To easily detach a spout from a paper container for liquid, to increase the volume reduction ratio of the whole paper container for liquid, and to facilitate the disposal, incineration and recycling by providing a half-cut from a surface of a carton blank along a thermal-adhesion area of a flange of the externally attached spout.
A spout 10 is firmly and thermally fused to a heat panel P through a hollow disk-like flange 4 in a thermally-fused area around a punched hole 2 in the heat panel P. Half-cuts 3, 3' from the surface of the head panel P are provided around a thermally fused area 6 of the flange 4 of the spout 10 to be attached. After the use of the paper container for liquid, the spout 10 is held by fingers and pulled upward, or the spout 10 is collapsed in the horizontal direction. Then, a part of the half-cuts 3, 3' is first broken, the interlayer separation of a cardboard occurs, and when the separation is propagated to the whole area in the circumference of the half-cuts 3, 3', the spout 10 can be detached.
YAMADA KAZUKI
FUKUDA ATSUSHI
