PACKAGE FOR LIQUID PRODUCTS LIABLE TO RELEASE A GAS, IN PARTICULAR FOR
WASHING LIQUIDS
The present invention relates in a general manner to packs for liquid products, and more particularly for washing liquids.
Such packs are already known which consist of a bag made from a strong, flexible and leaktight material, preferably a plastic, and of a rigid box, for example made from cardboard, containing the said bag. The liquid product contained in the bag may flow out through a nozzle or pipe which traverses the said box. Such packs are both light and relatively strong since they have the combined strength of the box and the bag and the lightness of the constituent materials of the bag and of the box. The raw materials of the two com¬ ponents, for example cardboard and plastic, may further- more be recycled separately, which makes the pack "ecolo¬ gical", the amount of plastic being reduced.
Such packs of known type are not, however, entirely suitable for packaging liquid products liable to release, while being stored, a gas whose pressure creates the risk of causing the bag to rupture and hence the liquid to flow out, which liquid escapes to the outside of the pack since the box is not leaktight.
This applies particularly in the case of packag¬ ing washing liquids which contain a decomposable oxygenic compound, such as a bleaching agent of the perborate type, which releases oxygen when it is subjected to an increase in temperature and/or in the presence of any impurity.
Moreover, the flow of the liquid, for example washing liquid, out of the pack may slow down and then accelerate dangerously as a result of the leaktightness of the bag, apart from the emptying nozzle, and hence of the irregular supply of outside air into the bag as the liquid flows out; a nozzle whose opening has an over- dimensioned cross-section must consequently be provided, which may have disadvantages.
It was thought that these two disadvantages, and in particular the first which is the most serious, could be overcome by arranging in the box a slightly
gas-permeable bag, but if the bag is too permeable, there is a risk of the liquid itself seeping out and if the bag is not permeable enough, the gas escapes only with diffi¬ culty and there is a further risk of the bag bursting, in particular in the case of a violent release of gas.
The object of the present invention is to over¬ come reliably the double problem (a) of the risk of the bag rupturing in the event of the gas inside it having an elevated pressure and (b) of the irregularity of the flow of the liquid leaving the bag, and hence the pack, when the pack consists of a bag arranged inside a box and when it is intended to package a liquid product, in particular washing liquid, liable to release a gas while being stored. To this end, according to the invention, a pack is provided for a liquid product, in particular for washing liquid, capable of releasing gas, comprising, in the known manner, a box and, housed in this box, a flexible bag or sack made from a gastight material for the liquid product, and an outlet nozzle for the liquid product, traversing the said bag leaktightly, which pack is characterized in that it furthermore comprises a ventilation system which, after the liquid product has been packaged in the pack, connects that portion of the space inside the bag not filled with liquid product to the outside of the bag, this ventilation system comp¬ rising, on the one hand, a float capable of floating on the open surface of the liquid product, which separates the mass of liquid product from the mass of gas in the said portion, this float being gas-permeable, and, on the other hand, a duct which connects the inside of the float to the outside of the bag, traversing the wall of the bag whilst preserving the bag's leaktightness.
The bag is generally made from a plastic such as polyethylene and the box from cardboard; the box is advantageously collapsible so that it may be folded flat after the liquid has been emptied from the bag.
The float has, preferably in its vicinity, filtering means allowing only gases or a certain type of
gas to pass through.
The float may also be equipped with at least one valve which opens only when the difference in gas pres¬ sure (in one or other direction) between the mass of gas in that portion of the space not occupied by the liquid inside the bag and the outside of the bag exceeds a certain predetermined value.
In a general manner, the float may have any shape
(round, oval, pyramidal, cylindrical, polyhedral, for example cubic, etc..) and may be made from any material or any combination of appropriate materials (polystyrene, polyethylene, polypropylene, polyurethane, rubber, latex, metal or alloy, glass etc... ) .
In a particularly advantageous embodiment which will be described hereinbelow in the detailed description with reference to the attached drawings, the float has substantially the shape of a truncated cone which has, in its upper part in the widened area, peripheral micro- filter vents which allow only gases or a particular type of gas, for example oxygen, to pass from the outside of the float to its inside which is connected to the outside of the bag by a duct, the inner end of which penetrates inside the float.
The dimension of the vents may be chosen by a person skilled in the art as a function of the charac¬ teristics of the gas or gases to be allowed to pass through, for example so as to enable only oxygen to pass through.
The float may be fixed to the bag during the manufacture of the latter.
In all cases, the main object of the ventilation system, which is a feature of the invention, is to prevent an increase in pressure inside the bag and additionally, in certain embodiments, to enable outside air to be brought inside the bag, when the liquid leaves through the nozzle in order to be used, so as to regulate the flow of the liquid out of the bag, and hence the pack.
It is also very advantageous for the ventilation
system provided in the pack according to the invention to have a float situated above the surface of the packaged liquid product and for this to be so independent of the position of the pack. This is of particular importance in practice as during transport and storage the location of the dispensing tap is not systematically in the lower part of the pack. Indeed, for obvious reasons of bulk and safety, the dispensing tap is concealed up until the time of use such that the pack is handled without taking any account of the position of this tap. The ventilation system of the invention, by virtue in particular of the presence of the float, is efficient in all positions of the pack in space.
The invention will be illustrated further by the detailed description hereinbelow made with reference to the attached drawings, in which:
Figures 1 and 2 show, diagrammatically and in cross-section, the improved pack according to an embodi¬ ment of the invention, in storage with the release of gas, in particular 02 oxygen, and with the liquid being emptied so as to be used, respectively.
Figure 3 illustrates, on a larger scale and in elevation, another embodiment of the ventilation system of the pack according to the invention with a float according to the preferred embodiment of the invention.
Figures 4 and 5 illustrate this float, on a still larger scale, in axial cross-section and viewed from beneath, respectively.
Referring first to Figures 1 and 2, it can be seen that a pack for a liquid according to the invention comprises:
- a parallelepipedal box 1, made preferably from cardboard and whose faces may be folded up on top of each other when the pack is empty; - a bag or sack 2 made preferably from a flexible and strong plastic, for example from polyethylene, which has a volume slightly less than the internal volume of the box 1 so as to be able to be housed inside it; when it is almost entirely filled with the liquid 3 to be
packaged, the bag occupies substantially all the space inside the box 1, as illustrated in Figure 1;
- a nozzle 4 for removal of the liquid 3 from the bag 2 and from the cardboard box 1, it being possible for this nozzle to consist of a tube, which may be bent as illustrated in Figures 1 and 2, one end of which is welded to the bag 2 at 4a about an orifice 2a of the bag and the other end of which opens out outside the card¬ board box 1 which has an orifice la traversed by the said tube; this nozzle is provided with a tap (not shown), for example a metering tap, outside the box 1, which may be actuated by the user; and
- a ventilation system, a feature of the inven¬ tion, which consists of a hollow float 5 and a flexible duct or tube 6 which connects the inside 5a of the float to the outside of the bag 2 which it traverses through an orifice 2b, in particular to the space 7 between the bag 2 and the box 1, the duct being connected to the float 5 at 6a and to the outside of the bag 2 at 6b. A gas filter is advantageously provided at the level of the float (for example at 6a) and/or in the vicinity of the exit of the tube or duct 6 (for example at 6b) .
In the embodiment illustrated in Figures 1 and 2, the float 5 consists of a hollow ball made from natural or synthetic rubber and pierced with at least one hole 5b, for example with two holes 5b, in the zone opposite the join, at 6a, of the ball 5 to the duct 6.
Another embodiment of the float 5 will be descri- bed hereinbelow with reference to Figures 3, 4 and 5.
In Figure 1, the pack according to the invention has been illustrated during storage, for example in the user's home, filled with a liquid capable of releasing a gas, in particular with a washing liquid containing a perborate which is likely to release 02 oxygen, in par¬ ticular when it heats up.
In this case, the 02 oxygen is released from the mass 8 of washing liquid, passing through its open surface 8a on which the float 5 is floating in order to
reach the space 9 above this open surface inside the bag 2 which, for obvious reasons of safety, has not been completely filled with liquid since the latter is incom¬ pressible. An elevated pressure consequently forms in the space 9 and, but for the presence of the ventilation system according to the invention, could well cause the bag 2 to explode.
As a result of the presence of this system, however, the 02 oxygen which is released in the space 9 passes through the hole or holes 5b of the float 5 and penetrates to the inside 5a of this float, then reaches, via the tube or duct 6, the outlet 6b of the tube 6 into the space 7, and then, lastly, passes through the box 1 which is not leaktight. Any elevated pressure in the space 9, and hence untoward rupture of the bag 2, is thus prevented.
Furthermore (Figure 2) , when the liquid 8 is emptied gradually from the pack through the nozzle 4 (emerging jet of liquid 8b), outside air, marked "air" on Figure 2, penetrates through the opening 6b into the duct 6, reaches the inside of the float 5 and leaves by the hole or holes 5b in the latter in order to reach the space 9 above the liquid 8, which permits a regular flow of the latter into the nozzle 4 and hence ensures the regularity of the rate of the jet 8b of liquid intended, for example, to fill a washing ball (not shown) for a washing machine.
It can be clearly seen that the ventilation system both prevents the risk of the bag 2 rupturing as a result of a release of gas and ensures the regular flow of liquid out of the pack.
Another embodiment of the ventilation system, and in particular of the float, has been illustrated in Figures 3 to 5. In this embodiment (in which elements similar to those in Figures 1 and 2 have the reference numerals of these Figures 1 and 2 increased by 10), the float 15 is connected by a flexible tube or duct 16, for example made from plastic, to the outside 17 of the bag or sack 12;
one end 16a of the tube 16 penetrates inside the float 15, whereas the other end 16b of the tube is fixed against the wall of the outlet nozzle 14 for the liquid 13, on the open surface 18a of which floats the float 15. As for the actual float 15 (Figures 3, 4 and 5), it has substantially the shape of a rounded truncated cone (shape of some car headlights), the tube 16 ter¬ minating (at 16a) in its inside 15a, into which the tube penetrates by way of the narrow part (in the lower part when the float 15 floats on the open surface 18a of the liquid mass 18) of the float.
The float 15 consists of three parts, namely:
- a rounded conical shell 21;
- an inner cylindrical "chimney" 22 connected by a rounded joining surface 23 to the lower part (in the floating position of the float) of the shell 21, the upper part of the duct or tube 16 adjacent to its end 16a being fixed inside this chimney, and
- a cap 24 fixed, for example adhesively bonded, to the upper part of the shell (in the floating position of the float), microfilter vents 15b enabling the gas to pass between the inside 15a of the float 15 and the space 19 above the open surface 18a inside the bag.
The circulation of the gases, in particular of the 02 oxgen, from that portion of space 19 in the bag 12 which is occupied by gas above the open surface 18a of the liquid product is, in the embodiment in Figures 3, 4 and 5, similar to the circulation of the gases in the embodiment of Figures 1 and 2. The above detailed description illustrates, without any limitation being implied, a pack, of the type having a bag enclosed in a box, which is light, strong and ecological and is provided with the improvements according to the invention for liquids, in particular the ventilation system for the pack; the improved pack enables the gases to be removed from the bag so as to prevent the formation of an elevated pressure inside the bag which is likely to cause it to explode, and may also regulate the flow of the liquid out of the bag through
the removal nozzle.
The invention, as defined by the following claims, is not limited to the embodiments described specifically but embraces all variants and modifications of them which will occur to a person skilled in the art. The pack has thus been illustrated with a single filter combined with the float. In this case, the filter is designed so as to allow a gas or a given mixture of gases to pass through. It is also possible for more than one filter to be provided so as to allow selectively several different gases to pass through. For example, in addition to the filter combined with the float, a second filter with different properties to the first one, may be fitted in the vicinity of the orifice 2b of the tube 6. The sole purpose of the reference figures inserted after the technical features mentioned in the claims is to facilitate comprehension of these features and in no way limit their scope.