Note: Descriptions are shown in the official language in which they were submitted.
411)
-- 1 --
This application is a division of our co-pending
patent application Serial No. 339,158 filed on October
30, 1981 and is concerned particularly with a carton
making apparatus as described therein.
The invention relates to a pack or carton for
fluid filling materials, comprising side walls which
are joined together to form a tube by at least one
longitudinal sealing seam, and end walls which are
mounted at the ends of the tube and which form the
bottom and cover of the pack, one end wall being made
of thermo-plastic material without any supporting material,
being moulded onto the side walls along its outer edge
and having a pouring device which is pushed inwards
inside the outer contour of the pack, wherein the side
walls are made of supporting material, e.g. carton,
which is coated with thermo-plastic material at least
on one side.
The type of pack which nowadays has proved to be
most successful for transporting liquids, particularly
milk and fruit juices, is a parallelepipedal pack,
comprising a tube of supporting material which is coated
on both sides with plastics, sealed by transverse ribs
at the ends in the region of the end walls and brought
into a parallelepipedal shape, so that two opposed,
double-walled triangular flaps are formed at each end
wall, the flaps initially projecting outwardly from the
end walls of the pack and finally being folded over onto
adjacent side walls or the end walls of the pack.
Many packs of this type are used, even for
powdered and granular type filling materials. In some
known packs the pouring aperture is formed by punching
lines of perforation or other lines of weakness in the
outer layer of the pack; the lines are then torn when
li~78'~10
- la -
the appropriate triangular flap has been unfolded.
An opening already punched out of the pack material
and covered by a fluid-tight strip is also known.
The covering strip is taken hold of and pulled upwards
by means of a free gripping portion not fixed to the
side wall, and the tear-open a~perture, located on
the inside of the triangular flap, is then exposed
in the form of a round or elongated hole. A disadvantage
of this known pack is that the filling material is
:1 1'7~10
- 2 -
not poured out in the desired jet, which would avoid spilllng.
In another type of pack an attempt has been made to provlde
a rectangular slot, covered with a sealing strip, as the pouring
aperture, this being located at one side of the end wall ad~acent
the transverse seam. However, the sealing on of a cover strip
quite commonly creates problems (a) of sealing and (b) of ease in
tearing off. Similar problems arise when the pouring aperture,
which has first been punched out and then sealed with a cover
strip, is located in the upper wall of the triangular flap.
Various different opening devices have therefore been developed,
in the field of parallelepipedal packs alone, where the trans-
verse seam sealing the end wall is itself ripped open over a
certain width, or where tearing aids are used, such as threads
which are welded in.
Particularly since petroleum has become expensive, it has
been imperative for the manufacturers of packs for fluid
materials that they should use as little plastics as possible,
particularly for coating the supporting material, and that the
machine for manufacturing the pack should be of the simplest
possible construction, if possible without using a cover strip
which has to be sealed on from inside and possibly even
separately from outside. Time and time again compromises have
had to be made between the reliability of the seal on the one
hand and ease in opening on the other.
In a liquid pack known from DE-OS 2 210 013 the side walls
are similarly made of carton coated with thermo-plastic plastics,
but the cover and base are made of thermo-plastic plastics
without any carrying material. In the "ready to fill" state the
pack is constructed with the cover moulded onto the side walls
along its far edges, but with the base moulded on only along one
edge for the purpose of filling the pack. A pack of this type is
cheap to produce, of a practical construction and reliable in
use. Like the most widely used and best known parallelepipedal
liquid pack, this known pack has an exact shape with good
stability and the possibility of shrinkage when bundled together.
The pack known from this publication so as to
speak standson its head for filling; for the cover,
which is integral with the opening devlce, i9 initially
at the bottom, while the base, which is moulded on
only along one side edge, is located at the top
adjacent the open tube of the pack ready for filling. The
manufacture of such an opening device does not require any
complex injection moulds for moulding on the thermo-
plastic end walls, as the tools can easi-ly be pushed or
pulled out of the tube.
After the filling process the known pack is sealed
at what will subsequently be its base. Here difficulties
may sometimes arise in centering and welding with exact
imperviousness, or at least the outlay on machinery for
welding the end wall forming the base is not insignificant,
although the main centering operation has already been
carried out in folding the base onto a side wall.
The invention described and claimed in our
copending application Serial No. 389,158, identified
above, provides a pack of the above type. It must
be possible to manufacture a stable pack which has
good impervious properties, with optimum economy in
material, and the pack must be easily opened and reclosed
by the final consumer without any special instructions.
The invention also provides a method of making such
a pack or carton and an apparatus for carrying out the
method.
As means of achieving this aim, the new pack
according to the invention is characterised in that the
end wall made only of thermo-plastic material forms the
cover, and the end wall forming the base is square and
has a transverse sealing seam with triangular flaps
which are folded over onto an adjacent wall.
iO
- 3a -
Here a fluid pack, with an unaccustomed combination of
completely different closures at the end walls, is
provided for the first time. In contrast with the known
pack last described, only the end wall forming the cover
is to be made of pure thermo-plastic plastics; the
base on the other hand, as in conventional packs, is
to be sealed by a transverse seam and shaped in known
manner, by folding over the triangular flaps, into one
of the usual end ...................................
8410
wall configurations, the opening of which always created difflcul-
ties in the past.
This combination of the two completely different systems for
making end walls is in no way obvious, since there are no
production machines which promise any solution to the problem
posed above if such a principle were applied.
With the new principle according to the invention, of making
one end wall as a pure plastic cover and the base in the
conventional square form, fluid packs can be made in cube,
parallelepipedal or other shapes. For example, it is desirable
according to the invention for the cover and the cross-section of
the pack at least in the region of the cover to be round, and for
the shape of the cover during and immediately after the moulding
process to be the utilisation shape. This last feature means
that the cover, made exclusively of thermo-plastic plastics, is
moulded in the shape in which it will be utilised. Thus it will
be in the utilisation form, i.e. the form in which the final
consumer opens the pack, pours out the filling material and
possibly recloses the pack, obviously during the moulding
operation and also up to the next stage in the process, which may
e.g. involve deformation of the cover. The advantage of this
measure is that thermo-plastic plastics generally tend to return
to the shape in which they were moulded, after undergoing any
deformation. In contrast with this, in the known packs the end
walls, which may form the cover with an opening device, are
moulded as an entity so that the transporting shape is
immediately obtained. After being filled and sealed the pack can
then be put into a bundle at once and transported away. However
it has been found, particularly with packs in the household, that
a cover thus moulded is difficult to open. It is far easier and
more pleasant e.g. for the housewife to bring an opening device
from a deformed shape into the shape in which it was moulded by
pushing or pulling. In the present case the cover moulded onto
the side walls has its opening device pushed in, so that the
outside contour is not troubled by projecting parts of the
:'
410
- 5 -
opening device, immediately before and then after filling and
during transportation. Before using the opening device in the
cover, the final consumer therefore has to pull it out, and thls
very process is greatly facilitated slnce the thermo-plastic
material in any case tends to return to the shape in which lt
was moulded.
The round cover and the round construction of the cross-
section of the pack in the region of the cover enables
particularly simple tools to be used, and yet the pack neverthe-
less still has the advantages of stability, good space utilisation,the ability to fit together in bundles and imperviousness.
According to the invention it is further advantageous for the
pouring device to have an upwardly and outwardly projecting
annular collar, the upper edge of which is joined to a stopper with
a gripping ring welded onto it and is located within the outer
contour of the pack for transportation. Even in the form in which
it is moulded, the gripping ring projects somewhat from the
stopper, so that the user can easily take hold of it, use it to
pull the pouring device up into the utilisation shape, and open the
aperture by pulling off the stopper along the top edge of the
collar. Before such opening the gripping ring preferably projects,
turned laterally through 180 from the stopper.
With a special pack shape it may be desirable for an arched
portion extending away from the collar to be provided in the
stopper at the place where the gripping ring is joined to it, and
for its hinge to be moulded onto the diametrically opposed side of
the stopper. When the gripping ring is pulled up and the
utilisation shape reached, the arched portion enables a first
small air inlet to form, thus also facilitating opening, i.e. the
pulling of the stopper from along the upper edge of the collar.
On one side of the top edge of the collar there is thus the
weakened portion to be severed and to form the air inlet, while
on the diametrically opposed side a thickened portion is
provided; this prevents the stopper from being pulled right off
even if it is raised carelessly, so the stopper remains on the
~ ~1
8410
- 6 -
thickened portion and is connected as around a hinge.
In the method of making the pack, the coated supportlng
material is first pre-corrugated, ~ed from a coll ln web form to
bending and folding stations, and pulled agalnst an outer ring
under tension to form a tube. Only then is the tube closed by
longitudinal sealing. There are already some development
proposals for making a tube which will later be closed by
longitudinal sealing, by taking a web of material which has been
impressed and cut to a suitable size, and guiding the material
through an outer ring, so as to form the tube, at a tension such
that the web of material is applied to the ring and thus takes
on a circular cross-section. If these development proposals are
used to solve the problem of the invention, then the tube is
desirably drawn onto a jig mandrel. Longitudinal sealing takes
place, according to the invention, between the mandrel and outer
jaws. One length of tube each time is pulled off the mandrel in
time with the machine, transferred to a lower moulding tool
component and moved laterally out of the advancing direction,
into position relative to an upper tool component. The cover is
moulded, thereby joining it to the end of the length of tubing,
and cooled. The length of tubing, sealed at one end, is then
pulled off the lower moulding tool. When the cover has finally
been pressed into the transporting shape the pack, after being
filled, is sealed at the base by block base welding.
Whereas in the prior arrangements the web for forming the
tube is pulled against an outer ring from inside and thereby
given a circular shape in cross-section, the invention additionally
provides - through the above features - for the tube thus being
formed to be pulled onto a jig mandrel. Owing to the special
nature of the new pack, with the two different types of closure
at the end walls of the length of tube (corresponding to a pack),
filling takes place later, so that the space in the tube is
available for the jig mandrel. The formation of the longitudinal
sealing seam takes place interm~ttently between the mandrel and
one or more outer jaws, so that the tube requiring a longitudinal
seal is arranged between the mandrel and the jaws. For further
'`:,i
1178
-- 7 --
processing, including dividing the tube in the web into
individual lengths, the tube is pulled off the mandrel and trans-
ferred to a different mandrel, which is also constructed as a
lower component of the moulding tool. To increase processing
speed, the length of tube separated from the web is moved out of
the advancing direction and into the moulding machine, where the
end wall forming the cover is moulded onto the still open edge of
the length of tube. This moulding method is well known in the
artl and a good bond between the thermo-plastic material of the
cover and the plastic coated side walls, and hence a satisfactory
seal, are thus obtained. The newly moulded cover, arranged in
its utilisation shape, is now cooled, after which the length of
tube is pulled off the lower moulding tool. This preferably
happens over a conveyor, in a position such that when the length
of tube has been pulled down off the lower mould component and
when the now cooled cover has been placed on the conveyor, the
cover is immediately pressed in into its transporting shape. In
other words, once the cover has been pressed in, the opening
means, which are moulded and shaped integrally with the cover, no
longer project beyond the overall outside contour of the pack.
At the same time the new pack, sealed at the cover and with the
cover standing on the conveyor, i.e. so as to speak upside down,
stands with its base open to be conveyed further for filling and
subsequent sealing. Sealing is effected by welding along the
transverse seam in known manner, in the same way as a block base
is welded, to form the end wall which shapes the base.
The advantage of the method of the invention as compared
with the manufacture of the known pack with the two end walls
made only of thermo-plastic material, is that sealing after
filling is simpler. Whereas in the known case the welding of the
th~ee free edges of the end wall forming the base is difficult,
partly because the machine components have to engage the pack
exactly and the individual tools need to be made and to move very
accurately, and whereas the space inside the pack, above the
filling level, is very confined to provide correct engagement for
the machine components and welding jaws, and nevertheless too
much air space needs to be left in this part of the pack
~L178~10
8 --
adjacent the filling material, the measures according to the
invention provide far better conditions and more space. Although
the liquid level or the upper level of the pouring material
inserted can be taken to a desired upper edge, the level of fluid
material is far enough away from the weld to ensure that no
filling material will come between the tools or between the
surfaces to be welded during cross sealing. In accordance with
the block base forming operation, the sides are folded together
at the edge of the tube in question without making any contact
with the filling material, so that after the folding process the
welded seam can be applied without any problems. When the
transverse seam has been cooled, the triangular flaps are then
folded over in known manner and welded to an adjacent wall,
preferably the actual end wall which forms the base. For the
purpose of forming the block base and then welding it, the
cross-section of the pack in the region of the end wall which
will later form the base must clearly be rectangular.
On the other hand it is very advantageous, as mentioned
above in connection with the description of the pack itself, for
the end wall which will later form the cover and the adjacent
cross-section of the tube to be given a round shape. If the
greater part of the tube cross-section is round, as seen e.g. in
the direction of the longitudinal seam or in the direction of
the tube, a maximum filling volume can be obtained relative to
the packing material used. Optimum stability is also obtained,
so that the thickness of the supporting material and/or that of
the plastic coating on the web of material can be reduced even
as compared with the known parallelepipedal packs, without
stability suffering.
Further according to the invention, the axis of the tube is
advantageously provided in the conveying direction. It is of
course quite conceivable and even common practice for the axis
of the tube to be arranged transversely to the conveying
direction. However, the manufacture of the pack by the new
process of the invention allows a higher manufacturing speed to
be obtained, with less relative movements between the lengths of
' ';
li784~0
g
tubing from one working station to the next, if the axis of the
tube is in the conveying direction. Experiments with the
apparatus of the invention have shown special advantages can be
obtained if the coiled web of paper is pre-impressed and of a
width such that two or even three pack blanks could be made from
it side by side, if only two or three pieces of apparatus could
be arranged adjacent one another to carry out the method. This
is quite possible and even desirable, although one should work
from one reel of paper or coil of web, since the web is pulled
through roller-shaped severing knives, so that each of the two
or three adjacent production means is charged with a web of the
appropriate width for the pack blank. In this way a machine
comprising two of the apparatuses described below, adjacent one
another, can have an output of e.g. 3,600 packs per hour.
According to the invention, the apparatus for carrying out
the method described above is characterised in that a jig mandrel
is provided coaxially and in alignment with an outer moulding
ring, a movable longitudinal sealing jaw being provided adjacent
the mandrel; that a transporting jaw, oscillating in the
conveying direction in time with the machine, is provided
downstream of the sealing jaw, and a cutter is arranged downstream
of the mandrel, with a rotatable mandrel wheel, with at least
three radially projecting mandrel-shaped lower moulding tool
components arranged beside the cutter; that a moulding means
with an upper moulding tool component is mounted at an angular
spacing from the axis of the jig mandrel, and that a conveyor
with open-topped shape carriers at a distance a from one another,
and also a filling station and a sealing station are provided
under the wheel. The apparatus built up in this way can be set
up in a relatively confined space; for all the impressing,
cutting and longitudinal sealing stations may be arranged in
front of or behind direction changing rollers, so that the jig
mandrel can be located adjacent the mandrel wheel in the desired
position, e.g. at an inclination of 45 to the horizontal, yet
can be charged without difficulty in the desired conveying
direction. In a desirab~e embodiment of the invention one or two
pairs of rollers in the form of circular knives are provided
410
-- 10 --
between the coil of web and the jig mandrel, to divide theweb
into two or three part-webs, so that during the continuous or
thrust-wise operation the web withdrawn from the co~l will
continuously be severed to the correct width. Further folding
stations could possibly be arranged downstream of the knives,
e.g. to impress edges of the pack.
There has so far been no mention of protecting the inside of
the longitudinal seam. The station dealing with this may be
located upstream of a direction changing roller which may be the
last one before the jig mandrel. At this station a sealing
strip is placed on what will later be the inside of the coated
web of paper, in the region of the subsequent longitudinal seal,
to prevent a surface which is uncoated because of the cut at
the side edge of the web from coming to rest opposite the filling
material, particularly the liquid. If this were not done the
liquid could penetrate into the cut edge, unprotected by
plastics, and soften up the pack there. Cover strips or sealing
strips for the cut edge have therefore been provided here, so
that the cut edge can also be covered with plastics and the
above difficulties avoided. After this station the coated web
of paper thus treated can desirably be guided through a direction
changing roller, so that the fully prepared web can be taken to
the jig mandrel described and alsot coaxially and in alignment,
to the outer shaping ring.
In a preferred embodiment of the pack making machine, the
individual operations take place in stages, and consequently the
web of paper and thus the tube are conveyed in stages or
intermittently; for this reason one or two longitudinal sealing
jaws are arranged movably. The longitudinal seam is sealed by
this jaw or these jaws, engaging from outside onto the jig
mandrel or shaping mandrel.
The sealing of the cut edge, so-called LS protection, can
be effected not only by applying an appropriate cover strip as
1~1'78410
-
described above it may alternatively take place later on the
mandrel wheel, when the end wall which will later form the cover
is moulded on. To enable the longitudlnal seam to be correctly
welded and the further operations to be correctly positioned, an
annular stop is provided on a mandrel-shaped lower mouldlng tool
component, and when the seam has been finished the length of
tube is pushed against this stop which is slid down off the
mandrel and transferred to the lower tool. It is brought thus
into abutment by means of transporting jaws arranged downstream
of the sealing jaw; one or more transporting jaws may be
provided here, oscillating in time with the machine.
In accordance with the invention it is desirable or the
conveyor to have two transporting jaws, arranged diametrically
opposite outside the hollow jig mandrel, and midway between the
jaws an inner member adapted to move in a longitudinal slot of
the jig mandrel. In this way no disadvantageous friction mark
forms on the outer wall of the pack, preferably the side wall,
~; caused by traces of friction between transporting jaws and the
side wall; this is because it is not such friction, but rather
a clamping action, that is responsible for moving the tube
forwards.
Behind the jig mandrel - in the direction in which the tube
is conveyed - there is a cutter which, in a special embodiment
of the invention, preferably has a rotating ring carrying cam-
controlled blades which are distributed around the periphery.
Thus the procedure followed by the pack making machine is for
the longitudinal seam to be made first on the jig mandrel, and
for the tube then to be moved on one length onto the mandrel
wheel, so that the seam can cool and harden. In the course of
this movement the foremost length but one is transferred from
the jig mandrel to the lower tool component, over a gap where
the cutter described is located. This is of course the last
place where the tube can be separated or divided into individual
lengths, since if it were not the mandrel-shaped lower tool
component would not be able to move away by turning laterally
~ out of the conveyor on the mandrel wheel.
,-~
' ;
1178410
- 12 -
The rotatable mandrel wheel arranged adjacent the cutter has
at least three and preferably eight radially projecting, mandrel
shaped lower moulding tool components, arranged at an appropriate
angular spacing from one another. The mandrel wheel turns in
cadence, and the whole apparatus operates in cadence. When the
mandrel wheel is turned through a specific angle, the length of
tube described, which has been separated by the cutter, is moved
below the moulding machine and in particular below the upper
component of the moulding tool, so that the upper and lower
components of the moulding machine are in exact alignment. In
this state the end wall which will later form the cover can be
moulded. These moulding operations are technically well under-
stood, and particularly with the web of supporting material,
i.e. the upper edge of the length of tube, being coated even if
only thinly, the plastics material applied by the moulding
machine forms an excellent bond, thus guaranteeing absolute
impervious~ess between the side wall and the cover of the
subsequent pack.
The mandrel wheel and thus the length of tube in question
move on intermittently, until the conveyor arranged preferably
horizontally under the mandrel wheel is reached. This may be
one of the known chain conveyors which offers sufficient
rigidity and resistance to enable the stop described above, i.e.
the ring movable relative to the mandrel-shaped lower tool
components, to strip off the length of tube in question with
the cover (which has hardened in the meantime) and to set it
down firmly enough for all the parts projecting at the end of
the tube, beyond the end line perpendicular to the axis of the
tube, and in particular the opening device in the cover, to be
pressed in to the transport shape. After the stripping operation
the stripping ring, which was also a stop, moves over the
mandrel-shaped lower tool component during the next intermittent
turn towards the centre of the mandrel wheel, so that when the
above-mentioned angular position is reached it can again act as a
stop to arrest the next length of tube. In the meantime the
pack, which is initially still upside down with the cover on the
; conveyor and the base uppermost and open, is brought by the
11~ 10
- 13 -
conveyor e.g. the so-called station chains, under a piston charger
or the like in which the pack is filled with the material. For
stabilisation and also shaping and to provide the requisite for
the later shaping of the block base, shape carriers are provlded
on the conveyor. ~hese are preferably open at the top and, in a
further preferred embodiment, comprise at least two parts which
are movable relative to one another. In accordance with the
invention, when these parts are retracted they give a round
cross-section at least in the region of one, lower end and a
square cross-section at the other, upper end. This provides the
prerequisite for shaping the block base and then welding it.
The shape carriers are desirably arranged on the conveyor at a
spacing from one another, so that they move with the conveyor and
always stand in alignment below the mandrel-shaped lower tool
components to receive the length of tube sealed at one end.
Furthermore these shape carriers, together with the then open-
topped packs, stand in alignment below the filling station and,
an appropriate time later, under the various stations for sealing
the end wall which later forms the base, for preparing the
triangular flaps for application, and for heating the triangular
flaps and also under the plunger for pressing down the corners.
A desirable embodiment of the apparatus operates at a two
second cadence and has eight mandrel-shaped lower tool components
; distributed evenly around the periphery of the mandrel wheel. In
this special preferred apparatus the axis of the jig mandrel is
inclined 45 to the horizontal, the longitudinal axis of the
moulding tool has an angular spacing of 45 from the jig mandrel,
so that the upper and lower tool components are arranged sub-
stantially vertically below the moulding machine, and the newly
moulded cover, after leaving the moulding machine, takes three
operating cadences, i.e. three times two seconds, to progress
from its next position, turned out of the moulding machine
through 45, to the stripping position and for the length of tube
to be transferred to the open-topped shape carrier; that is to
say, it takes six seconds altogether for the cover to cool.
Since some of the components of the above apparatus are
`' known per se, it is possible to produce the apparatus for
, . .
`
.
1178410
- 19 -
carrying out the method of the invention, using the know-how of
the branch in question, without an excessively large outlay.
Such an apparatus can therefore be constructed relatlvely qulckly
even with known plant, after appropriate converslon. Various
units together form the apparatus, so that by exchanging one unit
for an appropriate different one the whole apparatus becomes
highly adaptable, e.g. to different shapes of desired packs,
round, square, rectangular cross-sections and the like. The
apparatus works satisfactorily with fairly thin paper, to produce
a pack of the same stiffness. The web of paper, i.e. the
supporting material, need only be given a fairly thin coat of
plastics, and the longitudinal welding and formation of the
transverse seam are nevertheless guaranteed to be satisfactory;
for block base welding is a dry type of weld. The tendency to
have simple processing and a small number of components in the
apparatus is encouraged if the web of material to be processed is
pre-impressed during its manufacture. The coating of the web of
supporting material with a fairly thin layer of plastics has the
advantage of enabling the speed of the extruder to be increased.
One can benefit from years of experience in making the material.
Other advantages, features and applications of the invention
will emerge from the following description of a preferred
embodiment. This refers to the accompanying drawings, in which:
Fig. l is a perspective view of the closed pack, ready
for use, in a preferred embodiment of the invention,
Fig. 2 is a perspective view of the same pack but bottom
up, with the cover, which is here underneath and not visible,
pressed in so that no parts of the opening device project from
the lower edge of the cover beyond the overall contour of the
pack,
Fig. 3 is a perspective view of the base when the block
base has been folded and before the transverse sealing seam has
been made,
Fig. 4 shows the top end of the pack with lines for
forming the block base impressed in it, where the base will
. subsequently be formed by folding,
11~78~10
Fig. 5 is a diagrammatic cross-sectional view of the
cover in the state in which it is transported, with no parts of
the opening device projecting beyond the overall contour of the
pack,
Fig. 6 is a sectional view through the ready-moulded
cover, without the side walls,
Fig. 7 is a section through the upper and lower tool
component of the moulding machine (not shown) with the pack
broken away, and
Fig. 8 is a diagrammatic view of the overall construction
of the apparatus for making the pack according to the invention.
The pack will first be described with reference to figures
1 to 6, then the apparatus for making the pack with reference to
figures 7 and 8, and finally a possible mode of operation for
the apparatus.
The finished pack for fluid filling materials shown in
figures 1 and 2 comprises side walls which are together defined
as 1. This is because in this embodiment a round cross-section
is provided in the region of the cover 2 (since the cover 2 is
circular in plan), so that one could possibly distinguish
between four side walls at the end forming the base 3. For the
sake of simplicity the side walls will be referred to as 1 in
this description. As shown in figures 1 to 4 they are shaped
into a tube and joined along the longitudinal sealing seam 4,
thereby definitively forming the closed tube. It will be seen
from figure 2 that the seam 4 extends into the base 3. This
results from the blank used, as will also be seen from figure 4.
In the figure 2 form thetube has a height H which (taking into
account the shaping shown in figure 4 before the base 3 is
finished) is clearly smaller than the length A of the section
from the exposed upper edge 5 of the tube to the upper edge 6
of the cover 2.
The top edge of the finished pack is the line 7 shown in
figures 2 to 4. The various unspecified folding and impression
117~3410
- 16 -
lines shown in figure 4 form the double strip 8 of carton
~figure 3) in the shaping of the block base; this strip contains
the transverse seam 9 which is contained in figure 2 and hardly
visible. The triangular flaps 10 are ormed ln the sam~ process.
The formation of the base 3 progresses from the figure 4 state,
through the figure 3 state to that shown in figure 2. The
corners, which will later be the tips of the flaps lO, are first
moved outwardly in the direction shown by the arrows ll (figure
4), and pulled until the state shown in figure 3 is reached. The
double carton strip 8 is pressed together, the seam 9 formed, and
the triangular flaps lO folded over onto the base and held there
e.g. by spot heating, so that the state shown in figure 2 is
reached.
This sealing of the base 3 takes place when the pack has
been filled, as will be described below. In other words, the
cover 2 has already had a fluid-tight seal formed in it at the end
of the pack which is at the bottom in figures 2 to 4. In contrast
with the square base 3, the preferably - but not necessarily -
round cover 2 in the new pack is made only of thermo-plastic
material and constructed without any supporting material. The
cover can therefore be moulded on along the outer edge 12 of the
tube or side walls l (figure 5), in the form in which it will be
used, as shown in figure 1. Figure 5 on the other hand shows its
shape during transport; the pouring device shown generally at 13
is pushed inwards, inside the outer contour of the pack, so that
none of its component parts project beyond the outer edge 6. This
gives perfect stability and satisfactory repacking (using sheets
of shrink film or the like).
The pouring device 13 is seated in the middle of the cover 2.
It is in the form of an upright annular collar 14 extending
outwardly, i.e. upwardly in figure 1. Its upper edge 15 is
joined to a stopper 16 with a gripping ring 18 welded onto it.
The exact shape when the cover 2 has been moulded can be
seen clearly from figure 6. The top edge 6 of the cover 2 is
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virtually only a rlng, with a wedge-shaped support 18 moulded
onto the outside of it, so that the top of the tube or side wall
1 comes to rest below the edge 12 (figure 5) around the support
18. This provides a particularly strong and rigid connection
between the cover 2 and the side wall 1. Between the outer edge
of the cover and the collar 14 is a frusto-conlcal surf~ce 20.
This extends outwardly in the state shown in figures 1 and 6,
i.e. in the form in which it is used, and inwardly at approxi-
mately the same angle in the form in which it is transparted. At
the top edge 15 of the collar 14 a line of weakness 22 is
provided, in a circular shape apart from the point 21 shown at
the right hand side of figure 6. This line forms a weak point
extending round the stopper 16 through almost 360, so that the
stopper can easily be pulled out to open the pack. Beside the
point 22 on the line of weakness (at the left hand side of
figure 6) is the point 23 (figure 1) where the gripping ring 17
is connected, and adjacent the point 23 there is an arched
portion 24. This projects from the ccllar 14, inwardly towards
the centre, so that the wall of the arched portion 24 extends
inwardly (figure 6) and is separated from the environment only
by the line of weakness 22. When the user tears open the line of
weakness 22 by pulling on the gripping ring 17 (upwards in
figure 6), the line 22 breaks first in the region of the arched
portion 24, so that air can advantageously enter the base below
the cover 2.
The hinge 25 for the stopper 16 is provided diametrically
opposite the arched portion 24, at the right hand side of the
stopper 16 in figure 16, near the point 21. As indicated in
figure 6 therefore, the stopper can be moved clockwise about the
hinge 25, i.e. turned in the opening direction, without the
stopper 16 being simultaneously torn off. This enables the
container to be advantageously reclosed, since the stopper 16
has an edge 26 extending substantially parallel with the collar
14, and this edge is closed only by the flat base 27.
The apparatus for making the pack includes a moulding
machine 30, which is shown as a detail in figure 8 and the
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upper component 31 and lower component 32 of which are shown
on a larger scale and in section in figure 7. Familiarity wlth
the cover shown in figure 6 makes the figure 7 embodiment easier
to understand. The exact contour of the two lnwardly facing
surfaces of the upper and lower components 31, 32 is ob~alned by
machining to match the shape of the cover 2, so it will be
sufficient here to mention only a few parts: for example, the
hopper 33 for injecting plastics into the cavity, the support 34
for the moulding plunger 35, and the forming and sealing members
36 to prevent the plastics material, preferably polyethylene,
from being squeezed laterally outwards past the mandrel-shaped
lower component 32 of the moulding tool. It will be clear from
igure 7 that a lower moulding tool component 32 of one length
may be replaced by one of a different length, without the cover
2 having to be differently shaped and the rest of the machine
fitted with different parts.
The whole apparatus for making the pack described above can
best be explained with reference to figure 8. At the left hand
side of a frame 40 there is a coil 41 of carrier material 42 in
web form, thinly coated on both sides with plastics, preferably
polyethylene, and here rotatably mounted on bearings 43. An
endless conveyor 44 is shown diagrammatically on the right hand
upper half; this is provided with drives in known manner and may
be a station chain conveyor. The upper and lower sides of the
conveyor 44 are horizontal and some distance to the right of the
coil of paper 41. Some distance above the frame 40 there is a
support 45, on which cutters in the form of round knives 46,
for separating the webs of carrier material 42, are rotatably
mounted at the left hand side. 47 is a preliminary bending
station for making the edges of the pack; behind this there is
a first direction-changing roller 48, over which a second
direction-changing roller 49 is located. Between the rollers
there is a diagrammatically illustrated sealing jaw 50 with an
unspecified backing member. A strip 52 of plastics withdrawn
from a reel 51 is sealed up longitudinally over the cutting edge
for LS protection by the jaw 50, so that no direct contact edge
between paper and fluid is possible there when fluids are being
packed.
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The tube formlng station 53, which will be described in
greater detail below, is arranged between the last-mentioned LS
sealing station 50-52 and the moulding machine 30 which is flxed
to the support 45 at the right hand slde. The essential component
is the jig mandrel 54, which is covered by the tube lllustrated
and which is marked "54" at the place where it is arranged under
the tube. The axis of the mandrel 54 is at 45 to the horizontal.
In a continuation of the mandrel 54 downwards and to the right
there is a mandrel wheel, shown generally at 55, with eight
mandrel-shaped lower moulding tool components 32. To the right of
the wheel 55 a piston charger 56 is provided on the support 45,
and further to the right the block base welding station, referred
to generally as 57, is shown diagrammatically.
Finally, a shape carrier 58 is indicated only at two
positions on the upper side of the conveyor 44. It is arranged on
the conveyor 44 at a spacing a from the adjacent shape carrier,
and is moved forwards therewith below the block base welding and
sealing station 57 in the direction of the arrow 59.
The tube shaping station 53 comprises a support 60, also at
45 to the horizontal, with the forming or jig mandrel 54 fixed to
it by way of the mandrel curving portion 61. Below and to the
right of the direction changing roller 49, the coated web of paper
42 is laid around the curving portion 61 in the form of a shell
open at the bottom. The bottom right hand end of the shell is in
contact with and under tension inside the outer ring 62, which is
also coaxial with the mandrel 54. The transporting direction
should here be thought of as running from the direction changing
roller 49, downwards to the right at 45, towards the mandrel
wheel 55. Behind the outer ring 62 in the transporting direction
a longitudinal sealing jaw 63 is provided, and a transporting jaw
64 some distance further in the same direction. The transporting
jaw oscillates in time with the whole apparatus, in the direction
of the double arrow 65. The mandrel 54 extends a further length
A in the conveying direction, i.e. as far as the cutter 66. This
is here indicated diagrammatically by two knives, butmay in fact
be a circular knife with a backing knife arranged inside it to
exert a shearing action.
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Functionally speaking the mandrel wheel 55 comes after the
tube shaping station 53. It can move around the central spindle
in the direction of the arrow, i.e. clockwise, and in time with
the machine, i.e. intermittently, wlth each cycle advancing a
mandrel-shaped tool component 32 45 clocXwise. Each lower
component 32 carries an annular abutment 70, which is driven so
that it can make an oscillating movement to exert a wiplng action,
axially of the mandrel-shaped component 32. The abutment or wiper
ring 70 is in its lowermost position when in the bottom position
III.
Vertically above position III, i.e. in position II, the
appropriate lower tool 32 is vertically below the moulding machine
30 as in the figure 7 arrangement. The upper tool 31 can move
vertically up and down (so that it can be lifted off the lower
tool 32 and release the cover 2 just moulded) r with a stroke
larger than the oscillation stroke of the injection cylinder 80
with the dosing plunger 81 and granulate container 82. A detailed
description of the moulding machine 30 appears to be just as
unnecessary here as one of the sealing station 57 with the means
90 for sealing the base, means 91 for preparing the triangular
flaps lO for application to the base 3, means 92 for heating the
triangular flaps lO and means 93 with the stamps for pressing down
the flaps lO. The pack shown on top of the conveyor 44 is so to
speak standing on its head; the cover 2 can be seen at the bottom,
while the end wall which will later form the base 3 is at the top.
For this reason, when the filled and sealed pack is taken away in
the direction of the arrow 59, it is turned the right way up.
The machine operates as follows: The web of paper 42 is
divided, e.g. by the roller blades 46, into three separate,
adjacent webs, each of which is fed to the same apparatus as shown
altogether in figure 8. However, it will be sufficient to des-
cribe the functioning of one machine in order to explain the
operation and method of the invention. The web of paper 42 is
pre-bent by the means 47, into the as yet not pre-impressed edges,
after which it is diverted by the roller 48 and guided into the
edge protecting station 50. Here the plastics strip 52 withdrawn
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from the reel 51 is sealed over the non-plastic coated cutting
edge of the web 42 by the sealing jaw 50. The web of paper thus
prepared is directed downwards to the right by the direction
changing roller 49, so that the transporting direction ls from
the upper outer periphery of the roller 49, through the axis of
the mandrel 54 towards the centre of the mandrel wheel 55. As a
result of the tension generated by the transporting jaws 64, the
web of paper 42 is first wrapped round the mandrel extension 41
in a semi-circle, like a shell open at the bottom, and then
fully surrounds the jig mandrel 54 while lying against the
inside of the outer ring 62. This surrounding action produces
the tube shape and is such that the two free edges of the tube
overlap some distance, so that the longitudinal seam 4 can be
made at the overlap by means of the sealing jaws 63. The tube
section of length A is stationary during the sealing process.
When the sealing jaws 63 have opened, the transporting jaws 64
draw the next length of tube but one one length A towards the
mandrel wheel 25, thereby bringing the length of tube in
question, where the seam has just been made, to the right hand
bottom end of the mandrel 54. Here it is severed by the cutter
66 from the part which has just been pushed over the lower tool
32 as far as the stop 70 by the above-mentioned action of the
transporting jaws 64.
During the next step the length of tube in question is
pushed past by the cutter 66 into position I on the mandrel-
shaped lower tool 32. The lower tool 32 is approximately 0.5 mm
smaller in diameter than the mandrel 54.
The mandrel wheel 55 now turns one step further, i.e. 45
clockwise, so that the length of tube in question reaches station
II under the moulding machine 30. The upper tool 31 moves into
the position shown in figure 7, engaging round the top edge of
the tube or side wall 1. In this way the cover 2 is moulded
directly onto the top edge 12 of the side walls 1. The upper
tool 31 and the additional injection mandrel 35 then move away
from the cover 2, and the mandrel wheel 55 can move through 180
to position III, the cover with the new moulding being cooled
simultaneously.
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The mandrel wheel 55 is so adjusted and synchronised with
the other stations 53, 30 and the shape carrier 58 that exactly
registering positions are obtained at the various stations,
particularly stations I, II and III between the axes of opposed
parts. In station III the annular stop 70 acts as a strlpper and
pushes the length of tube in question, which is sealed at one end
by the cover 2, downwards towards the conveyor 44, into the shape
carrier 58. In the figure 1 embodiment, i.e. with a round cover
and square base, the carrier 58 is initially open to let through
the cover 2 which projects further and has a'larger area; it then
closes over the smaller square surface. In pushing the cover
down, the ring 70 pushes it onto the top of the conveyor 44, with
the aid of the stiff side wall 1, in such a way that the cover 2
moves into the transporting shape shown in figure 5. This inward
movement creates no difficulties since the pack is still empty.
The station chain conveyor 44 conveys the pack, still open
at the top and ready for filling, and a shape carrier 58 takes up
a position a distance a from the next. The pack passes under the
filling station 56, in the form of a piston chargerr and is filled
to the top edge 7. In means 90 the base is closed from the state
shown in figure 4 to that in figure 3. In the means shown
diagrammatically at 91, after transverse sealing, the triangular
flaps 10 are prepared for application; at station 92 they are
heated, while means 93 attach them to the base 3 with a pressure
plunger, to give the shape shown in figure 2.
The triangular flaps mentioned may be folded over onto the
base itself or onto a side wall, depending on the construction
of the block base closure.
On the opposite side is the cover made only of thermo-plastic
material; its collar may be circular, oval, polygonal or the like
and stands upright facing outwards. With the frusto-conical shape
of the cover shown in the figures it is desirable for the collar
to be arranged in the centre. With differently shaped covers,
however, the collar may perfectly well be arranged laterally or
- nearer to the edge, so that the pouring edge is nearer the edge of
the cover when the fluid is pollred out.
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When the cover has been pushed in from the manufacturing and
moulding shape to give the transporting shape, all parts of the
opening device, including the gripping ring welded onto it, are
preferably within the outer contour of the pack, slnce this glves
an optimum shape for transport. The embodiment illustrated shows
a gripping ring moulded onto the stopper and raised obllquely at
30. However, in a particularly desirable embodiment (not shown)
the gripping ring is moulded on, turned through 180. In other
words, the main plane in the gripping ring is parallel with the
upper edge of the pack or parallel with the plane extending
through the edge of the cover. The ring is nevertheless still in
its transporting shape within the outer contour of the pack. The
arrangement of the ring in the position turned through 180 out
of the stopper is desirable because the moulds for making the
cover can then be simpler.
It will be seen from the above that the choice of the shape
of cover can be varied somewhat according to the moulding tool
used. For example, the pouring aperture might be moulded onto a
concertina-like or bellows-like device. The main point is the
"below deck shape" for transporting the pack and the "above deck
shape" for pouring. The invention enables many required
opening arrangements to be obtained, particularly for covers
made only of thermo-plastic material. It also enables the
possibilities of cold bending to be exploited to give the cover
a different shape, e.g. the optimum shape for transport and the
optimum form for the pouring process. Here the term "cold
bending" refers to pressing the cover into the transporting
shape or pulling it out into the utilisation shape.
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