Bioplastics Recycling

Growing environmental concerns have given a boost to the use of bioplastics in the world of packaging. While bioplastics certainly have their place in the market place, they have also created challenges in the recycling stream of traditional plastics. In order to recycle bioplastics, they must be sorted and processed separately from traditional plastics. Unfortunately, this rarely happens and they are collected together leading to wasted resources.

There is also often confusion about the terminology. Bio based plastics and bio degradable plastics are often confused as the same, they aren’t.

Bio-based vs. Biodegradable

• Bio-based have the same characteristics (such as bioPE and bioPET) as plastics made from natural gas or oil as the raw material. Plastics made from a renewable source (bio-based) simply use a different input material for creating the plastic molecule. The actual plastic that is made through this process is exactly the same as plastic made from non-renewable resources. It will not degrade in the environment.

• Biodegradable plastic materials on the other hand are for example starch-based materials or polylactic acid (PLA) made from agricultural biomass. They are made from a renewable resource and can (under certain conditions) degrade in the environment. Biodegradeable plastics are a different family of plastics and don’t have the same performance characteristics as “traditional” plastics. They require different processes when being recycled.

Can biodegradable plastics be recycled?

It is important to note that biodegradable plastics don’t easily degrade when simply placed into the environment. For example, a biodegradable water bottle thrown carelessly into the forest will not degrade for years. It will degrade faster compared to a bottle made from traditional plastics, but the process requires basically industrial type composting (heat and moisture) to be accelerated.

The alternative to industrial composting is to recycle the biodegradable plastics similar to traditional plastics. Assuming that the biodegradable material has been separatly collected it can be washed and processed to make new pellets. Erema has processing experience with PLA materials and developed a process to recycle these resins. The material is cut, mixed, pre-warmed, and dried in the cutter / compactor system. This process is so efficient, that the material does not need to be degassed later in the extruder and is therefore subjected to less overall shear stress. After extrusion, the PLA is filtered and made into high quality pellets. Throughout this process, the PLA still maintains the same viscosity and other material properties. The outcome of the recycling process provides biodegradable material pellets that can be formed into new products again.