Methods for improving multimodal polyethylene and films produced therefrom
A blown film composition including a first high density polyethylene component and a second high density polyethylene component, wherein the blown film contains a mixture of three or more discrete molecular weight distributions, and wherein the second high density polyethylene component has at least one more discrete molecular weight distribution than the first high density polyethylene component.
1. A composition comprising:
a first polyethylene component;
a second bimodal or multimodal polyethylene component, wherein the first polyethylene component has a density ranging from 0.880 g/cm 3 to 0.940 g/cm 3 , wherein the second polyethylene component has a density ranging from 0.880 g/cm 3 to 0.940 g/cm 3 , or wherein the first polyethylene component and the second polyethylene component have densities ranging from 0.880 g/cm 3 to 0.940 g/cm 3 ; and
a polyethylene compatible nucleating agent.
2. The composition of claim 1 , wherein the first polyethylene component has a density ranging from 0.880 g/cm 3 to 0.940 g/cm 3 , and wherein the second bimodal or multimodal polyethylene component is a high density polyethylene having a density ranging from 0.950 to 0.970 g/cm 3 .
3. The composition of claim 1 , wherein the second bimodal or multimodal polyethylene component has a density ranging from 0.880 g/cm 3 to 0.940 g/cm 3 , and wherein the first polyethylene component is a high density polyethylene having a density ranging from 0.950 to 0.970 g/cm 3 .
4. The composition of claim 1 , wherein the first polyethylene component and the second bimodal or multimodal polyethylene component have densities ranging from 0.880 g/cm 3 to 0.940 g/cm 3 .
5. The composition of claim 1 , wherein the first polyethylene component is present in amounts ranging from 75 to 85 wt % based on a total weight of the composition.
6. The composition of claim 1 , wherein at max frost line height, a 2 mil film of the composition comprises a water vapor transmission rate (WVTR) of less than 0.250 g/100 in 2 /day, wherein the WVTR is measured at 100° F. in accordance with ASTM test method E96/66.
7. The composition of claim 1 , wherein a two mil film of the first polyethylene component exhibits an Elmendorf Tear strength, measured using the ASTM test method D 1922, in the machine direction ranging from 10 to 50 g, and in the transverse direction ranging from 200 to 600 g.
8. The composition of claim 1 , wherein a two mil film of the second polyethylene component exhibits an Elmendorf Tear strength, measured using the ASTM test method D 1922, in the machine direction ranging from 1 to 30 g, and in the transverse direction ranging from 100 to 10000 g.
9. The composition of claim 1 , wherein a two mil film of the first polyethylene component exhibits a tensile strength at yield, measured using the ASTM test method D 882A at 20 in/min, ranging from 1000 to 6000 psi in the machine direction, and ranging from 1000 to 6000 psi in the transverse direction.
10. The composition of claim 1 , wherein a two mil film of the first polyethylene component exhibits a tensile strength at yield, measured using the ASTM test method D 882A at 20 in/min, ranging from 1000 to 6000 psi in the machine direction, and ranging from 1000 to 4000 psi in the transvers direction.
11. The composition of claim 1 , wherein a two mil film of the second polyethylene component exhibits a tensile strength at break ranging from 5000 to 10000 psi in the machine direction, and ranging from 2000 to 5000 psi in the transverse direction.
12. The composition of claim 1 , wherein a two mil film of the second polyethylene component exhibits a tensile strength at break ranging from 5000 to 10000 psi in the machine direction, and ranging from 1000 to 4000 psi in the transverse direction.
13. The composition of claim 1 , wherein a two mil film of the first polyethylene component exhibits an elongation at break in both the machine direction and transvers direction, measured using ASTM test method D 882A at 20 in/min, ranging from 100 to 1000%.
14. The composition of claim 1 , wherein a two mil film of the second polyethylene component exhibits an elongation at break, measured using ASTM test method D 882A at 20 in/min, ranging from 100 to 500% in the machine direction, and less than 100% in the transverse direction.
15. The composition of claim 1 , wherein a two mil film of the first polyethylene component exhibits a secant modulus at 1% strain, measured using ASTM test method D 882A at 20 in/min, in the machine direction ranging from 50 to 200 kpsi, and in the transvers direction ranging from 50 to 200 kpsi.
16. The composition of claim 1 , wherein a two mil film of the second polyethylene component exhibits a secant modulus at 1% strain, measured using ASTM test method D 882A at 20 in/min, in the machine direction ranging from 50 to 250 kpsi, and in the transvers direction ranging from 100 to 300 kpsi.
17. The composition of claim 1 , wherein a two mil film of the first polyethylene component exhibits a secant modulus at 2% strain, measured using ASTM test method D 882A at 1 in/min, in the machine direction ranging from 50 to 200 kpsi, and in the transverse direction ranging from 50 to 200 kpsi.
18. The composition of claim 1 , wherein the second polyethylene component exhibits a dart impact, measured using ASTM test method D 1709A, of less than 100 g.
19. A blown film made from a composition comprising:
a first polyethylene component;
a second bimodal or multimodal polyethylene component, wherein the first polyethylene component has a density ranging from 0.880 g/cm 3 to 0.940 g/cm 3 , wherein the second polyethylene component has a density ranging from 0.880 g/cm 3 to 0.940 g/cm 3 , or wherein the first polyethylene component and the second polyethylene component have densities ranging from 0.880 g/cm 3 to 0.940 g/cm 3 ; and
a polyethylene compatible nucleating agent.
20. A method of making a composition comprising:
combining a first polyethylene component, a second bimodal or multimodal polyethylene component, and a polyethylene compatible nucleating agent, to form a multimodal resin;
wherein the first polyethylene component has a density ranging from 0.880 g/cm 3 to 0.940 g/cm 3 , wherein the second polyethylene component has a density ranging from 0.880 g/cm 3 to 0.940 g/cm 3 , or wherein the first polyethylene component and the second polyethylene component have densities ranging from 0.880 g/cm 3 to 0.940 g/cm 3 .
21. The method of claim 20 , wherein the first polyethylene component or the second polyethylene component is a high density polyethylene having a density ranging from 0.950 to 0.970 g/cm 3 .
22. The article of claim 19 , wherein the first polyethylene component or the second polyethylene component is a high density polyethylene having a density ranging from 0.950 to 0.970 g/cm 3 .
23. The composition of claim 1 , wherein the polyethylene compatible nucleating agent comprises a carboxylic acid salt, phosphate, metallic-silicate hydrate, sorbitol acetal, or combinations thereof.
24. The composition of claim 1 , wherein the composition comprises from 75 to 99 weight percent of the first polyethylene component based on a total weight of the composition, wherein the first polyethylene component has a density ranging from 0.880 g/cm 3 to 0.940 g/cm 3 , and wherein the second bimodal or multimodal polyethylene component has a density ranging from 0.950 to 0.970 g/cm 3 and a melt flow index of from 0.1 to 5.0 g/10 min. as measured in accordance with ASTM D 1238 at 190° C. and a load of 2.16 kg.
25. The composition of claim 1 , wherein the second bimodal or multimodal polyethylene component comprises a polyethylene homopolymer and has a density ranging from 0.880 g/cm 3 to 0.940 g/cm 3 , and wherein the first polyethylene component is a high density polyethylene having a density ranging from 0.950 to 0.970 g/cm 3 and a melt flow index of from 0.1 to 5.0 g/10 min. as measured in accordance with ASTM D 1238 at 190° C. and a load of 2.16 kg.
26. The composition of claim 1 , wherein the composition comprises from 75 to 99 weight percent of the first polyethylene component based on a total weight of the composition, wherein the first polyethylene component has a density ranging from 0.880 g/cm 3 to 0.925 g/cm 3 and the second bimodal or multimodal polyethylene component has a density ranging from 0.880 g/cm 3 to 0.940 g/cm 3 .
27. The composition of claim 1 , wherein the second polyethylene component is bimodal.