The deep-tech company recycling the scrap nobody else wants - turning oily, contaminated swarf into clean alloy briquettes, on-site, with near-zero CO2.
EXHIBIT A: A puck of recycled alloy, looking suspiciously pleased with itself for a former pile of contaminated swarf.
Somewhere on a factory floor near Chicago, a box roughly the size of an industrial oven hums through its cycle. Into it goes a slurry of metal swarf - the oily, twisted shavings that come off a lathe and usually end up in a skip bound for landfill or a distant smelter. Out of it comes a clean, dry briquette of the original alloy. Same chemistry. No CO2 to speak of. That box is the point of Sun Metalon, and the entire pitch fits on it.
Sun Metalon is a binational deep-tech company, headquartered in Wood Dale, Illinois, with engineering roots in Japan. Thirty-seven people. Roughly $42 million raised. A founder who got the idea while doing a PhD near the very foundries he now wants as customers. It is small. It is also sitting on a claim large enough to make Toyota, Sumitomo, Nippon Steel and Airbus Ventures all write checks.
Here is the inconvenient arithmetic of metal manufacturing. You start with a block of alloy, you machine it into a part, and a startling share of that block becomes chips, dust and swarf on the floor. Sun Metalon puts the figure as high as 20%. Some of that scrap is clean enough to recycle the ordinary way. A lot of it is not - it is contaminated with cutting oils, coolants and grit, which makes it expensive to haul, dirty to remelt, and prone to forming oxides that degrade the metal.
So it gets downcycled into something less valuable, or it gets landfilled. Either way, the manufacturer pays twice: once for the metal it lost, and again to make the loss go away. Conventional remelting, meanwhile, is energy-hungry and carbon-heavy. The metal industry is one of the harder corners of the economy to decarbonize, and contaminated scrap is one of its more stubborn problems.
The skeptic's question writes itself: if recycling oily, contaminated swarf were easy and cheap, someone large and well-capitalized would already be doing it. They mostly are not. That gap is the company.
Kazuhiko Nishioka, Sun Metalon's co-founder and CEO, did not arrive at this from a whiteboard. He was an engineer at Nippon Steel, sent to study for a PhD at Northwestern University near Chicago with the company's backing. The problem of contaminated, hard-to-recycle scrap was not abstract to him - it was an industry he already knew from the inside.
In 2021 he and two Nippon colleagues started running what were, by their own account, DIY experiments: trying to clean up tiny metal scraps too oily to recycle conventionally. The experiments turned into a patented process. The colleagues turned into a company. The PhD-near-the-foundries detail turned out to be strategy in disguise - years later, the company moved its world headquarters to the Chicago area precisely to sit next to the foundry, die-casting, smelting and machining clients it wants to serve.
The flagship is the Venus-L6: a six-furnace, on-site recycling system sized for foundries and machine shops. It takes in contaminated swarf and chips and returns clean, dry briquettes of the original alloy, without CO2 emissions. The word "on-site" is doing real work in that sentence. The recycling happens where the scrap is made, which means no long-haul trucking, no waiting on a smelter, and no losing custody of your own alloy.
Underneath sits the patented part. Sun Metalon's process uses electromagnetic energy plus what it calls booster materials to heat metal fast and efficiently. Speed and efficiency matter because they are what let the system handle contaminated, non-ideal scrap while minimizing the oxides that normally ruin recycled metal. The contaminants are driven off; the chemistry of the alloy is left unchanged. The company claims the approach can cut energy consumption and CO2 emissions by up to 85% compared with existing methods for heating and purifying chips and swarf.
Six-furnace, oven-scale system that lives on the shop floor and turns swarf into clean briquettes.
Patented energy + booster materials for fast heating with minimal oxide formation.
Contaminants leave; the metal's chemistry stays put. No downcycling.
A startup can claim 85% anything. What's harder to fake is the cap table. Sun Metalon's Series A came together at $21 million from JIC Venture Growth Investments, HITE Hedge Asset Management and Sumitomo Corporation Global Metals, alongside earlier backers UTEC, Globis Capital Partners, D4V, i-nest capital, Scrum Ventures and Berkeley SkyDeck. In May 2025 it added a $9.1 million second close from Nippon Steel, Japan Bank for International Cooperation, Airbus Ventures and Shimadzu's innovation fund, bringing total capital to roughly $39.8 million including loan facilities - about $42 million all in.
Read that investor list again. Nippon Steel is the founders' former employer and one of the largest steelmakers on earth. Sumitomo is a trading and metals giant. Toyota co-developed an aluminum recycling process and presented the results publicly. Airbus Ventures suggests interest from aerospace, where scrap is expensive and alloys are fussy. These are not tourists in the metal industry; they are the metal industry, and they are validating both the technology and the customer demand.
Worth a caveat the company itself would survive: the 85% figure is Sun Metalon's own, and "up to" is carrying weight. Independent, audited numbers across many real installations are the next thing the skeptic should ask for. The funding says serious people find the claim plausible enough to fund. It does not, on its own, prove it at scale.
Strip away the funding theatre and the mission is unfussy: reimagine metal recycling so that contaminated, low-value scrap gets recovered on-site, cheaply, with near-zero emissions, instead of being trucked off or buried. The economic and the environmental case are meant to be the same case. Recover the alloy you already paid for, cut the carbon, lose the disposal bill. CEO Kazuhiko Nishioka frames it plainly.
That dual framing is the smart part. Plenty of climate hardware asks a buyer to pay a green premium and feel good about it. Sun Metalon's bet is that decarbonizing the metal industry can be the cheaper option, not the virtuous one - which is, historically, the only kind of green technology that scales.
Heavy industry is where decarbonization gets hard and where good intentions go to be expensive. If a shop-floor machine can genuinely turn a manufacturer's worst scrap back into usable alloy, on-site, for less energy and money than the status quo, the implications run well past one factory near Chicago. Automotive, construction machinery, aerospace, steel - every sector that machines metal makes the exact waste Sun Metalon wants to eat. That is a very large room full of very expensive swarf.
The honest version is that Sun Metalon is still early. Thirty-seven people, a flagship product, a fistful of strategic checks, and claims that deserve independent verification at scale. The next few years are about installations, audited numbers, and whether the unit economics hold outside a pitch deck. But the direction is coherent, the backers are the right ones, and the problem is real.