Stadler sorting plant at work in Japan

Germany-based sorting technology provider Stadler says it has designed a facility to automatically sort light plastic packaging and LIMEX, a new limestone-based material developed and produced by Japan-based TBM Co. Ltd.

“The plant will be part of a collaboration between TBM and the city of Yokosuka to promote the collection and recycling of plastic [scrap] and LIMEX for the entire city and surrounding areas,” says Stader.

TBM and Stadler describe LIMEX as “an effective alternative to plastic and paper that can be used in the production of a wide variety of products, such as packaging, food containers, shopping bags and backlit film.”

The recently developed material is mainly made of limestone and is claimed to have a carbon footprint of up to 40 percent smaller than plastic on a life cycle basis (depending on the type of plastic) and uses less water than in paper production.

Once used, LIMEX can be recycled to produce new plastic alternative materials, according to TBM.

As part of its strategy to accelerate the use of LIMEX products, TBM commissioned Stadler to design and install the new sorting plant. The facility uses Stadler technology to separate LIMEX and plastic light packaging. The plastic sorted is recycled into pellets for use in the production of packaging, according to Stadler.

The sorting plant receives bales of light packaging made of plastic materials and LIMEX and sorts the incoming stream into metals, polypropylene (PP), polyethylene (PE), polystyrene (PS), polyethylene terephthalate (PET) and mixed plastics (converted into refuse-derived fuel, or RDF), a two-dimensional fraction and fines.

The sorted output materials are stored in bunkers, and the PP, PE, PS, PET and mixed plastics for RDF are subsequently fed to a baler. Stadler technology used includes a double-deck ballistic separator, 2.9-meter-wide (9.5-foot-wide) high-speed conveyors and a bunker system, as well as five near-infrared (NIR) optical sorters.

“The plastic material we are processing at the plant is extremely light,” says Ursina Mutzner of Stadler. “When we ran trials with similar materials at our test center in Germany, we saw that the paddles in the double deck ballistic separator needed to be inclined more than the maximum 25 degrees the machine is designed for. So, when we designed the plant, we decided to place the ballistic separator on a slightly sloping steel structure in order to achieve the inclination of the paddles required to ensure the best sorting quality.”

Takuya Sugiyama of TBM says, “The plant roof is quite low, so there wasn’t much space between the ballistic separator and the ceiling. At first, we thought we might have to remove part of the roof to place the machine, but Stadler’s commissioning team made the installation without any additional work. We at TBM greatly appreciate their effort.”

Takuya says he is impressed by the “European cutting-edge, beautiful design, the simple material flow and high levels of safety standards” of the system. “Every small detail is designed beautifully. Everyone who visits the plant feels the same and gives us positive comments. This makes us happy to have worked with Stadler.”

When developing the design, Stadler says it conducted tests in Germany and then further tested TBM’s materials at a different Stadler installation in Hyüga, Japan. Says Takuya, “We already had a good feeling about the Stadler plant, but the test gave us confidence on our decision and important evidence of what they could do for us.”

Stadler also provided training to TBM’s operators and says it will continue to support the company as the plant operates. “Our real operation has just started, so that continuous support and communication between Stadler and TBM is very important,” says Takuya.