PAPER PACKAGING MATERIAL FOR LIQUID FOOD AND METHOD FOR PRODUCTION THEREOF

摘要

In manufacture of the paper container from the packaging materials, the damage of internal layer of packaging materials is promptly inspected, and degradation by light exposure of content can be prevented. Method of manufacturing light barrier paper packaging materials for liquid food formed from a laminate having a paper layer, a thermoplastic resin outside layer and a thermoplastic resin inside layer comprising a step of preparing substantially complete bleached white bleached paper layer of weight of 50-350g /m<2>, a step of providing light barrier layer of light barrier material in the inside of the bleach paper layer before or during the lamination of the inside thermoplastic resin layer, a step of inspecting defect of the obtained laminate by observation of the visible or invisible inside-surface of the bleach layer from the inside thermoplastic resin layer side of the obtained laminate through the light barrier layer.