DK2665664T3 - PROCESS FOR TEMPORARY INCREASE RESISTANCE TO VERTICAL COMPRESSION FOR A BAG FOR TRANSPORT AND HANDLING OF FLUIDS and quasi-LIQUIDS AND BAG OBTAINED BY THE PROCESS - Google Patents

Description

Description

The present invention relates to a method for temporarily increasing the resistance to vertical compression of a bag for transporting and holding 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, in particular fruit juice concentrates, for example, is a significant branch of world trade. In order to transport such substances, the first idea that comes to mind is to place them in rigid containers such as tanks with metal or plastic walls.

However, such rigid containers have a major drawback, which is that they occupy the same amount of space when they are empty as when they are full. Transporting empty containers over very long distances to return them to the filling point is economically and ecologically absurd. That is why preference is logically given, when they are available, to flexible containers that can be deployed for filling or, on the contrary, folded up to occupy minimal space during the return trip to the filling location.

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

Document WO 2009/010928 A2 briefly describes an outer enclosure formed from assembled bolts of canvas assembled so as broadly speaking to form a roughly cubic bag in which a second enclosure, a liner, is placed, designed to be filled with a liquid or quasi-liquid substance. The four sides of the outer enclosure are made from double canvas and compartmentalized so as to be able to receive reinforcing plates. The four vertical edges of the bag forming the outer enclosure are separated from the liner by strips of canvas sewn vertically parallel to said edges, so as to combat the tendency of the bag once filled to curve outwardly under the pressure from the liquid it contains.

The trade of liquid or quasi-liquid substances, and in particular of fruit juice concentrates, is special in that the quantity of liquid actually transported in a container rarely depends on the maximum inner volume of the container. The container is not filled to the brim; it is filled based on the order to be fulfilled or the volume of liquid available in the tank to be emptied. For this reason, the majority of containers (flexible or not) travel only partially filled, and not filled to full capacity.

Rigid containers have drawbacks, which have been mentioned, but they have one advantage over flexible containers: even when only partially full, they can be partially superimposed, stacked on top of one another two or three high.

Stacking flexible containers, particularly when they are only partially filled, is therefore problematic, which has been resolved to date by the use of wooden crates in which the flexible containers are deposited for transport. Given that the weight of such a crate can reach 100 kg for each container, there would be significant savings achieved if they could be eliminated.

The present invention aims to temporarily increase the resistance to vertical compression of a bag for transporting and holding liquid and semi-liquid substances, so as to allow them to be stacked and thus eliminate the need to use crates for that purpose alone.

To that end, the present invention proposes a method according to claim 1. The aim of the present invention is to propose a bag according to claim 4.

According to a first embodiment, the bag is generally cubic and comprises receptacles in each of its corners. The bag can include four receptacles, one in each corner of the bag.

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

According to one embodiment, at least one wedging bag per receptacle is inserted.

According to one embodiment, the wedging cushions comprise two films, for example polyethylene, welded to one another, and an inflation/deflation valve

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

In figure 1, a bag is shown for transporting and holding liquid or quasi-liquid substances according to the teaching of document WO 2009/010928.

One thus recognizes the bag 1, the four sides of which are made from a double canvas. Each side of the bag includes three sections delimited by two vertical seams, [and] one can see a reinforcing panel 2, introduced between the two canvas parts of each of the three sections.

One can see that the four corners of the bag have receptacles 3, forming triangular rhombs, and that the upper mouth of these four receptacles is free and not closed.

The space formed by the four receptacles can be occupied by any members designed to make it possible to stack the bags. It should be borne in mind that the entire inside of the bag, its central part, is occupied by a liner designed to be filled with the liquid to be transported.

One could certainly consider introducing additional frames into the receptacles, for example billets with an appropriate size, but it is much more elegant not to make the entire transported weight heavier while obtaining the expected result.

Yet in the transport field, in particular port transport, inflatable wedging cushions (dunnage bags) are used to stabilize loads for example inside large ISO containers measuring 40 feet. When these cushions are deflated, they resemble a flat, empty pillowcase. These cushions are produced using two polyethylene films welded to one another over their entire perimeter and are provided with an inflation and deflation valve. When they are inflated with compressed air, these cushions look like large, particularly plump pillows.

Various sizes and shapes of such inflatable cushions are commercially available.

These cushions are very strong, and the internal pressure may be high enough for them to be hard as stone.

In all cases of normal application, these cushions are used to laterally occupy space between two loads, so as to separate them from one another along a horizontal axis determined by the center of the two faces of the cushion. However, on the contrary, nothing encourages using the properties of those cushions along a different axis.

Yet that idea is the key to the inventive method.

Figure 1 shows that a wedging cushion 4 has been chosen whose measurements correspond to those of the receptacles 3 in terms of height and width. The cushion is also chosen based on the position of its inflation valve 5, which should ideally be close to a longitudinal end of the cushion.

Four cushions are selected for each bag and each of them is inserted, deflated, into one of the four receptacles 3.

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

This inflation inside the receptacles 3 has a dual effect. First, the pressure applied on the inner faces of the receptacles increases the tension of the canvas and contributes to cleanly locking the reinforcing panels 2 in position. This first effect has an immediate beneficial consequence, i.e., that the optimal rigidity of the entire structure of the bag is guaranteed, even if the liner is only partly filled with liquid. However, this interaction between the structure of the bag and the cushions leads to a second effect, namely capturing each cushion in the only position allowed for it by the structure of the bag, the orientation of the receptacles 3, respectively, i.e., a globally vertical position. Jammed in its support, each of the cushions is then capable of offering considerable resistance to vertical forces, which nothing predestined it to do. One may in particular think about the vertical forces generated by the weight of one or more other bags filled and stacked on top of the first. The two effects being present and, in reality, interdependent, it is difficult to attribute a further advantage to only one of them, i.e., that the optimal rigidity of the structure of the bag and its greater resistance to vertical compression are not compromised in the case where a damaged liner allows its contents to escape. The stability and rigidity of the bag are certainly better when the liner is at least partially filled with liquid, but the functional threshold allowing several bags to be stacked is reached owing to the inventive method even if the liner is empty.

One could consider permanently or reversibly securing the inflatable cushions in the receptacles of the bag, so as only to have to apply the method once for each bag, and keeping them there during the inflations and deflations, for example using a maintaining strap or tab that prevents the cushion from leaving its receptacle once deflated.

The advantages resulting from the application of the inventive method are reflected on the one hand by a gain during the journey from the filling location to the delivery location, and on the other hand during the return trip.

During the first trip, it is possible, without any weight increase, to stack filled bags on one another and, of course, to store other loads above one or more of the stacked bags.

During the second trip, the deflated cushion represents an insignificant bulk on that scale, and a still quasi-zero weight, as stated above.

Lastly, the price of a cushion chosen in this way is also practically null, and therefore does not increase transport costs at all, whereas its judicious use according to the invention allows significant savings in terms of transported weight and volume.

Claims (6)

A method for temporarily increasing the resistance to vertical compression of a bag for transporting and handling liquids and quasi-liquids, said bag (1) comprising a liner and four containers (3), one in each corner of the bag, characterized by that inflatable wedge pads (4) of elongated shape are selected for each bag, the length, width and spread of the bag being proportional to the length, width and inner volume of the bag containers, and by inserting the wedge pads into the containers for subsequent use. inflating the pads and thus holding them in a vertical position which enables them to withstand compression along their vertical axis. Method according to claim 1, characterized in that the wedge pads are inflated inside the containers when the amount of liquid for transport has been introduced into the casing. The method of claim 1 or 2, wherein the bag is generally cubic in shape and at least one wedge pad (4) is inserted into each container (3). A bag with resistance to vertical compression for transport and handling of liquids and quasi-liquids comprising a liner and four containers (3), one in each corner of the bag, characterized in that the containers each have an inner wedge pad (4 ), which is attached to the bag if necessary, and which has an elongated shape, the length, width and spread of which is proportional to the length, width and inner volume of the bag containers, the pads being inflated when held vertically position which allows them to withstand compression along their vertical axis. A bag according to claim 4, characterized in that it has a generally cubic shape. Bag according to claim 4 or 5, characterized in that the wedge pads (4) comprise two welded polyethylene films and an inflation / discharge valve (5).