In general, most plastics are quite easy to recycle. You have to sort them by type, shred them and then remelt them into new shapes. This requires very little energy and recycling can be done many times with little or no loss of properties.
But why do we know so little about it?
We should teach children this in school because it is fundamental. Plastic types one to six can all be recycled through the melting process, and together they make up87% of plastics.
Although the recycling rate in Europe is around 45%, individual countries such as Lithuania (75% recycling rate) show that even more is possible. From a purely technical point of view, there is no reason not to recycle more than is already being done. It should be no secret that this is the most environmentally friendly solution and that investments in recycling infrastructure are of primary importance.
Plastics are very sensitive to contamination, which is a barrier to recycling. This means that they must be washed properly and then sorted very precisely. PE may only be recycled together with other PE of the same type, PP may only be mixed with PP, and so on. The reason for this is that plastics cannot be mixed with each other. So if you melt a mixture of two or more plastics, you get particles of one plastic inside the other.
This is comparable to the emulsion you get when you shake oil and water together. These plastic droplets can drastically reduce the mechanical properties of the material, especially the resistance. Fortunately, there are so-called compatibilisers that acts like surfactants and can improve the properties of immiscible plastics.
This is comparable to the emulsion you get when you shake oil and water together. These plastic droplets can drastically reduce the mechanical properties of the material, especially the resistance. Fortunately, there are so-called compatibilisers that act like surfactants and can improve the properties of immiscible plastics.
Improved performance can be obtained by adding a compatibilising agent that reduces the interphase tension in the mixed polymer and strengthens the polymer phase.
So what could be the reason that governments or companies don't just set up more sorting and recycling facilities. Surely that would make economic sense. Unfortunately, it doesn't. If there was money to be made, it would certainly become popular. It turns out that recycled plastic is currently still much more expensive than new, unprocessed material. In addition, you can't get a bright and attractive color from the recycled plastic material.
You have the same scenario with grey water, no matter how much pigment you put in the water, you fail to give it an intense color. Often companies ask for recycled material only to find that it is more expensive and often looks less attractive. Nevertheless, customers may have to get used to less luminous packaging in the future.
"Purchasing decisions are often made unconsciously, and many customers still reach for the more attractive-looking new plastic packaging", (Sängerlaub, 2021)
1. Products should primarily be made of mono-materials, so that there is no mixture of plastics and they are more recyclable
2. The use of PE, PP, PET are the three plastics that simplify the sorting of materials and recycling.
3. Plastics must be made more robust in order to prolong their usefulness and at the same time so that they can be recycled more often
The long-term question should therefore be dedicated to packaging design in order to strengthen the simplicity of separating, sorting and recycling. In this way,the goal of bringing the packaging back into the cycle can be achieved.
You will often find a so-called recycling code on packaging.
You can recognize the recycling code by the recycling symbol with three arrows(recycling cycle), a number in the middle and, if applicable, the material abbreviation.
Information about the material used in the product can be obtained from the recycling code on the packaging. This recycling code can be helpful for waste separation. The symbol of the "recycling cycle" is marked with one of the following numbers for plastics:
Recycling code 1 to 6 mean that the plastic packaging is made of one of six specific types of plastic:
1 means polyethylene terephthalate (like PET plastic bottles).
2 means highdensity polyethylene (HDPE)
3 means polyvinyl chloride (PVC)
4 means lowdensity polyethylene (LDPE)
5 means polypropylene (PP)
6 means polystyrene (PS)
The number 7 means that the packaging is made of a plastic other than the six above or a mixture of plastics.
This category includes, for example, bioplastics, composite plastics (such as crisp packaging), plastic-coated wrapping paper and polycarbonate (which contains BPA).