Bioplastics as PLA (Polylactide) have become very popular in the packaging industry. For example, PLA is often used as a material for yogurt cups and is the most widely used material in the private 3D printing sector.
They are considered to be resource-efficient to produce and compostable. But does that really make them better for the environment?
The pollution of the sea by plastic waste is one of the unfortunately many big ecological problems of our time. Every year, 10 million tons of garbage are dumped into the sea, 75% of which is plastic waste that hardly decomposes and poses a serious problem for the marine ecology, especially fish, birds and turtles mistake the plastic waste for food and die from the consequences.
For example, a plastic bag takes about 10 to 15 years to decompose in the ocean, and a PET bottle takes up to 500 years to decompose. On the other hand, the food industry tries to increase the shelf life of food by clever packaging, thus reducing food waste as much as possible. Therefore, alternatives to classic plastic packaging are being searched for.
Bioplastics as PLA (Polylactide) have been become very popular in the (packaging) industry recently. For example, PLA is often used as a material for yogurt cups and is the most widely used material in the private 3D printing sector. Ordinary plastics require petroleum to manufacture and are not compostable. PLA belongs to the so-called bio-based biodegradable plastics, i.e. PLA is produced from renewable resources and can be decomposed by microorganisms using enzymes under certain conditions. But doesn’t this sound a little bit too good?
Advantages of of PLA:
However, from a purely ecological point of view, composting is not the most efficient way to recycle PLA.:
Conclusion: From an environmental point of view, PLA waste stored in a pure form is a big step forward compared to ordinary plastic waste. In all other cases it depends on local factors (for example: Are there sorting plants that seperate the plastic waste?)
The reduction of (plastic) waste and the overall protection of the environment has been a prominent youth issue, at least since the Fridays for Future movement. Bioplastics are often used in an attempt to improve the eco-balance of a product. As the task shows, from an ecological point of view the use of PLA can only be advocated if an ecologically sensible recycling of the materials is subsequently guaranteed. For this reason, many companies, from start-ups to corporations, are now focusing on the recycling of PLA and comparable plastics.In addition to the synthesis of PLA, the further processing, e.g. through mechanical or chemical recycling, can also be discussed in the context of the plastics lesson, and local companies that have specialized in the further processing of bioplastics can also be presented.
Are bioplastics an alternative to classic plastics? The answer to this question is important both for the students' personal lives and for the economy as a whole.
Authentic Contexts are characterized as follows:
Generic tasks should be used, i.e., tasks which product might be an outcome in the real world (of work) or, at least, are similar in such a way that it illustrates how real world (of work) problems are solved.
Optionally, these tasks include…