1. Top
  2. Sustainability
  3. An Illustrated Guide to Recycling Unicharm Disposable Diapers
  4. Study Note 1

[Study Note 1] Unicharm’s circulation-based recycling of disposable diapers [Study Note 1] Unicharm’s circulation-based recycling of disposable diapers

Study Theme: What is circulation-based recycling?

illust: Circular recycling flow

There are many ways of recycling. Recycling used diapers to turn them into something else such as, for example, solid fuel or building materials is one of them. Another method known as “circulation-based recycling” makes it possible to use them once again for the same purpose as diapers.


One advantage of circulation-based recycling is that it allows us to use the limited natural resources repeatedly rather than simply throwing them away. Disposable diapers are mainly made of wood-pulp which comes from trees, therefore, reusing this pulp over and over again helps preserve the world’s forests. That is why Unicharm has decided to aim at developing this type of circulation-based recycling of used disposable diapers.

World first! Unicharm’s diaper circulation-based recycling

illust: Unicharm’s Circular recycling flow

*Lower-grade: Unsuitable quality level to be reused as disposable diaper as there still remains a certain amount of residual bacteria and other wastes
*Higher-grade: Meets the required quality standards for reuse as diapers

The chart above shows the world’s first circulation-based recycling model for used disposable diapers developed by Unicharm.


First, the used diapers are finely grinding up, washed and then separated by the materials mainly pulp and super-absorbent polymer (SAP). At this stage, the materials are still somewhat soiled and smelly. Therefore, the pulp is given a special ozone treatment to destroy the bacteria while the SAP is given an acid treatment that restores its absorbing capability. After these treatments, both pulp and SAP become clean and safe sufficiently enough to be reused to manufacture new disposable diapers.

Share On