GROOVED ROLLER, AND APPARATUS AND METHOD FOR MANUFACTURING PLASTIC FILM USING SAME

摘要

The present invention provides a grooved roller having a helical groove or an annular groove formed on a roller surface, wherein a protruded portion sandwiched between the grooves is shaped in a manner such that rectilinear light causes the shadows of the protruded portion to be projected to the respective grooves sandwiching the protruded portion, the rectilinear light irradiating the protruded portion in a direction that passes through the center axis of the roller and is perpendicular to the center axis. The present invention provides a grooved roller that will never cause a web or sheet to be electrically charged or scratched even at both edges of the protruded portion.