A large metal arm in a Japanese factory swept a cluster of fluffy white fabric rectangles off a carousel into a group to be wrapped in plastic before packaging for shipment.

The items were adult diapers being turned out by automated production lines that stretch for 80 meters at a facility run by Daio Paper in Fujinomiya, Shizuoka Prefecture, near Mount Fuji.

Factory overseer Naoto Sugaya said output has grown year on year, as he held a pair of the "paper pants" close to his thigh and explained their features.