Sustainability strategies for users was one topic at TECHBOX. Professor Dr. Dirk Burth from the Munich University of Applied Sciences, Department of Packaging Technology, spoke about the calculation of sustainable packaging.
What is sustainable? This is a difficult question to answer because there are many different aspects included in the term sustainability, says packaging engineer Professor Dr. Dirk Burth from Munich University of Applied Sciences. “But what has what CO2 emissions can be concretely stated in a number,” Burth clarifies. He has developed a packaging calculator called SPOC (Sustainable Packaging Online Calculator). SPOC is a general-purpose tool for calculating the environmental impact of packaging. Burth refers to it as a compass or tool for those responsible for packaging design such as packaging engineers, packaging material manufacturers, marketing and sales people.
An entire life cycle assessment is very time-consuming and not feasible for the packaging designer in practice. But on the basis of a simplified data analysis, very meaningful results can already be achieved, Burth explains the background to the development. SPOC quantifies the differences between various packaging solutions in terms of CO2 emissions and energy consumption. The packaging calculator is specifically designed for food and non-food packaging.
The primary goal of SPOC is to enable users to independently and quickly determine the CO2 footprint and energy consumption for the production of planned and used packaging. However, the CO2 emissions determined with SPOC are only for internal use or for exchange between partners in the process chain – as long as they are also familiar with SPOC.
To calculate the environmental impact of packaging, Burth says the key elements to include in the calculation are packaging materials, manufacturing processes, transportation, and end-of-life. With SPOC, all standard materials such as paper, plastic, glass, metal, but also recycled materials and biomaterials can be calculated. In addition, it is possible to include your own material and process data. But SPOC also makes climate gas emissions transparent for the various end-of-life options such as reuse, landfilling, composting, different thermal disposal routes and recycling.
The expert emphasizes that a sustainability assessment must not only examine the packaging itself, but also include the packaged product. “The earth only feels the overall environmental impact, but not whether it was caused by the packaging or the food.”
Example: bottles made from organic PLA with PET bottles
Polylactide (PLA) is a bioplastic made from lactic acid, so it has a clear advantage in the carbon footprint from the materials side. However, PLA is not recyclable because the quantities of material are currently too small. PET made from fossil raw materials, on the other hand, has the advantage that there is an “excellently developed infrastructure for recycling.” So what does a lower carbon dioxide emission have on a bottle of the same weight? “A recyclable PET has similar emissions to bio-PLA,” Burth says. However, the high benefit of recycling also becomes clear in comparison to PET without recycling: This has approximately three times higher emissions than bio-PLA.
Reusable has a lot of potential to minimize environmental impact. Decisive factors are how much more stable must a reusable bottle be designed than a single-use bottle, how high are the cleaning and transport costs, and how well does the recycling infrastructure work? With SPOC, this can be calculated quickly.
Correlation between shelf life of food and environmental impact of packaging
Food shelf life can be extended for oxidation-sensitive products by using an oxygen barrier such as PA. PA layers of different thicknesses provide longer food shelf life, but also result in greater CO2 emission. There is a good linear correlation between CO2 emission and shelf life extension.
Impact of food spoilage from packaging
Burth cites the cucumber as an example. It has an average shelf life of four days without packaging, and up to 28 days with film packaging. “The CO2 costs for the packaging here are significantly lower than the CO2 savings from reducing the spoilage of the cucumbers. Shrink-wrapping cucumbers is worth it if it reduces approximately 1.5 percent of spoilage.” In other words, if packaging prevents spoilage in 1.5 cucumbers out of 100 packed, the packaging makes ecological sense, he said.
The packaging calculator does not replace life cycle assessment, Burth emphasizes. However, SPOC delivers results in a few minutes that show whether a new packaging idea is heading in the right direction. The comparison of several packaging solutions gives reproducible data based on the clearly comprehensible procedure, which fairly reveals advantag