Sir Sidney McSprocket’s been in action capturing facts – all about manufacturing!

Today he’s finding out all about light bulbs!

What on earth would we do without good old marker pens? They’re invaluable for making colourful artwork and highlighting what’s important!

The first steps of making a marker pen are to build the outside parts; the barrel and the lid.

To do that, granules of coloured plastic are melted down to make a big sticky soupy mix. The molten plastic is pushed into the required shapes using high powered hydraulic presses.

Each press has the same force as over three hundred elephants!

three gray elephants on green grass field during daytime

As they cool, the barrel and lids harden. The barrels are lined up on a conveyor belt and a spongy ink cartridge is pushed inside by a robotic arm. An end cap is also pushed in and the marker pen is ready for its ink.

The ink is mixed to really exact standards.

Every batch must be the same colour and have the same consistency – neither too runny nor too thick. A chemical called a humectant is added to prevent the ink drying out too quickly.

pink and purple pen with white background

Tiny needles inject the correct amount of ink into each pen. And the ink cartridge soaks it all up!

Finally the nib, which is moulded and baked into the correct shape, is attached and the lid put on. Again they use a conveyor belt to move the pens along and robotic arms push all the parts together.

It’s funny to think that marker pens have been around for less than a hundred years! Before that if you wanted colourful inks you’d have to get your fountain pen out – or even a paint set!

Sidney McSprocket is Fun Kids’ resident inventor!

When he’s not in Edinburgh, tinkering with wacky contraptions in his workshop, he’s finding out all about manufacturing!

In the latest series, Sidney is finding out about a whole load of everyday objects from tin cans and toothbrushes to plastic bottles and Pyrex…