SELF-STANDING BAG AND METHOD AND DEVICE FOR MAKING SAID BAG

摘要

A self-standing bag composed of a trunk part comprising multi-layer plastic films having an inner heat-bonding plastic layer and of a bottom part, in which linear ribs each having a cross-sectional shape in which projections and recesses alternate are provided on the inner or outer layer of the multi-layer plastic films. The linear rib is formed in such a manner that a stamper having a linear projection at the tip thereof is pressed to the multi-layer plastic film to thin the pressed part of the film to be turned into a linear groove and a raised part is fixedly formed on the upper end of the groove.