Sumitomo Chemical Company, Limited

Hiroko Nakashima

Daizaburo Yashiki

Takahiro Okugawa

Daijiro Hoshida

Mariko Kunai

An inclination of an outer circumferential surface of a film roll with respect to a widthwise axis is restricted. The roll includes: an outer cylinder part having a material thickness that is smaller toward a negative side of a y-axis than it is toward a positive side of the y-axis; and a slit separator which is wound around an outer circumferential surface of the outer cylinder part and which has a thickness that is larger toward the negative side of the y-axis than it is toward the positive side of the y-axis.

Film roll, method of producing the same, and method of testing the same

In regard to at least one of long separator sheets (), measurement is carried out to measure the amount of curl at an edge of the at least one of the long separator sheets () while applying tension to the at least one of the long separator sheets () in the lengthwise direction (MD) of the at least one of the long separator sheets (), the edge being parallel to the lengthwise direction (MD) of the at least one of the long separator sheets (). This makes it possible to provide a method of measuring the amount of curl in a separator, a slitting apparatus, and a curl amount measuring apparatus, each of which is capable of carrying out a highly accurate nondestructive measurement of the amount of curl without having to cut a sample from a long separator sheet.

Growing community of inventors

Niihama, Japan

Hiroko Nakashima