Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This is a dlvision of our co-pending Canadian Patent
Application Number 413 101 filed October 8, 1982.
The present invention relates to apparatus for pro-
ducing a packaging means for fluent materials comprising side
and end walls which are joined by means of at least one sealing
seam and which comprise coated paper, cardboard or the like in
which bending lines are provided.
Packaging means or cartons for liquids, comprising
paper coated with plastics material on both sides and which may
also be referred to as board, paperboard or cardboard, are
known. Such packaging means is used in particular for distri-
buting milk. There is a very wide range of forms of milk pack-
ing means or cartons, including also a parallelepipedic shape.
However, all milk packaging means or cartons have at least one
sealing seam along which the web of paper, which is first drawn
in a flat condition from a supply roll, is closed to form a tube.
It will be appreciated that, when using plastics-coated paper
webs, the closure operation is performed by means of welding or
sealing.
In most liquid packaging means, at least on one side
thereof, a pattern of bending lines is formed in the web of
paper in order to facilitate mechanical folding, shaping and
sealing operations. It is also known that in the operation of
bending or folding the paper, which is generally already
previously coated with plastics material, stresses in tne paper,
or contact with tools, cause damage to the web cf paper, at
least in the plastics coating on the web of paper. Such damage
causes the packaging means to become pervious to liquid, which
is obviously undesirable. It is precisely the action of sealing
jaws on plastics-coated paper webs, and flow of the plastics
material caused by the effect of heat, that give rise to unde-
sired leakage areas. In order to prevent this, the web of
paper carrier material is coated with a layer of plastics
material of suitable thickness, so that the above-mentioned
disadvantages cannot arise.
In order to save material in the manufacture of
liquid packaging means which are mass-produced, in particular
plastics material, efforts have been made up to make the coat-
ing of plastics material thinner, which is a development in the
opposite direction to the efforts to increase the safety margin
of the packaging means, as referred to just above. Therefore,
consideration has already been given to securing cover or seal-
ing strips of plastics material to parts of the packaging means
which are in particular danger, by a sealing join. However,
such processes have not achieved the desired result hitherto,
since the fact that the cover strips are sealed on the web of
paper, which is coated with a thin layer of plastics material,
over the entire area thereof, still gives rise to damage in the
bending or welding operations, which in turn can result in leak-
age in the above-described manner. In addition, applying a
cover s'_rip is a step which must be carried out by a separate
operation in the packaging means production line, and according-
ly increases costs.
The invention provides apparatus for producing a
packaging means from a web of paper, cardboard or the like
coated on one side with a thin layer of plastics material, said
blank being formed with bending lines and having at least one
strip of reinforcing material on the coated surface thereof, in
the region of the bending lines, the contact surface between
the strip and the blank being spaced from said bending lines,
said apparatus comprisinc a plastics film supply roll arran~ed
on one side of the coated web, and two mutually oppositely
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operative sealing jaws of which at least one is movably arranged
on opposite sides of the web, the face of the sealing jaw which
is towards the coated surface of the web comprising at least in
part grooves arranged in accordance with the pattern of the
bending lines.
The cross-sectional shape of the grooves may be
quadrangular, in particular rectangular, or rounded, in partic-
ular circular, oval or the like. The grooves preserve the
region of the bend line from welding or sealing engagement of
the sealing jaw with the thinly coated paper web. Even slight
damage to the thin coating of plastics material in the region of
the cover strip is sealed off again by applying the plastics
cover strip with the above-indicated manufacturing apparatus.
In addition, there is no fear of fresh leakage locations, for
the cover strip applied to the packaging means forms, in the
region of the bending lines, loose regions which are movable
relative to the paper web and which can carry considerable load-
ings when stresses are applied, without tearing.
It is desirable for the a~is of rotation of the supply
roll to be arranged transversely with respect to the direction
of transportation of the paper web. In contrast to the arrange-
ment which involves applying one or more cover strips to the
paper web from the side transversely with respect to the direc-
tion of movement or transportation thereof, the arrangement of
the suppl~ roll in the above-defined manner permits a long period
of use thereof for, because the cover strip is frequently compar-
atively narrow, performance of the entire manufacturinq process
may in this way involve only a few changes of roll.
A further preferred embodiment of the invention is
characterised in that the sealing jaw which is arranged on the
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side of the paper web, which is to be treated, is driven movably
substantially normal to the plane of the paper web, and is
provided with a severing welding means. Preferably, the pro-
duction apparatus is of such a design that the paper web which
is thinly coated with plastics material and which is initially
flat is transported horizontally and, in the course of that
conveying movement, the cover strip is laid from above onto the
paper web. In other words, the surface of the paper web which
is to be treated is upwards, while the co-operating jaw is
arranged stationarily below it in such a way that the paper web
is conveyed over the bottom jaw. It will be appreciated that
the operation of sealing the cover strip in place occurs in a
cyclic manner so that the paper web is only advanced when the
preferably vertically movable upper sealing jaw is in the
raised position. The severing welding means which is preferably
arranged at the downstream edge of the sealing jaw, as viewed in
the direction of movement of the paper web, means that there is
no need for a separate cutting means, especially as the heat
for the severing-welding operation is available in any case.
Use of the combined severing-welding operation, which is con-
sidered as a particularly simple procedure by persons skilled
in the art, advantageously makes it possible to eliminate over-
hanging or upwardly projecting edges on the cover strip which is
secured in place on the paper web by a sealing action, so that
there is no danger of any fouling or soiling. The production
apparatus defined hereinbefore seals the cover strip to the
paper web, up to the severing location.
It is even desirable for the sealing jaw, at its
trailing edge, to extend one or two millimetres for example
beyond the cover strip or the region to which the cover strip is
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to be secured by a sealing action. That then ensures that the
sealing join is produced without any doubt, as far as the edge
of the cover strip, even when tolerances are involved, and there
is no damage to the layer of plastics material on the paper web
for the reason that at that location the blank terminates at
the edge of the cover strip, particularly when employing the
above-described packaging means which has a block bottom
arrangement.
It is also advantageous in accordance with the inven-
tion to provide at least one clamp means which is movable in a
controlled fashion synchronously with respect to the movement of
the sealing jaw, for advancing the plastics film by the width of
the cover strip, between the sealing jaw and the paper web.
The clamp means may advantageously also co-operate with the
severing welding means in such a way that, directly after the
severing welding operation, a brief retraction or pull-back
movement of the web of film is effected, from the cover strip
which was last sealed in position, so as to produce a cleaner
cut and prevent fraying.
It is desirable for the next cover strip to be pulled
from the supply roll by way of a movably disposed and drivable
pull-off roller, in such a way that, after the
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temporary pull-back movement referred to above, the clamp
means clamps the web of film or foil on a feed or delivery
surface so that the movement of the pull-off roll pulls film
or foil from the supply roll, by increasing the length of the
path of movement of the web of film or foil.
Further advantages, features and possible uses of the
present invention will be apparent from the following descrip-
tion, with reference to the drawings in which:
Figure 1 is a perspective view of a particularly
preferred packaging means in which the end wall at the cover
end comprises plastics material without a carrier material,
whereas in this embodiment the bottom end wall is of a square
configuration, in the form of a block bottom,
Figure 2 shows the tubular side walls of the packag-
ing means shown in Figure 1 in an inverted position so that the
bottom which is not yet fully finished is at the top, towards
the person viewing the join,
Figure 3 shows the bottom end of the tubular side
walls of the packaging means shown in Figure 2, to show the
configuration of the bending lines,
Figure 4 is a diagrammatic side view of the apparatus
for applying the cover strip to the paper web,
Figure 5 is a diagrammatic perspective view of the
apparatus for applying the cover stri.p, ~ith some machine
components omitted,
Figure 6 is a view of a part of the paper web with
the pattern of bending lines on the individual blanks,
Figure 6a shows a broken-away view on an enlarged
scale of a portion of the grooves in the sealing jaw, corres-
ponding to the pattern oE bending lines,
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Figure 7 is a cross-sectional view of the sealing
jaw, with diagrammatic illustration of its engagement activity,
Figure 8 shows a part of the fo.~Jar~ feed and control
arrangement for the web of plastics material, for applying cover
strips to the paper web, and
Figure 9 shows the same machine as that shown in
Figure 8, except that other machine components are shown, to
illustrate the mode of feeding the respective cover strip.
The specific packaging means which is shown in a
finished condition in perspective view in Figure 1 and of which
only part is shown in Figures 2 and 3 comprises side walls 1
which are of a tubular configuration, a cover portion 2 of
plastics material without carrier material, the cover portion 2
being joined to the side walls 1 by an injection process at
the top end as shown in Figure 1, and a bottom portion 3 which
is arranged at the opposite end to the cover portion 2. Taking
the paper web 61 ~see Figures 4 to 9) which is initially in a
flat condition in manufacture of the illustrated packaging
means, the tubular side walls 1 are closed up to form the
tubular configuration shown in Figures 1 and 2, by means of a
longitudinal sealing seam 4. In this packaging means, after
the tube portion has been produced, that is to say, after the
longitudinal sealing seam 4 shown in Figure 1 has been formed,
the cover portion is injected onto the top thereof. It com-
prises a frustoconical cover wall portion 20, and a cylindrical
or slightly frustoconical spout or mouth rim portion 10 which
projects upwardly from the centre of the cover wall portion 20.
The rim portion 10 is closed by means of a closure member 13
which is connected by way of a tongue or bar portion 53 to the
grippin~ ring 17. The hinge 52 is also provided for the closure
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member 13, while the gripping ring is attached to the hinge by
way of the attachment strip 51. To open the packaging means,
the user thereoE tears off the strip 51, pulls up the gripping
ring 17 and thus tears the closure member 13 off the rim portion
14. After the packaging means has been opened in that way, it
can be re-closed by using the closure member 13 and the hinge 52
thereof.
At the end of the packaging means opposite the cover
portion 2 as shown in Figure 1 is the bottom portion 3 which can
be particularly clearly seen from Figures 2 and 3. It wil~ be
seen that in this case the longitudinal sealing seam 4 goes over
into the double cardboard strip 8 and the packaging means at
this end finally terminates at the edge 5. The lines 7 shown in
Figures 2 and 3 are formed by folding in the appropriate por-
tions of the packaging means, in the manner sho~ in Figure 2.
As shown in Figure 2, the lines 7 define the packaging means
and hereinafter, together with the other lines, represent the
bending lines 7. If the bottom end of the packaging means,
which is folded to form a quadrilateral as shown in Figure 3, is
pulled apart in the manner indicated by the arrows 11, and fold-
ed into the condition shown in Figure 2 along the bending lines
7, the result is then also the double-layer triangular flaps 10.
There is no need at this point to describe in greater detail the
way in which the doubled cardboard strip 8 is sealingly closed
after the packaging means has been filled, and -the triangular
flaps are secured to the bottom portion after having been
folded over thereonto.
As can be particularly clearly seen from Figure 3,
the liquid packaging means produced in the above-indicated
manner is provided at its bottom end with a cover strip in the
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region of all bendlng lines 7. The cover strip extends
completely over the bending lines and is secured by welding in
a given manner to the inside of the paper web which is thinly
coated with plastics material, in such a way that the welding
and contact surface between the cover strip 15 on the one hand
and the coated paper web on the other hand terminates from all
sides at a spacing from the bending lines 7, as will be describ-
ed in greater detail hereinafter.
First of all, Figures 4 and 5 show diagrammatic views
of the basic principle of the manner in which the cover strip
15 is sealed to the paper web 61 which is thinly coated with
plastics material 62. The axis of r~tation 17 of a supply roll
18 with the plastics film or foil which is drawn off in the form
of the web 19 in the direction indicated by the arrow 20, ex-
tends tranversely with respect to the direction of transporta-
tion of the paper web 61, as indicated by the arrow 16. Figure
4 shows the way in which the web 19 of plastics film or foil is
taken around the drive roller 20 and co-operating or backing
roller 21, and over a guide plate member 22, under the upper
sealing jaw 23. The lower sealing jaw is not shown in the
drawings. The sealing jaw 23 is disposed at tAe side of the
paper web 61 whose surface or plastics coating 62 is to be
treated, that is to say, joined to the cover strip 15. The
sealing jaw 23 is arranged to be movable vertically up and down,
as indicated by the double-headed arrow 24.
The mode of operation of the apparatus is shown
diagrammatically in Figures 4 and 5, illustrating that the drive
roller 20 intermittently advances the web 19 below the sealing
jaw 23, with a forward feed means which will be described in
greater detail hereinafter with reference to Figures 8 and 9.
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~ach intermittent movement of the web 19 under the sealing jaw
is over a distance corresponding to the width of a cover strip
15. When the leading edge of the web 19, that is to say, the
cover strip 15 which is the next one to be secured in position
by a sealing action, is disposed below the sealing jaw 23 and
over the correct position on the paper web 61, then the sealing
jaw moves downwardly as indicated at 24, and seals the cover
strip 15 in place. At the same time as that operation, the
severing-welding operation is performed by means of the severing
-welding device 25 which may be for example an extended or pro-
jecting wedge member as shown in Figures 4, 5 and 7 or an edge
25' as shown in Figure 9. When the material reaches the soft-
ening temperature or severing-welding temperature, the web 19
is torn away from the secured cover strip 15 by briefly revers-
ing the direction of drive of the roller 20. The paper web 61
is then advanced intermittently again in the direction indicated
by the arrow, and the forward feed movement of the film or foil
web 19 is then re-commenced, to apply the next cover strip. The
forward feed or pull-back movements referred to above are pro-
duced in a somewhat different manner in the specific embodimentdiscribed with reference to Figures 8 and 9, namely, not with
the drive roller 20 and the co-operating roller 21.
Reference will now be made to Figures 5 to 7 showing
the face 26 of the sealing jaw 23, which is towards the thin top
plastics coating or surface 62 to be treated, of the paper web
61. Figure 6a shows a direct plan view of the surface 26 of the
sealing jaw 23, with a channel-like pattern which corresponds
to the pattern of the bending lines 7 shown in Figure 6. The
pattern shown in Figure 6 in the operative surface 26 of the
sealing jaw 23 is formed by grooves 27, the cross-sectional
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configuration of which can best be seen from ~igure 7. The
channel system shown in Figure 6a is therefore simply yrooves
27 formed in the surface of the jaw, in a configuration which
corresponds to the pattern of the bending lines 7 in the paper
web 61. It would also be sufficient for only the critical
locations to be reinforced or strengthened.
The cross-sec-tional view shown in Figure 7 illus-
trates, starting from the bottom of the drawing and goint3 up-
wards therein, the paper web 61 which rnoves in the direction
10 indicated by the arrow 16, and the thin plastics layer 62.
The coated paper web 61 with the plastics layer 62 thereon has
the bending lines 7 at two selected locations, such that the
thin plastics layer 62 together with the paper web 61 is raised
in a rib-like configuration at 7', on the top side of the lam-
inate web. The cover strip 15 is shown as being laid thereover
(all layers 61, 62 and 65 are broken away at the right-hand and
left-hand sides in the drawing), and curves over the ribs 7' to
a greater or lesser degree into the grooves 27 in the sealing
jaw 23, with the curved portions and grooves being illustrated
20 in an exaggerated fashion. For that purpose for example hehting
or cooling passages 28 are only inaicated in highly diagramrnatic
form. Figure 7 shows welding and contact surfaces 29 as between
the cover strip 15 and the thin plastics layer 61. It will be
seen that the welding and contact surfaces 29 are provic'.ed only
under the operative surface 26 of the sealing ~aw 23 at loca-
tions where there are no grooves 27. In other words, each weld-
ing and contact surface 29 between the co~!er strip 15 on the one
hand and the thin plastics layer 62 on the paper we~ 1 on the
other hand terminates in front of the ~ending line 7, and then
continues thereafter, as far as the ne~;t ~endint7 line, and
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so forth. Therefore, there is a weld-free area in the region
of the bending line.
The blank shown in Figure 6 is suitable for making
up the side walls 1 of the packaging means shown in Fiyures 1 to
3, including the bottom portion 3. In this case, the blank
shown in Figure 6 is moved from right to left in the direction
indicated by the arrow 16 directly between two further blanks,
forming the paper web 61. Therefore, the blank begins at the
edge 30 and terminates at the edge 31 at which the next follow-
ing blank begins. The drawing also shows the simple quadrila-
teral shape of the blank on which the region of the bending line
7 occurs only at the right-hand edge, being the trailing edge
as viewing in the direction of transportation movement indicated
by the arrow 16. In this case, the cover strip 15 may be in the
shape of an elongate rectanale and is sealed in position at the
right-hand edge, beside the line 61, over the area indicated by
hatching.
Another and particularly preferred embodiment of the
feed means for advancing the film web 19 to form the cover film
or foil strip 15 will now be described with reference to Figures
8 and 9.
The film or foil web 19, in this case polyethylene,
is pulled off the supply roll 18, around direction-changing
rolls 32, 33, 34, 35 and 36, by way of a drive means which is
shown in Figure 9 in the form of a pull-off feed roller 37.
The feed roller 37 is carried by means of an arm 38 on a lever
40 which is rotatable about an upper pivot point 39. The lever
40 is only diagrammatica~ly indicated in Figure 8, in the form
of radii 40'. In its lower region, a push rod 41 of a pneumatic
cylinder 42 engages the upper pivot point 43 of a L-shaped lever
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44 which is mounted rotatably about a pivot point 45 on the
lever 40. ~hen the rod 41 pulls the lever 40 towards the right
in the direction indicated by arrow 46, the roller 37 is moved
from position ~ in Figure 9 into position ~. As a means for
blocking return movement of tne film web l9, comprising a
rubber bar member 47 providing a high degree of fri_tion, and a
rotary member 48, retains the film web 19 in the region of the
rubber bar member 47 as shown in Figure 9, a portion of web l9
is drawn off the supply roll 18 and stored in the region of the
feed roller 37, when the feed roller 37 is moved upwardly into
position B.
The movement of the rod ~l of the pneumatic cylinder
42 towards the right in the direction indicated by arrow ~16 and
thus the pivotal movement of tne lever 40 about the upper pivot
point 39 in a counter-clockwise position also causes t~le angle
lever 44 to be moved into the pOSitiOIl ~ shown in broken lines
in Figure 9. In that condition, the web l9 is disposed above
a tapered or wedge-like sliàe plate 49, in such a way that the
leading edge 50 is disposed at a small spacing of for example
5mm from the severing welding edge 25' of the sealing jaw 23.
If the direction of actuation of the pneumatic cylinder 42 is
reversed so that the rod 41 now moves towards the left in the
direction indicated by arrow 51, the above-mentioned means for
blocking return movement of the film 19 is lifted by the rotary
member 48 being lifted away from the rubber bar member 47. At
the same time, the angle lever 44 can pivot about its pivot
point 45 in a counter-clockwise direction so that a rubber punch
member 52, with a surface providing a high degree of friction,
moves downwardly substantially into the position indicated at
52C in Figure 9, and comes to bear against the film web l9.
So that the angle lever 44 can reliably rotate about
the pivot point 45 in the counter-clockwise direction when the
lever 40 is pivoted in the cloc~wise direction, the upper pivot
point 39 of the lever 40 provides a certain resistance to move-
ment, that is to say, it produces a certain retarding or bra~ing
action in regard to rotary movement of the lever 40.
By virtue of the rubber punch member 52 bearing
against the web 19 of film material from above, the web 19 can
be advanced towards the left and downwardly in the direction
indicated by the arrow 53 with a sliding movement on the plate
member 49, with the angle lever, for the angle lever 44 is moved
towards the left in the direction indicated by the arrow 51,
together with the lever 40, with the rubber punch member 52 in
its condition of bearing against the web 19, by virtue of the
vement of the rod 41.
During that movement, a roller 54 secured to the
outer left-hand arm of the anyle lever 44 moves at a spacing
below an inclined surface 55 on an angular guide member 56 which
is arranged approximately in a region to the left of and beside
the point 4~ of attachment of the rod 41 to the angle lever 4~.
When the leading edge 50 of the web 19 has reached the severing-
welding edge or trailing edge 25' of the sealiny jaw 23, the
roller 54 has moved towards the left on a cam surface 57 by the
above-mentioned distance of 5mm which is selected by way of
example, from the inclined surface 55 of the guide member 56.
The cam surface 57 ensures that the rubber punch member 52
remains in secure pressing engagement with the film web 19.
The leading edge 50 of the film web 19 is on the one
hand the leading edge of the next cover strip 15, but at the
same time it is the leading edge of the cover strip 15 which is
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subsequently fed forward, in conjunction with the film web 19.
When therefore the above-mentioned condition is attained, in
which the roller 54 is positioned under the cam surface 57,
then as shown in Figure 9 the sealing jaw 23 is lifted upwardly
in the direction indicated by the arrow 24 and the foremost
cover strip 15 is so disposed below the sealing jaw 23 that the
trailing edge thereof is under the severing-welding edge 25',
beside which is disposed the leading edge of the next cover
strip 15 and thus the leading edge 50 of the web 19, in the
above-described manner.
~fter the piston 59 of the pneumatic cylinder 58 has
rotated the drive lever 60 and thus the support arm 63 of the
sealing jaw 23, in such a way that the sealing jaw is pressed
firmly downwardly in the direction indicated by the arrow 24,
and the sealing and severing-welding temperature has been
attained, the film web 19 performs the return movement, which
has been referred to above in a different context, over the
above-mentioned distance of 5mm, so that the leading edge 50 of
the film web 19 resumes the position shown in Figure 9.
This return movement of the film web is effected by
the direction of actuation of the pneumatic cylinder 42 being
reversed so that the rod 41 moves towards the right a~ain in
the direction indicated by the arrow 46. This causes the lever
40 to be pivoted about its pivot point 39 in a counter-clockwise
direction, by means of the angle lever 44, with the angle lever
44 being pulled towards the right in Figure 8. It cannot at
first pivot about its pivot point 45 for the roller 54 is held
down by the cam surface 57. That causes the rubber punch member
52 to remain pressing against the film web 19, whereby it is
puiled back by the above-mentioned distance of Smm as required.
That produces a cleaner cut, and avoids fraying of the cover
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strip. After the above-mentioned pull back movement over a
distance of 5mm has taken place, the join between the cam sur-
face 57 and the inclined surface 55 of the angle guide member 56
is reached, and, by virtue of the upper pivot point 39 of the
lever 40 providing resistance to movement, the angle lever 44
can now rotate about its pivot point 45 in a clockwise direc-
tion, because the roller 54 can now move up along the inclined
surface 55. Because of that however, the rubber punch member 52
is lifted off the film or foil 19 and can move back from the
position shown in solid lines in Figure 9, into position 52C.
Controlled in synchronism therewith, ~he means for
preventing return movement of the web now comes into action
again by the rotary wedge member 48 being pressed against the
rubber bar member 47. During the above-described pivotal move-
ment of the lever 40 about its pivo-t point 39 in the counter-
clockwise directionr the feed roller 37 is again moved from its
position A into position B, in order to feed film web 19 forward.
The working cycle is now repeated in the above-
described manner.
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