Ballistic-resistant panel including high modulus ultra high molecular weight polyethylene tape
View Patent ↗A ballistic-resistant panel in which the entire panel or a strike-face portion thereof is formed of a plurality of sheets of high modulus high molecular weight polyethylene tape. The sheets of high modulus polyethylene tape can be in the form of cross-plied laminated layers of tape strips or a woven fabric of tape strips. The strips of UHMWPE tape include a width of at least one inch and a modulus of greater than 1400 grams per denier. The ballistic-resistant panel may include a backing layer of conventional high modulus fibers embedded in resin. A wide variety of adhesives were found acceptable for bonding the cross-plied layers of high modulus polyethylene tape together for forming the ballistic-resistant panels of the present invention.
1. A ballistic-resistant panel comprising:
a metallic strike-face;
a backing including a plurality of interleaved layers of non-fibrous ultra high molecular weight polyethylene (UHMWPE) tape; and
said UHMWPE tape including a tensile modulus of at least 1,400 grams per denier.
2. The ballistic-resistant panel of claim 1 wherein said metallic strike-face includes a layer of high hardness steel and a layer of aluminum.
3. The ballistic-resistant panel of claim 2 wherein
said layer of high hardness steel is 0.25 inch thick;
said layer of aluminum is 1.5 inches thick; and
said aluminum is grade 6061 aluminum.
4. The ballistic-resistant panel of claim 1 wherein said backing includes an areal density of 1.6 pounds per square foot.
5. The ballistic-resistant panel of claim 1 wherein said UHMWPE tape includes
strips of tape having a width of at least 1.0 inch;
a viscosity-average molecular weight of at least 2,000,000; and
a thickness of between 0.0015 and 0.004 inch.
6. The ballistic-resistant panel of claim 1 including an adhesive on at least one side of said interleaved layers of said non-fibrous UHMWPE tape.
7. A ballistic-resistant panel comprising:
a metallic strike-face;
a backing including a first portion and a second portion;
said first portion consisting of a plurality of interleaved layers of non-fibrous ultra high molecular weight polyethylene (UHMWPE) tape; and
said second portion consisting of a plurality of interleaved layers of cross-plied fibers embedded in resin.
8. The ballistic-resistant panel of claim 7 wherein said UHMWPE tape includes a tensile modulus of at least 1,400 grams per denier.
9. The ballistic-resistant panel of claim 7 wherein said metallic strike-face includes a layer of high hardness steel and a layer of aluminum.
10. The ballistic-resistant panel of claim 7 wherein
said layer of high hardness steel is 0.25 inch thick; and
said layer of aluminum is 1.0 inch thick.
11. The ballistic-resistant panel of claim 7 wherein said aluminum is grade 6061 aluminum.
12. The ballistic-resistant panel of claim 7 wherein said backing includes an areal density of at least 2.5 pounds per square foot.
13. The ballistic-resistant panel of claim 7 wherein said UHMWPE tape includes
strips of tape having a width of at least 1.0 inch;
a viscosity-average molecular weight of at least 2,000,000; and
a thickness of between 0.0015 and 0.004 inch.
14. The ballistic-resistant panel of claim 13 wherein said tape strips include a width to thickness ratio of at least 400:1 and a denier of 6,000 or greater.
15. A ballistic-resistant panel comprising:
a plurality of layers of non-fibrous ultra high molecular weight polyethylene (UHMWPE) tape;
each of said layers of non-fibrous UHMWPE tape including a plurality of monolithic tape strips woven together to form a woven layer;
said non-fibrous UHMWPE tape strips including a modulus of greater than 1,400 grams per denier;
said plurality of woven layers of non-fibrous UHMWPE tape molded together by heat and pressure.
16. The ballistic-resistant panel of claim 15 wherein said ballistic-resistant panel includes an areal density of 2.2 pounds per square foot.
17. The ballistic-resistant panel of claim 15 wherein
each of said woven layers are interleaved with a low density polyethylene film, said low density polyethylene film acting as a binder for binding together said woven tape strips upon application of heat and pressure; and
said low density polyethylene film is 18-microns thick.
18. The ballistic-resistant panel of claim 15 wherein said non-fibrous UHMWPE tape includes
a viscosity-average molecular weight of at least 2,000,000;
a width of at least 1.0 inch; and
a thickness of between 0.0015 and 0.004 inch.
19. The ballistic-resistant panel of claim 15 wherein said heat of molding is 250 degrees F. and said pressure is 500 psi.