Today we’re taking a look at HP’s inkjet manufacturing operation facility where they test, develop and manufacture inkjet cartridges.

The 200-acre site in Dublin was built back in 1995 and is the company’s main R&D HQ. According to HP, the precision required for an inkjet nozzle to perform correctly is similar to dropping a penny from a 40-storey building and hitting a bucket on the pavement below! If that fails to impress, then consider the fact that the nozzle can spit out ink at 36,000 times a second – not too shabby for a component that is the smaller than a human hair. With this in mind, it’s not surprising that it takes HP between three and five years to test and develop a new ink cartridge.

The HP facility looks like the inside of Willy Wonka’s chocolate factory – cartridges whizz around the plant on small conveyor belts to eliminate any human contamination. Each HP inkjet cartridge comes with an individual 16-digit number lasered on to the side with a date so that the company can trace back an item if something were to go wrong. Across the other side of the facility is a series of labs, illuminated by an eerie yellow glow – this is where the micro-chip wafers are processed, but due to sensitivity with UV light must be kept in the right lighting conditions.

Once the cartridge has been assembled they are then moved on to the filling process. The inkjet cartridges are placed in a high pressure vacuum where they are filled from 1,000 litre tanks – it takes around 5 seconds to fill four cartridges!

After the cartridges are filled, the nozzles are fired to test accuracy. They are then sealed by tape which is then removed by the end user when installed into their home HP printer.

HP also have a dedicated testing centre filled with hundreds of printers and old machines. They use X-ray devices to see inside cartridges to determine whether there are any problems in the manufacturing process, they also have an autopsy area where they cut open the flesh of the cartridge to seek out any issues.

Pat Harnett, a member of the HP R&D team explains the extraordinary physics that goes on inside a printer. “It’s not as simple as millilitres of ink – there’s a lot more behind that in terms of nozzle balance, temperature and fluid dynamics”. It’s evident that it takes a lot of fine tuning to get it right, which probably explains why the facility trials thousands of different inks a year to find the perfect solution.