Biopolymers / PLA
The term bioplastic (biopolymers) is composed of the two words bio (organic) and plastic. For many people these are two contradictory terms. However, plastic can very well be biological / organic. However, the term is not sufficiently protected, which is why different definitions exist.
What is bioplastics and what is it used for?
For some, bioplastics are plastics that are produced on the basis of renewable raw materials. For others, they are all plastics (including petroleum-based ones) that are biodegradable. Our bioplastics are both: made from renewable raw materials as well as biodegradable. Most of our plastic products consist of the bioplastic polylactic acid (PLA), which is produced on the basis of plant starch. Only our carrier bags are made of Mater-Bi®, which contains plant oil (no palm oil!) in addition to plant starch.
Bioplastics are used as more environmentally friendly alternatives to petroleum-based plastics such as PP (polypropylene) and PS (polystyrene). They have comparable properties: they are transparent and can be easily processed into various objects, such as cups or bowls. This is also where we find their most important sales market: the packaging industry, especially for food. This is because, unlike conventional plastics, biological plastics can be disposed of together with food waste. The legal framework for disposal is regulated by the German Packaging Act (Verpackg) and the Biowaste Ordinance (BioAbfV).
Currently, only 0.05 percent of industrial starch production is used for biobased plastics. This means that only a small proportion of conventional plastics are currently substituted. Nevertheless, according to various studies (including "Global Bioplastic Market Forecast to 2020", 2016 & "Market Study Bioplastics" by Ceresana, 2014), bioplastics have an enormous market and growth potential, because production technological progress and capacity increases make them more competitive than petroleum-based plastics. It is expected that the share of bioplastics will continue to increase in the coming years and replace the old plastics.
From plant starch to cups from bioplastics
Every plant performs photosynthesis and converts absorbed CO2 and water into glucose and oxygen with the help of sunlight. The sugar that is not needed is stored in the form of starch. It is precisely this plant starch that is important for us, as it forms the raw material basis for the production of bioplastics.
Only industrially grown plants (e.g. corn) that are not suitable for human consumption are used as the basis for our PLA products. In the following, we will explain in individual steps how plant starch is turned into environmentally friendly greenbox PLA cups and trays.
Production steps for bioplastic products
- The plant starch is fermented by lactic acid bacteria to lactic acid and then converted by polymerisation to long-chain carbon polymers - polylactic acid
- Small plastic granules are formed from polylactic acid (PLA), from which any desired objects can then be formed. In our case, the granules are used to make bioplastics film. The film passes through various machines and is formed into cups and bowls with the help of moulds, punches and heat effects.
- Fertig! Die greenbox PLA Becher und Schalen sind bereit für den Transport zu Dir und freuen sich auf den Einsatz in Deinem Unternehmen.
Special characteristics of bioplastics
- High stability
- Free from BPA and other harmful substances
- Based on plant starch
- Fully biodegradable according to EN/DIN13432
- Thermoplasticity and therefore mouldable into any object
Sustainability: Conservation of non-renewable resources
Bioplastics consist of a renewable, plant-based raw material (e.g. corn) and thus contribute to the conservation of non-renewable resources such as crude oil. The plants grown for starch production are not suitable for human consumption, but are cultivated specifically for industrial use. In turn, only 0.05 per cent of global starch production is used for the production of bioplastics. Cultivation therefore has no influence on the supply situation for humans and animals. Of course, the plants used for bioplastics also require land for cultivation. In Europe and the USA, a total of just 1,500 hectares of sustainably cultivated land are used to grow maize plants for further processing into PLA. For comparison: The german state of Mecklenburg-Western Pomerania alone has 1.36 million hectares of agriculturally used land. If the proportion of bioplastics continues to increase, larger areas of land will of course also be required. For this reason, it is important that other agricultural waste such as cellulose from maize straw or millet is also used for starch production in the future.
Advantage over conventional plastics
According to studies by our suppliers, bioplastics such as polylactic acid (PLA) also have an advantage over conventional plastics in terms of production. In contrast to petroleum-based plastics such as PS and PET, the production of polylactic acid (PLA) causes around 60 percent fewer CO2 emissions and also consumes 50 percent less non-renewable energy.
Also in "cradle to cradle" studies, PLA has advantages in terms of the greenhouse gas effect and resource conservation, as well as positive results for the overall environmental balance. However, it should be noted that studies may differ due to different calculation factors for the overall environmental balance.
Short life instead of durable plastics
Polylactic acid (PLA) is a biodegradable and compostable bioplastic. PLA is certified according to DIN 13432 and decomposes to at least 90 percent within 90 days in an industrial composting plant. Outdoor decomposition usually takes longer due to various factors. After its decomposition, no toxic residues such as chlorine-hydrocarbon compounds or inorganic substances remain, apart from the organic basic substances. In contrast, the decomposition of petroleum-based plastics can take centuries or millennia. Even then, tiny, possibly poisonous, micro-particles remain, which are eaten by animals and therefore partly by us. In the sea, the micro-plastic particles even absorb toxins from the water. Also on land, plastic can release toxic substances and affect the fertility of the soil. For this reason it is important to replace the plastic products that outlive us with short-lived bioplastic products.