Flexible composite material and use hereof, process for making a flexible composite material

1. A flexible composite material comprising:

at least two fibrous layers comprised of high strength fibers, wherein the high strength fibers are formed of polyaramide or ultra-high molecular weight polyethylene, wherein

the at least two fibrous layers establish opposed surfaces of the composite material, wherein the flexible composite material includes consolidated elements and unconsolidated elements formed in each of the opposed surfaces of the at least two fibrous layers such that the consolidated and unconsolidated elements of one of the opposed surfaces are coincident with the consolidated and unconsolidated elements of another of the opposed surfaces, respectively, and wherein

each of the coincident consolidated elements establish a thickness of the material sheet which is less than a thickness of the material sheet established by the coincident unconsolidated elements, and wherein

a surface area of the unconsolidated elements is 60% or more of a total surface area of the flexible composite material.

2. The flexible composite material according to claim 1 , further comprising a polymer sheet on at least one outer surface of the flexible composite material.

3. The flexible composite material according to claim 1 , wherein the flexible composite material has an areal density of at least 400 g/m 2 and a flexibility of at least 25 mm.

4. The flexible composite material according to claim 1 , wherein the consolidated elements are arranged in a regular pattern and the consolidated elements have a triangular, quadrilateral, pentagonal, hexagonal, circular or ellipsoidal shape.

5. The flexible composite material according to claim 1 , wherein the unconsolidated elements are interconnected.

6. The flexible composite material according to claim 1 , wherein the high strength fibers in the at least two layers are arranged in a parallel fashion in one layer of the at least two layers.

7. The flexible composite material according to claim 1 , wherein the flexible composite material has a width and a length, and wherein the length is at least 5 times the width.

8. The flexible composite material according to claim 1 , wherein the flexible composite material includes two outer surfaces and further comprises at least one polymeric film on at least one of the two outer surfaces thereof.

9. The flexible composite material according to claim 1 , wherein the flexible composite material exhibits an Eabs of more than 200 J/kg/m 2 against 9 mm Parabellum FMJ, as measured for an areal density of 2.5 kg/m 2 , on any location of the flexible composite material.

10. The flexible composite material according to claim 9 , having an Eabs of more than 225 J/kg/m 2 .

11. A ballistic resistant object comprising the flexible composite material according to claim 1 .

12. A process for the manufacture of a flexible ballistic resistant composite material according to claim 1 , comprising the steps of:

(a) providing at least two layers comprising the high strength fibers;

(b) consolidating the at least two layers to obtain the coincident consolidated elements and the coincident unconsolidated elements, wherein the unconsolidated elements have a smallest width U which is more than 4 mm;

(c) cooling the product obtained after step (b); and

(d) flexing the product obtained in step (c) along the unconsolidated elements over a radius of 75 mm for at least 2 times.

13. The process of claim 12 , wherein the consolidation step (b) is practiced at least 10 degrees below a melting point of the high strength fibers at a pressure of at least 1.0 MPa.

14. A flexible composite material comprising:

at least two fibrous layers comprised of high strength fibers, wherein

the at least two fibrous layers establish opposed surfaces of the composite material, wherein the flexible composite material includes consolidated elements and unconsolidated elements formed in each of the opposed surfaces of the at least two fibrous layers such that the consolidated and unconsolidated elements of one of the opposed surfaces are coincident with the consolidated and unconsolidated elements of another of the opposed surfaces, respectively, and wherein

each of the coincident consolidated elements establish a thickness of the material sheet which is less than a thickness of the material sheet established by the coincident unconsolidated elements, and wherein

a surface area of the unconsolidated elements is 60% or more of a total surface area of the flexible composite material, and wherein

the flexible composite material has an areal density of at least 400 g/m 2 and a flexibility of at least 25 mm.

15. The flexible composite material according to claim 14 , wherein the high strength fibers are selected from the group of polyolefins; polyamides; polyaramides; poly(tetrafluoroethylene); poly{2,6-diimidazo-[4,5b-4′,5′e]pyridinylene-1,4(2,5-dihydroxy)phenylene}; poly(p-phenylene-2, 6-benzobisoxazole); poly(hexamethyleneadipamide), poly(4-aminobutyric acid); polyesters; polyvinyl alcohols and thermotropic liquid crystal polymers.

16. The flexible composite material according to claim 15 , wherein the high strength fibers are formed of polyaramide.

17. The flexible composite material according to claim 15 , wherein the high strength fibers are formed of ultra high molecular weight polyethylene.

18. A flexible composite material comprising:

at least two fibrous layers comprised of high strength fibers, wherein

the at least two fibrous layers establish opposed surfaces of the composite material, wherein the flexible composite material includes consolidated elements and unconsolidated elements formed in each of the opposed surfaces of the at least two fibrous layers such that the consolidated and unconsolidated elements of one of the opposed surfaces are coincident with the consolidated and unconsolidated elements of another of the opposed surfaces, respectively, and wherein

each of the coincident consolidated elements establish a thickness of the material sheet which is less than a thickness of the material sheet established by the coincident unconsolidated elements, and wherein

a surface area of the unconsolidated elements is 60% or more of a total surface area of the flexible composite material, and wherein

the high strength fibers in the at least two layers are arranged in a parallel fashion in one layer of the at least two layers.

19. The flexible composite material according to claim 18 , wherein the high strength fibers are selected from the group of polyolefins; polyamides; polyaramides; poly(tetrafluoroethylene); poly{2,6-diimidazo-[4,5b-4′,5′e]pyridinylene-1,4(2,5-dihydroxy)phenylene}; poly(p-phenylene-2, 6-benzobisoxazole); poly(hexamethyleneadipamide), poly(4-aminobutyric acid); polyesters; polyvinyl alcohols and thermotropic liquid crystal polymers.

20. The flexible composite material according to claim 19 , wherein the high strength fibers are formed of polyaramide.

21. The flexible composite material according to claim 19 , wherein the high strength fibers are formed of ultra high molecular weight polyethylene.