High modulus ultra high molecular weight polyethylene tape
View Patent ↗A non-fibrous, high tenacity, highly oriented UHMWPE tape or sheet of high molecular weight having a substantially large aspect ratio, a high tenacity, and a substantially higher tensile modulus. The UHMWPE tape includes an average molecular weight of 2,000,000 or greater, a width of ½-inch or greater, a thickness of between 0.0008 and 0.004 inch, and a modulus of between 1600 and 2500 grams per denier.
1. A monolithic non-fibrous ultra high molecular weight polyethylene tape usable in ballistic resistant panels comprising:
ultra high molecular weight polyethylene (UHMWPE) having a viscosity-average molecular weight of 2,000,000 or greater;
a thickness of between 0.0008 and 0.004 inch;
a width of ½ inch or greater; and
a modulus of 1600 to 2500 grams per denier.
2. The UHMWPE tape of claim 1 wherein said ultra high molecular weight polyethylene tape includes a total draw ratio of from 100:1 to 180:1.
3. The UHMWPE tape of claim 1 wherein said tape has a denier of from 3,000 to 670,000.
4. The UHMWPE tape of claim 1 wherein said tape is formed from ultra high molecular weight polyethylene powder having
a crystallinity of at least 75% as determined by X-ray diffraction; and
a specific heat of fusion of greater than 220 joules/gram as determined by differential scanning calorimeter.
5. The UHMWPE tape of claim 1 wherein said tape includes a width to thickness ratio of at least 125:1.
6. The UHMWPE tape of claim 1 wherein said tape includes a density of 0.78 to 0.97 g/cm 3 .
7. The UHMWPE tape of claim 1 wherein said tape has a width of from 0.5 to 160 inches.
8. The UHMWPE tape of claim 1 wherein said tape includes a width to thickness ratio of from 125:1 to 200000:1.
9. The UHMWPE tape of claim 1 wherein said polymer has a viscosity-average molecular weight above 4,000,000.
10. The UHMWPE tape of claim 1 wherein said tape has an elongation to break between 1.6 to 3%.
11. The UHMWPE tape of claim 1 wherein said tape forms all or a portion of a ballistic-resistant article.