What is the LIMEX business?

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Last updated: October 4, 2023

LIMEX is Inorganic filler-dispersed composite materials containing more than 50% inorganic materials such as calcium carbonate. LIMEX, which was born in Japan, uses limestone as the main raw material to mold alternative products to plastic and paper, and can be recycled. In addition to our own factory, we have realized the construction of a supply chain with a fabless model overseas including OEM production.

About limestone

The material name LIMEX is a combination of the English name for limestone, "Limestone," and the letter "X," which stands for "infinite possibilities." Limestone is a rock that is mainly composed of calcium carbonate (CaCO 3) and is abundant all over the world. There are 220 limestone mines operating in Japan * 1, and it is one of the few natural resources that can be self-sufficient even in resource-poor Japan. Therefore, the price is cheap and stable.
With LIMEX, even in areas where water resources are scarce or in inland areas, it is possible to use raw materials that can be obtained locally. We can build a model of local production for local consumption around the world with a compact supply chain that is less subject to location restrictions and does not require long-distance transportation.

LIMEX global patent

Obtained a domestic patent for “LIMEX” in 2014. Basic patents have been registered in 40 countries around the world, including Japan, China, Europe, and America. In addition, we have filed over 100 patent applications. In addition to being introduced at international conferences such as COP and G20, it has been registered as an excellent Japanese technology on the Sustainable Technology Dissemination Platform of the United Nations Industrial Development Organization (UNIDO). In the future, we will export the technology and brand as a technology originating from Japan, and aim to make it a material that is commonly used around the world.

Manufacturing method of LIMEX

The raw material composition of LIMEX is more than 50% (by weight) inorganic substances such as calcium carbonate derived from limestone, and the remainder is thermoplastic resin and various additives. These are uniformly kneaded to form a molten composite. Limestone is inherently difficult to mix with other materials, which is why we have our unique technology.

LIMEX Pellet is made by cutting the molten composite into pellets (granules) using an extruder into uniform sizes and shapes. On the other hand, LIMEX Sheet is a composite extruded from a mold called a T-die, passed through a metal roll, and formed into a uniform sheet.

*Stone paper and LIMEX Sheet are different products.


 Diverse molding methods

LIMEX is capable of not only extrusion molding and inflation molding, but also vacuum molding and injection molding. As a composite material, LIMEX does not require specialized equipment to manufacture, and LIMEX products can be molded using existing machinery and manufacturing methods. LIMEX has been adopted by more than 10,000* companies and local governments.

*Including the number of registered offices


Recycable material

Compared to polypropylene (PP), which is a plastic petroleum-based, LIMEX has the advantage of suppressing deterioration of physical properties, as there are fewer changes in resin properties such as fluidity and impact resistance before and after recycling. Therefore, it is suitable for mechanical recycling, and there have been many recycling cases to date.
Furthermore, at Yokosuka Plant, one of the largest recycling plants in Japan operated by TBM, waste plastics are collected along with used LIMEX, and can be automatically sorted and recycled.

Using this Yokosuka Plant as a model case, this scheme will be used as a solution for building a recycling system in various areas of Japan that rely on incineration and heat recovery to process waste plastics, as well as in overseas areas where household plastic separation systems are underdeveloped. We plan to expand.

In order to respond to the growing need for plastic alternative and recycled materials around the world, TBM is working through CirculeX, which recycles LIMEX and used plastics as raw materials, and MaaR, a service that coordinates material circulation of used LIMEX and plastic products. We promote mechanical recycling and contribute to the realization of a circular economy.

Click here for more information on material circulation

Future of LIMEX

Regarding LIMEX's resource recycling, we have plans to expand the material recycling of LIMEX and conventionally burned plastics both domestically and internationally, using the Yokosuka Factory, a recycling plant operated by TBM, as a model. To this end, we are also focusing on building a resource recycling infrastructure that collects and recycles LIMEX and plastics from businesses and general consumers.

In terms of technology development, ventures and large companies around the world are now using CO 2 We regard carbon dioxide as a resource and are embarking on CCU (Carbon Capture and Utilization), which separates, recovers, and effectively utilizes carbon dioxide. As part of this effort, TBM is collaborating with external partners to reduce the amount of CO emitted from factories, power plants, etc. 2 We are working on immobilizing and producing calcium carbonate. In the future, CO2 that has already been emitted rather than limestone, which is a mineral resource, will be used. 2 By using LIMEX, which is made from raw materials, we aim to create a material that will further reduce greenhouse gas emissions.

On the other hand, regarding plastic, which is an auxiliary raw material for LIMEX, we are already developing technology to replace it with plant-derived, biodegradable, marine biodegradable plastic, and recycled plastic, and actual commercialization has begun. We are working to further expand its use, including mass production.

In order to further improve the environmental performance of the current LIMEX, we will expand the material compatibility of LIMEX's main raw material "calcium carbonate" and auxiliary raw material "plastic" to reduce CO2 emissions. 2 We will increase our contribution to reducing GHG emissions and realize the development of carbon negative materials in the future.

C.O. 2 For more information about the next generation LIMEX that reuses This way

LIMEX and SDGs

SDGs are international goals for the period from 2016 to 2030 listed in the "2030 Agenda for Sustainable Development" adopted at the United Nations Summit in September 2015.

TBM mapped the relationship between each stage of the value chain and the 169 targets of the SDGs, and identified the points of contact between business and the SDGs. In doing so, we analyzed both the impact of TBM's value chain on SDGs and the impact of trends surrounding SDGs on TBM's value chain. We have established eight core goals where TBM's business can have a particularly large impact.

<Core goals>
The LIMEX project focuses on SDG 12 "Responsible consumption and production", 6 "Conservation of water resources", 13 "Climate change countermeasures", 14 "Conservation of marine ecosystems", 15 "Conservation of terrestrial ecosystems", We will proactively contribute to the eight core goals: 8. Job creation, 9. Industry creation, and 17. Collaboration.


LIMEX as  JSA standard

The JSA standard (JSA-S1008) aims to clarify the definition of "inorganic/organic composite materials whose main components are inorganic materials" including LIMEX, expand the market, stabilize quality, and lead to fair trade. Published by the Japanese Standards Association on April 19, 2021.

JSA-S1008 specifies that the main constituent materials (among the constituent materials, the largest mass fraction For materials that are one type of inorganic substance and the total amount of inorganic substances exceeds 50% in mass fraction, ``Measurement of the mass fraction of the total amount of inorganic substances'', ``Confirmation of the presence or absence of thermoplastic resin'', and ``Major It stipulates the confirmation and testing methods for the types and mass fractions of constituent materials and secondary materials.

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