ExxonMobil has collaborated with the value chain to develop a high-barrier, recyclable MDO-PE//PE laminate to address the growing demand for recyclable packaging options.
This advanced packaging solution has been engineered to provide excellent barrier properties against oxygen and moisture, ensuring optimal product freshness and protection.
The new solution is said to not only meet the functional requirements for a wide range of food packaging applications – from dry goods to liquids – but also offers "outstanding stiffness and clarity".
According to ExxonMobil, “This makes it a viable alternative to traditional materials, such as PET and BOPP”. Additionally, the solution is said to address the challenge of maintaining barrier properties, while ensuring ease of recyclability – given programs and facilities are in place to collect and recycle plastic film.
A high barrier duplex MDO-PE//PE laminate was produced from a high-barrier PE sealant film and MDO-PE printing web. The MDO-PE printing web incorporated ExxonMobil HDPE HD7165L, which was specifically designed to produce MDO-PE films.
The MDO-PE film was produced on an Alpine 5-layer blown film line with inline MDO. The blown PE sealant film was produced using ExxonMobil’s performance polyethylene resins such as Exceed S, Enable and Exceed. Evonik’s TEGOMER 6810, an organo-modified siloxane, was used to help control the coefficient of friction (COF).
Two thin barrier coatings (BC) were then applied on the blown PE sealant film to help deliver outstanding barrier properties: the first layer contains vacuum-metallised aluminium, while the second layer contains 1gsm of Henkel’s newly developed barrier coating LOCTITE LIOFOL BC 1582 RE1.
Both functional layers were applied using Nordmeccanica's Vacuum & Coating machinery (Nordmet 12F Plus/Super Combi 5000). These technologies are said to “offer industry leading performance in terms of reliability, uniform laydown, thickness control and energy consumption”.
The MDO-PE film was printed by Univel. In the following step, the coated PE sealant film was laminated with the printed MDO-PE web on a Nordmeccanica SC 5000 Coating-Laminating machine using Henkel's solvent-free adhesive LOCTITE LIOFOL LA 7102 RE/LA 6902 RE from their RE range of products which are designed for mechanical recycling, resulting in a duplex high-barrier MDO-PE/printed//BC/metPE laminate.
An innovative combination of metallisation and barrier coating to produce a very high PE-content laminate provides ultra-high oxygen barrier properties (similar to aluminium foil) and excellent moisture barrier properties.
The ExxonMobil MDO-PE printing web is primarily composed of our new ExxonMobil HDPE HD7165L high-density grade, which can provide enhanced stiffness, processability and excellent gel performance. Enable performance PE resin was incorporated to help increase the stiffness and bubble stability. Exceed S performance PE was incorporated to help improve the process stability.
ExxonMobil says that the MDO-PE solution exhibits outstanding stiffness at both room and elevated temperature, which are results similar to the BOPP reference at the same thickness. Due to the stiffness performance, the MDO-PE solution is suitable for most converting operations that require resistance to elongation.
A challenge associated with duplex lamination of metallised films is the controlling of the co-efficient of friction (COF) since typically used migratory slip additives, such as erucamide, can readily interfere with metal adhesion and thus can lead to a loss of barrier properties.
In the duplex laminate tested in this study, a non-migratory organo-modified siloxane was used to achieve a COF of approximately 0.3, which can enable its use on packaging converting lines.
