The specialist banknote and security paper manufacturer has a history stretching back over three centuries and is the world’s second-biggest commercial supplier of banknote paper, and the number one maker of passport paper.

It became an independent business again in early 2018, when De La Rue sold a majority stake to the management team and private equity firm Epiris.

PM1 at its Overton site in Hampshire has been shuttered since late last year for the complex rebuild, which Portals said had involved most of the machine being replaced with state-of-the-art technology.

It means Portals can now meet growing demand for wider security threads in banknote paper.

After testing during last month, PM1 made its first batch of customer paper yesterday (30 September).

Portals chief executive Ross Holliday said he was delighted to see the machine back in operation.

“Two years ago we embarked on an investment journey that has seen us transform our business and ensure that we are able to improve performance for our customers and partners around the globe,” he said.

“This project comes after successful investments already commissioned in our pulp mill and finishing operations. I am extremely proud of what Portals has achieved in the past two years and would like to recognise the Portals team and our partners who have been involved in this project and who have made it happen in a safe and socially distanced way. I look forward to welcoming our customers at a later stage to the grand unveiling.”

The PM1 project is the culmination of a £21m investment programme intended to transform quality, efficiency and sustainability at the business.

Overton makes cotton banknote and other papers and runs three paper machines, while the Bathford site near Bath makes wood-based passport paper and has one machine.

Portals chief commercial officer Laura Wheeler explained that despite the burgeoning use of contactless payments in the UK, the use of cash worldwide was still growing.

“Things elsewhere in the world are very different. Cash is in demand because people would rather use cash, and cash circulation has grown,” she explained.

The revamped machine also improves Portals’ environmental footprint as it less energy and water.

The technology partners involved in the rebuild were not disclosed for security reasons, but PM1 is a Bellmer machine.

“The introduction of an advanced quality control system has brought improved real-time data with online quality control check points, with a new state of the art vision system checking that our paper meets our customers technical and visual requirements,” Portals stated.

“The wealth of information from these new technologies offers even greater control, less variability and quality assurance that is second to none.”

The business employs around 500 staff and had sales of just under £134m in the year to 28 March.

As well as paper for banknotes and passports, Portals also makes security paper for other applications such as certificates and brand protection.