Polyethylene fibers and processes of forming the same
Fibers and methods of forming the fibers are described herein. The fibers generally include an ethylene based polymer exhibiting a molecular weight distribution of from about 2 to about 8.
1. A method of forming fiber comprising:
providing an ethylene based polymer exhibiting a molecular weight distribution of from about 2 to about 8 wherein the ethylene based polymer comprises at least 50 wt. % polyethylene relative to a total weight of the ethylene based polymer;
heating the ethylene based polymer to a molten state;
extruding the ethylene based polymer to form a fiber, wherein the fiber exhibits a tenacity at maximum load of from about 2.0 g/denier at a draw ratio of 3:1 to about 3.3 g/denier; and
spinning the fiber at a desired spinning speed.
2. The method of claim 1 , wherein the ethylene based polymer is formed by a Ziegler-Natta catalyst.
3. The method of claim 2 , wherein the Ziegler-Natta catalyst is formed by:
contacting an alkyl magnesium compound with an alcohol to form a magnesium dialkoxide compound;
contacting the magnesium dialkoxide compound with a plurality of first agents to form reaction product “A”;
contacting reaction product “A” with a second agent to form reaction product “B”, wherein the second agent comprises a transition metal and a halogen;
contacting reaction product “B” with a third agent to form reaction product “C”, wherein the third agent comprises a first metal halide and wherein the third agent is a stronger halogenating agent than the second agent;
optionally contacting reaction product “C” with a fourth agent to form reaction product “D”, wherein the fourth agent comprises a second metal halide and wherein the fourth agent is a stronger halogenating agent than the third agent; and
contacting reaction product “D” with fifth agent to form a Ziegler-Natta catalyst component, wherein the fifth agent comprises an organoaluminum compound.
4. The method of claim 1 , wherein the ethylene based polymer is linear.
5. The method of claim 1 , wherein the ethylene based polymer is uni-modal.
6. The method of claim 1 , wherein the ethylene based polymer exhibits a density of at least about 0.94 g/cc.
7. The method of claim 1 , wherein the fiber is a soft touch fiber.
8. The method of claim 1 , wherein the fiber is a fine denier monofilament that exhibits increased resistance to gamma radiation sterilization over a fiber formed from an identical process with a Ziegler-Natta formed polypropylene homopolymer.
9. The method of claim 1 , wherein the ethylene based polymer comprises at least 70 wt. % polyethylene relative to a total weight of the ethylene based polymer.
10. The method of claim 1 , wherein the ethylene based polymer comprises at least 75 wt. % polyethylene relative to a total weight of the ethylene based polymer.
11. The method of claim 1 , wherein the ethylene based polymer comprises at least 80 wt. % polyethylene relative to a total weight of the ethylene based polymer.
12. The method of claim 1 , wherein the ethylene based polymer comprises at least 85 wt. % polyethylene relative to a total weight of the ethylene based polymer.
13. The method of claim 1 , wherein the ethylene based polymer comprises at least 90 wt. % polyethylene relative to a total weight of the ethylene based polymer.
14. The method of claim 1 , wherein the ethylene based polymer has a melt index (MI 2 ) of from 0.01 to 15 dg/min, as measured by ASTM D-1238.