In a groundbreaking development, researchers have discovered a novel way to repurpose aluminium-plastic composite (APL) films, commonly found in food packaging like potato chip bags, into energy-efficient cooling films.
Led by Prof. Dr. Markus Retsch from the University of Bayreuth in Germany, the team has developed an upcycling process that addresses the recycling challenges posed by APL films.
A Solution to Global Energy Demands
By applying a simple coating, these used APL packages are transformed into high-performance cooling films, offering a solution to the rising global energy demands of cooling systems. APL films, known for their extensive use in preserving the freshness of foods like chips and coffee, have been a recycling conundrum due to their composite nature.
The innovative upcycling process not only enhances the recycling of APL waste but also aims to curtail global energy consumption.
The Science Behind Passive Daytime Cooling
Cooling systems currently account for approximately 15% of the world’s energy use, a figure that’s set to increase with the escalating effects of climate change.
The brilliance of this upcycling method lies in the aluminium layer of the APL packaging, which acts as a reflective surface akin to emergency blankets. When combined with a clear polymer layer that amplifies the radiation of thermal energy, it results in an effective cooling system.
Practical Applications and Future Potential
This newly created cooling foil can be applied to various outdoor surfaces, such as umbrellas and awnings, to deflect intense sunlight and channel ambient heat into cooler spaces without external energy, a phenomenon termed “passive daytime cooling.”
The Bayreuth researchers, using commercial potato chip bags as a model, showcased that about 87% of sunlight is reflected by the aluminium layer. The added polymer coating further enhances radiation, directing heat straight into space.
With the potential for industrial and personal applications, this upcycling process could revolutionize the way we view waste and energy consumption.
Journal Papers
The research results are presented in the journals ACS Sustainable Chemistry & Engineering (“Passive Daytime Cooling Foils for Everyone: A Scalable Lamination Process Based on Upcycling Aluminum-Coated Chips Bags”) and Advanced Materials Technologies (“Upcycling Chips-Bags for Passive Daytime Cooling”).
Source: University of Bayreuth.
Photo: Credit NY Times
