Environment The wisdom of circulation sprouting in Toyama City - Waste Plastic Recycling Model 2002

Environment The wisdom of circulation sprouting in Toyama City - Waste Plastic Recycling Model 2002

In 2002, the amount of waste plastic generated in Japan amounted to approximately 9.97 million tons per year, but only 1.39 million tons were recycled, most of which were incinerated or landfilled. With the tightening of final disposal sites and the generation of dioxin during incineration becoming increasingly serious, an effective recycling model in line with the principles of the Basic Law for Establishing a Recycling-Oriented Society (enacted in 2000) was required. Toyama City Eco-Town's waste plastic recycling business attracted attention as a pioneer of such a model.

The core of this model was based on the three pillars of "resin unification," "yield improvement," and "cascade use. In terms of technology, an automatic identification and sorting machine using near-infrared (NIR) spectroscopy was introduced to enable highly accurate sorting of major resins such as polyethylene (PE), polypropylene (PP), and polystyrene (PS). In addition, electrostatic sorting and specific gravity separation have been combined to reduce the amount of contaminants and stabilize the quality of recycled pellets.

In the crushing and washing processes, friction washers and hot water treatment technology are utilized to remove labels and foreign matter to reduce residues and increase yield. In addition, dewatering and drying facilities were enhanced to reduce the moisture content of the recycled material so that it can be shipped in a condition suitable for injection molding and extrusion. This has made it possible to supply recycled materials with more stable physical properties than before, and has created a market environment that is easier for companies to use.

In addition, based on the concept of cascade utilization, Toyama secured a sales channel for recycled plastic not by returning it to high quality products, but by gradually allocating it to applications with relatively low performance requirements, such as civil engineering materials, construction boards, pallets, and planters. This has enabled the company to reverse the problem of "recycled materials having limited uses" and establish a sustainable business model linked to local industries.

The Toyama City Eco-Town case was groundbreaking in that it combined cutting-edge sorting and sorting technology with local industrial infrastructure to create a local model that supports a recycling-oriented society. This initiative later became a design guideline for eco-towns and advanced waste plastic processing projects throughout Japan, and is highly regarded as a pioneering example of how to combine recycling technology and industrial promotion.