An expansion film, an expansion film manufacturing method, and a stretch film expansion method

摘要

An expansion film adapted to be held and expanded by an expansion device in the state where a plate-like workpiece is attached to the expansion film is provided. The expansion device includes a first support unit and a second support unit that are opposed to each other with the workpiece interposed therebetween in a first direction. The first holding unit and the second holding unit are movable away from each other in the first direction. The expansion device further includes a third holding unit and a fourth holding unit facing each other with the workpiece interposed therebetween in a second direction perpendicular to the first direction. The third holding unit and the fourth holding unit are movable away from each other in the second direction. The expansion film has a circumferential area around the workpiece in which the expansion film is adapted to be held by the first, second, third and fourth holding units. The expansion film includes a base film and an adhesion-promoting layer formed on the base film, the adhesion-promoting layer having an adhesion promoter adapted to be reduced by application of ultraviolet light. The adhesion promotion of the adhesion-promoting layer in the peripheral area of the expansion film is lower than that in the other area of the expansion film.