The company has taken on the name as of 1 June, after it announced last year that it was to sell its Nampak Cartons and Nampak Healthcare business to the private equity firm.
Contego Packaging chief executive Tom Reid said the company planned to continue to grow, and will do that through investing in the business in certain regions such as the UK, which he said was key.
"We are putting in additional capacity and are planning to build a new carton site in Portsmouth after the previous site became too small," he said.
"This development is now under way and we are relocating all the staff. We are also building a new leaflet factory in Germany."
He added that the business would also continue to invest in certain regions where it was less dominant, such as central and Eastern Europe.
The company's new name Contego is the Latin word for "protect, shield, cover and defend", which Reid said mirrored its commitment to supplying customers with high quality packaging for their products.
Contego Packaging produces cartons for the food and beverage sectors from two sites in the UK and one in Holland.
It also supplies the pharmaceutical industry with cartons, leaflets, labels and blister pack foils from 10 sites across Europe.
In December last year, Nampak announced that its Nampak Cartons and Nampak Healthcare companies were to be acquired by US-headquartered investment company Platinum Equity.