Abstract: A process for controlling the swell ratio of a polyethylene composition, made from or containing three or more polyethylene components and having a specified melt flow rate, including the steps of (a) preparing the polyethylene composition in a polymerization apparatus including three or more polymerization zones in the presence of a polymerization catalyst and hydrogen as molecular weight regulator and (b) selecting different ratios of hydrogen to ethylene in the polymerization zones, thereby forming the three or more polyethylene components which differ in average molecular weight and effecting the swell ratio of the polyethylene composition, wherein a first polyethylene component has the highest average molecular weight and a second polyethylene components has the second-highest average molecular weight.

Abstract: A process for the continuous production of a polyolefin polymer in a gas-phase polymerization reactor in the presence of a polymerization catalyst and an antistatic agent, including the steps of (a) providing a mixture of polyolefin particles and gas, (b) conveying the mixture through a pipe at a gas velocity of greater than or equal to 2 m/s, and (c) introducing an antistatic agent into the mixture.

Abstract: A polyethylene composition particularly suited for producing blow-molded hollow articles, having the following features: 1) density from 0.948 to 0.960 g/cm3; 2) ratio MIF/MIE greater than 125; 3) MIF from 20 to 40 g/10 min.; 4) ER values from 5 to 10.

Abstract: A polyethylene composition particularly suited for producing blow-molded hollow articles, having the following features: 1) density from more than 0.955 to 0.965 g/cm3; 2) ratio MIF/MIE from 60 to 125; 3) MIF from 15 to 40 g/10 min.; 4) ER values from 3.0 to 5.5; 5) ?0.02 equal to or lower than 150,000 Pa·s.

Abstract: Embodiments of the present disclosure relate to a method of preparing polyethylene compositions comprising polymerizing ethylene in a first gas-phase reactor and polymerizing ethylene in a second gas-phase reactor in the presence of hydrogen; wherein at least one of the first or second gas-phase reactors comprises a first and second polymerization zone; wherein a hydrogen pressure of the first and second polymerization zones are different such that at least a portion of the second ethylene cycles through the first and second polymerization zones and a gas mixture of each polymerization zone is partially or totally prevented from entering the other zone.

Abstract: A polyethylene composition having the following features: 1) a density from 0.957 to 0.968 g/cm3; 2) a ratio MIF/MIP from 12 to 30; 3) a MIF from 41 to 60 g/10 min.; 4) a long-chain branching index, LCBI, equal to or greater than 0.45; and 5) a ratio (?0.02/1000)/LCBI from 45 to 75.

Abstract: A process for preparation of an ethylene polymer in a gas-phase polymerization unit comprising a gas-phase polymerization reactor by homopolymerizing ethylene or copolymerizing ethylene and one or more C4-C12-1-alkenes in a reaction gas made from or containing propane as polymerization diluent in the presence of a pre-activated polymerization catalyst, wherein a purified propane feed stream made from or containing at least 99 mol % propane and from 0.1 to 100 ppm mol propylene is fed to the gas-phase polymerization unit.

Abstract: A process for preparing an olefin polymer in a polymerization apparatus in the presence of a solid particulate polymerization catalyst and an organometallic compound, including the steps of withdrawing a gaseous stream from the polymerization apparatus, passing the gaseous stream through a bed of particulate solid having, at the surface of the particulate solid, chemical groups which are reactive with the organometallic compound, and feeding a sample of the gaseous stream into an analyzer.

Abstract: A polyethylene composition particularly suited for producing blow-molded hollow articles, having the following features: 1) density from more than 0.955 to 0.965 g/cm3; 2) ratio MIF/MIE from 60 to 125; 3) MIF from 15 to 40 g/10 min.; 4) ER values from 3.0 to 5.5; 5) 110.02 equal to or lower than 150,000 Pa·s.

Abstract: A polyethylene composition particularly suited for producing blow-molded hollow articles, having the following features: 1) density from 0.948 to 0.960 g/cm3; 2) ratio MIF/MIE greater than 125; 3) MIF from 20 to 40 g/10 min.; 4) ER values from 5 to 10.

Abstract: A polyethylene composition particularly suited for producing blow-molded hollow articles, having the following features: 1) density from 0.948 to 0.955 g/cm3; 2) ratio MIF/MIE from 60 to 120; 3) MIF from 15 to 45 g/10 min.; 4) ER values from 2 to 5.0; said composition being obtainable by contacting a precursor polyethylene composition with a radical initiator.

Abstract: A polyethylene composition for producing blown films, made from or containing an ethylene homopolymer or copolymer A) and an ethylene copolymer B) having a MIE value lower than the MIE value of A), the composition having the following features: 1) density from 0.948 to 0.960 g/cm3; 2) ratio MIF/MIP from 20 to 40; 3) MIF from 6 to less than 15 g/10 min.; 4) HMWcopo index from 0.5 to 3.5; 5) long-chain branching index, LCBI, equal to or lower than 0.82; 6) ?0.02 of equal to or less than 150000.

Abstract: A polyethylene composition for producing blow-molded hollow articles, having the following features: 1) density from 0.940 to 0.955 g/cm3, determined according to ISO 1183 at 23° C.; 2) ratio MIF/MIP from 12 to 40; 3) Mz from 500,000 to 3,500,000 g/mol; 4) ?0.02 from 80,000 to 300,000 Pa·s; 5) HMWcopo index from 1 to 15; and 6) Mz/Mw*LCBI lower than 6.4.

Abstract: A polyethylene composition for producing blow-molded hollow articles, having the following features: 1) density from 0.940 to 0.955 g/cm3 determined according to ISO 1183 at 23° C.; 2) ratio MIF/MIP from 12 to 30; 3) Mz from 2,000,000 to 4,500,000 g/mol; 4) ?0.02 from 160,000 to 300,000 Pa·s; and 5) long-chain branching index, LCBI, equal to or greater than 0.75.

Abstract: A polyethylene composition for producing blow-molded hollow articles, having the following features: 1) a density from 0.945 to 0.958 g/cm3, determined according to ISO 1183 at 23° C.; 2) a ratio MIF/MI10 from 2 to 10; 3) a ?0.02 from 200,000 to 800,000 Pa·s; 4) a LCBI equal to or lower than 0.80; and 5) a ratio (?0.02/1000)/LCBI equal to or greater than 350.

Abstract: A process for preparation of an ethylene polymer in a gas-phase polymerization unit comprising a gas-phase polymerization reactor by homopolymerizing ethylene or copolymerizing ethylene and one or more C4-C12-1-alkenes in a reaction gas made from or containing propane as polymerization diluent in the presence of a pre-activated polymerization catalyst, wherein a purified propane feed stream made from or containing at least 99 mol % propane and from 0.1 to 100 ppm mol propylene is fed to the gas-phase polymerization unit.

Abstract: A polyethylene composition for producing blown films, made from or containing an ethylene homopolymer or copolymer A) and an ethylene copolymer B) having a MIE value lower than the MIE value of A), the composition having the following features: 1) density from 0.948 to 0.960 g/cm3; 2) ratio MIF/MIP from 20 to 40; 3) MIF from 6 to less than 15 g/10 min.; 4) HMWcopo index from 0.5 to 3.5; 5) long-chain branching index, LCBI, equal to or lower than 0.82; 6) ?0.02 of equal to or less than 150000.

Abstract: A polyethylene composition for producing blow-molded hollow articles, having the following features: 1) a density from 0.945 to 0.958 g/cm3, determined according to ISO 1183 at 23° C.; 2) a ratio MIF/MI10 from 2 to 10; 3) a ?0.02 from 200,000 to 800,000 Pa·s; 4) a LCBI equal to or lower than 0.80; and 5) a ratio (?0.02/1000)/LCBI equal to or greater than 350.

Abstract: A process for preparing an ethylene polymer including the step of homopolymerizing ethylene or copolymerizing ethylene with one or more comonomers in a gas-phase polymerization reactor including a riser unit wherein growing polymer particles flow upwards under fluidization, fast fluidization or transport conditions and a downcomer wherein growing polymer particles flow downward in a densified form, wherein the hold-up of polymer particles in the downcomer is from 55 wt. % to 80 wt. % of the total hold-up of polymer particles in the gas-phase polymerization reactor.

Abstract: Process for preparing an olefin polymer including the step of polymerizing an olefin in the presence of a polymerization catalyst and hydrogen as molecular weight regulator in a gas-phase polymerization reactor to yield growing polymer particles, the reactor including three or more polymerization zones and at least two thereof are sub-zones of a polymerization unit wherein the growing polymer particles flow downward in a densified form and at least one polymerization zone has a ratio of hydrogen to the sum of olefins which is a factor of at least 1.5 lower than the ratio of hydrogen to the sum of olefins in the polymerization zone having the highest ratio of hydrogen to the sum of olefins and a factor of at least 1.5 higher than the ratio of hydrogen to the sum of olefins in the polymerization zone having the lowest ratio of hydrogen to the sum of olefins.