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Many of you I’m sure have used a printer. The most common type of printer is an injet, which fires dye from a cartridge, through a nozzel, and onto the paper.

My company make the dyes that go in the cartridges.

These dyes are made by mixing chemicals together. In a research laboratory, chemists mix small amounts of chemicals in a small glass flask, about the size of a mug, and produce grams of chemicals. However, to make many tonnes of the dye you need a massive reactor – the one my company uses is 20 cubic meters – 20,000 litres (60,606 cans of irn bru!).

Sadly, you cannot simply add more chemicals to the reactor (one tonne where you added one gram before), and at the same speed that you add them in lab (over a few seconds).

On reason for this is that many chemical reactions produce heat, and in a small flask, the heat given off is cooled by the surrounding air quite easily. However, it is very difficult to cool thousands of litres very quickly – it is easy to cool a cup of tea down by adding a few ice cubes, but would take AGES to cool a kettle of boiling water. If the massive reactor gets too hot, it could explode!

My job is to study the chemical reaction BEFORE it is put in the massive vessel, to make sure that it will be safe, but also using the most efficient process (could we use cheaper chemicals? Could we make the dye faster? etc).

I work in a laboratory, and use jacketed reaction vessels. These look like fancy glass buckets with a glass lid. Inside is a propeller that stirs the chemicals. We use glass as it does not dissolve in strong acid (like a chocolate teapot). The jacket is actually a cavity in the the wall of the bucket, that has flowing oil, that can be cooled or heated. I then add chemicals to the bucket and see the dye form magically before my eyes.

I record changes in temperature, look at crystals that form (using a microscope) and check the purity of the final product. I check purity as sometimes by-products (or the WRONG chemicals) form and I also have to see that the chemicals I added at the start have disappeared and the new product has formed correctly.