A major revolution in diaper design was brought about by the use of superabsorbent polymers, which enabled diapers to work more effectively and be made dramatically smaller. Their use in diapers was patented in 1966 by Carlyle Harmon of Johnson & Johnson and by Billy Gene Harper of Dow Chemical.
Diaper manufacturers began experimenting with superabsorbers as a partial replacement for fluff pulp in the early 1980s. The polymers could absorb between thirty and sixty times their weight in liquid, a significant advantage over conventional absorbent materials such as fluff pulp.
The first commercial use of superabsorbent polymer in a diaper occurred in Japan in 1983, first by Uni-Charm and then Kao. Procter and Gamble then introduced the technology in the US via Ultra Pampers. By the mid-1980s, ultrathin premium disposables were about one-half the size of their predecessors. Soon an acquisition layer was created between the liner and the core to quickly absorb urine and spread it the full length of the core to take full advantage of the superabsorber.
The thin and ultrathin models proved extremely popular around the world. Lower prices and the spread of the technology into store brands hastened the replacement of cotton diapers by disposables. By the late 1980s, disposables accounted for more than 95 percent of diaper changes in Japan, North America, and most European countries.
The superabsorber technology delivered the traditional advantages of disposables in a package not much bigger than cloth undergarments. It enabled infants and young children to move more freely, generated less waste, and delivered savings in distribution, shipping, and storage. Early clinical studies showed the benefits for individual children as well as children in group settings included reduced instances of diaper rash and improved skin health from drier skin and more stable skin pH.