High strength tape articles from ultra-high molecular weight polyethylene
View Patent ↗Tape articles having improved properties are made from ultra-high molecular weight (UHMW) multi-filament yarns. The tape articles can have a ratio of the low temperature area under the curve (120° C. to Tm-onset) to the total area under the curve (120° C. to 165° C.) of less than about 0.15 as calculated from an increasing temperature DSC scan from a temperature of 30° C. to a temperature of 200° C. at a constant rate of 10° C. per minute. Additionally, in some examples the tape articles can also have a tenacity at least about 24 g/d (2.06 GPa) when measured by ASTM D882-09 at a 10 inch (25.4 cm) gauge length and at an extension rate of 100%/min. Further, the tape articles can have no long period of less than 450 Angstroms (Å) when measured by small angle x-ray analysis.
1. A tape article made from ultra-high molecular weight polyethylene multi-filament yarn, the tape article comprising:
an average cross-sectional aspect ratio of at least about 10:1; and
a ratio of the low temperature area under the curve (120° C. to Tm-onset) to the total area under the curve (120° C. to 165° C.) of less than about 0.15 as measured by an increasing temperature DSC scan from a temperature of 30° C. to a temperature of 200° C. at a constant rate of 10° C. per minute.
2. The tape article of claim 1 , wherein the tape article has a tenacity of at least about 24 g/d (2.07 GPa) when measured by ASTM D882-09 at a 10 inch (25.4 cm) gauge length and at an extension rate of 100%/min, and wherein said average cross-sectional aspect ratio is at least about 50:1.
3. The tape article of claim 2 , wherein the tape article has no long period of less than 450 Angstroms (Å) when measured by small angle x-ray analysis.
4. The tape article of claim 1 , wherein the tape article has no long period of less than 450 Angstroms (Å) when measured by small angle x-ray analysis.
5. The tape article of claim 1 , wherein the tape article is formed from one ultra-high molecular weight polyethylene multi-filament yarn and wherein the tape article has a tenacity of at least about 30 g/d (2.59 GPa).
6. The tape article of claim 1 , wherein the tape article has a tenacity of at least about 40 g/d (3.45 GPa).
7. The tape article of claim 1 , wherein the ratio of the low temperature area under the curve (120° C. to Tm-onset) to the total area under the curve (120° C. to 165° C.) of less than about 0.05 as measured by the increasing temperature DSC scan from a temperature of 30° C. to a temperature of 200° C. at a constant rate of 10° C. per minute.
8. The tape article of claim 1 , wherein the tape article is void free and has an ultra-high molecular weight polyethylene content of 100% by weight of the tape article.
9. The tape article of claim 1 , wherein the tape article has an ultra-high molecular weight polyethylene content by weight of greater than 95%.
10. The tape article of claim 1 , wherein the tape article has an ultra-high molecular weight polyethylene content by weight of greater than 98%.
11. The tape article of claim 1 , wherein the tape article has an average cross-sectional aspect ratio of at least about 100:1.
12. The tape article of claim 1 , wherein the tape article has an average cross-sectional aspect ratio of at least about 1000:1.
13. The tape article of claim 1 , wherein the tape article has thickness less than 2 mils (0.05 mm), and consists of a twisted ultra-high molecular weight polyethylene multi-filament yarn having less than about 3 turns of twist per inch of length.
14. The tape article of claim 1 , wherein the tape article has a constant cross-sectional aspect ratio along its length.
15. The tape article of claim 1 , wherein the tape article has a variable cross-sectional aspect ratio that changes randomly or at a selected frequency along its length.
16. The tape article of claim 1 , wherein the tape article has a variable level of fiber consolidation along its length, with consolidation changing randomly or at a selected frequency.
17. A tape article made from ultra-high molecular weight polyethylene gel-spun, multi-filament yarn, the tape article comprising:
an average cross-sectional aspect ratio of at least about 50:1;
a tenacity at least about 24 g/d (2.07 GPa) when measured by ASTM D882-09 at a 10 inch (25.4 cm) gauge length and at an extension rate of 100%/min;
and a ratio of the low temperature area under the curve (120° C. to Tm-onset) to the total area under the curve (120° C. to 165° C.) of less than about 0.15 as measured by an increasing temperature DSC scan from a temperature of 30° C. to a temperature of 200° C. at a constant rate of 10° C. per minute,
wherein the tape article has an ultra-high molecular weight polyethylene content of greater than 98% by weight.