EP3325374A2

EP3325374A2 - Flexible storage device for packaging particulate solid substances or liquids,method for manufacturing this device and packaging method using this device

Info

Publication number: EP3325374A2
Application number: EP16753955.0A
Authority: EP
Inventors: Bernard Chartrel; Nicolas Chevalier
Original assignee: So Bag; Roquette Freres SA
Current assignee: So Bag; Roquette Freres SA
Priority date: 2015-07-24
Filing date: 2016-07-22
Publication date: 2018-05-30
Anticipated expiration: 2036-07-22
Also published as: CN107922110A; EP3325374B1; US20180194549A1; US11208259B2; FR3039140B1; LT3325374T; ES2804522T3; WO2017017361A3; FR3039140A1; WO2017017361A2; PL3325374T3; RS60491B1

Abstract

Flexible storage device (1) for packaging particulate solid substances or liquids, having a bottom and lateral walls defining a substantially parallelepipedal storage volume, said device comprising: - hanging loops (25) toward the top intended for lifting - an assembly (3) comprising: - a flexible external wrapper (30) forming at least the four lateral walls of the storage volume and possibly the bottom wall of the storage volume, - a flexible tubular internal wrapper (40) secured by vertical fixing lines (41, 42, 43, 44) to the four lateral walls of the external wrapper (30), dividing the storage volume into five vertical compartments including a central compartment which is defined by the interior volume of the internal wrapper, and four peripheral compartments which are respectively defined between the lateral walls of the external wrapper (30) and the lateral walls of the internal wrapper (40), and in which the internal wrapper (40) has an upper edge (50) defining the upper mouth of said central compartment and a lower edge (51) defining the lower mouth of said central compartment, the upper edge (50) of the internal wrapper (40) being situated at the same height as or below the upper edge of the lateral walls of the storage volume so that the upper edge (50) of the internal wrapper constitutes a spillway allowing material to overspill from the central compartment into the peripheral compartments, - and in which the external wrapper (30) is made up of a first polymer film and the internal wrapper (40) is made up of a second polymer film, said vertical fixing lines being weld lines where the first polymer film and the second polymer film are welded together.

Description

FLEXIBLE STORAGE DEVICE FOR THE PACKAGING OF ARTICULAR OR LIQUID SOLID MATERIALS

The invention relates to a flexible storage device for the packaging of bulk solids. The field of the invention is that of large containers intended for the packaging of large quantities of particulate solids, also known as GRVS (Flexible Bulk Container) or FIBC (Flexible Intermediate Bulk Container) bags. . These storage devices have been known for many years and used for the protection, storage and transport of bulk particulates such as food materials (sugar, flour, starch), polymer granules or chemicals.

These containers are conventionally made of polymer fiber webs (for example PP, HDPE, LLDPE), possibly sealed. The capacity of these containers is generally between 0.5 and 2 m. The large size and mass of the containers, once filled, make their handling difficult, even in some cases dangerous. In practice, with a view to optimal use of the storage spaces, the bags filled are stacked on several levels; it is thus essential to ensure the stability over time of the stacks. According to the experience of the Applicant, over time, the particulate matter continues to settle and move in the container, thus deforming the flexible container in a position which often deviates from the vertical, and which can go up to 'to provoke its imbalance. These containers conventionally have a rectangular bottom, often square, and vertical vertical side walls, which should allow, when the bags are juxtaposed, an optimal filling of the available storage area. In practice, the pressure exerted by the particulate matter on the side walls deforms outwardly, the filled container deviating from its ideal parallelepiped shape. The footprint of the container is then greater than the dimensions of the rectangular or square bottom. Thus, and in a truck with a surface area of 32 m ² , it is impossible to juxtapose more than 24 filled containers, each with a square base of 1 m unless subject to a high settlement at the loading and may cause damage. However, it is known from the state of the art of large flexible bulk containers, in particular documents WO 92/14660, WO 92/21572, or even WO 2010/131 961A, of substantially parallelepipedal shape whose resistance to deformation as well as Stability when filled are enhanced by stabilizing, internal, flexible elements.

For this purpose, flexible partitions, vertical, internal to the storage volume of the container, connect the side walls to each other, and divide the storage volume into several vertical compartments, namely a central compartment and four peripheral compartments.

In the containers of document WO 92/14660 or that of document WO 2010/130961, the edges of the partitions defining the upper mouth of the central compartment are positioned below the level of the upper edges of the side walls of the container so as to constitute overflows during filling. The filling of such a container is effected by pouring a flow of particulate material from above in the central compartment, the material first filling the central compartment, then by overflow over the overtures, the peripheral compartments .

Prior filling of the central compartment allows, by the pressure of the particulate matter on its walls to cleanly and uniformly stretch the flexible partitions of the central compartment, and before the material is poured into the peripheral compartments.

Once filled, the stability over time of the container is substantially improved compared to a traditional container (without stabilizing element) in that it does not deviate from the vertical once placed on the ground, thus limiting the risks of tilting of the container. container. In addition, the flexible partitions connecting the side walls (between them) limit the amplitude of the deformations of the side walls of the container to the outside. The size of the filled container is improved, optimizing the storage capacity. In these anteriorities, the flexible partitions of the stabilizing elements are, and like the walls of the flexible container, typically made of polymer fiber webs (for example PP, HDPE, LLDPE), optionally made more or less tight by coating or rolling.

When storage periods are prolonged, there is however a risk of moisture absorption of the material contained through the walls of the container, from the external environment. According to the findings of the Applicant, this recovery of moisture can go up to the formation of clumps in the container, which oppose the good flow of the material through the lower opening of the container, once it opened. In this case, and prior to unloading the container, it may be necessary to demote the contents of the container, by mechanical operations on the outer walls of the container. These mucking operations are undesirable in that they complicate the unloading of materials and also constitute a risk of tampering with the container.

The container of document WO 92/14660 however discloses in FIG. 9 a structure with the presence of an internal lining, marked 28 in a material impermeable to liquid such as polyethylene, which makes it possible to avoid (or at least limit) moisture recovery.

The structure of the storage device of WO 92/14660 thus comprises a container constituting the bottom and the four side walls of the container, typically made of fabric. Each side wall of the container is formed by two flexible halves, joined to each other by a vertical seam connecting their assembly edge, identified 23. Each flexible half, moreover, at the upper corners of the container a suspension loop. The four suspension loops of the device make it possible to lift the filled device, conventionally by means of a lifting system.

The stabilizing element, internal, is constituted by a flexible tubular element, having four vertical seams, thus forming a flexible tube whose volume internal forms the central compartment, and four vertical strips, marked 7, distributed at 90 ° around said tube, intended to be respectively fixed to the four side walls of the bag. For this purpose, each vertical strip edge 7 is sandwiched between the two assembly edges marked 23, and traversed by the same fastening seam. The inner liner 28 indicated in FIG. 9, internally covers the side walls, top and bottom of the container, forming a filler neck at its upper part, marked 34 and a discharge chute marked 35. This inner lining necessarily comprises four marked slots 29, each traversed by the corresponding vertical strip 7 which connects the central tube of the stabilizing element to the corresponding side wall of the bag. According to the findings of the Applicant, and if the flexible bulk container of WO 92/14660 not only responds to problems of optimization of storage and safety, as well as the problem of moisture recovery, it is necessary to a significant manufacturing complexity. Due to the large passage slots of the polyethylene inner lining, marked 29, the liquid tightness of such a large container may be perfectible.

The large flexible bulk container of document WO 92/21572 is also known for responding to problems of optimization of the storage, safety and moisture recovery surface, identified above.

For this purpose, the large flexible bulk container of this anteriority comprises three subsets, namely, as illustrated in FIG. 5:

a flexible container, typically made of fabric forming a rectangular bottom and four rectangular walls, provided with four suspension loops, intended to ensure the handling of the container,

an insert, marked 12, forming stabilizing means with the creation in itself of vertical filling compartments, namely a central compartment, and four peripheral compartments,

an internal lining, marked 15, interposed between the inner walls of the bag and the outer insert walls, and intended to give the container a seal.

The insert is a flexible element, comprising an outer envelope, covering the side walls of the bag, and may be provided, according to the embodiment of FIG. filler channel marked 29, upper, and a discharge chute marked 30, lower. The insert comprises an internal tubular element, including a tube ("core 34") internally forming the central vertical compartment, as well as locating elements marked "strip 25" distributed around the tube, and fastened to the tubes. internal side walls of the outer shell. In this predecessor, the tube ("core 34"), as well as the connecting elements 25 extend over the height of the container and divide the filling volume of the insert into the central compartment and the four peripheral compartments. The filling of such a container is effected by pouring a flow of particulate matter from above at the central compartment, the material first filling the central compartment, then the peripheral compartments through the holes 32, increasing dimensions on the height of the side wall of the tube.

According to the findings of the Applicant, the presence of marked holes 32, does not obtain, like the containers of the documents mentioned above, a good tension of the flexible walls forming the central compartment. On the contrary, and according to the findings of the Applicant, in large commercial containers whose wall of the tube forming the central compartment is provided with holes of large size (of the order of 10 cm or more), the tension is irregular on the height of the tube, giving rise to folds, extending over the height of the tube, which are then copied to the wall of the outer casing of the insert when the material fills the peripheral compartments. The filling of the container is therefore not optimal. Once the container is filled, and according to the findings of the inventor, the fabric of the side walls of the container is pleated in the direction of the height.

According to the embodiment of Figure 6, the central tube ("core 34") and the fastening elements ("strips 25") are made from a tubular flexible element in one piece, by means of first welds, marked 36, at the proximal end of the fastener 25, each delimiting one of the fasteners, marked 25 of the inner tube, marked 34. These fasteners 25 are then fixed in turn , each by their other end, distal, to the inner walls of the outer casing, via two other welds, marked 37. According to the findings of the inventor, each fixing element, identified 25, is itself a tubular element comprising, two walls marked 33 ("bars 33") extending from the identified tube 34, both connected to a marked wall. 35 ("bar 35"), forming the distal end of the marked element 25, this distal end being fixed by two distant welds, marked 37 to the outer casing.

In summary and according to the findings of the Applicant, such a flexible bulk container, and as taught by WO 92/21572 has the following disadvantages:

the container requires three distinct subassemblies, namely a bag, an insert, and an inner sealing liner, inserted to ensure the tightness of the container when the bag is not itself a sealed bag,

the marked holes 32 distributed over the height of the wall of the central tube ensuring the discharge of the particulate matter, from the central compartment to the four peripheral compartments are at the origin of folds during filling, not only on the height of the tube central of the insert, but also on the outer shell of the insert,

- The fastening elements ("strip 25") of the embodiment of Figure 6, are tubular, the inner space of each of these fasteners constituting a lost internal volume, not used to store particulate matter.

The object of the present invention is to overcome the aforementioned drawbacks by proposing a storage device, flexible, for the packaging of bulk solids, of footprint close to the rectangular or even the square when filled, so as to optimize storage capacities when the containers are juxtaposed, of increased safety as to the risk of tipping, and preferably, and at least according to one embodiment, suitable for limiting the moisture absorption of the contained material. Another object of the present invention is to provide such a structural device such that it can be manufactured at a limited cost. Other objects and advantages of the invention will become apparent from the following description which is given for information only and which is not intended to limit it.

The invention relates to a flexible storage device for the packaging of particulate solids having a bottom and side walls defining a substantially parallelepipedal storage volume, the device comprising:

- suspension loops at the top for lifting

an assembly comprising:

a flexible outer envelope forming at least the four lateral walls of the storage volume and, optionally, the bottom wall of the storage volume,

an inner, tubular, flexible envelope, secured by vertical fastening lines on the four lateral walls of the outer envelope, dividing the storage volume into five vertical compartments, including a central compartment, defined by the internal volume of the inner casing, and four peripheral compartments, respectively defined between the side walls of the outer casing, and the side walls of the inner casing, and wherein the inner casing has an upper edge defining the upper mouth of said central compartment and a lower edge defining the lower mouth of said central compartment, the upper edge of the inner envelope being located below or at the same height as the upper edge of the side walls of the storage volume, so that the upper edge of the inner envelope constitutes an overflow allowing the overflow of the materials from the central compartment l to the peripheral compartments,

and in which the outer envelope is constituted by a first polymer film and the inner envelope is constituted by a second polymer film, said vertical fastening lines being weld lines between the first polymer film and the second polymer film.

According to optional features of the invention taken alone or in combination: - The storage device has a flexible container, comprising a bottom and at least two side walls, said suspension loops being secured to the upper portion of said flexible container, and wherein said assembly is a separate element of said flexible container, provided in insert between the bottom and the side walls of said flexible container;

said flexible container consists essentially of said bottom wall, and only two, substantially parallel, side walls covering two of the four lateral walls of the outer casing, and so that the other two lateral walls of the outer casing are not covered by walls of said container; the outer casing of the assembly received as an insert in the container has no bottom, said bottom of the container being fixed to the side walls of the outer casing, the bottom of the container and the side walls forming the storage volume of the materials; solid;

the material of the container is a fabric of polymeric fibers, raw, coated or rolled; - the outer envelope forming said bottom wall of the storage volume, the bottom wall forming with the side walls of the outer casing, the storage volume for the particulate solids;

- The bottom wall is provided with a discharge chute formed by the outer casing, which, in the case where said device has said flexible container, through an opening in the bottom of the container;

the outer casing defines a lid provided with a filler neck;

- The gripping loops are secured directly to the corners of said assembly;

the inner casing is devoid of apertures of diameter greater than 1 mm, preferably having a diameter greater than 200 microns, between the upper edge of the inner casing and the lower edge of the inner casing; ;

- the upper edge of the inner envelope, has notches opposite the various peripheral compartments, favoring the discharge of materials particulates by overflow, from the central compartment to the peripheral compartments;

each weld line directly joins the outer envelope forming one of the side walls to the wall of the tube of the inner envelope defining the perimeter of the central compartment;

the inner casing and the outer casing are in the same extruded polymeric film, monolayer or multilayer;

the polymer film of the inner and / or outer casing is of wall thickness between 50 micrometers and 250 micrometers. According to one embodiment, the polymer film of the outer envelope and / or the inner envelope is chosen from:

a complex polyamide / polyethylene, a multi-layer 100% PE,

a complex of polyolefins of the same nature or of different natures, type EVOH, a complex of polyolefins and aluminum.

According to one embodiment, the outer envelope comprises, at the four corners of the storage volume, flaps, substantially vertical, on the height of the storage volume, each obtained by welding together two thicknesses of the first polymer film, said vertical flaps. being used as a bonding or seaming edge for securing said assembly to said container, or for directly fixing said suspension loops to the bibs.

According to an embodiment limiting the risks of explosion related to the occurrence of electric discharges of electrostatic origin:

- the inner casing and the outer casing are insulating, with a surface resistivity greater than 1.0 x 10 12 Ω (L3 type), without a conductive layer of static electricity and without a dissipative layer of static electricity , the inner and outer envelopes (30, 40) including micro-perforations, through, distributed over their entire surface and in such a way that the breakdown voltage of the internal and external envelope assembly is less than 4 kV, without requiring the device to be earthed,

- the material of the container, if any, is an insulator, without antistatic additive, nor electrically conductive layer, and the breakdown voltage of the wall of the container being less than 6 kV so that the storage device can be qualified as a Class B flexible bulk container in accordance with the 61340-4-4 Edition 2.0 2012-01 standard.

Alternatively and according to another embodiment, the outer casing and the inner casing have a surface resistivity of between 1.0 x 10 ⁹ Ω to 1.0 x

10 12 Ω (type L2) provided with dissipative agents in such a way that the storage device can be qualified as a large flexible bulk container classified as type B according to the 61340-4-4 Edition 2.0 2012-01 standard when the container is in an insulating material in the sense of the standard, or of type C when the container is in a conductive material.

Alternatively and according to yet another embodiment, the outer casing and the inner casing are made of an electrically conductive material with a surface resistivity of less than 1.0 × 10 Ω (type L1) so that the device Storage can be qualified as a Class C flexible bulk container classified in accordance with the 61340-4-4 Edition 2.0 2012-01 standard.

The invention also relates to a method of manufacturing a storage device according to the invention, wherein said set is obtained at least by the implementation of the following steps:

a first polymer film is provided for constituting the outer envelope and a second polymer film, preferably in the form of a tubular sheath of lower perimeter, possibly provided with discharge notches, intended to constitute the inner envelope,

the second polymer film is welded inside a tubular sheath formed by the first polymer film, obtaining two coaxial flexible sheaths formed respectively by the first and the second polymer film, the two sheaths being fixed one in the other, at least four first weld lines.

According to one embodiment, vertical bibs are formed at four angles of the storage volume of the outer envelope, each obtained by welding together two thicknesses of the first polymer film.

According to one embodiment of the method, the assembly having a bottom provided with a discharge chute and / or a lid provided with a filler neck and the bottom is obtained with a discharge chute and / or said lid with a chute. filling by the following successive steps: - two thicknesses of the first polymer film are welded together at four or eight angles of the sheath, each of the welds, called second welds, extending from the edge to one of the mouths of the the sheath and up to a longitudinal edge of the sheath, thus obtaining the filler neck and / or the discharge chute,

the corners of the sheath are removed by cutting the first polymer film along and outside the second welds.

The invention also relates to a method for packaging bulk solids (or a liquid) comprising pouring a bulk particulate solid (or alternatively a liquid) from above into the central compartment of the container. a flexible storage device according to the invention, the material (or the liquid) first filling said central compartment, then overflowing above the upper edge of the inner envelope only, the four compartments.

The invention will be better understood on reading the following description accompanied by the figures in which:

FIG. 1 is an exploded view of the structure of a storage device according to the invention according to a first embodiment, said device comprising, on the one hand, a container, typically made of polymer fabric, provided with loops. of suspension comprising four side walls and a bottom, and, secondly, a set formed of first and second polymeric films defining the particulate impermeable storage volume, including a cover with a filler neck and a bottom with a discharge chute, said assembly being provided as an insert in the container,

- Figure la is a view, in a horizontal section of the assembly, illustrating the central compartment and the peripheral compartments formed by the inner and outer walls of said assembly,

FIGS. 2a and 3a, 2b and 3b, 2c, 3d and 3e respectively illustrate various views of the successive steps of the manufacture of an assembly of a device according to the invention, according to one embodiment,

FIG. 4 is an exploded view of the structure of a storage device according to the invention according to a second embodiment, said device comprising, on the one hand, a container, typically made of polymer fabric, provided with loops. suspension, said container comprising only two sidewalls and a bottom, and, secondly, an assembly formed of the first and second polymeric films, defining the particulate-tight storage volume, including a cover with filler neck and a bottom with a discharge chute, said assembly being provided as an insert in the container,

FIG. 5 is a view of the device of FIG. 4, said assembly inserted in the flexible container,

FIG. 6 is a view of a storage device according to the invention according to a third embodiment, for which the gripping loops are fixed (by sewing or welding) directly to the assembly which forms the storage volume alone. for particulate matter,

FIG. 7 is a view of a storage device according to the invention according to a fourth embodiment, the storage volume for the particulate matter is obtained by the combination of said assembly and the container, more particularly by fixing the lower edges of the side walls formed by the outer shell to the bottom wall of the container. The invention relates to a storage device 1,, 1 "," flexible, for the packaging of particulate solids, having a bottom and side walls defining a substantially parallelepiped storage volume. Optionally, the storage device has a lid 35, closing the storage volume from above.

Such a storage device 1,, 1 "," comprises:

suspension loops 25 at the top for lifting

an assembly comprising:

an outer envelope 30, flexible, forming at least the four lateral walls 31, 32, 33, 34 of the storage volume and, optionally, the bottom wall of the storage volume,

an inner casing 40, tubular, flexible, secured by vertical fastening lines 41, 42, 43, 44 on the four side walls 31, 32, 33, 34 of the outer casing 30, dividing the storage volume into five; vertical compartments C1, C2, C3, C4, C5, including a central compartment C1, defined by the internal volume of the inner envelope, and four peripheral compartments C2, C3, C4, C5, defined respectively between the side walls of the chamber; outer casing 30, and the side walls of the inner casing 40.

The outer envelope 30 is essentially constituted by a first polymer film and the inner envelope 40 consists essentially of a second polymer film, said vertical fastening lines being weld lines between the first polymer film and the second polymer wire. The first polymer film and / or the second polymer film are typically obtained by extrusion, or co-extrusion when the first film and / or the second film are complexes, that is to say multi-layers of the same polymeric material or of several different polymers.

The welding lines, at least four in number, may be of a width of between 5 mm and 20 mm. These welding lines can be optionally doubled. As illustrated without limitation on the examples of the figures, each weld line can directly join the outer envelope 30 forming one of the walls. lateral 31,32,33,34 to the wall of the tube of the inner casing 40 defining the perimeter of the central compartment Cl.

The inner casing 40 has an upper edge 50 defining the upper mouth of said central compartment C1 and a lower edge 51 defining the lower mouth of said central compartment C1. The upper edge 50 of the inner casing 40 is located at the same height as the upper edge of the side walls 31, 32, 33, 34 of the storage volume, or even below the upper edge of the side walls 31, 32, 33, 34 of the storage volume, so that the upper edge 50 of the internal envelope constitutes an overflow allowing overflow of materials from the central compartment C1 to the peripheral compartments C2 to C5.

The filling of the storage volume of the device is thus obtained by pouring a bulk particulate solid (or a liquid) from above into the central compartment C1, the material first filling said central compartment C1, then by overflow of the material above the upper edge 50 of the inner casing 30, the four peripheral compartments C2, C3, C4, C5.

Preferably, the inner casing 40 is devoid of apertures (s) with a diameter greater than 10 mm, or even greater than 1 mm, preferably devoid of an opening of diameter greater than 200 microns, between the upper edge 50 of the internal casing 40 and the lower edge 51 of the inner casing 40. The side wall of the central compartment C1 is thus impermeable to the particulate material, so that the discharge of the material from the central compartment C1 to the peripheral compartments C2 to C5 only above the upper edge 50 forming the overhangs, and not through holes in the wall of the central compartment as taught by the device of WO 92/21572, these holes being marked 9 in FIG. WO 92/21572, or 32 in Figure 6 of WO 92/21572. According to the findings of the inventor, the absence of such holes makes it possible to uniformly tighten the wall of the central compartment C1, and contrary to the teaching of the document WO 92/21572 whose holes generate an irregular tension of the wall of the central compartment according to the height, with the formation of folds on the height during filling, which are then recopied when the peripheral compartments are filled. The inner casing 40 may be optionally perforated, but only for the purpose of promoting the deaeration of the storage volume, and / or still, and as will be described later in order to limit the breakdown voltage of assembly 3: in both cases, the perforations are micro-perforations whose diameter is determined so as to be impermeable to the particulate matter.

According to a first embodiment, not limited to the examples of FIGS. 1, 4, 5 and 7, said storage device may comprise a flexible container 2 comprising a bottom 20 and at least two side walls 21, 22, 23, 24 , said suspension loops 25 being integral with the upper part of said flexible container 2. The material of the container 2 is typically a web of polymer fibers, in particular raw, coated or rolled.

According to this first embodiment, said assembly 3 is then a separate element of said flexible container 2, provided as an insert between the bottom and the side walls of said flexible container. The side walls 31, 32, 33, 34 formed by the outer envelope 30 of said assembly are covered, respectively, in whole or in part, by the side walls of the flexible container 2.

According to one embodiment, illustrated without limitation in Figure 1, the container 2 may have a bottom 20, and four side walls 21, 22, 23, 24, these four side walls then covering respectively the four side walls 31, 32 , 33, 34 of the outer shell 30.

According to another embodiment, illustrated non-limitingly in FIG. 5 or in FIG. 7, the container 2 may have a bottom 20 and only two, substantially parallel, lateral walls 22, 24 covering two of the four side walls of the envelope. external 30. In other words, the other two side walls of the outer casing 30 are not covered by walls of said container 2. Such a construction is advantageous in that it saves material (canvas polymer) for the realization of the container 2. Preferably, said assembly 3 is secured by stitching or gluing to the two side walls 22, 24 of the container, for example at four fastening lines extending vertically at the corners of the container. storage volume. According to an embodiment illustrated in non-limiting manner to the examples of FIGS. 1, 4, 5 or 6, the outer envelope 30 also forms a bottom wall 38, said bottom 38 forming with the side walls 31, 32, 33, 34 of the outer shell 30 solids storage volume, impermeable to particulate matter.

The bottom wall 38 may be provided with a discharge chute 36, which, in the case where said device has said flexible container 2, passes through an opening 26 in the bottom 20 of the container 2. The outer envelope 30 can still define a cover 35 provided with a filler neck 37. The filler neck 37 and / or the discharge chute 36 may be closed by a link. A method of manufacturing an assembly comprising a bottom 38 provided with a discharge chute 36, and / or a cover 35 provided with a filler neck 37 is described below.

In the case where said outer envelope 30 forms a lid 35, and a bottom 38 forming with the side walls 31, 32, 33, 34, a storage volume impermeable to the particulate material, the storage device may advantageously be devoid of said container 2, typically canvas. The suspension loops 25 are then secured directly to said assembly 3, typically at the four corners of the storage volume.

Such an embodiment, illustrated in a nonlimiting manner in FIG. 6, is intended more particularly for moderate load transport, as compared to the storage device with flexible container 2, typically made of fabric, which will make it possible to lift more substantial loads.

According to another embodiment, illustrated without limitation in FIG. 7, the outer envelope 30 has no bottom, that is to say open in its lower part, said bottom 20 of the container 2 being fixed to the walls. In such an embodiment, the bottom 20 of the container 2 and the side walls 31, 32, 33, 34 of the outer casing 30 form the storage volume 31,32,33,34 of the outer casing 30. of the solids, impermeable to particulate matter, the bottom 20 of the container thus closing the lower opening. For this purpose, the marked lower edges 39 of the side walls 31, 32, 33, 34 of the outer casing 30 may be fixed (in leaktight manner to the particulate material) at the periphery 27 of the bottom wall 20 of the container 2. The bottom is then preferably coated or laminated to be impervious to particulate matter.

According to one embodiment, the upper edge 50 of the inner casing 40 has indentations 52, in particular V-shaped, facing the different peripheral compartments C2 to C5, promoting the spillage of particulate matter overflow from the compartment central C1 to peripheral compartments C2 to C5.

According to one embodiment, the polymer film of the inner and / or outer casing is of wall thickness between 50 micrometers and 250 micrometers, preferably between 90 micrometers and 150 micrometers, such as 120 micrometers. The inner casing 40 and / or the outer casing 30 are preferably in the same monolayer or multilayer film, in order to facilitate the recycling of the assembly 3.

The polymer film of the outer envelope 30 and / or the inner envelope 40 may be chosen from:

a complex polyamide / polyethylene, a multilayer 100% polyethylene,

a complex of polyolefins of the same nature or of different natures, in particular of the EVOH type,

a complex of polyolefins and aluminum.

According to the filling tests conducted by the Applicant, good results have been obtained with a polyamide / polyethylene (PA / PE) complex, and more particularly a multilayer (PE / binder / PA / binder / PE), that is, ie comprising a layer of polyamide between two polyethylene layers, and two layers of binder respectively interfacing between the polyamide layer and the polyethylene layers as well as a PA / PA / PE film on the same principles as above.

Such a tested film, with a thickness of 120 microns, made it possible to constitute a good barrier to the humidity of the external environment. Due to the low stress elongation of this polyamide / polyethylene complex, the assembly has given good filling performance by limiting the amplitude of the deformations of the lateral walls of the outer shell towards the outside, under the pressure of the material. , and by comparison with a set of the same construction of which the first and second film are polyethylene only. In general, the outer envelope 30 may have substantially vertical flaps B1, B2, B3, B4, at the four corners of the storage volume, over the height of the storage volume. Each of the bibs B1, B2, B3, B4 is obtained by welding together two thicknesses of the first polymer film.

These vertical flaps B1, B2, B3, B4 are used as bonding or seaming edge to fix said assembly 3 to said container 2 of the container, for example as shown in the embodiment of FIG. 1 or FIG.

These flaps Bl, B2, B3, B4 can still be used to directly fix said suspension loops 25, and as illustrated by way of non-limiting example in FIG. 6. Moreover, different construction arrangements can be taken to limit the explosion hazards related to the occurrence of electrostatic discharge.

According to one embodiment:

the inner casing and the outer casing may be insulating, with a surface resistivity of greater than 1.0 × 10 12 Ω, without a conductive layer of static electricity and without a dissipative layer of static electricity, the casings 30 , 40 internal and external comprising micro-perforations, preferably through, distributed over their entire surface and in such a way that the breakdown voltage of the inner envelope assembly and external envelope is less than 4 kV without requiring the grounding the device, - the material of the container, if any, is an insulator, without antistatic additive, nor electrically conductive layer, and the breakdown voltage of the wall of the container being less than 6 kV so that the storage device can be qualified as a Class B flexible bulk container in accordance with the 61340-4-4 Edition 2.0 2012-01 standard.

The diameter of the micro-perforations can be between 5 micrometers and 130 micrometers, and for example between 5 microns and 40 microns (μιη). The diameter of the micro-perforations will be chosen according to the particle size of the material to be stored and in order to prevent the material from passing through the wall of the outer envelopes 30, or even of the inner envelope 40. The density of the micro-perforations on the the outer and inner envelope 40 is between 0.2 perforations per cm 2 and 2 perforations per cm 2 'and preferably uniform.

Advantageously, such a storage device is of increased safety as to the risk of dangerous electrostatic discharge, and without requiring dissipative agents capable of migrating to the stored product and contaminating it, and without requiring the storage device to be grounded. during filling and emptying operations. For more details on the realization of micro-perforations, the skilled person can refer to the patent application PCT / FR2014 / 051836 of the present applicant.

According to another embodiment, the outer casing 30 and the inner casing 40 have a surface resistivity of between 1.0 × 10 9 Ω and 1.0 × 10 12 Ω (of the L 2 type), that is to say provided. of dissipative agents such that the storage device can be qualified as a large flexible container classified type B according to the standard 61340-4-4 Edition 2.0 2012-01 when the container is in an insulating or dissipative material according to the of the standard, or type C when the container is in a conductive material. Such an embodiment does not require the storage device to be grounded during the filling and emptying operations when type B, but contains dissipative agents capable of migrating the stored products.

According to another embodiment, the outer envelope 30 and the inner envelope 40 are in an electrically conductive material of lower surface resistivity. η

at 1.0 x 10 Ω (type L1) such that the storage device can be qualified as a type C flexible bulk container classified in accordance with standard 61340-4-4 Edition 2.0 2012-01. Such a device, however, requires the grounding of the storage device during filling and emptying operations, and to ensure safety vis-à-vis the risk of electric shock.

The invention also relates to a method of manufacturing a storage device according to the invention, in which obtains said set 3 at least by the implementation of the following steps:

a first polymer film is provided for constituting the outer envelope 30 and a second polymer film, preferably in the form of a tubular sheath of smaller diameter, possibly provided with discharge notches 52, intended to constitute the envelope; internal 40 (see FIGS. 2a and 3a),

the second polymer film is welded inside a tubular sheath formed by the first polymer film, obtaining two coaxial flexible sheaths, formed respectively by the first and the second polymer film, the two sheaths being fixed one to the other; other, at the first four welding lines 41 to 44 (see Figures 2b and 3d).

These steps make it possible to obtain said assembly, with the outer envelope 30 and the inner envelope 40 which mutually define the vertical compartments C1 to C, namely the central compartment C1, and the peripheral compartments C2 to C5. Optionally and before these two steps, the first polymer film and the second polymer film may be perforated, over their entire surface, uniformly, said micro-perforations diameter preferably between 5 micrometers and 130 micrometers and preferably between 0.2 perforations per cm ² and 2 perforations per cm ² , as previously described. Each of the two tubular sleeves can be obtained from the first polymeric film (or second polymeric film), originally in the form of a sheet, which is folded over itself and two of the edges of which are welded to get the sheath. According to another alternative, the first polymer film and / or the second polymer film can be advantageously present from the beginning in the form of a bellows sheath, extradited in one piece.

Thus, and according to an embodiment illustrated in FIG. 2a, the first polymer film and / or the second polymer film may already be each in the form of a bellows sheath, typically extruded in one piece.

The method may also have an additional step for forming on said set of vertical bibs B1, B2, B3, B4, which will then serve as bonding edge or seam and as explained above.

Thus and as illustrated without limitation in FIG. 2c, vertical bibs B1, B2, B3, B4 are formed at the four corners of the storage volume of the outer casing 30, each of the bibs being obtained by welding together two thicknesses of the first polymer film, especially over several centimeters.

When said assembly has a bottom wall 38 provided with a discharge chute 36 and / or a cover 35 provided with a filler neck 37, it is possible to obtain the bottom 38 with emptying chute 36 and / or said cover 35 with filler neck 37 by the following successive steps:

two thicknesses of the first polymer film are welded together at four or eight angles of the sheath, each of the welds, called second welds, extending from the edge to one of the mouths of the sheath and up to one longitudinal edge of the sheath, thus obtaining the filler neck and / or the discharge chute (see Figure 3d),

- The corners of the sheath are removed by cutting the first polymer film along and outside the second welds (see Figure 3e).

The four upper welds S1, S2, and S1 ', S2' make it possible to make the cover 35 with its filler neck 37, the four lower welds S3, S4 and S3 ', S4' the bottom with the discharge chute 36. can realize only the upper welds SI, S2, and SI ', S2' or the lower welds S3, S4 and S3 ', S4' or the eight, as needed. Naturally other embodiments could have been envisaged by the skilled person without departing from the scope of the invention defined by the claims below.

NOMENCLATURE

1. Γ, 1 ",". Storage device,

2. Flexible container,

20. Bottom (container),

21, 22, 23, 24. Side walls (container)

25. Suspension loops,

26. Opening (Bottom 20),

27. Periphery (Bottom)

3. Set or Insert,

30. External envelope

31, 32, 33, 34. Lateral walls

35. Lid,

36. Drain chute,

37. Filling chute,

38. Bottom (set or insert),

39. Bottom edges (side walls formed by the outer shell 30),

40. Inner envelope,

41 to 44. Vertical welds (first welds)

50. Upper edge,

51. Bottom edge,

Cl. Central compartment,

C2 to C5. Peripheral compartments, S1, S2 and S1 ', S2'. Superior welds, S3, S4 and S3 \ S4 '. Lower welds.

Claims

A flexible storage device (1) for packaging particulate or liquid solids having a bottom and side walls defining a substantially parallelepipedal storage volume, said device comprising:

- suspension loops (25) at the top for lifting

an assembly (3) comprising:

an outer flexible envelope (30) forming at least the four lateral walls (31, 32, 33, 34) of the storage volume and, optionally, the bottom wall of the storage volume,

- an inner casing (40), tubular, flexible, secured by vertical fastening lines (41,42,43,44) on the four side walls (31,32,33,34) of the outer casing (30) , dividing the storage volume into five vertical compartments (C1, C2, C3, C4, C5), including a central compartment (C1), defined by the internal volume of the inner envelope, and four peripheral compartments (C2, C3) , C4, C5), respectively defined between the side walls of the outer shell (30), and the side walls of the inner shell (40), and wherein the inner shell (40) has an upper edge (50). ) defining the upper mouth of said central compartment (C1) and a lower edge (51) defining the lower mouth of said central compartment (C1), the upper edge (50) of the inner envelope (40) being located at the same height or below the upper edge of the side walls of the storage volume, so that the upper edge (50) of the inner casing constitutes an overflow allowing overflow of the materials from the central compartment (C1) to the peripheral compartments (C2 to C5), and in which the outer casing (30) is constituted by a first polymer film and the inner casing (40) is constituted by a second polymer film, said vertical fastening lines being weld lines between the first polymer film and the second polymer film.

2. Device according to claim 1, having a container (2) flexible, comprising a bottom (20) and at least two side walls (21, 22, 23, 24), said suspension loops (25) being integral with the part upper of said flexible container (2), and wherein said assembly (3) is a separate element of said flexible container, provided as an insert between the bottom (20) and the side walls (21, 22, 23, 24) of said flexible container.

3. Device according to claim 2, wherein said flexible container (2) consists essentially of said bottom wall (20), and two side walls (22, 24) only, substantially parallel, covering two of the four side walls of the outer shell (30), and so that the other two side walls (31, 33) of the outer shell (30) are not covered by walls of said container (2).

4. Device according to claim 2 or 3, wherein the outer casing (30) of the assembly (3) received as an insert in the container has no bottom per se, said bottom (20) of the container (2) being attached to the side walls (31, 32, 33, 34) of the outer shell (30), the bottom (20) of the container (2) and the side walls (31, 32, 33, 34) forming the storage volume solids.

5. Device according to one of claims 2, 3 or 4, wherein the material of the container (20) is a web of polymeric fibers, raw, coated or laminated.

6. Device according to one of claims 1 to 5 wherein the outer casing (30) forming said bottom wall (38) of the storage volume, the bottom wall (38) forming with the side walls (31, 32). , 33, 34) of the outer casing (30) the storage volume for the particulate solids.

7. Device according to claim 6, wherein the bottom wall (38) is provided with a discharge chute (36) formed by the outer casing (30), which, in the case where said device has said flexible container (2) passes through an opening (26) in the bottom (20) of the container (2).

8. Device according to one of claims 1 to 7, wherein the outer casing (30) defines a cover (35) provided with a filler neck (37).

9. Device according to one of claims 6 or 7, optionally taken in combination with claim 8, wherein the suspension loops (25) are secured directly to the corners of said assembly (3).

10. Device according to one of claims 1 to 9, wherein the inner casing (40) is devoid of aperture (s) with a diameter greater than 1 mm, preferably an opening with a diameter greater than 200 microns, between the upper edge (50) of the inner envelope (40) and the lower edge (51) of the inner envelope (40).

11. Device according to one of claims 1 to 10, wherein the upper edge (50) of the inner casing (40), has notches (52) facing the different peripheral compartments (C2 to C5), promoting the overflow of particulate matter from the central compartment (C1) to the peripheral compartments (C2 to C5).

12. Device according to one of claims 1 to 11, wherein each weld line directly joins the outer casing (30) forming one of the side walls (31,32,33,34) to the wall of the tube. the inner envelope (40) defining the perimeter of the central compartment (C1).

13. Device according to one of claims 1 to 12, wherein the inner casing (40) and the outer casing (30) are in the same extruded polymer film, monolayer or multilayer.

14. Device according to one of claims 1 to 13, wherein the outer casing (30) comprises at the four corners of the storage volume, flaps (B1, B2, B3, B4), substantially vertical, the height of the storage volume, each obtained by welding together two thicknesses of the first polymer film, said vertical flaps (B1, B2, B3, B4) being used as bonding edge or seam edge to fix said assembly (3) to said container ( 2), or to directly fix said suspension loops to the flaps (Bl, B2, B3, B4).

15. Device according to one of claims 1 to 14, wherein the polymer film of the outer casing (30) and / or the inner casing (40) is chosen from:

a polyamide / polyethylene complex, a multilayer 100% PE,

16. Device according to one of claims 1 to 15 wherein the polymer film of the inner and / or outer casing is of wall thickness between 50 micrometers and 250 micrometers.

17. Device according to one of claims 1 to 16, wherein:

- the inner casing and the outer casing are insulating, with a surface resistivity greater than 1.0 x 10 12 Ω (L3 type), without a conductive layer of static electricity and without a dissipative layer of static electricity , the inner and outer envelopes (30, 40) comprising micro-perforations, passing through them, distributed over their entire surface and in such a way that the breakdown voltage of the internal envelope and outer envelope assembly is less than 4 kV without requiring the grounding the device, - the material of the container, if any, is an insulator, without antistatic additive, or electrically conductive layer, and the breakdown voltage of the wall of the container being less than 6 kV of such in such a way that the storage device can be qualified as a type B classified flexible bulk container according to the 61340-4-4 Edition 2.0 2012-01 standard.

18. Device according to one of claims 1 to 16, wherein the outer casing (30) and the inner casing (40) have a surface resistivity of between 1.0 x 10 ^9.

Ω at 1.0 x 10 12 Ω provided with dissipative agents in such a way that the storage device may be qualified as a large flexible bulk container classified as type B according to the standard 61340-4-4 Edition 2.0 2012-01 when the container is in an insulating or dissipative material within the meaning of the standard, or type C when the container is in a conductive material within the meaning of the standard.

19. Device according to one of claims 1 to 16, wherein the outer casing and the inner casing are in an electrically conductive material of surface resistivity less than 1.0 x 10 Ω so that the device Storage can be qualified as a Class C flexible bulk container classified in accordance with the 61340-4-4 Edition 2.0 2012-01 standard.

20. A method of manufacturing a storage device according to one of claims 1 to 19, wherein said set (3) is obtained at least by the implementation of the following steps:

a first polymer film is provided for constituting the outer envelope (30) and a second polymer film, preferably in the form of a tubular sheath of smaller perimeter, possibly provided with discharge notches, intended to constitute the inner casing (40),

the second polymer film is welded inside a tubular sheath formed by the first polymer film, obtaining two coaxial flexible sheaths, formed respectively by the first and the second polymer film, the two sheaths being fixed one to the other; other, at the first four welding lines (41, 42, 43, 44).

21. The method of claim 20, wherein said assembly has a bottom (38) provided with a discharge chute (36) and / or a cover (35) provided with a filler neck (37) and the result is obtained. bottom (38) with emptying chute (36) and / or said cover (35) with filler neck (37) by the following successive steps:

two thicknesses of the first polymer film are welded together at four or eight angles of the sheath, each of the welds, called second welds (S1, S2, S1, S2 ', S3, S4), extending from the edge at one of the mouths of the sheath and up to a longitudinal edge of the sheath, thereby obtaining the filling chute (37) and / or the discharge chute (36),

- The angles of the sheath are removed by cutting the first polymer film along and outside the second welds (SI, S2, SI ', S2 \ S3, S4, S3 \ S4').

22. The method of claim 20 or 21, wherein forming vertical bibs (B1, B2, B3, B4) at four corners of the storage volume of the outer casing. (30), each obtained by welding together two thicknesses of the first polymer film.

23. A method of packaging bulk solids comprising spilling a particulate solid material in bulk, or a liquid material from above into the central compartment (C1) of a flexible storage device according to one of the present invention. Claims 1 to 19, the material first filling said central compartment, then by overflow of the material above the upper edge (50) of the inner casing (40) only, the four peripheral compartments (C2, C3, C4, C5).