Upgrading Disposable Lunch Box Production Lines — PLA vs. PET Foam: How to Choose?
As global plastic-restriction policies continue to tighten, traditional PS foamed lunch boxes have been banned or restricted in many countries and regions, placing lunch box manufacturers under urgent pressure to upgrade their production lines. Currently, the two main alternative routes are PLA biodegradable foaming and PET foaming, corresponding to the PLA Foam Sheet Extrusion Line and the PET Foam Sheet Extrusion Line respectively. Each material has its own strengths, and selection should be based on a comprehensive assessment of target markets, cost budgets and product applications.
The core advantage of PLA foamed lunch boxes is full biodegradability. PLA is made from bio-based feedstocks such as corn starch. Finished products fully degrade within 180 days under industrial composting conditions without plastic residues, making them the preferred material for markets with stringent environmental regulations such as the EU and North America. However, PLA raw materials are relatively expensive, with low melt strength and a narrow processing window, imposing high requirements on equipment temperature-control precision. The PLA Foam Sheet Extrusion Line is equipped with dedicated screws and segmented temperature-control systems to precisely regulate the PLA foaming process and stably mass-produce qualified lunch box sheets.
PET foamed lunch boxes focus on heat resistance and cost-effectiveness. PET foam achieves a heat-distortion temperature above 100 °C, capable of holding high-temperature hot food, with oil and water resistance superior to PLA. Meanwhile, PET raw materials are widely available and priced lower than PLA. Post-consumer products can be 100 % melt-recycled for circular use, aligning with circular-economy policies. The PET Foam Sheet Extrusion Line features mature technology and high mass-production stability, with relatively controllable equipment investment and operating costs, making it suitable for high-volume production of take-away lunch boxes and fresh-food trays.
From the perspective of equipment compatibility, a mature PET Foam Sheet Extrusion Line can be retrofitted with modified screws, dies and temperature-control systems to support PLA processing. This enables a single line to switch between two materials, flexibly responding to different order requirements. Manufacturers are advised to prioritize equipment suppliers with multi-material compatibility, reducing future investment in additional production-line upgrades.
