French start-up transforming waste plastic into seating for the Paris Olympics

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For Marius Hamelot, the 2024 Summer Olympics in France will provide a glimpse into his vision of turning trash into treasure. An architect and entrepreneur, the 29-year-old Hamelot has been working for several years to transform waste plastic collected in local Parisian neighborhoods into high-quality, durable products.

Hamelot co-founded his company, Le Pavé, along with longtime friend Jim Pasquet in 2018. The following year the firm patented a thermal compression molding technology for use in the building sector. In 2023 they earned another patent, for the process itself.

"We contacted about 200 plastics companies, and we worked with about 15, but no one could do what we wanted," Hamelot said. So they created their own.

Using its novel technology Le Pavé and its partners have molded, cut and shaped some 11,000 seats from recycled plastic bottles and caps for use in two Olympic arenas –– the Arena at Porte de la Chapelle in Paris and the Olympic Aquatic Centre in Seine-Saint-Denis, just northeast of the capital. Those seats alone will consume about 100 metric tonnes of waste HDPE, according to Hamelot.

Le Pavé now has two plants, having recently begun production at its second facility in Bourgogne, in the city of Allériot. The new plant will have the ability to transform 1,000 tonnes of plastic a year into panels measure up to 240 by 135cm (about 8 feet by 4.4 feet), in thicknesses ranging from 5 mm up to 15 mm (0.2 to 0.6 inches). The new plant quadrupled the company’s production capacity, according to Hamelot.

The firm's first plant in Aubervilliers, France, produces smaller panels –– up to 140 x 90 cm –– out of HDPE or polystyrene. This facility produced the panels used to make all 11,000 of the seats for the Paris Olympics, set for next July 26-Aug. 11.

The Games' organizers have promised to make them the greenest Olympics yet, stating "Our goal is to halve the emissions arising in relation to the Games, while offsetting even more CO2 emissions than we will generate."

Previous Summer Games emitted an average of 3.5 million tonnes of carbon dioxide. Paris 2024 considered this as its starting point and has developed a pioneering tool to gauge its carbon footprint and is applying a methodology to measure and control its emissions. Using recycled HDPE seating in two of its venues is one small step toward achieving this.

"For the Olympic Games," Hamelot said, "we were contacted three to four years ago. We work with five companies –– two for the molding of the product. Our team works at the plants where they mold our products, using our own molds. We just use their machines to melt down the panels and produce the seats." The other company called Global Concepts, near Paris –– cuts the seats from the material. All partners are located within a radius of about 100 km.

Le Pavé works with three companies for the collection of the trash. Some seats are black, with the waste plastic coming from residents in St. Denis. The white plastic comes from industrial plastic waste from shampoo bottles. 

For the yellow seats to be used in the Olympic pool arena, Le Pavé is working with a local collecting network called Lemon Tri SAS. The small, Paris-based recycler uses 60 collection points for bottle caps that are sorted according to color by another company that is a social enterprise that employs people in need.  

Speaking of the waste they collect, Lemon Tri co-founder Augustin Jaclin told the website Tomorrow's World Today: "It's collected in Seine-Saint-Denis, shredded in Seine-Saint-Denis, processed in Seine-Saint-Denis, all for a swimming pool that’s still in the area."

After Lemon Tri shreds the material, Le Pavé mixes these reclaimed plastic chips to obtain the desired, even distribution of colors. It then heats and compresses the resulting materials in their customized machines.

The panels made via Le Pavé's thermal compression molding process usually are black or white, but with flecks of colors. "We didn't use a regular screw on the extruder," Hamelot explains, “because we want the color to show through." This aesthetic helps to reinforce that the materials are indeed recycled.

Le Pavé then smooths and sands the panels before sending them to other partner companies in France who cut and assemble them. The material can be sawn, drilled, sanded and thermoformed.

Le Pavé makes many products beyond seating. The company's website cites numerous building-related applications, including wall coverings, baseboards, countertops and various types of furniture and other objects. It notes that the material is perfectly suited for vertical applications, both indoors and outdoors. 

Hamelot explains: "We worked with a French lab to make our HDPE fire-resistant, bromine-free, halogen-free and fluorine-free."

The product is water repellent, chemical-resistant and non-porous. Resistant to temperatures up to 120°C, it can even be used in a kitchen. Polystyrene tends more heat- and temperature-stable and is suitable for interior design applications, said Hamelot, adding, "We use HDPE mostly for furniture and wall cladding."

Hamelot said that, going forward, each of their ideal factories will cover 3,000 square meters (about 32,300 square feet), with the ability to expand to up to 10,000 square meters. In addition to the firm’s new plant, he has hugely ambitious plans to collaborate with local partners to launch factories worldwide.

"We are looking to expand by collaborating with partners," he noted. "We've spoken with many potential partners in Africa, Asia, Europe, Canada, etc. We want our partners to be able to address the material to the building sector, to architects, craftsmen, real estate companies, etc. We also want people who are excited by the project, as well. ... We aim to transform more than 100,000 tonnes of waste into sustainable resources by 2030 and become the European leader in sustainable materials."