Cut resistant rope

Abstract

A rope having a core for providing strength to the rope, where at least a metal or composite woven or warp knitted fabric having multiple substantially parallel elongated metal elements is provided around the core for protecting said core from impact and cutting, and where the multiple substantially parallel elongated elements are in the warp direction and held by yarns.

Claims

1. A rope comprising a core for providing strength to said rope, wherein at least a metal or composite fabric comprising multiple substantially parallel elongated metal elements is provided around said core for protecting said core from impact and cutting, and wherein said multiple substantially parallel elongated elements are in the warp direction and held by yarns, wherein said multiple substantially parallel elongated metal elements are individually coated with a polymer.

2. The rope according to claim 1, wherein the composite fabric further comprises multiple substantially parallel elongated fiber or polymer elongated elements alternating with the multiple substantially parallel elongated metal elements.

3. The rope according to claim 1, wherein said metal or composite fabric is a woven fabric or a warp knitted fabric.

4. The rope according to claim 1, wherein said metal or composite fabric is in a form of strip and said strip is helically wrapped around said core.

5. The rope according to claim 4, wherein two layers of metal or composite fabrics are wrapped around said core with an angle in the range of 20 to 60 for one metal or composite fabric layer and with an angle in the range of 60 to 20 for another metal or composite fabric layer.

6. The rope according to claim 1, wherein said core is made from synthetic material.

7. The rope according to claim 1, wherein said multiple substantially parallel elongated metal elements are steel cords.

8. The rope according to claim 1, wherein the diameter of said multiple substantially parallel elongated metal elements is in the range of 1 to 3 mm.

9. The rope according to claim 1, wherein the thickness of the polymer coating is in the range of 0.05 to 1 mm.

10. The rope according to claim 1, wherein the polymer coating is any one selected from polyamide (PA), polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), polyurethane (PU), polysulfone (PES), ethylene tetrafluoroethylene (ETFE) or their combination.

11. The rope according to claim 1, wherein the yarns are made from a same material as the polymer coating on said multiple substantially parallel elongated metal elements.

12. The rope according to claim 1, wherein said metal or composite fabric is an open fabric having a cover factor in the range of 0.5 to 0.9.

13. A method of using a rope according to claim 1 comprising the steps of: wrapping the rope around a structure in a way such that said rope is used as a mooring line or a submarine rope.

14. A rope comprising a core for providing strength to said rope, wherein at least a metal or composite fabric comprising multiple substantially parallel elongated metal elements is provided around said core for protecting said core from impact and cutting, said composite fabric comprises multiple substantially parallel elongated fiber or polymer elongated elements alternating with the multiple substantially parallel elongated metal elements, said metal or composite fabric is a woven fabric or a warp knitted fabric, and wherein said multiple substantially parallel elongated elements are in the warp direction and held by yarns, wherein said multiple substantially parallel elongated metal elements are individually coated with a polymer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be better understood with reference to the detailed description when considered in conjunction with the non-limiting examples and the accompanying drawings, in which:

(2) FIG. 1 schematically shows a rope according to the present invention.

(3) FIG. 2 illustrates an example of a metal or composite fabric applied on the rope according to the present application.

MODE(S) FOR CARRYING OUT THE INVENTION

(4) FIG. 1 illustrates a rope 10 produced according to the present invention. As shown in FIG. 1, the core 12 of the rope is preferably made of synthetic yarns 13. The core may have any construction known for synthetic ropes. The core may have a plaited, a braided, a laid, a twisted or a parallel construction, or combinations thereof. Alternatively, the core may also be a combination of sub-ropes. Synthetic yarns 13 that may be used as the core of the rope according to the invention include all yarns, which are known for their use in fully synthetic ropes. Such yarns may include yarns made of fibers of polypropylene, nylon, polyester. Preferably, yarns of high modulus fibers are used, for example yarns of fibers of liquid crystal polymer (LCP), aramid such as poly(p-phenylene terephthalamide) (known as Kevlar), high molecular weight polyethylene (HMwPE), ultra-high molecular weight polyethylene (UHMwPE) such as Dyneema and PBO (poly(p-phenylene-2,6-benzobisoxazole). The high modulus fibers preferably have break strength of at least 2 MPa and tensile modulus preferably above 100 GPa. The diameter of the core 12 may vary between 2 mm to 300 mm. For example, the core 12 is made of a plurality of high modulus polyethylene (HMPE) yarns (e.g. any one or more of 8*1760 dTex Dyneema SK78 yarn, 4*1760 dTex Dyneema yarn or 14*1760 dTex Dyneema 1760 dTex SK78 yarn) and has a diameter of 150 mm.

(5) Preferably, the rope 10 has a filter fabric 14 around the core as a barrier for ingress of particles. The filter fabric 14 may be a non-woven cloth. As an example, a metal fabric 16 in a form of strip is wrapped or wound around the core 12 covered with a filter fabric 14.

(6) As an example shown in FIG. 2, the metal fabric is a warp knitted fabric 20. The warp direction is multiple of coated steel cords 22,24. The steel cords 22,24 have a carbon content less than 0.5 wt %. The steel cords are multi-strand cords, e.g. of the 77 type, i.e. comprising 7 strands with each 7 wires, such as 770.22, 770.25, wherein the number with decimal point designates the diameter of each wire, expressed in mm.

(7) The steel cords are extruded with polypropylene and preferably the thickness of coating is 1.5 mm. The yarns are preferably polypropylene and have a diameter of 0.2 mm assuming round yarn shape.

(8) FIG. 2 shows a schematic diagram of a warp knitted fabric 20 which can be represented by stitch notation. As shown in FIG. 2, half of the steel cords 24 are worked into the loop of the stitches 23 at the stitch line 27, and half of the steel cords 22 are worked alternating into the loop of one stitch line 27a and subsequently into the loop of an adjacent stitch line 27b,27c. In this way more than one metal element can be incorporated into a single plane parallel array. Each metal element is held between the legs of a stitch 28 and an underlap 29, so the elements are held strongly in position. As an example, the width of the strip is in the range of 20 to 100 cm, such as 30 or 40 cm.

(9) As another example, a composite fabric in a form of strip is wrapped or wound around the core 12 covered with a filter fabric 14. Instead of the half of the steel cords 22 in the example shown in FIG. 2, elongated elements made from fibers are used alternatively with the steel cores 24.

(10) As an alternative solution, the metal or composite fabric is first braided or knitted on the non-woven filter fabric 14. In such a case, the metal or composite fabric and the filter fabric 14 are preferably both in the form of strip and have a similar width, e.g. 50 cm. Then the metal or composite fabric and the filter fabric 14 can be applied in one wrapping step.

(11) As a last step, a braided jacket is preferably applied on top of the metal or composite fabric to further protect the rope. The braided jacket can be made from polyester although other jacket materials are possible.

(12) As yet another example, two metal fabric layers are applied on the top of the filter fabric 14. One metal fabric layer is formed by warping a strip, e.g. as shown in FIG. 2, with an inclination angle of 42 to the longitudinal direction of the rope, and another metal fabric layer is formed by warping a strip with an inclination angle of 42 to the longitudinal direction of the rope. The cut resistance of such a rope was tested and the rope appeared less than 10% damage after a displacement of 120 m in severe conditions with a load of 265 kN and a rope displacement of 0.4 m/s.

LIST OF REFERENCES

(13) 10 rope 12 core 13 synthetic yarns 14 filter fabric 16 metal fabric 18 jacket 20 warp-knitted fabric 22, 24 steel cords 27, 27a, 27b, 27c stitch line 28 legs of a stitch 29 underlap