Shimizu launches on-site plastic sorting system for recycling profit

On 8 May, Shimizu Corporation announced the launch of a new material recycling scheme that involves sorting diverse types of plastic waste on-site at construction locations by material type and selling the recyclable materials for profit. This initiative aims to advance the realisation of a circular economy.

Traditionally, plastic waste from construction sites has been primarily subjected to thermal recycling through incineration. While some attempts at material recycling have been made, they were often limited to specific types of plastic products, leaving a significant portion of industrial plastic waste unaddressed.

Shimizu’s new scheme introduces a more comprehensive approach. On-site workers use handheld plastic sensors to identify the type of plastic waste, such as polyethylene or polypropylene. Sorting is conducted primarily by designated waste management personnel, known as “Green Masters,” at “resource recovery yards” located within the construction site. During the sorting process, the condition of attachments and level of contamination are also considered to determine if the waste can be sold as recyclable material. Soft, non-PVC plastic waste is compressed to reduce volume, thereby lowering CO2 emissions during transportation.

This recycling initiative was first implemented at the construction site of the Nihonbashi 1-Chome Central District Type 1 Urban Redevelopment Project. At this site, both soft and hard non-PVC plastics as well as PVC pipes are targeted. It is estimated that approximately 4,000 cubic metres of plastic waste, or roughly 20% of the total site waste, can be sold as valuable recyclables.

The sorted plastic waste is evaluated by recyclers in the Kanto region to determine usability and then transported to recycling plants. At the plant, plastics are finely shredded by material type and turned into flakes. Some are further processed into pellet-shaped recycled resin. These flakes and pellets are sold to manufacturers of recycled plastic products to be used as raw materials.

Shimizu Corporation plans to gradually roll out this recycling scheme to its other construction sites, reinforcing its commitment to promoting resource circulation within the construction industry.

Orignally published on Circular Economy Hub.