MULTI-LAYER PAPER BAG PREVENTING POWDER LEAKAGE AND POWER BLOWOFF EVEN WHEN IT IS FILLED WITH CONTENTS, AND METHOD FOR MANUFACTURING SAME

摘要

PROBLEM TO BE SOLVED: To prevent powder from leaking and flowing out of a rear surface of a bottom label at a blow port side and of the blow port in a multi-layer paper bag having a blow port side bottom adhering section. SOLUTION: There is provided a multi-layer paper bag in which a first score folding section x, a second score folding section y and a slant score folding section z are folded at a first score 12, a second score 13 and a slant score 11 and a blown side bottom adhering section A is formed. A vertical slit 7 is cut at the second score folding section y to form a vertical folding-back section 7a and a valve paper 4 is overlapped on the lower surface of the overlapped sections of the second score folding sections y, y. A blow port 3 is formed among the first score folding sections x, x and the slant score folding section z. A hot melt hm4 is coated on the surface of the valve paper 4 at the side of the blow port 3. After filling contents in the multi-layer paper bag 1, the hot melt hm6 of the bottom label 6 and the hot melt hm4 of the valve paper 4 are thermally pressed to the surface of the blow port 3 of the valve paper 4, thereby both inside and outside of the blow port 3 are double sealed. Accordingly, the content is filled to enable power leakage and blowoff of powder can be prevented.