When plastic that has been recovered from used home appliances is recycled, it is typically recycled into knick-knacks, imitation wood and other such products, a process called downgrading. However, this also means that resources must be continually consumed. What is really needed is closed-loop recycling—recovering plastics from old products and recycling it in new products.

Hyper Cycle Technology for Closed-loop Recycling

Conventional plastic recycling is usually limited to plastic parts made of a single material that is easy to separate out. Moreover, separating and recovery are conducted manually, so only around 10% of the plastic can be retrieved from the recycled product; the remainder is incinerated or landfilled.

In order to make it possible to create products out of 100% recycled materials instead of new materials, Mitsubishi Electric took on the challenge of automatically separating, recovering and recycling recyclable materials taken from shredded mixed plastic, a material that had traditionally proven difficult to recycle.

The main types of plastic used in home appliances are polypropylene (PP), polystyrene (PS) and acrylonitrile-butadiene-styrene (ABS). Mitsubishi Electric has succeeded in accurately separating mixtures of these plastics at purity levels exceeding 99%. This high degree of purity is made possible by proprietary technologies for separating different plastics by specific gravity and by electrostatic properties. PP, which is lighter than water, can be separated out using technology for separating by specific gravity, whereas ABS and PS, which are heavier than water and cannot be isolated in this way, are separated using differences in their electrostatic properties. (See the next page for details on these separating technologies.)

Previously, we recycled approximately 600 tons of plastic in Mitsubishi Electric home appliances, out of a total of approximately 10,000 tons generated by our home appliance recycling plant, Hyper Cycle Systems Co., Ltd, a ratio of just 6%. Now, thanks to successfully developing high-purity separating technologies, we recover approximately 6,400 tons of the three major plastics for recycling in our home appliances in a closed-loop system. This represents Japan's very first large-scale high-purity plastic recycling system.

Promoting the "3Rs" (reducing, reusing and recycling) for home appliances is one of the pillars of Mitsubishi Electric's Environmental Vision 2021. Our large-scale high-purity plastic recycling system recycles the three major plastics in a closed loop from shredded mixed plastic. The system reduces use of these three major plastics by our home appliances business by around 18%. This translates into less new plastic produced, which in turn reduces carbon dioxide by 6,700 tons annually (Mitsubishi Electric estimate). The kind of closed-loop recycling pioneered by Mitsubishi Electric will be a driving force behind eliminating waste and preventing global warming.