Domestic general waste in fiscal 2024 will be 40.34 million tons, of which disposable diapers will be 2.16 million tons, or 5.4%. This 5.4% is expected to reach 2.38 million tons, or 6.4%, in fiscal 2030. Some companies are taking on this problem. Sumitomo Seika Chemicals has been working to solve the problem of used disposable diapers since around 2022, using its knowledge to date. The solution is “horizontal recycling.” Horizontal recycling is a recycling method in which used products are used as raw materials to remanufacture the same product. Sumitomo Seika Chemicals aims to collect 5,000 tons (about 47 million pieces) of disposable diapers per year by 2030. Disposable diapers are made of cotton-like pulp and superabsorbent polymer (SAP), which holds human waste within the pulp. SAP can absorb several dozen times the amount of human waste, so it becomes heavier after use. As it contains a lot of moisture, incineration causes many problems.
Looking at it from another perspective, the material used in disposable diapers, which is made up of plastic and pulp, is suitable for recycling. If we can take advantage of the fact that diaper materials are suitable for recycling, we can significantly reduce costs. If the collection cycle can be made smooth, it will be possible to use it as a resource. Unicharm is working on horizontal recycling, that used paper is used to make disposable diapers again. Unicharm owns the technology to recycle SAP, and is also working on developing products that use recycled SAP. It was the first company to release disposable diapers made from recycled materials. Disposable diapers made from recycled pulp are sold mainly in Kyushu as company-branded products. Unicharm is also a leader in collecting diapers from households. It separates and collects used disposable diapers from residents.
The diaper business is a declining industry in Japan. In Japan today, there are fewer than 700,000 newborns and over 1.5 million elderly people die each year. These companies are targeting other places outside of Japan. Their target areas are China and Southeast Asia. It is estimated that the silver market in China will be worth 360 trillion yen in 30 years. It seems that silver and nursing care businesses will develop into growth industries in the future. Daio Paper has expanded its paper diaper factory in China and is preparing a system to produce over 200 million diapers per month (over 2.4 billion diapers per year). If high-quality paper diapers can be used and recycled, China and Southeast Asia will become promising markets.
