Limestone Plastic? A New Sustainable Alternative to Plastic and Paper 

Limestone Plastic? A New Sustainable Alternative to Plastic and Paper 

Have you ever heard of TBM Co.? Or maybe LIMEX? It’s a Japanese startup that makes plastic and paper alternatives from limestone (Limex is the product/technology name).  

The company’s been around for a quite some time now, but recently it’s got a green loan, pushing its plan to expand production. 

According to Bloomberg, the company’s secured 3.62 billion yen ($33 million) of financing with its first long-term loans. It’ll use the funds for its new plant in Tagajo city, northeastern Japan. It intends to expand employment in that region as well. 

Until now, TBM has made products from bags to business cards out of limestone, but that won’t be everything. The company wants to prove the flexibility of the material globally.  

So, they’ve worked together with Bandai Spirits. They’ve planned to release plastic models “Dinosaur Skeleton Plastic Model Tyrannosaurus” and “Dinosaur Skeleton Plastic Model Triceratops” using Limex. The models are releasing this fall in North America and Asia. 

Bandai Spirits using Limex 

The company hopes that by molding some of their plastic models with Limex, Bandai can reduce their environmental impact and make them reminiscent of real fossils of dinosaur skeletons. 

Usually, these models are made from petroleum-derived plastics and polystyrene. Because of course, plastic has its own particular abilities when it comes to making toys (I realize models are not toys, but I’m just generalizing here). 

But, Bandai has worked together with TBM to make improvements of Limex in terms of moldability and strength using injection mold machines. The company hopes that these are the world’s first plastic model products using Limex. 

Due to the use of limestone as the main raw material instead of the usual petroleum-based plastics, the product has less than 50% of conventional plastic by weight.  

Bandai wants to reduce the use of petroleum-derived plastics by over 5 tons per year, while at the same time reduce carbon dioxide emissions. 

But that doesn’t mean this product’s gonna be very light. 

On the contrary, Limex makes the models paintable with heavier weight when compared to regular polystyrene resin. It’s all thanks to the minerals within limestones. So, the models will have a more premium, weighty feel than regular plastic. 

Another perk for using Limex for these models is the experience. When you assemble the dinosaur skeleton yourself, it’ll make you have a gist of being an archaeology or sorts. The texture and weight are different, so it’s like you’re holding ‘real’ fossils.  

The Limex models have a dry, gypsum-like feel and matte surface with a gentle sheen. And, the company has done its research thoroughly first in order to give you authentic shape. 

If you’re a dinosaur enthusiast who love collecting great models, I think you’re gonna love the results of this Bandai x TBM cooperation. 

A bit about Limex 

As mentioned, limestone is the raw material of Limex. According to the company, even though this resource is scarce in Japan, it can be self-sufficient.  

Per TBM the company, estimated recoverable years of limestone continue to grow, with 24 billion tons of resources reserved in Japan alone. Moreover, limestone is said to be a resource with a very low risk of depletion compared to oil, water, and forest resources 

Additionally, Limex is manufacturable with almost no use of water or forest, so it’s doable in many places. The company believes that by promoting local production for local consumption, a compact supply chain can be constructed, which could reduce impact on the environment. 

“Because it is a resource that is abundant everywhere, we believe it can save the world,” the company says. 

Using calcium carbonate as the main raw material for Limex can reduce carbon dioxide emissions by around 50 times compared to petroleum-based resins. The reason is processing difference—usual plastic needs high amount of heating, while Limex simply crushes limestone. 

We can argue that limestone can be scarce as well, but the company believes that it’s abundant all over the world, has excellent supply stability, and inexpensive. Not only that, mining and processing this resource is easier than petroleum and metal. 

Limestone is also physically more stable when compared to plastics and rubber, which can deteriorate due to many environmental factors like UV rays. So, according to the company, this raw material has the upper hand. 

Earlier I said that Limex has actually been around for a while. Well, it’s been introduced at international conferences like COP and G20.  

And, it’s registered in the sustainable technology dissemination platform of UNIDO (United Nations Industrial Development Organization) as an excellent technology of Japan. 

Effort to make other countries to use Limex 

Limex is applicable to a variety of molding methods like injection, extrusion, vacuum, and blow molding. Even though Limex is a composite material, it doesn’t need custom equipment and we can process it using existing, traditional methods and machinery. 

It’s convenient and cost-effective that as of June 2021, there are more than 6000 companies and municipalities using this technology.  

Since limestone is available everywhere, TBM has submitted Limex patent in over 40 countries worldwide. The company says, “We will export the LIMEX technology and brand as a new Japanese technology, so that LIMEX becomes a material used commonly in the world. ” 

Manufacturing and recycling possibilities 

Limex itself is a composite material, as mentioned above. It consists of something natural (Limestone or calcium carbonate) and a small amount of polymeric resin that functions as a binder. 

These materials are then processed and treated, resulting in material properties fit for post-processing. 

The company also pelletize Limex. Machines mold the molten composite into the shape of a pellets. According to the company, they can also manufacture Limex pellets by pelletizing edge waste produced through manufacturing and printing process or used LIMEX sheets collected from consumers. 

In short, Limex still uses a bit of plastic in order to produce pellets or plastic alternative. But the amount of the petroleum-based resin is cut. And probably after this, there can be a newer technology that doesn’t use petroleum resin at all for binding properties. 

However, it may not be all bad. Conventional plastic is usually recyclable only to a certain extent because it deteriorates. Limex, on the other hand, has a lower rate of that, with higher physical properties as well as recycling efficiency. 

Additionally, whenever there’s collected post-consumer Limex products like paper alternative products, the company will upcycle them into plastic alternative products.  

“TBM will promote the resource recycling of LIMEX by cooperating with domestic and overseas partner companies,” the company adds. 



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