Note: Descriptions are shown in the official language in which they were submitted.
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Title: Method for manufacturing an airtight and moisture-
proof cardboard box and box obtained by the method
according to the invention.
The present invention relates to a method for
manufacturing a box, and more particularly, an airtight
cardboard box.
Such a method is known from British patent GB-B-
2,155,908.
A problem of the known box resides in the application of
the adhesive by means of which the material strip is attached
to the blank. This problem occurs in particular when the box
is to be mass-produced. The end panels to which the material
strip is attached at least substantially completely must be
accurately provided with adhesive over the entire area over
which the material strip extends, without adhesive thereby
ending up on the adjacent end panels. This is of particular
importance because if adhesive ends up on the adjacent end
panels, it is no longer possible to temporarily fold these
adjacent end panels outwards while simultaneously folding
inwards the end panels to which the material strip is attached
at least substantially completely. When this situation occurs
in an automatic manufacturing process, the manufacturing
process halts, which leads to great losses. The application of
the adhesive to the end panels is therefore particularly
critical. In general, the adhesive is applied by means of a
stamp under which the blank from which the box is manufactured
should be positioned accurately. It is found in practice that
in mass production, that is, in the production of about
20,000-30,000 boxes per hour, the position of the blank under
the adhesive stamp can vary by about 1.5 mm. Accordingly, the
problem presenting itself is that it is not possible for
airtight and moisture-proof boxes as described in GB-B-
2,155,908 to be mass-produced.
In order to solve this problem, the invention is
characterized by the features of claim 1.
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2
Owing to the adhesive layer on the relevant end wall
panel terminating some distance from the edge of the adjacent
end wall panel, adhesive is prevented from ending up, during
the application of the adhesive to those relevant end wall
panels, on the adjacent end wall panels. Tn practice, this
means that in the case of an end wall panel that is bounded on
both edges by an adjacent end wall panel, the width of, for
instance, the stamp or a like facility for applying the
adhesive to that end wall panel, is slightly less than the
distance between the two sidewall fold lines of the sidewall
panel to which the end wall panel in question is connected.
The measures according to the invention preclude the
possibility of the manufacturing process halting as a result
of the fact that the situation occurs where it is not possible
Z5 to temporarily fold the adjacent end panels outwards while
simultaneously folding inwards the end panels with which the
material strip is at least substantially completely connected.
The recesses provided at the two edges of the end wall
panel, which are so wide that adhesive for the purpose of
attaching the material strip to the relevant end wall panel is
exposed at that point in that it is squeezed out at that point
between the end wall panel and the material strip, provide,
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firstly, that the relevant end wall panels, at the location of
these recesses, axe provided with adhesive over the entire
width, so that at that point between the end wall panel and
the material strip no formation of leakage tunnels is
possible. Because moreover the adhesive for the purpose of
interconnecting the end wall panels is applied so as to be in
communication with the above-mentioned exposed material strip
attachment adhesive, the formation of leakage tunnels is
prevented during foldingas well, since at the location of the
points where a leakage tunnel might form the glue for the
purpose of securing the end wall panels is in communication
with the glue for the purpose of attaching the material strip.
Accordingly, in the leakage tunnel, if any is present, there
is a "glue dam" at the location of the recess, which seals the
leakage tunnel hermetically.
Further elaborations of the invention are described in
the subclaims and will be further clarified on the basis of a
number of exemplary embodiments, with reference to the
drawing.
Fig. 1 shows a cross-sectional view of the top plan view
shown in Fig. la of a blank with a material strip attached to
the blank in the manner as known from the prior art;.
Fig. 2 shows a similar cross-sectional view to Fig. 1,
with the adhesive for the purpose of attaching the material
strip to the end panel terminating some distance from the
edges of the adjacent end wall panels;
Fig. 2a shows a top plan view of the blank shown partly
in cross section in Fig. 2;
Fig. 3 shows a similar cross-sectional view to Fig. 1,
where the end wall panels to which the material strip is
attached at least substantially completely are provided with
recesses which extend over the entire length of the edges of
' those end panels;
Fig. 3a shows a top plan view of the blank shown partly
° 35 in cross section in Fig. 3;
Fig. 4 shows a cross-sectional view as represented in
Fig. 1, where the end wall panels to which the material strip
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is attached at least substantially completely are provided
with recesses extending over a part of the length of the edges
of those end panels;
Fig. 4a shows a top plan view of the blank shown partly
in cross section in Fig. 4;
Fig. 5 shows a top plan view of a partly erected box,
where two end panels are disposed in an outwardly folded
position and two end panels are disposed in an inwardly folded
position;
Fig. 6 shows a perspective view of the box in partly
erected position as shown in top plan view in Fig. 5; and
Fig. 7 shows an exemplary embodiment of a blank with an
opening facility already described as such, which blank is
provided with recesses at desired positions in order to
guarantee the airtightness of the box.
Figs. 1-4 and la-4a show, respectively, a cross-
sectional view and a top plan view of four different blanks.
Each blank P represented comprises a number of sidewall panels
1-4 which are mutually connected through sidewall fold lines
5-7. The blank P further has a number of end wall panels 8-11
which are attached to the sidewall panels 1-4 through end wall
fold lines 13-16, respectively. The end wall panels 8-11 are
each bounded by two opposite free edges 8a, 8b, 9a, 9b, 10a,
10b, 11a, 11b and a free end wall edge 17-20 located opposite
the end wall fold line 13-16. After the blank P has been cut
out, at the location of the or each end wall fold line 13-16 a
flexible material strip S is connected at least substantially
completely with the sidewall panels 1-4 and a number of end
wall panels 8, i0 through adhesion. In addition, the material
strip S is attached to each of a number of other end wall
panels 9, 11 while leaving clear two triangular portions 21,
22, 23, 24 not provided with adhesive, located adjacent the
free edges 9a, 9b, 11a, 11b of the corresponding end panel 9,
11. Then the blank P is erected into a.box through folding and
a
adhesion.
The blank P, S represented in Figs. 1 and 1a is known
from GB-B-2,155,908. As is shown clearly in Fig. 1a, the edges
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8b, 9a; 9b, l0a and 10b, 11a are in close mutual adjacency and
the width-of the area provided'with adhesive G corresponds
accurately with the width of the relevant end wall panel 10.
This applies equally at the location of the edge 8b of the end
A
5 wall panel 8 and at the location of the edge 12a of the end
wall panel 12 which is connected with an adhesive panel 25. In
order to ensure that the end wall panels 8 and 10 can be
folded into their end position without difficulty, it is
essential that no adhesive G of an end wall panel 8, 10 to
which the material strip S is attached at least substantially
completely, ends up on the adjacent end wall panels 9, 11, to
which the material strip S is attached only partly.
Particularly in the mass production of the boxes, this is not
feasible when the width of, for instance, the stamp with which
the adhesive G is applied corresponds with the width of the
end wall panel 8, 10 to which the adhesive G is to be applied.
Mass production of boxes which are manufactured from a blank
with a material strip S arranged thereon in a known manner as
represented in Figs. 1, 1a is therefore not possible.
In order to solve this problem, the method according to
the invention is characterized in that the adhesive G for the
purpose of adhering the material strips S to the blank P is
applied to the blank P in such a manner that the adhesive
layer G on the relevant end wall panel 8, 10, 12 terminates at
some distance from, respectively, the edge 9a and 9b, and 11a
and 11b of the adjacent end wall panel 9 and 11, 12,
respectively. Such an embodiment is represented clearly in
Figs. 2, 2a, 3, 3a, 4 and 4a.
The embodiment most similar to the prior art is
represented in Figs. 2 and 2a, where the blank P is designed
in a known manner. That is, the edges 8b, 9a, 9b, 10a, 10b,
11a, 11b of the end panels 8, 9, 10, 11 are closely adjacent
' to each other. Only the manner in which the adhesive layer G
has been applied has been modified. As has already been
indicated in the introduction to the specification, this
embodiment still entails a slight chance of leakage. Owing to
the fact that the material strip S is not connected with the
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panels 8 and 10 over the full width thereof, a so-called
leakage tunnel 26 can form, along which air or liquid can flow
from the relevant corner point 27, 28, 29, 30 of the box to
the box interior.
r
In order to preclude this chance of leakage entirely,
according to a further elaboration of the invention, recesses ,
31, 32 are provided at the location of the edges 8b, 10a, 10b,
12a of the end wall panels 8, 10, 12 bounding an adjacent end
wall panel 9, 11, these recesses 31, 32 being so wide that
adhesive G for the purpose of attaching the material strip S
to the corresponding end wall panels 8, 10, 12 will become
exposed there in that the adhesive at that point, as the
material strip S is being rolled on, will be squeezed out
between the blank P and the material strip S. During erection
into a box, adhesive 33 for the purpose of interconnecting the
end wall panels 8, 9, 10, 11 is applied in such a manner that
this adhesive 33 is in communication with the exposed material
strip attachment adhesive~Gv. Owing to the adhesive 33 for the
purpose of interconnecting the end wall panels 8-11 being
applied so as to be in communication with the exposed material
strip attachment adhesive Gv, the formation of leakage tunnels
26 during the folding up of the end wall panels 8-11 is
prevented as well. For at the location of the points where a
leakage tunnel 26 might form, the adhesive 33 for the purpose
of fixing the end wall panels 8, 9, 10, 11 is in communication
with the adhesive Gv for the purpose of attaching the material
strip S. Accordingly, in the leakage tunnel 26, if any is
present, there is a "glue dam" at the recess 31, 32, which
"glue dam" seals the leakage tunnel 26 in a liquid-tight and
airtight manner.
As represented in Fig. 3, the recess 31 can extend over
the entire length of the edges 8b, 10a, 10b, 12a of the end
wall panels. In the case of the end wall panel 10, which is
bounded on both sides by an adjacent end panel 9, 11, the
distance between the free edges 10a, 10b of that end panel 10
is slightly less than the width of the associated adhesive
stamp or like adhesive applicator. It is thus provided that
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the end wall panel 10 in question is always completely
provided with an adhesive layer G. As a result of rolling the
material strip S onto the blank P, the adhesive G is squeezed
out at the location of the recesses 31 and at that point the
adhesive layer G then projects beyond the edges 10a, 10b on
opposite sides of the end wall panel 10. As the end wall panel
is folded inwards, the material strip S is also adhered to
the cut edges 10a, 10b and connected hermetically and liquid-
tightly to them. A small disadvantage of the recess 31
10 extending over the entire length of the edges 8b, 10a, 10b,
12a is that the box may deform or slant somewhat more easily.
In order to increase the stiffness of the box even
further, the method is characterized, according to an
alternative further elaboration, in that the distance between
the edges 8a, 8b, 10a, lOb of those end wall panels 8, 10 to
which the material strip S is attached virtually completely is
substantially equal to the distance between the sidewall fold
lines or sidewall edge 34,. 5, and 6, 7 of the sidewall panels
1 and 3, respectively, with which the relevant end wall panels
8 and 10, respectively, are connected, while the or each
recess 32 extends only over a part of the total length of the
relevant edge 8b, 10a, 10b. Owing to the fact that the
relevant edges 8a, 8b, 10a, 10b in the folded condition of the
box, apart from the recess 32, abut against the end wall fold
lines 14, 16, the possibility of slanting is reduced to a
minimum.
In all the exemplary embodiments shown, the blank P is
further provided with an adhesive panel 25 which is connected
via an adhesive panel fold line 35 to a longitudinal edge of a
sidewall 4 located at a free end of the blank P. By means of
the adhesive panel 25, the two sidewalls 2, 4 located at the
free ends of the blank P can be interconnected through
adhesion. The adhesive panel 25 is connected via an end. wall
fold line 36 to at least one end wall panel 12 with two
opposite edges 22a, 12b and a free end edge 37 located
opposite the end wall fold line 36. In order to prevent the
formation of any leakage tunnel 26 at this corner point 30 as
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well - since on this end panel 12 too the adhesive layer G
terminates at some distance from the edge 11b of the adjacent
end wall panel 11 - the edge 12a of the end panel 12, which is
proximal to the adjacent end wall panel 11, is also provided
with a recess 31, 32 of the above-mentioned type.
According to a further elaboration of the method
according to the invention, the result of which is represented
in Figs. 2-8, the blank comprises four sidewall panels 1-4
and, at least at one end, four, first through fourth, end wall
panels 8-11 connected to the sidewall panels 1-4. When
erecting the box by folding and adhesion, first the sidewalls
1, 4 located at the ends of the blank P are connected to each
other. Then the first and the third end wall panels 8, 10 to
which the material strip S is attached at least substantially
completely are folded inwards and the second and fourth end
wall panels 9, 21 are folded outwards to some extent. Then the
adhesive 33 for the purpose of joining together the end wall
panels 8-11 is applied anc'~ then the second end wall panel 9
and, lastly, the fourth end wall panel 21 is brought into the
end position.
It is clear that a box with more or fewer than four
sidewalls also falls within the scope of the invention. In the
exemplary embodiments shown, with a view to saving adhesive,
only a narrow ribbon of adhesive 33 is used for the purpose of
securing the end walls 8, 9, 10, 11. It will be clear,
however, that it is also possible to apply adhesive 33 to the
entire surface of the end wall panels 8-11 visible in Fig. 5.
To achieve a proper seal, however, this is not necessary.
If the second end wall panel 9 has a height which
corresponds with the width of the sidewall 1, 3 associated
with the first and third end walls 8, 10, it is possible, in
accordance with a further elaboration of the invention, for
this second end wall panel 9 to be provided at the free end
edge 18 thereof with two recesses 38, which prevents the
exposed material strip adhesive Gv from being covered as the
second end wall panel 9 is brought into the end position. In
this connection, the height of the end wall panel 9 is
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understood to indicate the distance between the free edge 18
and the end wall fold line 14.~
Needless to say, the invention also relates to a box
obtained by the method according to any one of the preceding
claims.
Fig. 7, finally, shows a blank P provided with a
dispensing or pour opening already described as such, with the
blank P provided with recesses 32, 38 made at the desired
points. This embodiment is shown by way of example only, to
indicate that different designs for dispensing or pour
openings are possible in the method for obtaining an airtight
and liquid-tight box.
Tt will be clear that the invention is not limited to
the exemplary embodiment shown, but that various modifications
are possible within the scope of the invention.
For instance, the end wall panels can be the top panels
as well as the bottom panels: It is also possible that the end
wall panels only form the bottom panels and that the top of
the box is closed liquid-tightly and/or hermetically in a
different manner, or the other way around. The material strip
S can also be attached to the blank P through a sealing
operation. The adhesive is then liberated by heating the
material strip S and/or a coating of the blank P. According to
the invention, the stamp with which the material strip S is
heated should then have such dimensions that the adhesive or
sealing material liberated by heating terminates at some
distance from the edges of the adjacent end wall panels. In
this case too, the positioning of the sealing stamp with
respect to the blank P can occur with less accuracy, which
enables mass production at a high production rate.
It will also be clear that the adhesive mentioned in the
specification and the claims can also be one of the components
~ of an epoxy, of which one component is applied to the entire
surface of the material strip S and the other component is
applied to the blank in the manner according to the invention
as described.
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