Note: Descriptions are shown in the official language in which they were submitted.
13~3 7~9
Blank for a packaging container
The present invention is directed to a blank for a
packaging container formed from a lengthy roll of web and
having two side margins and two straight parallel side margin
lines which intersect with the two side margin lines.
Further, the sealing property of the packaging container
formed from the blank is improved because of the overlapping
side margins.
The known packaging containers for liquid foods, e.g.
milk and juice, are brick shaped or gable-topped packaging
containers. These types of packaging containers ar~e
manufactured from a web having paper support layers and
eXternal liquid tight plastic layers, and often a further
- ~ web additionally~including, for example, aluminium foil.
The~gable-topped ones are usually formed one by one by means -~
of a lengthy web printed and laminated, both side margins
thereof being stuck to each other by means of heat welding
to form a packaging container. The bottom is formed, the
contents are packed into it, and the top is formed and sealed.
In the packaging container described above, when i
folding lines of the top lid are overlapped and the bottom
parts are folded the contact of both heat-welded side margin
parts deteriorates, often causing liquid leakage to occur.
An ob~ect of the present invention is to provide a blank for
a packaging container, which is arranged to prevent liquid ~i
leakage from the above-mentioned overlapped folding parts at
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both heat welded side marginal parts.
In accordance with one aspect of the invention there is
provided a packaging container comprising a paperboard blank
both surfaces of which are covered with thermoplastic coating
materials, said blank being formed from a paperboard web which
is made such that two opposite lateral edges are repeated in a
pattern along the width of a piece of the blank and is
separated by two straight parallel side edges which are
perpendicular to said lateral edges, said blank being provided
with four side wall panels which are sectioned one from
another along longitudinal folding lines; adjoining top panels
for forming a top lid section of said packaging container and
adjoining bottom panels for forming a bottom section of said
packaging container which are provided on both the upper and
lower sides of said side walls by way of upper and lower
lateral folding lines; sealing panels for forming a sealed fin
area which is located along a top folding line outside of the
panel for forming said top lid section; and a longitudinal
sealing panel provided along one of said side panels with a
folding line therebetween; wherein said longitudinal sealing
panel and one of said side wall panels on the opposite side
thereto are overlapped to form a cylindrical shape, and flat :~
portions are provided on both ends of the three lateral
folding lines and at intersecting points on said three lateral
folding lines with a side edge of said longitudinal sealing
panel; wherein said panels for forming the bottom section
includes a pair of central bottom panels located on the
lateral side edges of a pair of main bottom panels, which are
located opposite to each other when the container is made and
are in a convex shape between two narrow parallel boundary
lines: lateral side edges of triangular panels which overlap
said main bottom panels and are in a concave shape, an
insertable central bottom flap on a tip end of one of said
main bottom panels being inserted between said triangular
panels and one of said main bottom panels, when forming said
container.
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2a 133~ 7~9
In drawings which illustrate an embodiment of the present
invention,
Figure 1 is a plan view showing the relationship between
a blank for a packaging container according to one aspect of
the present invention and a material web;
Figure 2 is a perspective view showing the top of a
packaging container in an open condition;
Figure 3 is a perspective view showing the whole
packaging container in its sealed and closed condition; and
Figure 4 is a perspective view showing the bottom of a
packaging container.
In the present device, paperboard on which both surfaces
are covered with thermoplastic coating materials, is composed
of two opposite side margin lines (11) and (12) formed from a
web (1) which is formed in a repeated pattern maintaining the
width of the blank constant and which is separated with two
straight parallel side margin lines (9) and (10) perpendicular
to said side margin lines (11) and (12), adjoining panels (3),
(3a) and (3b) form the top lid of the packaging container and
adjoining panels (4), (4a) and (4b) form the bottom of the
packaging container. The upper and lower sides of the
packaging container are provided by four side wall panels (P
(P2), (P3) and (P4), which are separated from one another by -~
longitudinal folding lines (2), (2) and (2). The top and
bottom of the packaging container is separated from the side
panels by upper side folding line (5) and lower side folding
line (6) respectively.
~ Th~ sealing panels (16) and (16a) form a sealed fin part
which is separated from the top panels (3), (3a) and (3b) by
the top side folding line (7) on the outside of the panels for
forming the top lid. When longitudinal sealing panel (5) of ;~
the blank provided with longitudinal folding line (5) adjacent
to the outside of the side wall panel (P4) by way of
longitudinal folding line (2) and the side wall panel
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tP1) on the side opposite thereto is overlapped to form a
container, parts which break the side folding lines (8), (8)
and (8) are provided on the respective side folding lines (5),
(6) and (7) such that said parts which break the side
5 folding lines (8?, (8) and (8) break said side folding lines
(5?, (6) and (7) by a narrow width at the intersecting points
of the side margin (10) on the side of the longitudinal
sealing panel (P5) and the three side folding lines (5), (6)
and (7).
In the present device, when the top lid and the bottom
part are formed by the upper and lower folding lines after
the longitudinal sealing panel (P5) and the side marginal part
on the si~e of side wall panel (Pl) on the side opposite thereto
are overlapped to form a container and said overlapped part
15 is welded with heat, the parts which break folding lines (8?,
(8) and (8) are provided at the intersecting points of the
side margin (10) on the side of the longitudinal sealing panel
(P5) and the three side folding lines (5?, (6) and (7) and
thus no folding line is presented on either the inside or the
outside panels along the side margin (10) of the overlapped
part. The inside and outside panels of said part are folded
flatly and come closely into contact with each other. This
improves the close contact property and prevents the problem
that conventionally occurs when folding parts having the
25 same sectional shape are overlapped, i.e. both the inside
and outside panels are curved to interrupt the close contact
condition causing a liquid leakage problem.
A blank for a packaging container is formed out of a
leng~hy web (1) (usually rolled to form a roll?, which is
formed from paperboard both sides of which may be coated with
thermoplastic coating materials. The blank is made such that
two opposite side margin lines (11) and (12) are repeated in a
pattern maintaining an equal wid*h of the blank and each
blank is separated from other blanks on the roll by two
straight parallel left and right side margin lines (9) and
(10). The blank is formed such that it has four side wall
p e s (Pl)~ (P2?' (P3) and (P4) separated by parallel
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longitudinal folding lines (2?, (2) and (2) and such that
narrow width longitudinal sealing panel (P5) has the side
margin line (10) and is separated by longitudinal folding line
(2) from side wall panel (P4) on the one side (right side).
Panels (3?, (3a) and (3b?, which form the top lid of
the packaging container, are provided on the upper side of
the four side wall panels (Pl), (P2), (P3) 4
upper side folding lines (5). Panels (4?, (4a) and (4b),
which form the bottom part of the packaging container, are
provided on the lower side by way of lower side folding lines
(6). Further, sealing panels (16) and (16a),which form a
sealing fin of the top are provided on the outside of the top
lid forming panels by way of top side folding lines (7).
While the upper part of longitudinal sealing panel (P5) is
shown in Fig. 2, when the packaging container is formed, the
longitudinal folding line (2) in the inward direction of the
longitudinal sealing panel ~P5) is made to coincide with side
margin line (9) of the side wall panel (Pl) on the,side
opposite to said panel (P5) and the overlapped part is welded
with heat.
The container bottom part is formed by folding small
triangle panel (4b) intothe respective inside of opposite
main bottom panels (4) and (4) at the lower part of the
packaging container, said main bottom panels (4) and (4) being
folded to the outside and opposite large triangle panels (4a)
and (4a) being inwardly folded, using lower folding line (6)
as a hinge means.
The side margin is formed by the boundary line (15) on
the outside of main bottom panels (4) and (4) into a convex
30 shape, the triangle part of side margin (12) is formed by the ~-
boundary line (15') on the inside into a concave shape. The
bottom central parts (17) and (17') are formed on the main
` bottom panels (4) and (4) between both the boundary lines (15)
and (15'?, and when a packaging container is formed, the
- 35 central part (17') on the one side is formed insertibly
between the main bottom panel and triangle panel parts (4a)
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and (4b?, which are positioned opposite to each other. In
this manner, a pair of bottom central paris (17) and (17 ~ )
extending out of the inward boundary line (15') of a pair of
main bottom panels ~4) and (4) are overlapped to be
positioned symmetrically at the central position of the bottom
of t~e packaging container, and thereby, the bottom central
sealing part is uniformly strengthened (refer to Fig. 4).
This construction enables the bottom to have a reliably and
completely sealed property. After packing with liquids the
10 top lid is sealed and formed such that a small triangle panel ~-
(3b~ is arranged to be folded into the inside of the opposite
main top panels (3) and (3) on the top of the packaging
container (refer to Fig. 2?, said main top panels (3) and (3)
are folded outwardly, opposite large triangle panels (3a)
and (3a) are folded inwardly using the upper side folding line
(5) as a hinge means. ~urther, by way of top side folding
line (7?, opposite sealing panels (16) and (16) are overlapped,
wel~ed and sealed to form a top sealed fin with small sealing
panels (16a) and (16a) being interposed therebetween (refer to
Fig. 3). When a packaging container (refer to Fig. 3) is
formed from a blank (refer to Fig. 2) in this way, i.e. the
overlapped and welded part of longitudinal sealing panel (P5)
and the side marginal part on the side of opposite side wall
panel (Pl) are folded at respective positions of three side
25 folding lines (5?, (6) and (7?, and said overlapped and welded
part which has been welded with heat and parts which break
folding lines (8?, (8) and (8) provided on respective side
folding lines (5?, (6) and (7) are combined to enable inside
and outside panels along the side margin (10) of the over-
30 lapped and welded part to be folaed flatly and to come closelyinto contact, a state of close contact is satisfactorily main-
tained without destroying the sealing property.
As is evi~ent from the afore-mentioned description,
according to the present device, when manufacturing packaging
35 containers for liquids, it is possible to improve the close
contact property of the folding part of the overlapped side
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marginal part (longitudinal sealing part) by welding with heat
and therefore it is also possible to provide a blank for a
packaging container which will prevent liquid leakage from
said folding part from occurring.
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