Patent ID: 8696968
Filing Date: 2014-04-15
Classification: B29C

Abstract:
1. A method of producing a stretchable sheet that is stretchable along a machine direction of the sheet, the method comprising: passing a nonwoven fabric including a plurality of types of fibers through a gap between a pair of gear rolls that rotate while a plurality of teeth formed on an outer circumferential surface of each of the pair of gear rolls engage with one another, the teeth being formed in a wave shape on the outer circumferential surface along a circumferential direction at a formation pitch P, top portions and bottom portions of the wave shape extending parallel with a rotational axis of each pair of gear rolls; and drawing the nonwoven fabric in a circumferential direction of the gear rolls by the teeth, wherein a circumferential velocity of the gear rolls is within a range of 50 to 300 m/min, and a maximum value of distortion per unit time, dεdt, applied to the nonwoven fabric in the gap between the pair of gear rolls is within a range of 5 to 100 sec wherein a value ε of distortion when the plurality of teeth engage with one another at a maximum engagement depth F is calculated as: ε=2×(√(F