EP2665664B1 - Method for temporarily increasing the resistance to vertical compression of a bag for transporting and holding liquids and quasi-liquids, and resulting bag - Google Patents

Description

The present invention relates to a method for temporarily increasing the vertical compressive strength of a bag for the transport and handling of liquid or quasi-liquid substances. It also relates to a bag resulting from the implementation of the method.

The industrial scale transport of liquid and quasi-liquid substances, particularly fruit juice concentrates for example, is an important branch of world trade. To transport such substances, the first idea that comes to mind is to place them in rigid containers such as tanks with metal walls or plastic.

However, such rigid containers have a major disadvantage, namely that they occupy the same volume when empty as when they are full. Carrying empty containers over very long distances to return them to the filling point is economically and ecologically absurd. That is why the preference goes logically, since they are available, to flexible containers that can be deployed to fill them or on the contrary to fold to give rise to a minimum space requirement during the return trip to the filling location .

Such a flexible container is known in particular from the document WO 97/20758 which corresponds to the preamble of claim 1.

The document WO 2009/010928 A2 Briefly presents an outer envelope formed of assembled canvas coupons forming roughly a coarse cubic bag in which takes place a second envelope, a liner, intended to be filled with a liquid or quasi-liquid substance. The four sides of the outer shell are made of double fabric and compartmentalized in order to be able to receive reinforcing plates. The four vertical edges of the bag forming the outer envelope are separated from the liner by vertically sewn webs parallel to said ridges, in order to combat the tendency of the bag once filled to bend outwards under the pressure of the liquid it contains.

The trade in liquid or quasi-liquid substances, and in particular that of fruit juice concentrates, has the particularity that the quantity of liquid actually transported in a container rarely depends on the maximum internal volume of the container. The container is not filled to the brim, it is filled according to the order to be satisfied or the volume of liquid available in the tank to be emptied. For this reason, for the most part, containers (flexible or not) travel only partially filled and not at full capacity.

Rigid containers have many drawbacks, which have been mentioned, but they have an advantage over flexible containers, namely that even when partially filled, they can be stacked, stacked two or three on top of one another.

The stack of flexible containers, especially partially filled is therefore a problem, solved so far by the use of wooden boxes in which the flexible containers are deposited for transport. Knowing that the weight of such a box can reach 100 kilos for each container, there would be in all respects a serious economy to be able to emancipate.

The present invention aims to temporarily increase the vertical compressive strength of a bag for the transport and handling of liquid or quasi-liquid substances, so as to allow their stacking and thus eliminate the need to use crates for this purpose alone.

For this purpose, the present invention provides a method according to claim 1. The object of the present invention is to provide a bag according to claim 4.

According to one embodiment, the bag is of generally cubic shape and includes reserves in each of its corners. The bag may have four reserves, one at each corner of said bag.

According to one embodiment, four cushioning cushions are chosen for each bag.

According to one embodiment, at least one storage bag is introduced by reserve.

According to one embodiment, the cushioning cushions comprise two films, for example of polyethylene, welded to each other and an inflation / deflation valve.

The following description refers to the drawing in which the figure 1 is a partially exploded perspective view illustrating the application of the method according to the invention.

On the figure 1 a bag is recognized for the transport and handling of liquid or quasi-liquid substances produced according to the teaching of the document WO 2009/010928 .

We recognize the bag 1, whose four sides are made of double canvas. Each side of the bag has three sections delimited by two vertical seams in which can be seen a reinforcing panel 2, introduced between the two pieces of fabric of each of the three sections.

It is observed that the four corners of the bag have reserves 3, forming parallelepipeds of triangular section, and that the upper mouth of these four reserves is free and not closed.

It is the space made up of the four reserves which can be occupied by possible organs intended to make possible the stacking of the bags. It should be borne in mind that the entire interior of the bag, its central part, is occupied by a liner intended to be filled with the liquid to be transported.

One could certainly think of introducing additional reinforcement into the reserves, for example logs of suitable size, but it is much more elegant not to weigh down the total weight transported while obtaining the expected result.

However, it happens that in the world of transport, including ports, inflatable cushioning bags (dunnage bags) are used to stabilize the loads inside, for example large 40-foot ISO containers. These cushions, when deflated, look like an empty, flat pillowcase. These cushions are made using two polyethylene films welded to each other all around their circumference and are equipped with an inflation and deflation valve. When inflated with compressed air, these cushions are large, particularly chubby pillows.

Various sizes and shapes of such airbags are available on the market.

These cushions are very strong and the internal pressure can be high enough to be hard as stone.

In all cases of normal application, these cushions are used to occupy laterally space between two charges, so as to separate them from each other along a horizontal axis determined by the center of the two faces of the cushion. On the other hand, nothing invites, on the contrary, to exploit the properties of these cushions along another axis than this one.

However, this idea is the key to the process according to the invention.

We see on the figure 1 that we chose a wedging cushion 4 whose measurements correspond in height and width to that of the reserves 3. We also choose the cushion according to the position of its inflation valve 5, which is desired close to a longitudinal end of the cushion.

Four cushions are retained for each bag and each of them is introduced, deflated, into one of the four reserves 3.

Once the liner is filled with the amount of liquid to be transported, the four cushioning cushions are inflated with compressed air.

This inflation inside reserves 3 has a double effect. First, the pressure applied to the inner faces of the reserves increases the tension of the fabric and contributes to properly locking in position the reinforcing panels 2. This first effect has an immediate beneficial consequence, namely that the optimal rigidity of the The entire structure of the bag is guaranteed, even if the liner is only partly filled with liquid. But this interaction between the structure of the bag and the cushions gives rise to a second effect that is to imprison each cushion in the only position that authorizes the structure of the bag, respectively the orientation of the reserves 3, namely a generally vertical position. Stuck in his corset, each cushion is then able to offer great resistance to vertical forces, which nothing predestined to do. One thinks particularly of the vertical forces generated by the weight of one or more other bags filled and stacked above the first one. Since both effects are present and in fact interdependent, it is difficult to attribute to one another yet another advantage, namely that the optimal rigidity of the bag structure and its greater resistance to vertical compression are not compromised. in the event that a damaged liner would leak its contents. The stability and rigidity of the bag are certainly better when the liner is filled with liquid at least in part, but the functional threshold for stacking several bags is achieved by the method according to the invention even if the liner is empty.

It is conceivable, for not having to apply the method once for each bag, to permanently or permanently fasten the airbags in the reserves of the bag and keep them there during inflation and deflation by means of example of a hand strap or lug that prevents the cushion once deflated out of his reserve.

The advantages resulting from the application of the method according to the invention are expressed on the one hand in a gain during the journey from the filling location to the delivery destination and on the other hand during the reverse journey.

During the first trip, we have the possibility, without any increase of weight, that of the cushions being insignificant, to stack filled bags on each other and also of course to store other charges over a or several bags stacked.

During the second journey, the deflated cushion represents an insignificant space on this scale, and a weight that is still almost zero, as has been said.

Finally, the price of a cushion of the kind chosen is almost zero, and therefore does not increase the cost of transportation, while its judicious use according to the invention allows substantial savings in terms of weight and volume transported.

Claims (6)

1. A method of temporarily increasing the resistance to vertical compression of a bag for conveying and handling liquids and quasi-liquids, the bag (1) comprising a liner and four receptacles (3), one in each corner of the bag, characterised in that inflatable wedging cushions (4) are chosen for each bag, the cushions being elongated and having a length, width and spread related to the length, width and internal volume of the bag receptacles, and in that the wedging cushions are inserted into the receptacles in order subsequently to inflate the cushions and thus confine them in a vertical position enabling them to resist compression along their vertical axes.
2. A method according to claim 1, characterised in that the wedging cushions are inflated in the receptacles after having introduced the quantity of liquid for conveyance into the liner.
3. A method according to claim 1 or 2 wherein the bag has a generally cubic shape and at least one wedging cushion (4) is inserted in each receptacle.
4. A bag having resistance to vertical compression, for conveying and handling liquids and quasi-liquids, comprising a liner and four receptacles (3), one in each corner of the bag, characterised in that the receptacles each have an internal wedging cushion (4) secured to the bag if required, the cushions being elongated and having a length, width and spread related to the length, width and internal volume of the bag receptacles, the cushions, once inflated, being confined in a vertical position enabling them to resist compression along their vertical axes.
5. A bag according to claim 4, characterised in that it has a generally cubic shape.
6. A bag according to claim 4 or 5, characterised in that the wedging cushions (4) comprise two welded-together polyethylene films and an inflating/deflating valve (5).

Images