The machine that never sleeps: Meet the Yankee cylinder

To make a lot of toilet rolls, you need a lot of drying power. Toilet paper goes from wet pulp to dry sheets in just 1.4 seconds, and the machine that handles the drying is a serious loop of metal.

Today we’re talking about the Yankee cylinder. The tale of this rotating wonder was a highlight of our recent trip to the factory, so we decided to share its story and explain why it plays such a vital role in making Naked Paper.

A brief history of drying paper

When paper was first invented around 105 AD, drying was simple. Sheets of flattened paper pulp were laid out in the sun, hung on racks, or placed near a fire and left to dry naturally.

This method worked for centuries, but by the 18th century the demand for paper had grown rapidly. Imagine the space you would need to dry all the sheets of a newspaper on racks, then multiply that by all the people reading newspapers in London alone. Not to mention books, pamphlets, legal documents, financial records and receipts. Drying all that paper sheet by sheet would require incredible amounts of time, labour and space.

So manufacturers began searching for faster, more efficient techniques for drying paper.

The Yankee cylinder arrived in the 19th century as a breakthrough solution. It was named after the New England term “Yankee,” which at the time suggested something clever, innovative and efficient. The name stuck, and so did the technology.

What is a Yankee cylinder?

Early Yankee cylinders were made from cast iron, later evolving into steel, and they are essentially enormous single drum dryers powered by steam. Wet pulp is pressed against the surface of the rotating drum.

As the cylinder turns, heat evaporates the moisture from the paper. Once it is dry, it can be wound off the cylinder onto a spool, allowing for continuous, controlled drying.

The original machines were small compared to today’s standards. The Yankee cylinder in our factory is huge: 2.75 metres wide and weighing around 8 tonnes.

It is so large that when it was first delivered to our factory in Girona, the transport had to take place in the middle of the night, with roads temporarily closed to allow it through.

How does the Yankee cylinder make toilet paper?

At this stage the Yankee cylinder has been invented and installed in our factory. Now all we need is to run some heat through it.

When we say “some,” we mean a lot. To dry the paper quickly enough that it can spool onto the cylinder as wet pulp and spool off as dry paper, the cylinder carries air that reaches temperatures of up to 650°C.

In many toilet paper factories, the energy used to heat the Yankee cylinder comes from burning fossil fuels. This makes the drying stage the biggest contributor to CO2e emissions in standard paper making.

Our factory takes a different approach. The cylinder is heated using steam generated by our biofuel boiler, which is powered by renewable biofuels (more info on exactly what these are here).

This innovative way of generating heat means that our Yankee dries our paper with no fossil fuels, neatly side stepping the most energy intensive part of standard tissue making.

The machine that never stops turning

It’s fair to say the Yankee is an essential part of the Naked Paper operation. So essential, in fact, that it’s never switched off. One of the most fascinating facts about the Yankee cylinder is that it can never stop turning.

Because of the immense weight of the cylinder and the extreme temperatures it handles, if it were ever to stop completely, gravity would begin to subtly distort its shape. Instead of remaining perfectly round, it would become slightly teardrop shaped.

That tiny change would have a big impact on the quality of Naked Paper. Sheets passing over one side would end up too thick, while tissue on the opposite side would be too thin. It would spool off the cylinder in uneven thicknesses, affecting softness, strength and flushability.

To prevent this, the Yankee is kept in constant motion. Our factory is equipped with backup generators to ensure it keeps turning during power outages. And if those fail, there is a manual crank that can be used as a last resort.

We've never had to resort to raw manpower yet, but the option is there if we need it!

Yankee loo roll dandy

That’s the tale of the Yankee cylinder.

At Naked Paper we like to say that we never stop working to make soft, affordable tissue products with great environmental credentials. But the Yankee cylinder is the only part of the operation that literally never stops working. Night and day, come rain or shine, it turns endlessly, dries evenly, and ensures quality in every roll.

Curious to try the result of the Yankee cylinder’s labours for yourself?