# US 11,299,312 B2 · Method for producing a leak-tight vessel, and a leak-tight vessel

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- Number: US 11,299,312 B2
- Document ID: US11299312B2
- Status: Granted
- Kind: B2
- Application number: 16/408,570
- Filed: 2019-05-10
- Published: 2019-12-12
- Granted: 2022-04-12
- Earliest claimed: 2010-05-17
- Assignees: Covess N.V.
- Applicants: Covess N.V.
- Inventors: Tony Vanswijgenhoven; Dieter Vanswijgenhoven; Axel Seifert
- Web page: https://patentgrep.com/patent/US11299312B2

## CPC

- B65D 3/00: Rigid or semi-rigid containers having bodies or peripheral walls of curved or partially-curved cross-section made by winding or bending paper without folding along defined lines
- B29C 53/581: {using sheets or strips consisting principally of plastics material (using profiled sheets or strips B29C53/78)}
- B29C 53/602: {for tubular articles having closed or nearly closed ends, e.g. vessels, tanks, containers}
- B29C 53/824: {collapsible, e.g. elastic or inflatable; with removable parts, e.g. for regular shaped, straight tubular articles (B29C53/825 takes precedence)}
- B29C 70/086: {and with one or more layers of pure plastics material, e.g. foam layers (applying a non-preformed coating, e.g. a gel-coat, B29C37/0025; with foam blocks B29C70/86)}
- B29C 70/86: Incorporated in coherent impregnated reinforcing layers, {e.g. by winding}
- F17C 1/02: involving reinforcing arrangements {(F17C1/14, F17C1/16 take precedence)}
- B29K 2101/12: Thermoplastic materials
- B29K 2105/243: {Partially cured}
- B29L 2031/712: {Containers; Packaging elements or accessories, Packages (closures therefor B29L2031/56; ink or toner cartridges B29L2031/7678; squeeze tubes B29L2023/20; suitcases B29L2031/7418)}
- B29L 2031/7156: {Pressure vessels}
- F17C 2201/0109: with exteriorly curved end-piece
- F17C 2201/056: Small (<1 m3)
- F17C 2201/058: portable (<30 l)
- F17C 2203/0609: Straps, bands or ribbons
- F17C 2203/067: helically wound
- F17C 2209/2163: with a mandrel
- F17C 2209/234: of closing end pieces, e.g. caps
- F17C 2223/0123: gaseous, e.g. CNG, GNC
- F17C 2223/036: Very high pressure (>80 bar)
- Y02E 60/32: Hydrogen storage
- B65D: CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- F17C: VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES (storing fluids in natural or artificial cavities or chambers in the earth B65G5/00; construction or assembling of bulk storage containers employing civil-engineering techniques E04H7/00; variable-capacity gas-holders F17B; liquefaction or refrigeration machines, plants, or systems F25)
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

The present invention describes a method for producing a leak-tight vessel for holding a gas and/or liquid, comprising the steps of winding a heat-sealable thermoplastic barrier strip around a removable mandrel in such a way that each strip fragment overlaps with a substantially parallel strip fragment over at least a lateral overlapping distance, consolidating the overlapping strip fragments so as to form a gas and/or liquid tight layer, winding a fibrous material around the gas and/or liquid tight layer, thereby leaving an opening large enough for removing the mandrel. The invention also describes a leak-tight vessel produced in this way.

## Claims

### Claim 1

A leak-tight vessel for holding a gas and/or a liquid, comprising:
an inner barrier layer comprising a heat-sealable thermoplastic material, wherein the inner barrier layer is formed by winding a barrier strip;
an outer shell layer comprising a fiber-reinforced heat-sealable thermoplastic material, wherein the outer shell layer is formed by winding glass- or carbon-fibers, co-mingled, impregnated or pre-impregnated with a heat-sealable thermoplastic material; and
an end fitting positioned at the inner side of the inner barrier layer, covered at least partly at its outer concave surface with a heat-sealable thermoplastic material;
wherein the inner barrier layer, the outer shell layer and the end fitting form a unitary rigid structure able to withstand an overpressure of at least two bars.

### Claim 2 (depends on 1)

The leak-tight vessel according to claim 1, wherein the inner barrier layer comprises consolidated at least partially overlapping strip fragments comprising said heat-sealable thermoplastic material.

### Claim 3 (depends on 2)

The leak-tight vessel according to claim 2 wherein the lateral overlapping distance measured at the equatorial of the leak-tight vessel is 10-90% of the width of the barrier strip.

### Claim 4 (depends on 2)

The leak-tight vessel according to claim 2, wherein the width W of the barrier strip fragments is 4%-20% of the maximum outer diameter of the leak-tight vessel.

### Claim 5 (depends on 2)

The leak-tight vessel according to claim 2, wherein the at least partially overlapping strip fragments are applied by winding a continuous strip of a heat-sealable thermoplastic material around the outer rounded surface of a reusable and removable mandrel.

### Claim 6 (depends on 1)

The leak-tight vessel according to claim 1, wherein the thickness of the barrier layer is situated between 100 and 500 μm.

### Claim 7 (depends on 1)

The leak-tight vessel according to claim 1 wherein the heat-sealable thermoplastic material of the inner barrier layer consists of either a single layer or a multi-layer arrangement.

### Claim 8 (depends on 7)

The leak-tight vessel according to claim 7 wherein a multi-layer arrangement is a three-layer arrangement.

### Claim 9 (depends on 7)

The leak-tight vessel according to claim 7 wherein the heat-sealable thermoplastic material of the inner barrier layer includes polybutene-1.

### Claim 10 (depends on 8)

The leak-tight vessel according to claim 8 wherein the three-layer arrangement includes a metal.

### Claim 11 (depends on 1)

The leak-tight vessel according to claim 1 wherein the heat-sealable thermoplastic material is polypropylene.

### Claim 12 (depends on 1)

The leak-tight vessel according to claim 1 wherein the end fitting comprises an opening neither covered by the inner barrier layer nor by the outer shell layer, which opening is large enough to enable the disassembly and removal of a re-usable and re-movable mandrel used during the manufacture of the leak-tight vessel.

### Claim 13 (depends on 12)

The leak-tight vessel according to claim 12, wherein the end fitting comprises means such as a flange, positioned outside the vessel for connecting said vessel to external piping.

### Claim 14 (depends on 12)

The leak-tight vessel according to claim 12, wherein neither the end fitting nor the connection means comprise mechanical fastening means such as bolts and nuts, for securely integrating the end fitting into the rigid unitary structure comprising the inner barrier layer, the outer shell layer and the end fitting.

### Claim 15

The leak-tight vessel according to any of the preceding claims wherein an outer peripheral of the end fitting is dimensioned such that by covering the outer concave side of the end fitting outside the opening up to said outer peripheral by the inner barrier layer and the outer shell layer, the resulting rigid unitary structure formed by the inner barrier layer, the outer shell layer and the end fitting can withstand an overpressure of at least two bars.