UPM Specialty Papers and Unipaco have developed a heat-sealable salad pot wrapper made from paper and polyethylene (PE), designed to replace traditional plastic packaging.

UPM Specialty Papers is actively collaborating with partners throughout the food packaging value chain to co-create innovative products that drive the future of sustainable packaging. In a recent project with Unipaco S.A., a Polish converter of flexible packaging materials, they developed a recyclable, heat-sealable wrapper for salad and herb pots that ensures product safety. The packaging structure also complies with Germany's stringent 95/5 mono-material standards, where single-component materials make up 95% of the packaging's mass.

Rising Demand

As brands globally set more ambitious sustainability goals, particularly around recyclability, and regulations tighten, the demand for alternatives to flexible plastic packaging has surged. In response to this growing need, UPM Specialty Papers and Unipaco collaborated to address the challenge in a specific area: creating a sustainable wrapper for salad and herb pots.

UPM Solide Lucent 78 g/m² + 4 g/m² PE Coating

The collaboration has produced two packaging solutions that combine UPM’s papers with Unipaco’s coatings. The first uses UPM Solide Lucent, an innovative 78 g/m² barrier base paper paired with a 4 g/m² PE coating. This durable, highly versatile paper offers a natural look and feel while being ideal for coating and lamination. UPM Solide Lucent also provides an excellent surface for further conversion and printing, including rotogravure. The ultra-thin 4 g/m² PE layer ensures the necessary moisture resistance and heat-sealability.

“By combining our papers with an extremely thin PE coating, we set out to create a packaging that helped our customers both to meet their recyclability goals and also comply with all relevant regulations,” explained Kirsi Lahtela, Senior Manager, Product Portfolio Management, UPM Specialty Papers. “The project provided Unipaco with their first opportunity to test our barrier base papers in addition to more familiar coated one side papers. We were delighted to see that UPM Solide Lucent performed perfectly on the coating equipment.”

UPM FlexPack 80 g/m2 + 4 g/m2 PE coating

The second solution combines UPM FlexPack 80 g/m² with a 4 g/m² PE coating. UPM’s coated one-side FlexPack papers are designed to support various lamination processes, offering exceptional strength and superior print quality, particularly with flexo printing. As with the first version, the ultra-thin 4 g/m² PE layer ensures effective heat-sealability and provides the necessary moisture resistance.

“With growing demand for recyclable materials, we decided to focus on lowering the grammage of our coating to develop a unique product. Our goal was to create as thin a coating as possible while also maintaining quality, barrier properties, and heat sealability. By combining this coating with UPM’s papers, we achieved astonishing results that can be easily transferred to a full-scale production. This solution is available on many other papers and for a numerous end-uses such as meat and cheese wrapping, flexible packaging and even sack production,” said Aleksander Borysow, CEO and Chairmen of the Board, Unipaco S.A.

Source : UPM Specialty Papers