Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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METHOD FOR MANUFACTURING A SACK OR BAG WITH A BOTTOM BEING
RECTANGULAR IN THE FILLED STATE AND WITH A HANDLE PORTION,
AND A SACK OR BAG MANUFACTURED IN ACCORDANCE
WITH SAID METHOD
This invention relates to a method for manufacturing a sack or
bag with a bottom being rectangular i.. the filled st~te znd
with a handle portion, and to sacks or bags manufactured in
accordance with said method.
Sacks or bags of this kind are for instance known from the
German Utility Models 81 15 909 and 82 07 889. Said known
sacks or bags, however, show the drawback that the leg-like
strips forming a bottom leaf, so to speak, which in their
middle region are connected with the web section being
provided with the griphole, are bonded by an adhesive to the
bottom all-over or nearly allover, so that on the bottom or
the web section, i.e. in the region of the longitudinal center
plane running through the bottom of the sack, considerable
strains are exercised during carrying, said strains resulting
from the fact that the forces exercised by the web section are
introduced therewith substantially in the region of a line
extending centrically through the bottom square.
In order to avoid said drawback, in the German patent
application 40 12 896.2 a sack or bag was described which is
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formed by side tucks partially overlapping corner tucks, and
the handle portion joined thereto consists of a middle web
section with the griphole and lateral leg-like strips of
flexible material beins connected therewith, wherein the
bottom which is pulled open is conventionally bonded by an
adhesive or welded to a leaf connected sealingly with the
inner edges of the corner tucks and at least with the inner
edges of the side tucks adjacent to their fold lines, wherein
the handle portion is inserted in the still open bottom, and
the leg-like strips thereof are at least partially covered by
the side tucks and bonded by an adhesive or welded thereto. In
this sack or bag, the side of the lateral leg-like strips of
the portion facing the leaf constituted by e.g. a piece of
paper or fcil, wherein said strips carry in the center thereof
the web section having the griphole, is not bonded by an
adhesive to said leaf, but the side tucks overlap the lateral
leg-like strips and are bonded by an adhesive or welded
thereto through the sides thereof at which also the middle web
section with the griphole is located. Said sack or bag,
therefore, is characterized by a tunnel which is formed
between the lower side of the handle portion and the outer
side of the leaf. Due to this design, through the middle web
section and the leg-like strips connected therewith, the
carrying forces are substantially directly introduced into the
side walls of the filled sack or bag, so that the handle
portion can take up considerably greater carrying forces
without the sack being damaged thereby or bottom parts being
stripped thereoff.
But it has been proved to be disadvantageous that the sack or
bag described above cannot be easily and simply produced by
machines. Also the method for manufacturing a sack or bag with
a tunnel of the kind mentioned above, as described in the
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German patent application P 40 14 600.6, is relatively
complicated.
It is therefore an object of the present invention to provide
a method for manufacturing a sack or bag of the generic type
by which said sack or bag can be easily and economically
produced by machines in a production line.
Said ob;ect is solved by the methods according to claims 1 and
4. With said method it is possible to manufacture sacks or
bags in an especially simple manner, said sacks or bags only
requiring a relatively low amount of material but being,
nevertheless, of a very strong design in the handle portion.
By the inventivs ~.ethod according to claim 1 a sack or bag
with a so-called tunnel bottom is formed in a particularly
advantageous manner which has the advantage that the forces
introduced via said handles are introduced into the side walls
when the bag is taken up, without straining the bottom itself.
Further method steps for the solution of the problem result
from claim 4 according to which a sack or bag may be
manufactured with a handle portion joined thereto.
Sacks or bags manufactured according to the invention are of
particular advantage when they are manufactured by using one
single material, preferably paper. In this case, the bags or
sacks show a good suitability for recycling.
Despite the fact that it has been indicated as being
especially advantageous that the sacks or bags manufactured
according to the invention consist of paper, it must be
emphasized that within the scope of the invention they can
also consist of any other material, in particular also of
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plastic. Such plastic sacks or bags are not necessarily glued
within the scope of the invention, but may also be welded, as
is a measure belonging to prior art.
The ends still open after the filling of the sacks or bags are
sealed in any manner according to prior art.
Further details and advantages of the invention will be
explained in detail in the following by means of the
embodiments represented in the drawings. There is illustrated
in
Figures 1 ~
a first embodiment of the methcd accordins to the
invention for the manufacture of a sack or bag,
Figures 12 - 20:
a second embodiment of the method according to the
invention for the manufacture of a sack or bag.
In Figures 1 through 11 a first embodiment of the inventive
method for the manufacture of a paper napkin bag with a kind
of pinch-bottom is explained. According to Figure 1 it is
started with a tube piece 60 with side gussets 62, in which
pregroovings 64 and 66 are provided which extend in parallel
to each other and vertically to the side gussets 62. According
to Figure 2, the thus prepared tube piece is pulled open along
the pregrooving 66. Onto the bottom pulled open in said manner
a bottom cover sheet 70 is bonded by an adhesive. The design
of said bottom cover sheet 70 can be inferred in detail from
the detail reproduction of the bottom cover sheet in Figures 4
to 6. In Figure 4 the back side of the bottom cover sheet is
represented which is put on the open bottom. In
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this case a glue pattern 78 i9 shown by means of which the
bottom cover sheet 70 is joined by an adhesive with the corner
tucks 68 and the edge sections of the open bottom up to the
pregrooved lines 64. From Figure 3 it can be learnt that the
rectangular bottom cover sheet 70 projects beyond the pulled
open bottom of the bag at two sides. On one side of the
projecting portion of the bottom cover sheet 70 a bow-shaped
cardboard reinforcement 74 is bonded by an adhesive.
Therebelow a U-shaped folded sheet 72 with a leg is bonded by
an adhesive onto the bottom cover sheet 70 over the entire
width of the bottom cover sheet 70, as can be seen in Figure
6. On the opposite side in the section of the projecting strip
of the bottom cover sheet an additional cardboard strip 76 is
bonded by an adhesive at a location at which the griphole
punching is to be provided at a later point of time.
According to Figure 7 a glue pattern 80 is applied onto an
edge of the sheet 70 bonded by an adhesive, wherein the free
leg of the U-shaped sheet 72 is incorporated in the glue
pattern. The area correspondingly applied with a glue pattern
is referenced with 80 in Figure 7. Then, according to Figure
8, the lower bottom half is folded back at the inwardly lying
fold line 66 onto the upper bottom half. According to Figure 9
a griphole 82 is punched in below the reinforcement 74 and in
the section of the reinforcement 76. When the griphole is
punched, the longitudinal line 83 faciny the edge is not cut
through but only pregrooved.
After filling, the still open end of the bag is closed in any
manner known in prior art so that the packing is obtained
which is shown in Figure 10. Figure 11 is a lateral detailed
view onto the joint section of the handle portion, wherefrom
it becomes clear that again a tunnel-shaped bo~tom is formed.
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Figures lla and b show the sense of the reinforcements 74 and
76 in the section of the griphole punching 82. While the
bow-shaped cardboard reinforcement 74 due to its bow-shaped
formation above all prevents a tearing of the bag edge which
preferably consists of paper in particular due to the fact
that the forces are advantageously distributed by the ends of
the reinforcement which lead away from the edge, the
reinforcement 76 projects beyond the fold edge 83 of the grip
hole tabs and results in a thickening in the section of the
opened griphole, as can be seen in Figure llb, which improves
the carrying comfort by the fact that an unpleasant cutting of
the griphole edge into the palms is avoided.
With reference to Figures 12-20, the method according to a
second embodiment of the present invention is explained. It is
an economical method for the continuous production of diaper
bags. First of all, two cuts 92 and 94 aligned vertically to
the lateral edges and spaced apart are made in a continuously
advanced flat web 90, which are located on the elongation of a
line. Two cuts 96, 98 or 100, 102 which are parallel to each
other, are respectively aligned to said cuts. Glue is applied
to the flat web 90 at a lateral edge in a strip-like form. At
the same time handle portions 106 and 108 are respectively
bonded by an adhesive onto the web in the section of the cuts.
In doing so, the ends 110 or 112 of the handle portion 106 or
114 of the handle portion 108 are pasted in parallel to the
cuts 96 and 98 or 100 and 102. Each of the ends is bonded to
the flat web 90 by an adhesive over its entire sur~ace. The
connecting portion between the ends lies approximately in
parallel to cuts 92 and 94 and thus projects beyond cuts 96
and 98 or 100 and 102. Now the flat web 90 is cut
correspondingly and folded together to form a tubular piece
90' with side gussets 118 such that the handle portions
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lie on top of each othPr. A cutting of the flat web is
possible particularly in the sections of the handle portions
106 and 108 due to the *act that, already prior to the pasting
of the handle portions, cuts 92 and 94 had been provided (see
in this respect Figure 12).
In Figures 14a or 14 the tubular piece 90' is represented
directly after formation of the tubular piece. Figure 14a is a
view in which the tubular piece is slightly pulled apart from
the lower opening.
As is shown in Figure 15, at the and of the tubular piece 90'
to which the handle portions 108 and 106 are joined by an
adhesive, three pregrooved fold line~ 120, 122 and l~a are
formed which extend vertically to the lateral edges. The fold
line 120 arranged nearest to the end abuts approximately at
cuts 96 a~d 98.
In Figure 16 the bottom pulled open at the fold line 124 is
shown. As shown in Figure 17 a cover sheet 126 to which glue
is applied at its edge sides is put on the bottom and bonded
thereto by an adhesive. The folded over edge 128, i~s fold
edge lying approximatly above the fold line 120, is not
supplied with glue. According to Figure 18, a glue pattern is
applied to the folded over edge 128 and a plane section 130
above the fold edge 120. According to Figure 19 the bottom is
folded at the fold line 12~ and bonded by an adhesive in the
area of the glue pattern of the surfaces 130 and 128. The
napkin bag prepared in said manner is then filled from below
and closed in a known manner in the lower section which is
still open, whereby the package represented in Figure 20 is
obtained which advantageously has a tunnel-shaped bottom which
is particularly advantageous in the case of the force
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introduction of the force introduced by the handle 106, 108.
