Abstract: A reactor for carrying out a gas-phase olefin polymerization in the presence of a polymerization catalyst, made from or containing (i) a first polymerization zone adapted and arranged for growing polymer particles to flow upward under fast fluidization or transport conditions, (ii) a second polymerization zone adapted and arranged for the growing polymer particles to flow downward, and (iii) a set of bars for introducing feedstock or a barrier stream into the reactor, wherein each bar has (a) a hollow space along the length of the bar, (b) a particle deviating top, and (c) a multiplicity of openings arranged along the bottom half of the periphery of the bar.

Abstract: A process for producing a blended low density polyethylene composition including the step of: blending a first component made from or containing one or more recycled polymer compositions and a second component made from or containing one or more low density polyethylenes.

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 preparing a polyethylene composition made from or containing bimodal or multimodal polyethylene in an extruder device including the steps of (i) mixing a bimodal or multimodal polyethylene having a density from 0.940 g/cm3 to 0.968 g/cm3, in the form of a polyethylene powder, with an additive, in a mixing device at a temperature from 10° C. to 100° C. without melting the polyethylene powder; (ii) melting and homogenizing the mixture within the extruder device, thereby forming a molten polyethylene composition; and (iii) pelletizing the molten polyethylene composition, and further (iv) adding a liquid made from or containing an organic peroxide, in an amount from 20 ppm to 200 ppm of organic peroxide with respect to the polyethylene powder, to the polyethylene powder at a position where mixing occurs and the polyethylene powder has a temperature of from 10° C. to 100° C.

Abstract: A polymer blend made from or containing: A) from 65 to 98 wt. % of a first polyethylene component, having a density from 0.948 to 0.960 g/cm3, a Melt Index MIF from 30 to 100 g/10 min, and a Melt Flow Ratio MIF/MIP from 15 to 30; and B) from 2 to 35 wt. % of a second polyethylene component, having a density from 0.910 to 0.945 g/cm3 and a Melt Index MIE of 0.1 to 3 g/10 min.

Abstract: A process for preparing ethylene polymers including the step of polymerizing ethylene or copolymerizing ethylene and one or more comonomers at a temperature from 100° C. to 350° C. and a pressure of from 110 MPa to 350 MPa in a continuously operated tubular polymerization reactor, thereby yielding a reaction mixture, wherein the tubular polymerization reactor has a reactor cooling jacket for removing the heat of the reaction and a pressure control valve, the reaction mixture leaves the reactor through the pressure control valve, the reaction mixture then passes a post-reactor cooler equipped with a post-reactor cooling jacket, the reactor cooling jacket is provided with a reactor coolant having an inlet temperature and the post-reactor cooling jacket is provided with a post-reactor coolant having an inlet temperature, and the inlet temperature of the post-reactor coolant is independently controlled from the inlet temperature of the reactant coolant.

Abstract: A process for polymerizing or copolymerizing one or more ethylenically unsaturated monomers with a controlled gas velocity of the gaseous reaction. A process for polymerizing or copolymerizing one or more ethylenically unsaturated monomers at temperatures from 100 to 350 ° C. and pressures in the range from 110 to 500 MPa, comprising the steps of: (a) compressing a gaseous reaction mixture in a hyper compressor, (b) providing the reaction mixture to each compressing stage through a suction pipe system, and (c) discharging the compressed reaction mixture from the compressing stage through a discharge pipe system.

Abstract: A high-pressure polymerization system having a) a polymerization reactor and b) a reactor blow down system having b1) a reactor blow down vessel, having a circular design over a major portion P having a L/D-ratio in the range from 1.75 to 10.0 and containing an aqueous quenching medium, b2) a release line connecting the polymerization reactor with the reactor blow down vessel and having an outlet located above a maximum level for the aqueous quenching medium, b3) a first emergency valve in the release line to open and close fluid communication between the polymerization reactor and the reactor blow down system, and wherein the release line outlet has a joining piece having an angle (?) between the central axis and a tangent at the reactor blow down vessel in the range from 5° to 70° and the reactor blow down vessel has a vent stack containing a constricted section.

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 visbreaking process, in which either vacuum is applied or not, using low density polyethylene recyclates (rLDPE) comprising also amounts of linear low density polyethylene (rLLDPE). Application of a low energy-intake and vacuum during visbreaking treatment, by limiting temperature and RPM of the extruder's screw, a superior visbroken material is obtained, suitable for films with less gels. A method and visbroken, degassed LDPE recyclate having less odor. The visbroken LDPE recyclate shows only minor increase in or almost the same MFR compared to the starting material, and only moderate increase of density, by a removing of at least 90% of the defects and gels and showing superior optical performance when processed to films.

Abstract: A lower-energy visbreaking process with lower energy-intake of the polymer for visbreaking of low density polyethylene recyclates, derived from film waste material, via visbreaking thermal and mechanical processing conditions in an extruder, performed for at least two different temperatures, greater than 220° C. and lower than 340° C. Providing a visbroken LDPE with a low increase in MFR compared to the starting material, and lower increase of density. Resulting in a visbroken LDPE material, showing superior optical performance when processed to film, with second generation gels per cm2.

Abstract: A process for preparing an ethylene polymer in a suspension polymerization including the steps of separating the formed suspension of ethylene polymer particles in a solid-liquid separator into ethylene polymer particles and mother liquor, transferring a first part of the mother liquor into a work-up section including an evaporation unit for producing a wax-depleted portion of the mother liquor, wherein a protic agent is added to the part of the mother liquor which is transferred into the work-up section, and recycling a first part of the wax-depleted portion of the mother liquor to the polymerization reactor or the series of polymerization reactors.

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 made from or containing: A) from 75% to 97% by weight of a copolymer of ethylene having: 1) a density of 0.925 g/cm3 or higher; and 2) a MI2 value of 0.5 g/10 min. or greater; and B) from 3% to 25% by weight of a polyolefin composition made from or containing: BI) from 5% to 35% by weight of a propylene homopolymer or a propylene copolymer; BII) from 20% to 50% by weight of a copolymer of ethylene containing from 1.0% to 20.0% by weight of alpha-olefin units and 25.0% by weight or less of a fraction soluble in xylene at 25° C.; and BIII) from 30% to 60% by weight of a copolymer of ethylene and propylene containing from 25.0% to 75.0% by weight of ethylene derived units and from 40.0% to 95.0% by weight of a fraction soluble in xylene at 25° C.

Abstract: A continuous process for preparing a multimodal polyolefin composition made from or containing one or more antioxidants, including the steps of: preparing a multimodal polyolefin in form of a polyolefin powder, having a mass-median-diameter D50 in the range from 300 ?m to 2500 ?m, in a series of polymerization reactors; mixing the polyolefin powder and an organic peroxide without melting the polyolefin powder; melting and homogenizing the mixture within an extruder device; adding one or more antioxidants to the molten polyolefin composition; homogenizing the combination of molten polyolefin composition and antioxidant, thereby forming an antioxidant equipped molten polyolefin composition; and pelletizing the antioxidant equipped molten polyolefin composition.

Abstract: The disclosure provides methods for removing polymeric fouling on process equipment during low density polyethylene manufacture. A purge cleaning composition with ethylene gas containing at least one C3+ hydrocarbon alkene for a period of time is used to remove polymer build-up in at least one location in the polymerization plant, such as, without limitation, the reactor or in tubing between a reactor and a pre-heater or between a cooler and a preheater.

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: An apparatus for carrying out a gas-phase olefin polymerization having a first polymerization zone having a cylindrical segment of diameter D01, a second polymerization zone having a cylindrical upper part of diameter D05 and a cylindrical lower part of diameter D06, a separation zone of diameter D04, a first connecting element of diameter D03, which is a bend of radius R03 or has a bend part of radius R03, a gas recycle line of diameter D08, a transition segment of diameter D02, and a second connecting element of a diameter D09, which is a bend or has a bend part, wherein the ratio D04 to D05 is 1.0 to 1.5, the ratio D05 to D06 is 1.2 to 2, the ratio R03 to D03 is 1 to 6, the ratio D03 to D01 is 0.3 to 0.85, and the ratio D08 to D02 is 1.0 to 2.2.

Abstract: Apparatus for carrying out a catalytic gas-phase olefin polymerization having a first polymerization zone for growing polymer particles to flow upward under fast fluidization or transport conditions, a second polymerization zone for the growing polymer particles to flow downward, and a gas/solid separation zone; wherein the second polymerization zone has an upper part being connected to the separation zone and a lower part being connected to the upper part; wherein the ratio of the height H01 of the separation zone to the diameter D01 of the separation zone is 2.5 to 4.5.

Abstract: An extrusion-based additive manufacturing process for producing a 3D printed article, the process involving the steps of: (i) providing a build material in pellet form, containing a propylene polymer composition with specific weight percentages of heterophasic propylene copolymer, propylene homopolymer or copolymer, elastomeric block copolymer, elastomeric ethylene copolymer, glass material as filler, and a compatibilizer, the propylene polymer composition having MFR of at least 1.0 g/10 min; (ii) providing an additive-manufacturing system; (iii) at least partially fusing the build material within the system to create a fused build material; and (iv) extruding the fused build material to form the final 3D printed article.