Note: Descriptions are shown in the official language in which they were submitted.
The present invention relates to a container or package for
containing liquid substances, especially viscous substances,
in a hermetically sealed condition, and comprising a
substantially rigid or stiff peripheral wal].
Such containers or packages containing liquid or viscous
substances are often stored for a long period of time
under greatly varying temperature conditions before the
content of the container is used.
.. . .. . . .. . . .......... . . ............... . . . .. . ..
~~~` ` - As the thermal coe~icients~`of expansion of the conta1ner~
; 10 and its content, respectively, are normally different a
partial vacuum may be generated in containers or packages
of the type in question. When sealing compounds, adhesives,
and other similar viscous masses or substances are packed
in containers or packages of this known type the more fluid
components, such as solvents, have a disadvantageous ;
tendency to separate during storage of containers or
packages containing such viscous substances or masses.
.. .. . . ... .
~ It has been found that this tendéncy to separation of fruid
components is substantially reduced by using the container
according to the invention which is characterized in that
the peripheral wall is air~tightly closed at one end there-
of by a distendable membrane or wall part. This advantage
is presumably due to the fact that even during storage with
greatly varying temperature conditions the content of a
container according to the invention is not exposed to
pressure conditions differing substantia]ly from the
ambient atmospheric pressure because the distendable
membrane or wall part will function as a kind of thermal
expansion and contraction compensator. The said membrane
or wall part may possibly be protected against mechanical
stresses, for example by means of a lid-shaped rigid end
wall. However, in this case the said end wall must be
provided with one or more greater or smaller air passages
securing that the outer surface of the distenaable membrane
or wall part is always exposed to the ambient atmospheric
pressure. If desired, the distendable membrane or wall part ,l
may be sealed to the lid-shaped end wall along its peri-
phery, and when the content has been filled into the con-
tainer or package the distendable membrane or wall part
may be fastened thereto together with and possibly also
by means of the lid-shaped end wall. Alternatively, the
rim portion of the membrane or wall part may be wedged or
clamped between the container and the lid-shaped end wall
without being united with the Latter. In any case, the lid-
shaped end wall may have a form so that the distendable
membrane or wall part may freeLy move so as to compensate
for variations of the volume of the substance or mass
;~; contained in ~he container~
Thus, the container or package according to the invention
may, for example, have the form of a bucket or pot provided
with a lid. The invention may, however, with special
advantage be used in connection with a cylindrical container
or cartridge for containing a sealing compound, an adhesive,
or other viscous masses or substances, and of the type being
closed at one of its ends by means of an ejection piston
displaceable within the cylinderO When the content of such
a container or cartridge is to be used the cartridge is
normally placed in a socalled ejection pistol which
comprises a plunger to cooperate with the ejection piston
of the cartridge, and which may be operated manually or by
means of pressurized air so that the viscous substance, for
example a sealing compound, is discharged through a spout
~.~2~
or nozzle.
Containers or cartridges of the said type provided with
an integrally formed spout the free end of which is closed,
but adapted to be cut off immediately before the content
of the cartridge is to be discharged, are known. It is also
known to provide cartridges with a discharge opening d
defined by a threaded pipe stub on which a discharge spout
or nozzle may be fastened. In that case the discharge
opening of the cartridge or container rnay be closed by a
perforatable wall which is stretched -tightly across said
tube stub and which may be perforated by~means of a pointed
tool immediately before the content of the cartridge is
to be discharged or ejected.
In practice containers or cartridges with a content of a
viscous substance is often stored for a long period of time
before use,under greatly varying temperature conditions as
mentioned above. As the thermal expansion coefficients of
the container or cartridge and its content, respectively,
are normally different, the varying storing temperatures
cause that the ejection piston is displaced backwards and
forwards in the cylinder-shaped container or cartridge.
It has been found, however, that a temperaiure caused
reduction of the content o~ the containex or cartridge is
...... .. . .
often partly or totally compensated for by suction of air from
; 25 the ambient atmosphere through the space between the inner
wall of the container and the outer wall of the cylindrical
skirt of the ejection piston into the inner space of the
cylindrical container or cartridge. Such suction of air
into the container or cartridge may be rather disadvantage-
ous, partly because the air reacts with the content of the
container in an undesired manner, and partly because air
bubbles included in the viscous substance in the container
or cartridge may cause an undesired splashing or spattering
of the substance when it is later discharged or ejected
from the contalner or cartridge.
According to another aspect of the invention the said
peripheral wall may have the shape of a circular cylinder
which at its other end opposite to said distendable
membrane or wall part is adapted to be closed by an ejec-
tion piston displaceable in said cylinder. The containeraccording to the invention may -then be used as a cartridge
of the type described above. In that case the distendable
membrane or wall part will not only hermetically close or
seal said other end of the cylinder, but due to its dis-
tendability it may also serve as a thermal expansioncompensator, because without exerting any substantial
resistance it may be distended more or less dependent on
the actual temperature of the mass or substance contained
in the cylinder. Consequently, the ejection piston may
remain stationary in relation to the cylinder, and -
undesired suction of air into the cylinder may be avoided.
Furthermore, the tendency of solvents and other fluid
components to separate from the remaining content of the
cylinder or cartridge is reduced as explained above.
The container or package may at said one end comprise an
end wall defining a discharge opening therein, and
according to the invention the distendable membrane or ~all
part may then be arranged within the container so as to cut
off communication between said discharge~opening and the
inner space of the container. A distendable membrane or
wall part will then be arranged well protected within the
cylinder.
When the inner surface of said end wall has a concave
shape, the edge portion of said distendable membrane or
wall part may, according to the invention, be sealingly
fastened to the inner surface of said end wall, preferably
along the transition to said peripheral wall, and adapted
to engage with and be supported by said end wall in its
fully or partly distended condition. By this embodiment it
;p~
is obtained that the distendable membrane or wall part may
be made from a relatively weak or thin-walled material because
when distended it is supported by the adjacent, much more
heavy concave end wall. When the viscous substance is
filled into the container in a hot condition and a-t a
temperature substantially above the ma~imum temperature
to which the container or package may be exposed during
storage, the membrane or wall part may be distended and
caused to engage with the end wall of the cylinder during
the filling operation whereby the membrane is supported
and a complete utilization of the space of -the cylinder is
,
obtainable. When the viscous substanceis later cooled, the
membrane or wall part may move away from the~cylinder end
wall to an extent corresponding to the thermal contraction
of -the viscous substance or mass.
The distendable membrane or wall part may be of any
suitable material, for example an elastic rubber or plastic
material which may be stretched withou-t offering-any su~stantial
resistance when the temperature of the container content is
increased. It is preferred, however, to produce the membrane
or wall part of a substantially~inelastic material of a
type permitting heat sealing or gluening of the rim por-
tion of the membrane or wall part to the container. When
the said membrane or wall part is of a substantially
inelastic material it is preferably provided with folds or
pleatings in its non-distended condition, whereby collaps-
ing of the distendable membrane or wall part is facilitated
when the volume of the liquid or viscous substance
contained in the container is reduced due to thermal con-
traction.
The distendable membrane or wall part is preferably madefrom a thin sheet material which is impervious to air and
which may easily be heat sealed -to the container wall.
Therefore, according to the invention the said membrane or
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~L22~
wall part is preferably made from a metal ~oil such as an
aluminum foil, coated by a layer of heat sealable plastic
material, such as a plastic film or a hçat sealable lacquer.
The present invention also provides a method of making a
cylinder-shaped container or cartridge of the above type,
and the method according to the invention is characterized
in closing one end of a cylindrical tube length or section by
positioning a thin stretchable sheet'material, s'uch'as a '
film or a foil across said one end and sealing it to the
surface of said tube length, filling the liquid substance
to be packed into the tube length through the open other
end thereof and exposing said substance to a compressive
force so as to stretch said sheet material permanently.
The sheet material may then be fastened to the tube length
in a tight condition whereby the fastening process is
facilitated, and the distendable membrane or wall part is
then provided by the later stretching process.
The liquid substance is preferably filled into the tube
length in a heated condition. Thereby the filling process
is facilitated, and provided that the temperature of the
heated mass or substance exceeds the maximum temperature
to which said substance is expected to be exposed during
the later storage, the membrane or wall part will never
be distended to the same extent during storage as during
filling of the container. On the contrary it may be
expected that the mass or substance is contracted so that
the membrane or wall part will become more slack. Because
the sheet material has been stretched permanently during
the filling process and thereby obtained a certain over-
size, it will be able to compensate even for the reductionsof volume occurring at extremely low temperatures.
.
The said compressive force may be applied to the liquid or
- viscous mass filled into the tube length by any suitable
means. The said compressive force may, however, advantage-
ously be applied by means of an ejection piston which is
inserted into the open end of the tube length or section.
As mentioned above the membrane or wall part may be fastened
to said one end of the cylindrical tube length in any
suitable manner, for example by gluening or heat sealing
depending on the ma-terials ~rom which the tube length and
the membrane or wall part are made. The sheet material
being used for making the distendable membrane or wall part
may, for example, be a laminate of a metal foil, such as
an aluminium foil, and a plastic film, such as a poly-
ethylene film. The plastic film may be used as the innerlayer, and the sheet material may then be heat sealed to
the cylindrical tube length which may also be made from
plastic material. The purpose of the plastic film is to
make the membrane or wall part impervious to vapour and
solvents.
The invention will now be further explained with reference
to the drawings illustrating various embodiments of the
method and container according to the invention, and
wherein
Fig. 1 is a side view and partially sectional view of a
container or cartridge according to -the invention filled
with a viscous mass and comprising a membrane shown in a
substantially distended condition,
Fig. 2 is a view similar to that in Fig. l, but with the
membrane in a non-distend~d condition,
Fig. 3 is a side view and partially sectional view of a
second embodiment of the container or cartridge according
to the invention,
Fig. 4 is the same as Fig. 3, but with the membrane in
another position,
Figs. 5 to 7 illustrate various steps of a me-thod for making
a third embodiment of a cylindrical container or cartridge
provided with an ejection piston,
Fig. 8 is a side view and partial sectional view of a
cylindrical container or cartridge made by the method
,
' ' ~ . ,'~, ~'
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illustrated in Figs. 5 to 7 and being provided wlth an end
wall having a discharge spou-t,
Fig. 9 is a side view and partial sectional view of the
container or cartridge and the end wall shown in Fig. 8
arranged in a conventional, manually operatable ejection
pistol, and
Fig. 10 is à side view and partially sectional view of
a modified embodiment of the container or cartridge shown
in Fig. 8 and 9 placed in an ejection pistol which may be
actuated by means of pressurized air.
Figs.l to 4 show a cylindrical container or cartridge 10
having an end wall 12 provided with a threaded tube stub
11. The other end of the cartridge or cylinder 10 is
closed by an ejection piston 13 which is displaceable in
the cylinder~ The threaded tube stub 11 defines a discharge
passage 14 therein. Tne passage 14 is separated from the
inner space of the c~linder 10 which contains a viscous
substance or mass 15, by means of a distendable wall part
or membrane 16.
In the embodiment shown in Figs. 1 and 2 the rim portion
of the membrane 16 is sealingly fastened to the end wall
12 along a transitional zone 17 between said end wall and
the cylindrical wall of the cartridge or container 10. The
membrane 16 has such a si~e that it may be brought into
engagement with the concave inner surface of the end wall
12 as shown in Fig. 1. The membrane 16 may/ for examplej
be in this position immediately after the filling process
by which the viscous mass 15 has been filled into the
cartridge or container 10, preferably in a heated condition.
When the mass or substance 15 is cooled so that the
volume thereof is reduced the piston 13 may remain in the
position shown in Fig. 1 in relation to the cylinder
because the reduction of the volume is compensated for by
the distendable membrane 16 which is moved a suitable
2~
distance towardsthe piston 13 as indicated in Fig. 2. In
this manner the membrane 16 may serve as a thermal volu~e
change compensator as well as for hermetically sealing the
inner space of the cylinder or cartridge 10.
When the content of the cartridge 10 is to be used it is
placed in an ejection pistol of a type as that shown in
Fig. 9 or 10 and comprising a plunger by means of which
an inwardly directed pressure may be applied to the piston
13 of the cartridge 10. Thereafter,the membrane or wall
part 16 is perforated by means of a suitable,pointed tool
or instrument and a kind of discharge spout, not shown,
may be mounted on the threaded tube stub 11. The viscous
; substance or mass 15 may now be ejected or discharged at
the place of use in a manner known per se.
The embodiment shown in Figs. 3 and 4 corresponds to that
shown in Figs. 1 and 2 apart from the fact that in Fig. 3
and 4 the rim portion of the membrane 16 is fastened to the
inner surface of the end wall 12 immediately adjacent to
the discharge passage 14, and the distendable membrane or
wall part 16 has a folded or pleated shape. Also in-this
embodiment the membrane may serve as a thermal volume change
compensator as illustrated in Fig. 3 and 4 so that dis-
placement of the piston 13 in relation to the cylinder isavoided even when the cartridge or container 10 is stored
under varying temperature conditions~ Consequently, suction
of air through the space between the piston and the
cylinder wall and into the inner of the cylinder is avoided.
The cylinder 10 and the piston 13 may be of any suitable
material, but they are preferably made by ejection moulded
plastic ~aterial. In principle, the membrane or wall part
16 may be made as an integral part of the container or
cartridge 10. However, in order to facilitate production
it is preferred to make the membrane 16 and the cylinder
: .
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,
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-- 10 --
10 separately and the membrane may then be fastened to the
cylinder by heat sealing, gluing, or in any other suitable
manner. The membrane or wall part 16 is preferably a laminate
of metal foil, preferably aluminium Eoil, and a heat sealable
plastic material, such as polyethylene. Such a laminate is
impervious to vapour, gases, and liquid solvents and may be heat
sealed to the cylinder or container 10.
~ igs. 7 to 10 show other embodiments of a cylinder-
shaped container or cartridge 10 made from a relatively stiff
or rigid cylindrical tube length 18, one end of which is closed
by means of an ejection piston 19 and which cooperates wi-th a
separate piston engaging member 20. At its other end the tube
length 18 is closed by means of a distendable membrane or end
wall 21, the rim portion of which is sealingly fastened to the
adjacent part of the outer surface of the tube length 18. The
; end wall or membrane 21 may be of the same type as the membrane
16 previously described, and the membrane 21 may be fastened to
the tube length 18 in any of the manners described above in
connection with the membrane 16. In its mounted condition, the 20 end wall or membrane 21 has a certain oversize, which means that
its area exceeds the cross-sectional area of the tube length 18.
The end wall or membrane may, alternatively, be of a highly
elastic material. As indicated by bro~en lines in Fig. 8, the
membrane or end wall 21 may be moved to such an extent that it
may compensate for thermal changes of volume of a viscous
substance or mass 15 contained in the container or cartridge 10
so that at any time the substance or mass will be subjected to
a pressure corresponding substantially to the ambient atmospheric
pressure whereby the advantages previously described may be
obtained.
~'
The substance or mass 15 contained in the cartridge 10 may,
for e~ample, be a sealing compound, an adhesive, or a
slmilar viscous mass. When the content of the cartridge
or con-tainer shown in Fiy. 8 is to be used,the cartridge
may be placed in a conventional ejection pistol as that
shown in Fig. 9 and generally designated by 22. Immediately
before the container or cartridge 10 is placed in the
pistol 22 a discharge spout 23 having a socket 24 is
mounted on the end of the cartridge which is closed by the
membrane or end wall 21. A cutting edge 25 forming an
extension of the wall of the spout 23 extends axially from
the inner surface of the socket 24, and a pair of concentric,
annular sealing ridges 26 surround -the cuttin~ edge 25 as
best shown in Fig. 8. When the trigger 27 on the pistol 22
is operated in the usual manner the piston 19 of the
cartridge 10 is pressed inwardly by means of a plunger 28
of the pistol 22. Thereby -the membrane or end wall 21 of
the cartridge 10 is caused to move outwardly, and the
cartridge 10 will be pressed tightly against the inner
; 20 surface of the socket 24. ~s a resultjthe cutting edge 25
will make a curved cut in the membrane 21 whereby
communication is established between the inner space of
the cartridge 10 and the passage oE the spout 23. At the
same time the membrane 21 is pressed tightly against the
; 25 sealing rid~es 26 (Fig~ 9) so that the content of the
cartridge is prevented from penetrating between the end
wall or membrane 21 and the inner surface of the socket 24.
~n the embodiment shown in Fig. 10 the outer surface of the
cylindrical tube length 18 is provided wi-th locking pro-
jections or cams 29 and 30, respectively, at both ends. The
socket 24 of the discharge spout 23 is provided with
corresponding inner cam surfaces 31 by means of which the
spout 23 may be fastened to one end of the cartridge 10 as
shown in Fig. 10. When the socket 24 is mounted on the
cartridge -the cutting edge 25 will perforate -the membrane
:
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P~7~
or end wall 21 as described above. sy means of the locking
cams 30 the other end portion of the cartridge 10 may be
fastened to a conventional ejection pistol generally
designated by 32 and being of the type operatecl by
pressurized air. When the triyger 33 of the pis-tol 32 is
operated the piston 19 of the container or cartridge 10
will be pressed inwardly by means of pressurized air so
that the viscous substance 15 is ejected from the cartridge
through the discharge spout 23 as described above.
In conventional sealing compound cartridges of the type
described the discharge spout forms an integrating part of
the cylindrical wall of the cartridge or container, and
therefore these conventional cartridges must be produced
by ejection moulding for which reason they are relatively
expensiveO In the embodiments of the container according to
the invention shown in Figs. 7 to 10 the tube length may
be cut from a tube of a longer length which may be produced
in a substantially cheaper way, for example by extrusion.
The tube length 18 may be made from plastic or metal, such
as aluminium, or it may be made from a laminate of plastic
material and metall for example an extruded plastic tube
being outwardly coated by an aluminium foil in order to
make it impervious to gases, vapoursl and liquid solvents.
As shown in Fig. 7,the membrane or end wall 21 may
similarly consist of a laminate formed by an inner plastic
film, such as polyethylene, and an outer metal foil, such
as aluminium. It may, however, involve certain technical
difficulties to fasten the membrane or end wall 21 to the
tube length 18 so tha-t a hermetical seal is obtained
because,as mentioned above,the membrane must have a certain
oversize and must consequently be in a folded or pleated
condition when fastened.
~owever, according to the invention a method has been pro-
vided by means of which a container or cartridge as that
13
described above may be produced in a much more simple
manner. This new method is illustrated in Figs. 5 to 7.
As shown in Fig. 5 a stretchable sheet material 21' which
may be a laminate of films or foils or may consist of a
single layer of ma-terial, is fastened to one end of a tube
length 18. The sheet material 21' is fastened to the inner
or outer surEace of the tube length 18 in a substantially
tight condition, preferably by heat sealing or gluening.
The container or package manufacturer may then deliver this
semi-manufactured article together with associated piston
parts to the manufacturer of the viscous substance or mass
15 to be packed in the container or cartridge. The viscous
substance 15 is filled into the open end of the semi-
manufactured article shown in Fig. 5 in a hot condition,
the said article being arranged so that the end of the tube
length 18 closed by the sheet material 21' is engaging
with a concave surface of a die 34 as shown in Fig. 6. The
open other end of the filled tube length 18 is now closed
by the piston 19 whereafter an inwardly directed force is
applied to the piston 19 by means of a plunger 35 of a
suitable force applying apparatus, not shown. The plunger
35 applies such a force or pressure to the piston 19 that
the sheet material 21' is stretched permanently to such an
extent that it is brought into en~agement with the concave
surface of the die 34 whereby the distendable membrane or
end wall 21 is formed. The plunger 35 may now be removed
and the piston engaging member 20 may be mounted on the
- container or cartridge which is now ready for storage or
shipment. When the mass or substance 15 contained in the
container or cartridge 10 is cooled the volume of the mass
or substance is reduced, and the membrane or end wall 21
will then take up a folded or pleated shape as shown in
Fig. 7. Provided that the maximum temperature to which the
- content 15 of the container 10 is exposed during storage
and shipment does not exceed the temperature during the
filling process~ the end wall will be able to compensate
7~
14
for the thermal volume changes which will occur during
storage and shipment.
Even thouyh the container or package according to the
invention has predominantly been explained wi-th reference
to so-called cartridges for sealing compounds and similar
substancesj it should be understood that the invention may
also be used in connection with packages and containers of
other types being adapted to contain a viscous mass or
substance in a hermetically sealed condition. As an example,
the container according to the invention may be shaped as
a can having its upper end closed by means of a membrane
like distendable end wall which may possibly be protected
by means of a removable lid provided with one or more air
passages securing that the membrane like end wall is exposed
to the ambient pressure.
It should also be mentioned that even though the distend-
able membrane or wall part is preferably made from a
substantially inelastic sheet material it may, alternative-
ly, be made from an elastic ma-terial extending across the
end of the cylinder 10 in its strainless condition. ~he
membrane may then have such a resiliency that it may be
stretched sufficiently to for example engage with the
concave inner surface of the end wall 12 shown in Figs.
1 to 4 without applying any substan-tial elas-tic force to
the content 15 of the container 10.
