FILM FOR FRESHNESS KEEPING BAGS, PRODUCTION METHOD AND PRODUCTION APPARATUS OF THE SAME

To provide a method of manufacturing films for freshness keeping bags for vegetable and fruit with high productivity, punching proper holes for freshness keeping in a film without heating.SOLUTION: A polyolefin film with thickness from 15 μm or more to 60 μm or less has an opening part 11 and a punched hole part 15 which has two cut lines 12, 13 crossing at the opening part 11 as a center. The surface area of the opening part 11 is from 0.001 mmor more to 0.1 mmor less. Regarding the two cut lines, the ratio of the length of the longer cut line 13 to the length of the shorter cut line 12 (L/L) is from 1.5 or more to 20 or less, and the length of shorter cut line Lis from 0.1 mm or more to 1 mm or less. The punched hole part 15 is surrounded by the polyolefin film with thickness less than or equal to the double of the original thickness.SELECTED DRAWING: Figure 1 【課題】加熱することなく鮮度保持に適当な孔をフィルムに穿孔し、生産性の高い手法で青果物鮮度保持袋用フィルムを製造可能にする。【解決手段】厚さ１５μｍ以上６０μｍ以下のポリオレフィンフィルムであり、開口部１１と、開口部１１を中心とする２方向の切れ目１２，１３を有する穿孔部１５とを有し、開口部１１の面積が０．００１ｍｍ２以上０．１ｍｍ２以下で、前記２方向の切れ目のうち、長い方の切れ目１３と短い方の切れ目１２の長さの比（ＬＬ／ＬＳ）が１．５以上２０以下であり、短い方の切れ目の長さＬｓが０．１ｍｍ以上１ｍｍ以下で、穿孔部１５は、前記ポリオレフィンフィルムの元の厚さの２倍以下の厚さの部位で囲まれている鮮度保持袋用フィルムを用いる。【選択図】図１