Japan makes breakthrough in dirty diaper recycling
The Earth has a big diaper problem. Families in the United States throw away more than 1 trillion pieces of soiled clothing each year, making it the third most commonly accumulated consumer product in landfills. They’re not going anywhere anytime soon either. Thanks to their plastic polymer components, most diapers take more than 500 years to completely decompose.
When it comes to the solution to our big problem number two, there are two main lines of thought. On the one hand, it is important to promote the development and use of reusable alternatives made from environmentally friendly materials. At the same time, it is essential to find ways to recycle existing disposable diapers. While promising progress has been made in both areas in recent years, Japanese engineers say they now have an even more effective method for getting the most out of dirty diapers. According to AFPit even has the support of Unicharm, one of Japan’s leading manufacturers of hygiene products.
This new technique builds on a strategy that has already proven successful in the municipalities of Shibushi and Osaki, in southern Japan. About 25 years ago, the area’s approximately 40,000 residents realized their local landfill was quickly running out of space. After significantly expanding their recycling, Shibushi and Osaki now only throw about 20% of their household waste in the trash. With a recycling rate four times that of the average Japanese home, experts now say the nearby municipal landfill can remain open for another 40 years.
In 2024, Shibushi and Osaki included dirty diapers in their recycling program. Once collected, the materials are cleaned, shredded and separated into their main components: plastic, textile pulp and super-absorbent polymer (SAP). Unicharm could already turn these materials into other hygienic products like toilet paper, but a new ozone treatment designed to whiten, sterilize and deodorize the pulp further expands the possibilities. Meanwhile, the company is finalizing a method to incorporate SAP and plastic waste into new layers which it aims to deploy by 2028.
Although its recycled products are only available in a handful of test markets and cost about 10% more than standard options, they could help reduce production water needs. Unicharm also hopes to integrate its diaper program into 20 municipalities over the next decade.
While it’s true that soiled diapers are a problem all over the world, they are especially so in Japan. The country is home to the oldest average population in the world, with around 10% of residents aged over 80.
“Demand for baby diapers is declining. But an increasing number of older people are wearing diapers and, more recently, even pets are wearing them,” Unicharm President Takahisa Takahara explained in a recent interview. “If we can turn the feeling of guilt that ordinary consumers may feel towards using disposable products into something positive and make the use of recycled products the norm in society, it will become economically viable. »
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