The iconic Danish toymaker is moving to carbon neutrality, but virgin polymer is tough to replace.
This summer, the legendary Danish toy manufacturer LEGO announced a breakthrough: lasting bricks made from recycled PET, derived from soda bottles. The research project was considerable, requiring a staff of 150 working through 250 different plastic compositions to create a recycled plastic brick that met LEGO’s tough quality standards. Although an engineering success, on September 25, the company announced the suspension of the project, as an analysis of the carbon footprint of the recycling process showed no net benefit compared to oil-derived plastic resin. The company is switching research efforts to versions of resin derived from e-methanol, feedstock made from waste CO2 and hydrogen. Made from hydrogen derived from electrolysis powered by clean energy, this could prove to be truly zero carbon polymer resin.
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Episode Transcript:
For decades, plastics engineers working in the injection moulding industry acknowledged that one of the global leaders in advanced technology and efficient production is a very familiar Danish company: LEGO.
The iconic toy resin bricks have been a staple under Christmas trees for decades, and the relative handful of simple shapes that emulated building bricks have been joined by a stunning array of complex, moving parts. Lego is as much a culture as a toy, and like many European manufacturing concerns, the company is addressing environmental issues. A net zero carbon footprint is promised by 2050, and the company has a realistic action plan to achieve this goal.
Another angle toward sustainability has been the company’s experiments in using recycled resins for its plastic bricks. On the 23rd of June, LEGO developed a brick made from recycled PET resin, derived from soda bottles. The research effort was considerable, involving a team of 150, and testing over 250 different plastic resin compositions.
The recycled resin used was sourced from U.S. suppliers and was approved by the FDA and the European Food safety Authority. A single 1L PET soda bottle contained material for about 10 small Lego bricks.
But in a surprise move announced on September 25, Lego is suspending the recycled plastic initiative. From an engineering perspective, the project was a success, producing plastic parts with the necessary durability and physical properties to match LEGO’s standards. Although an engineering success, the overall carbon footprint of recycling the PET bottles, then reprocessing them into clean, injection-mould-ready regular resin, was no better than that of the current petroleum-derived version thermoplastic.
The company announced that it still intends to make Lego bricks from sustainable materials by 2032. The LEGO experiment was an engineering success, but failed to meet its objective of lowering carbon emissions.
Well, that’s a failure in one sense. It represents a sea change in the way environmental issues are handled in the manufacturing of mass production consumer goods. The carbon footprint of recycled products must represent the entire production process, and when selection, shipping, sorting, cleaning and reprocessing are factored into the equation, it’s possible that recycling is not only not environmentally more sustainable, but may be a net negative if the oil-derived version resin is recycled at the end of its lifetime, and repurposed into products where the carbon balance is net negative.
LEGO is an especially demanding user of plastic resin, operating some of the world’s most advanced injection moulding equipment to produce low price consumer goods with consistently outstanding surface finish and dimensional stability. For firms that don’t require the quality attributes necessary at LEGO, recycled resin may still provide a carbon benefit.
In the meantime, LEGO is investigating thermoplastics derived from e-methanol instead of crude oil. E-methanol is generated by reacting waste carbon dioxide with hydrogen, which itself can be generated through electrolysis, powered by green energy. These e-resins are definitely carbon neutral, but cost remains a concern.
LEGO is a toymaker, but in the plastic injection moulding sector, when they talk, people listen.
