Biobased biodegradable multi-layer barrier packaging realizes the processing of intermediate exam papers, and the shelf life of biscuits and chocolates exceeds 9 months

The bio based multi-layer barrier structure has completed pilot scale verification. With the increasing complexity and globalization of the food supply chain, the demand for packaging materials continues to rise, and the environmental pressure caused by the disposal of traditional petroleum based plastics has become increasingly prominent. A study published in Packaging Technology and Science conducted technical feasibility and pilot scale processability verification of a new packaging solution based on fibrillated cellulose, poly (butanediol adipate co adipate) (PBSA), and paper. The research team constructed a barrier layer structure of PBA fibrillated cellulose PBSA and prepared and characterized it in two forms: multi-layer film and paper coating.

Barrier performance and processing method

According to the paper, the water vapor transmission rate of this multi-layer structure is less than 33 g/(m ² · day), and the oxygen transmission rate is less than 5 cm ³/(m ² · day) under 23 ° C and 50% relative humidity conditions. The oil and fat barrier performance reaches KIT 12 level.

. In terms of processing, the study used pilot scale roll to roll casting film extrusion, extrusion coating, and dispersion coating techniques to prepare multi-layer structures. The obtained materials can be heat sealed and made into demonstration packaging for biscuits and chocolates. The packaged food has undergone over 9 months of shelf life testing, including sensory quality evaluation. The study also supplemented soil biodegradation and disintegration tests, and comprehensively characterized the physical, mechanical, and barrier properties of the materials.

Significance for the polymer additives and packaging materials industry

From the perspective of packaging materials, the significance of this research lies in advancing the exploration of bio based biodegradable materials from formulation to paper to paper processing and functional packaging transformation.

. Casting extrusion and extrusion coating are common industrial routes for packaging films and paper-based composite materials. PBSA undergoes a thermal history during the processing, and there is a practical need for processing stability and antioxidant systems; Although the specific formulation of the additives was not disclosed in the paper, the success of the pilot scale extrusion and coating indicates that this type of polyester system has the potential to form films and composites under industrial conditions. For food contact applications, the study completed food shelf life testing for more than 9 months, providing application level references for subsequent food contact compliance assessments. However, the paper did not involve specific migration tests or regulatory compliance statements. In terms of recycled materials and recyclable design, this structure focuses on biobased and biodegradable materials, and proposes alternative ideas for use scenarios with high environmental scattering risks such as snacks and takeout. The research results show that the multi-layer structure based on fibrillated cellulose, PBSA, and paper can be produced on a pilot scale and transformed into functional barrier packaging, providing process and performance data for the packaging industry to explore degradable multi-layer barrier solutions. However, its industrialization still needs to be comprehensively evaluated based on factors such as cost, production capacity, food contact regulations, and end of pipe degradation conditions.

Information source:Roll‐to‐Roll Processing of Biodegradable Multilayer Barrier Packaging Structures， Organized by Herun Chemical.