Flexible storage device comprising a flexible container and an inner liner
AssigneesRoquette Freres, So Bag
InventorsJean-Pierre Lecocq, Nicolas Chevalier
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Abstract
A storage device (1) for bulk material intended for powdery materials, includes a flexible container (2) for bulk material and an insulating inner liner (3), of which the surface resistivity is greater than 1.0×1012Ω, without a static electricity conductive layer and without a static electricity dissipation layer, the inner lining (3) covering the inner walls of the container, the inner lining (3) including micro-perforations that pass there through, distributed over the whole surface of the inner lining (3) in such a way that the breakdown voltage of the inner liner (3) is lower than 4 kV and the breakdown voltage of the wall of the container is lower than 6 kV.
Claims23
A bulk storage device (1) intended for powdery materials, said device comprising:
- a flexible bulk container (2), the material of the container being an insulator, without antistatic additive or electrically conductive layer,
- an insulating inner liner (3), of surface resistivity greater than 1.0×1012Ω, without a static electricity conducting layer and without a static electricity dissipation layer, said inner liner (3) covering the inner walls of the container, the thickness Δ of the inner liner (3) being greater than 60 microns and inferior or equal to 700 microns, said inner liner (3) comprising micro-perforations (4) that pass therethrough, the diameter of the micro-perforations (4) being between 5 microns and 130 microns, the micro-perforations being distributed over the whole surface of said inner liner (3), the density of the micro-perforations on the inner liner (3) being between 0.2 perforations per cm2 and 2 perforations per cm2, and in such a way that the breakdown voltage of said inner liner (3) is lower than 4 kV and in that the breakdown voltage of the wall of the container is lower than 6 kV without requiring the device to be earthed,
- such that the storage device can be qualified as a intermediate flexible bulk container classified as type B according to the standard 61340-4-4 Edition 2.0 2012-01.
A method for manufacturing a bulk storage device (1) for powdery materials, said device comprising:
- a flexible bulk container (2), the material of the container being an insulator, without antistatic additive or electrically conductive layer, and
- an insulating inner liner (3), of surface resistivity greater than 1.0×1012Ω, without a static electricity conducting layer and without a static electricity dissipation layer, said inner liner (3) covering the inner walls of the container, the thickness Δ of the inner liner (3) being greater than 60 microns and inferior or equal to 700 microns,
- said method comprising a step of microperforating said inner liner (3) with micro-perforations (4) that pass therethrough, the diameter of the micro-perforations (4) being between 5 microns and 130 microns, the micro-perforations being distributed over the whole surface of said inner liner (3), the density of the micro-perforations on the inner liner (3) being between 0.2 perforations per cm2 and 2 perforations per cm2, and in such a way that the breakdown voltage of said inner liner (3) is lower than 4 kV and in that the breakdown voltage of the wall of the container is lower than 6 kV without requiring the device to be earthed, such that the storage device can be qualified as an intermediate flexible bulk container classified as type B according to the standard 61340-4-4 Edition 2.0 2012-01.
Dependencies are inferred from the claim text.