Fuel containers made from polyethylene compositions with improved creep resistance
OwnerMridula Kapur, Stephanie M. Whited +1inventors
InventorsMridula Kapur, Stephanie M. Whited, Josef J. Van Dun
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Abstract
Fuel containers made from polyethylene compositions exhibiting improved creep resistance are provided. The polyethylene compositions include two components, a first component ethylene-based interpolymer, and a second component ethylene-based polymer. A process for producing a fuel container from the polyethylene compositions by blow molding is also provided. The fuel containers may include vehicle fuel tanks.
Claims12
A fuel container comprising:
- a polyethylene composition comprising:
- a first component comprising an ethylene-based interpolymer, wherein the first component is a heterogeneously branched linear or a homogeneously branched linear ethylene-based interpolymer, having a density from 0.922 g/cc to 0.945 g/cc, and a high load melt index I21 between 0.1 and 1 g/10 min;
- and
- a second component comprising an ethylene-based polymer,
- wherein the polyethylene composition has a density in the range of from 0.937 to 0.960 g/cc and a high load melt index I21 in the range of from 3 to 15 g/10 min.
A process for blow molding a polyethylene composition into a fuel container comprising:
- extruding a polyethylene composition having a density in the range of from 0.937 to 0.960 g/cc and a high load melt index I21 in the range of from 3 to 15 g/10 min and comprising a first component comprising an ethylene-based interpolymer, wherein the first component is a heterogeneously branched linear or a homogeneously branched linear ethylene-based interpolymer, having a density from 0.922 g/cc to 0.945 g/cc, and a high load melt index I21 between 0.1 and 1 g/10 min and a second component comprising an ethylene-based polymer and optionally a filler, in an extruder through a die;
- forming a molten tube-shaped parison, holding the parison within a shaping mold;
- blowing a gas into the mold so as to shape the parison according to a profile of the mold;
- and yielding a blow molded article in a shape for use as a fuel container.
A method for preparing a polyethylene composition comprising a first component ethylene-based interpolymer and a second component ethylene-based polymer (interpolymer or homopolymer) comprising:
- a) polymerizing either the first component ethylene-based interpolymer, or the second component ethylene-based polymer (interpolymer or homopolymer), in a first reactor, in the presence of a Ziegler-Natta catalyst system, to form a first polymer product;
- b) transferring the first polymer product to a second reactor;
- and
- c) polymerizing, in the second reactor, the ethylene-based polymer that was not produced in the first reactor, in the presence of the Ziegler-Natta catalyst system;
- wherein the first component is a heterogeneously branched linear ethylene-based interpolymer, and has a density from 0.922 g/cc to 0.945 g/cc, and a high load melt index I21 from 0.1 g/10 min to 1 g/10 min;
- and
- wherein the polyethylene composition has a density in the range of from 0.937 to 0.960 g/cc and a high load melt index I21 in the range of from 3 to 15 g/10 min.
Dependencies are inferred from the claim text.