Revolutionizing Food Packaging: The Preparation Method of Quick-Forming, High-Temperature Resistant Polyester Composite Materials for Meal Boxes

Plastic packaging, led by polypropylene (PP) for its strength and safety, is the norm in the take-out industry, with polystyrene (PS) and polyethylene terephthalate (PET) also in use. Despite its lower market presence, PET's high recyclability makes it a promising sustainable option. This indicates a shift towards eco-friendly materials in the take-out packaging sector, with polyester materials poised for growth.

Wankai's newly developed PET composite material leverages the material's inherent recyclability, contributing to the development of a circular economy. This innovation has the potential to partially promote sustainable development in the take-out packaging industry by reducing environmental impact and enhancing the recycling of resources.

1. Innovation Breakthrough of this material: Suitability and Sustainability

This modified PET material developed by Wankai represents a significant innovation, offering rapid formability and resistance to high temperatures, thereby addressing the limitations of traditional polyester food containers. Moreover, this material actively contributes to the overall sustainability of the packaging, providing a solution that is both efficient and environmentally friendly.

2. Application Advantages of the Modified Polyester Material

Food containers made from this modified polyester material have a shortest thermoforming cycle of 5 seconds and can withstand temperatures of up to 230°C in an oven for 30 minutes without deformation, while also maintaining sufficient strength and toughness. 

The development of this innovative material not only enhances the sustainability of food delivery packaging but also improves packaging efficiency and food safety, providing the global food delivery industry with a more environmentally friendly and efficient packaging solution.

3. Several key steps of Preparation Method
A. Preparation of the Modified Polyester Base Material with Composite Nucleating Agents: The nucleating agents consist of Nucleating Agent A and Nucleating Agent B. 

B. Preparation of the Toughening Masterbatch for Polyester Food Containers: A specialized toughening masterbatch is prepared for the production of polyester food containers.
C. Mixing and Extrusion: The modified polyester base material, specialized masterbatch, and color masterbatch are mixed and then extruded through a screw to form polyester sheets.

4. Key Points of Technological Innovation: Composite Nucleating Agents
The crux of this material's research and development lies in the addition of composite nucleating agents during the in-situ polymerization stage. Nucleating Agent A is an alkali metal compound that can react with hydrogen ions to produce H2O or gas; Nucleating Agent B includes one of or more of nano-sized inorganic salt whiskers and nano-ceramic-based whiskers.

Nucleating agent A reacts with a polyester matrix and can significantly increase the crystallization rate. This, in turn, significantly shortens the molding cycle and improves the toughness of the polyester. In addition, the addition of nucleating agent A in the in-situ polymerization stage can effectively avoid the severe degradation of polyester that may occur when the nucleating agent is added during the screw extrusion stage.

Nucleating agent B can provide backbone support, which to some extent ensures that the food container retains its shape under high-temperature baking conditions. These nanoscale whiskers also enhance the crystallinity and crystallinity of the material, giving the composite material higher temperature resistance to meet the requirements of high-temperature baking.

Conclusion
Wankai's PET composite material represents a significant innovation in food packaging, addressing sustainability and efficiency. Its rapid formability, high-temperature resistance, and recyclability make it an ideal choice for the food delivery industry, contributing to a more sustainable future.