Note: Descriptions are shown in the official language in which they were submitted.
2 1 9381 8 -;
CONTAINER OF THERMOFORMABLE MATERIAL WITH A CLOSURE
The invention concems a container, a method and apparatus for
producing the container, and a method of cleanlng the container.
It is known to blow-mould disposable containers from plastics parisons.
GB-A-1059930 ~IjY~IQSeS a container of large dimensions made from
particular polyamide and formed in each major side wall with a
moulded reinforcement of a rib formatiion internally .with a
corresponding furrow formation externally. US-A4046275 dislcoses a
plastics milk bottle whereof each major side wall is stiffened against
bulging under the weight of the contents by a wide, intemally
projecting, substanlially horizontal band which extends around the
corners. This band is preferably of continuously varying depth along
the side wall, projecting inwardly to its gratest extent midway between
the corners and tapering toward the corners. Each band has a cross-
section in a vertical plane which may be described as trapezoidal. DE-
A-2714917 and US-A-3398427 both disclose blow-moulding from
parisons of containers in which cap-form closures therefor are moulded
integrally with the container and are attached thereto by integrally
moulded, flexible ties. In DE-A-2714917 the closure is severed from a
neck of the container to open the container and is reclosed by placing
the cap-form closure over the neck. In US-A-3398427, the cap-form
closure is compression moulded by bringing an undercut male die
member fixed to one mould half to project into a female die member
fixed to the other mould half as the two halves approach and reach
their closed condition. A stripping sleeve encircles the male die
member and is arranged for axial motion along that member under the
action of a pneumaffc piston-and-cylinder device when moulding is
completed and the mould-halves opened, to assure separation of the
moulded cap-form c~osure from the undercut male die member. The
closure is flexibly ffed to a hooked-over discharge end of a discharge
tube of the container and serves to close a neck which is spaced from
the discharge tube and has its axis parallel to the axis of the container
and to that side of ~e container axis opposite to the discharge tube.
Other prior art involves disposable containers of therrnoforrnable and
heat-weldable ~nate,ial, particularly for liquids, comprising a pair of
halves having opposing concavities, joined together at a peripheral
weld, the halves defining a top portion of the container that may be
opened by cutting and which has a part with a smaller cross-section
constituting a neck for pouring.
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- - - ~ - 2i938i8
1 bis
Such containers are not easy to handle when pouring as they tend to
cause the product to be discharged in irregular surges rather than in a
more desirable continuous flow, this frequently causing uncontrolled-
spillage of the liquid and, consequently, undesirable wastage of the
product.
Moreover, some containers cannot be closed after opening and,
therefore, once they have been opened, the product contained in them,
if liquid, tends to evaporate so causing further wastage.
It has also been found that, in the case of milk, which is a product that
is particularly suited to being packaged using the disposable
containers as des~ibed above, a further inconvenience arises
consisting initstendencytoabsorb the aromas of foods stored in
the environment in which the open containers are kept, in particular
the refrigerator, thereby causing an unacceptable deterioration in the
taste of the beverage.
There is also the risk of the product being contaminated by external
agents, such as dust or particles present in the environment and,
sometimes, even insects, particularly in the case of beverages that
contain a certain amount of sugars, thereby causing an unacceptable
reduction in the hygiene of the product.
GB-A-1129877 discioses a container comprised of a pair of plastics
shells joined together peripherally. The container includes a handle to
one side and a pouning spout to the opposite side, the spout being of
pear-shaped intemal cross-section with the pear apex pointing towards
the handle. The spo~t half-sections have outumed flanges for receiving
a cover.
International patent ~pplication publication No. WO 94/08852 discloses
a system for blow moulding containers from a pair of webs of
thermoformable and heat-weldable material including a preheating
station for preheating sheets, a heating, forming and welding station
for welding the webs and commencing forming of the containers and a
final forming and shape-stabilizing station.
Mould halves at the heating, forming and welding station are formed
with moulding channels whereby forming fluid introduced between the
heated webs forms conduits between the sheets.
The top portions of the containers include centrally arranged pouring
spouts which are co-axial with the intermediate portions of the
WO 96/01212 ~ ~ 9 38 ~ 8 PCI/lb5S~'tS538
containers. To one side of the pouring spout and in the welding plane
of the container is a wing formed integrally with the periph'eral welding
flange of the container. A closure in the form of a plug has a sealing
surface to seal against the internal surface of the spout. Those
surfaces may take the shape of truncated cones with oval bases. V\llth
the container in its sealed condition, the plug is a press-fit in a hole in
the wing. The plug can be a separate component, or integral with the
container and removable from it along a predetermined fracture line.
Alternatively, the plug may be connected to the wing by means of a
cord wound in a spiral around the plug with the container in its sealed
condition. The plug is integral with the container and fixed to the
container; the cord is obtained by punching or incision in a continuous
or broken spiral. The closure may take the form of a cap.
Such prior art may be subject to considerable improvements with a
view to eliminating its drawbacks.
One of the aims of the present invention is to provide a disposable
container which enables the product contained in it to be poured out in
a continuous and regular stream, making the pouring easier, whilst
maintaining discharge cross-sections of limited dimensions, and whilst
enabling easy closing of the pouring opening.
A further aim of the invention is to provide a container, particularly for
liquids, in which hygiene is considerably improved when conserving
the product after the container has been opened, preventing
contamination of the product that may compromise its condition or
organoleptic qualities.
A further aim is that of'inventing a container which is stiffer and which
is easier to handle.
According to a first aspect of the invention, there is provided a
container, comprising a top portion, a base portion, and an annular
intermediate portion interconnecting said top portion and said base
portion, said top portion including a pouring neck at least a major part
of which is disposed to one side of a longitudinal axis of said
intermediate portion,'and mounting means at least a major part of
which is disposed to the opposite side of said axis and which mounts a
closure for closing said neck.
Owing to this aspect of the invention, the volume available at the top
of the container is used more efficiently, enabling a closure to-be
included in the container as sold, particularly in the case of a relatively
narrow container, or enabling a relatively wide pouring neck to be
provided even when a closure is arranged beside it.
Another advantage is that if a sheet material tie extends from the neck
2 1 ~381 8
Wo 96/01212 PCI~/IB95/00538
to the closure, the tie can be made relatively longer and thus be more
readily flexed, while retaining its tensile strength. In addition to the tie
linking the closure to the neck, it may be advisable to provide
additionally one or more frangible ties between the closure and the
remainder of the container to anchor the closure during transport of
the container and yet to allow fiming of the closure to the neck
following opening of the container.
According to a second aspect of the present invention, there is
provided a container including a wall formed with a pear-shaped
opening, and a closure insertable into said opening for closing the
same, said closure including an annular sealing surface of a pear
shape to close said opening sealingly.
Owing to this aspect of the invention, the pear shape of the opening
allows liquid to flow from the container through the larger-width, lower,
part of the opening during pouring, while air enters the container
through the narrower-width, upper, part of the opening; moreover, the
pear shape of the sealing surface of the closure enables it to be
introduced easily and reliably into the opening, through the mutual
wedge action of the pear shapes. This is particularly advantageous
where the pear-shaped opening has been formed by consumers
cutting through a pear-section neck of the container, since such
cutting by consumers inevitably produces a variety of opening
formations.
According to a third aspect of the present invention, there is
provided a container moulded from plastics sheet material and
comprised of a top portion, a base portion and an annular intermediate
portion interconnecting said top portion and said base portion, said
intermediate portion being comprised of stiffening corrugations
obliquely inclined to the horizontal.
According to a fourth aspect of the present invention, there is
provided apparatus for moulding a container from plastics sheet
material, comprising a mould having a recess having a first wall
portion, a second wall portion and a third wall portion intermediate said
first wall ~ortion and said second wall portion, to shape a top portion, a
base portion and an intermediate portion, respectively, of said
container, said third wall portion being comprised of corrugations
obliquely inclined to a plane tangential to those parts of said second
wall portion further from said third wall portion.
Owing to these aspects of the invention it is possible to provide a
container which is capable of sustaining both considerable vertical
forces and significant horizontal forces.
21 ~381 8
WO 96/01212 P~ b55~ 38
. ' .
Nevertheless, the base portion of the container can advantageously
include approximately vertical corrugations, preferably branching from
at least one of the corrugations of the intermediate portion, in order to
facilitate flow of the plastics sheet material towards the very bottom of
the container, which flow could otherwise be seriously obstructed by
the corrugations in the third wall portion of the recess during moulding.
This feature is especially advantageous for containers of relatively
large capacity.
The corrugations in the intermediate portions preferably become
shallower as they approach a separation plane of the mould, in order
to facilitate separation of the mould dies from the container following
moulding.
According to a fifth aspect of the present invention, there is
provided a container moulded from plastics sheet material and
comprised of a top portion, a base portion and an annular intermediate
portion interconnecting said top portion and said base portion, said
intermediate portion including protrusions in the form of islands
distributed over said intermediate portion and serving to stiffen said
intermediate portion.
According to a sixth aspect of the present invention, there is
provided a method of cleaning a container moulded from plastics
sheet material and comprised of a top portion, a base portion and an
annular intermediate portion interconnecting said top portion and said
base portion, said intermediate portion including protrusions in the
form of islands distributed over said intermediate portion and serving
to stiffen said intermediate portion, said method comprising injecting
downwardly through said top portion a gaseous cleaning fluid, said
fluid travelling down to said base portion, and thereupon returning to
said top portion via substantially rectilinear routes among said islands.
Owing to these aspects of the invention it is possible not only to stiffen
said intermediate portion but also to facillitate a flow of gaseous
cleaning fluid, especially gaseous sterilizing fluid, for example steam,
upwardly from bottorn to top of the interior of the container, when the
fluid has been injected into the container downwardly at its top portion.
According to a sevcnth aspect of the present invention, there is
provided a method of producing a container, comprising heating a
plastics web to a temperature at which said web is formable,
moulding a larger part of said plastics web to form a body portion for
said container and a smaller part of said web to form a closure for
said container, said moulding of said larger part being performed
within larger internal surface portions of a mould and the moulding of
WO 96101212 2 1 q 3 ~ 1 8 PCI'IIB95/00538
said smaller part being performed within smaller internal surface
portions of said mould at least one of which is displaced relatively to
substantially all of the other internal surface portions of the mould
during the moulding of said closure.
According to an eighth aspect of the present invention, there is
provided apparatus for use in producing a container, comprising
heating and moulding means for heating a plastics web to a
temperature at which said web is formable and moulding a larger part
of said plastics web to form a body portion for said container and a
smaller part of said web to form a closure for said container, said
heating and moulding means comprising a mould having larger
internal surface portions for moulding said larger part and smaller
internal surface portions for moulding said smaller part, first driving
means which serves to displace at least one of said larger internal
surface portions, and second driving means which serves to displace
at least one of said smaller surface portions relatively to substantially
all of the other internal surface portions of the mould.
Owing to these aspects of the invention, it is possible not only to
mould the body portion of said container directly by differential
pressure of fluid but also to form the closure directly by mechanical
pressure produced by differential pressure of fluid.
The closure can be~ formed and the mould can heat the web at
substantially the same time.
In a prefered embodiment of the container, it is of thermoformable and
heat weldable material and comprises a pair of halves having
opposing concavities, joined together at a peripheral weld, the halves
defining a top portion of the container that may be opened by cutting
and which has a part with a smaller cross-section constituting a neck
for pouring, the neck having a longitudinal axis positioned close to one
of the sides of the container, the transverse cross-section of the neck
being in the shape of a pear, with the apex preferably pointing towards
the opposite side of the container.
An advantage of this embodiment lies in the regularity of the outflow of
the liquid achieved with the special pear-shaped section of the neck,
~ made even more advantageous by its positioning that enables the
outflow of the liquid from an area of the container close to one of its
sides whilst at the same time allowing air into the container.
In a particularly advantageous variant, associated with the neck of the
container there is a closure for the outlet opening, said closure
forming an integral part of the container obtained during the forming
process of the container and positioned in its top portion on the side
2193818
-- WO 96/01212 PCI~/~95/tlO538
opposite to that containing the neck.
This gives the further advantage of improving the hygiene of the
container, of simplifying its manufacture and optimising the material
used by reducing the amount of material wasted.
In a further advantageous version, the container has, on the surfaces
of the halves that make up the body of the container, a forrnation of
stiffening and gripping elements made up of imprints or protuberances
distributed over the greater part of the extent of the said surfaces.
The stiffness of the container, already improved by its peripheral weld,
is thereby increased, so making it easier to hold.
In a further advantageous version the closure is attached to the
peripheral weld by means of connecting elements: a first connecting
element, which may be easily broken, being positioned on an upwardly
directed part of the peripheral weld of the top portion of the container,
a second, flexible, connecting element being positioned on the neck.
This gives the further advantage of making it possible to position the
closure accurately, it being connected to the body of the container at at
least two points, whilst at the same time making the closure easy to
use by breaking the said first connecting element.
In a further advantageous version the closure and the said neck are
provided with insertion and sealing devices, co-operating with each
other for the snap-insertion and retaining of the closure. -
This enables losses by evaporation to be limited and improves thehygiene of the container once it has been opened.
In a further advantageous version the insertion devices consist of at
least a pair of apper~dages, substantially radial, that may be engaged
in a corresponding peripheral groove.
This gives the further advantage of reducing to a minimum the effort
required to close and open the container whilst ensuring its effective
closure.
In order that the invention may be clearly understood and readily
carried into effect, reference will now be made, by way of example to
the drawings attached in which:-
Figure 1 is a lateral elevation of a blow-moulded container for liquid;Figure 2 is the top view of Figure 1;
Figure 3 is a partial and enlarged vertical section in the forming plane
of the area of the neck of the container;
Figure 4 is section IV-IV of Figure 3;
Figure 5 is a section as in Figure 3, but showing a variant of the cap
for closing the container;
Figure 6 is section Vl-VI of Figure 5;
WO96/01212 21 938 1~ P~ S~ t53~
Figure 7 is a view of the container as in Figure 1, but showing a
version with stiffening corrugations provided in its lateral walls;
Figure 8 is a side view of Figure 7;
Figure 9 is a top view of Figure 7;
Figure 10 is a section through a mould for use in producing the
container of Figures 7-9;
Figure 11 is section Xl-XI of Figure 7;
Figure 12 is a view similar to Figure 3 but showing a variation; - --
Figure 13 is fragmentary lateral elevation showing a modification of the
container of Figures 1 and 2;
Figure 14 is a diagrammatic section through a mould employed in
manufacturing a container according to Figure 12; and
Figure 15 is a fragmentary section through the mould and container of
Figure 14, but in a plane parallel to the section plane of Figure 14 and
showing the mould closed. ~ l !
Referring to the drawings, the container 1 is obtained by blow-
moulding, for example, in a forming apparatus as described in
International Patent Application Publication W094/08852, from a pair
of sheets of thermoformable and heat-weldable material, connected to
each other in a welding plane by means of a peripheral weld 2, or
even from a single folded sheet, provided with an analogous
peripheral weld.
The peripheral weld 2 joins together the halves 3 constituting the body
of the container 1: the halves 3 are preferably provided with a
formation of stiffening and gripping elements 4 made up of recesses in
the outside surface of each half and/or even bulges on that surface.
These recesses and/or bulges naturally result in corresponding bulges
and/or recesses in the inside surface.
The distribution of the said elements 4 over each said surface is
preferably symmetrical with respect to a vertical centreline of each
lateral surface of the container in order to achieve a uniform stiffness.
Furthermore, the halves 3 can be provided with formations of stiffening
and gripping elements 4 which are either the same on both sides or
different from one side to another, so that, respectively, the orientation
in which the user holds the container is either indifferent or
preferential.
The distribution of the elements 4 is preferably determined as a
function of the position of the fingers when holding the container.
In a particularly advantageous version, shown in ~igure 1, the
formation of stiffening and gripping elements 4, the same for both
halves 3, comprises a pair of sets of three circular recesses 5,
2~3818
--- WO 9G/01212 PCT/~9_J'U~53~
between which is positioned an elongate recess 6 with above it
another circular recess 7 and an upper elongate recess 8, arched
upwards: the recess 6 can be as large as is required to apply a label to
it.
In the area of the join between the lateral walls of the container 1 and
its base, there can be a pair of stiffening elements 5a, for example,
having a curved outline, set partly in the lateral wall and partly in the
base.
The top portion of the container has a neck 9, for pouring, having an
axis A offset towards one of the sides of the container 1 and, on the
opposite side from the neck, a closure 10 for the opening 11 (Figure 3)
of the container 1 after it has been opened.
It is to be noted that the axis A can be inclined with respect to the
adjacent side of the container 1, preferably upwardly outwards from it.
Whatever the angle of inclination of the axis A, the mid-point of the
pouring edge resulting, from the removal of the top stretch 14 of the
weld 2, is substantially tangential to the extension 14b of the stretch
14a of weld 2 joining the neck 9 and the opposite side of the container
1, as shown in Figure 3 in the particular case of a vertical axis.
The closure 10 is obtained during the blow-moulding of the container
1, and, as such, is made from the same sheets of thermoformable and
heat-weldable material that the halves 3 of the container 1 are made
of.
The weld 2 extends continuously around the container 1 and its top
stretch 14 is formed affer the rest of the weld 2, in particular after the
product to be poured~ has been placed in the container 1.
On use, the top stretch 14 is removed, for example by cutting or
tearing, from the weld 2; the closure 10 is then detached at its first
connecting element 12 and the body 15, advantageously tapered, of
the said closure is subsequently inserted in the opening 11 of the
container 1.
The plan view profile of the body 15 of the closure 10 has a shape
corresponding to that of the cross-section of the opening 11 of the
container 1, the said section preferably being in the shape of a pear to
improve outflow of the liquid whilst, at the same time, allowing air to
enter into the container 1.
It is to be noted that the first connecting element 12 has to be made so
that it is much weaker than the second connecting element 13 so that
the element 12 may be broken easily, for example by tearing; the
second connecting element 13, on the other hand, has to be relatively
strong and flexible to enable the closure 10 to be turned when
2193~18
~t'VO 96101212 PCI~rlb5S/QQ538
inserting it into the opening 11.
The closure 10 may be provided with retaining means for retaining the
body 15 in the opening 11, the retaining means comprising a pair of
opposing projections 16 receivable in a groove 17 correspondingly
provided in the intemal surface 18 of the neck 9.
Alternatively, as shown in Figures 5 and 6, the retaining means can
consist of a groove 19 in the body 15, to co-operate with a pair of
corresponding protuberances 20 extending from the inside surface 18.
The depth of the groove 17 or 19 and the height of the corresponding
protuberances 16 or 20 with which it co-operates is such as to permit
the correct positioning of the body 15 in the neck 9 and to resist the
elastic force of the second connecting element 13 connecting the
closure 10 to the weld 2.
In the version of container 1 shown in Figures 7-11, a formation of
transverse grooves 21 is set into the external surfaces of the halves 3
and thereby provides stiffening corrugations in the intermediate
portions of the halves 3: each groove having a central stretch 22,
substantially horizontal, such as slightly inclined upwards 'towards the
neck 9, the said central stretch extending into a pair of straight or
slightly curved end stretches 23, inclined away from each other with
respect to the said central stretch 22: the end stretches 23, as
they approach the weld 2, beginning to turn oppositely as indicated at
24. The grooves 21 are symmetrical about the plane of the weld 2.
It is to be noted that the formation obtained with a number of
superimposed grooves 21 stiffens the container 1 against radial
stresses, i.e. those that arise when it is gripped, and against axial
stresses, which is advantageous for the purposes of stacking.
The central stretches 22 of the grooves 21 can be interrupted by a
central, flat area 25 where printing or a label can be applied.
The pair of transverse grooves 21 closest to the base of the container
1 in each half 3 is advantageously joined with a pair of'substantially
vertical grooves 26 to further stiffen the bas'e.
The mould 30 shown in Figure 10 comprises two major parts 31
sen/ing to shape the top portion and the intermediate portion of the
container 1 and two minor parts 32 se~ing to shape the base portion
of the container 1, the two parts 31 being displaceable towards and
away from each other as indicated by the arrows Z in Figure 10, and
the parts 32 being displaceable not only towards and away from each
other as indicated by the arrows Y, but also towards and away from
the parts 31 as indicated by the arrows W. It will be understood that
the walls of the mould recess 33 are formed with ribs 34 for forming
2193818
-_ WO 96101212 PCI/~b~S~ 38
~ :.
the grooves 21 (and 26).The ribs 34 extend obliquely relative to a
planeT tangential to those surface portions of the recess~ 33 furthest
from the parts 31. As the ribs 34 approach the separation plane P of
the mould 30 they shallow gradually so that the grooves 22 (and 26)
also shallow gradually as they approach the weld plane, so
discouraging retention of the moulded container in the mould 30 after
its shape-stabilization.
It is sometimes required to clean, in particular to sterilise, the whole of
the internal surface of these stiffened containers prior to filling, by
injecting vertically downwardly through the as yet unsealed neck 9 a
gaseous sterilising fluid, for example steam. The steam is injected with
the intention that when the jet of steam reaches the bottom of the
interior it returns to the top of the interior by flowing upwardly while in
substantially direct contact with the internal surface of the annular
intermediate portion of the container 1 (see the arrows V in Figure 14).
The version of Figures 1-6 is particularly advantageous in that respect
because, among the six vertical columns of stiffening elements 5,6
and 7, there are vertically upward routes 35 in Figure 1, via which
routes the steam can more readily return to the top portion of the
container.
As shown in Figure 12, instead of the body 15 being throughout of a
downwardly tapering form, it can be of a form more like a barrel in
cross-section whereby, on press-fitting of the body 15 into the neck 9,
the outer end of the neck tends to engage behind the body 15 to retain
the body in the neck. This version dispenses with the retaining means
in the farms of the p~otuberances 16 and 20 and the grooves 17 and
19 of Figures 1 to 6.
Figure 13 shows that the connecting element 13 in particular can be
relatively long in order to make manipulation of the closure 10 much
easier.
Referring to Figures 14 and 15, Figure 15 in particular illustrates an
advantageous manner of producing the body 15 of Figure 12, wherein
the body is relatively stiff through being a double thickness of the
sheet material. Included in one of the mould parts 31 is a single-acting
spring-return, piston-and-cylinder device 36, 37, whereof piston 36 is
fixed to a plunger 38. The plunger 38 has a head of a shape
corresponding to that of the body 15 to be produced and, upon supply
of compressed air via a duct 39 to the cylinder 37 is forced into a
correspondingly shaped recess 40 in the opposite part 31. Air exhaust
vents 41 extend from the recess 40. As the plunger 38 is advanced
into the recess 40 it presses into the recess 40 those portions of the
21938~8
WO 96/01212 PCr/~gS~'vûS138
two plastics webs 42 which cover that recess 40, the two webs having
immediately previously been heated to their softening temperature in
the mould 30. Formed through the piston 36 is a bore 43 whereby
compressed air entering the duct 39 can enter the cylinder chamber
containing the spring 44. A duct 45 extends through the wall of the
cylinder 37 to a chamber 46 containing the head of the plunger and
formed in the active face of the part 31 containing the device 36,37.
Thereby, when non-heated compressed air is supplied to the duct 39
to drive plunger 38 fo~ard, a proportion thereof reaches the chamber
46 and flows around the head of the plunger 38 to cool the head and
the web material being displaced, thereby to prevent the shaped body
15 from returning with the plunger.
