Next Generation of Barrier Papers: Sappi Focuses on the Circular Economy
With its extensive range of barrier papers, packaging manufacturer Sappi aims to replace non-recyclable materials such as paper-film laminates.
Food manufacturers are increasingly looking for alternatives to plastic packaging. But leaving items unpackaged is rarely a solution, when it comes to food. Pure paper packaging is not always possible, nor is it more environmentally friendly per se. Sappi, one of the world's leading providers of paper-based packaging solutions, relies on barrier papers. According to the company, it is the manufacturer with the widest range of barrier papers. In contrast to “normal” paper, these have a barrier, a coating to protect the product from external influences such as moisture, light and oxygen.
“Three points are particularly important for our customers: firstly, product protection. It is crucial that this is not compromised in comparison to the current packaging. One example of this is ensuring a secure best-before date,” says René Köhler, Director Paper & Packaging Solutions at Sappi Europe. The second important point: “Ideally, the barrier papers should run on existing equipment. Our customers are keen to avoid major investments in machine components or even entire systems in order to switch to a new material. In such cases, optimization is necessary,” says Köhler. For this reason, the company works closely with packaging machine manufacturers to carry out preliminary tests. “It often depends on the settings of the machines that make it possible to switch from conventional materials to new, more sustainable materials.”

Recyclability
The third and, according to Köhler, most important point is to use a material that can actually be reused later in the recycling cycle instead of ending up as ordinary waste. “This is not the case with much of today's packaging and is the main driver for our customers. So if we can fulfill the first two points and also guarantee this third aspect, it is decisive for the choice of barrier papers,” says the packaging expert from Sappi.
Barriers are not only important for packaging such as chocolate, cheese or sausage products: so-called dry products such as cereals, coffee, flour or ready-made powdered soups also require an individual barrier to ensure effective protection and guarantee the minimum shelf life.
Although glassine, a highly compressed paper, is largely greaseproof, it offers no protection against moisture, Köhler explains.
“It is suitable for packaging butter, for example, but is less suitable for other applications. Furthermore, neither normal paper nor glassine can be sealed. Barrier papers, on the other hand, offer a combination of optimally adapted protection and functionality that makes them ideal for many dry products.”
Compatible with Packaging Machines
How flexible are barrier papers in terms of their machinability on existing packaging lines? “Our barrier papers can of course be processed on existing systems. However, this depends heavily on the type of packaging required,” says Köhler. A small chocolate bar has different requirements than a large bag containing many small products. “In most cases, the brand manufacturers' technicians manage to convert the existing packaging lines to paper-based packaging materials, especially barrier papers, on their own. A changeover is often necessary because the plastic films and laminates used today are very thin, flexible, robust and tear-resistant. Paper, on the other hand, is less tear-resistant and requires more sensitivity in the packaging process. Although there are cases where machines can be converted 1:1 to paper-based packaging, this is the exception rather than the rule.”
Sappi, headquartered in Johannesburg, South Africa, is continuing to invest in this area, with a new barrier coating line that opened at the Alfeld site in Lower Saxony in 2023. Previously non-recyclable materials such as multilayer and flexible plastic packaging can be replaced by fiber-based materials with the help of the new plant in order to meet different packaging requirements and also meet the requirements as well as the posed by the PPWR. Sappi also produces its own pulp in Alfeld, using beech and spruce from a radius of around 100 kilometers.
By Anna Ntemiris, Editor