next stop in the manufacturing process is the assembly halls where details are printed on and multi-part pieces are put together. Faces, control panels, numbers, words and other decorative details are stamped onto bricks by a giant printer. Some LEGO® pieces like minifigure legs are made up of several pieces that fit together. These complex pieces are snapped together by machines that apply pressure with great precision.
 

We pack it up

The final step is putting all the right pieces together to make complete LEGO® sets. Sets can have hundreds of different pieces, so the packaging process has to be fast and accurate. Boxes called cassettes roll on conveyor belts underneath the bins that hold each type of piece. The bins open and close to release the right number of pieces into each cassette. Finally, packing operators fold the boxes, add additional pieces and the building instructions and watch out for any machine-made mistakes.