Abstract: A process for producing a low density polyethylene with modified melt flow index, comprising subjecting to thermal visbreaking a precursor polyethylene (I) comprising 35% by weight or more of LDPE.

Abstract: A process for producing a low density polyethylene with modified melt flow index, comprising subjecting to thermal visbreaking a precursor polyethylene (I) comprising 35% by weight or more of LDPE and blending the so obtained intermediate polyethylene product (II) with an additional polyethylene (III).

Abstract: An extrusion-based additive manufacturing process including the step of selectively depositing a molten thermoplastic material (P) on a film or sheet made from or containing a polymer blend obtained by melt blending a mixture made from or containing: (A) 60% to 98.8% by weight of a polyolefin; (B) 0.1% to 30% by weight of a compatibilizer; (C) 0.05% to 20% by weight of an amino resin; and (D) 0% to 5% by weight of an additive, wherein the amounts of (A), (B), (C) and (D) are based on the total weight of (A)+(B)+(C)+(D).

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) 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 0.955 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 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 articles with an extrusion-based additive manufacturing system using a consumable filament made from or containing a propylene polymer composition made from or containing: A) from 20% to 60% by weight of a heterophasic propylene copolymer; B) from 5% to 33% by weight of a propylene homopolymer or copolymer, wherein the copolymer contains up to 5% by weight of an alpha olefin; C) from 2% to 15% by weight of an elastomeric block copolymer made from or containing styrene; D) from 4% to 32% by weight of an elastomeric ethylene copolymer; E) from 5% to 50% by weight of a glass material as filler; and F) from 0.1% to 5% by weight of compatibilizer.

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 thermoplastic composition made from or containing (i) a polyolefin portion made from or containing (a) an ethylene/alkyl acrylate, (b) a polyolefin elastomer selected from copolymers of ethylene with a C3-C15 alpha-olefin, and optionally with a diene, having a density of from 0.860 to g/cm3, (c) an ethylene polymer grafted with carboxyl groups or organic silane groups, and optionally (d) a copolymer of ethylene with a C4-C10 alpha-olefin, having a density of from 0.910 to g/cm3, and (ii) a mineral portion made from or containing (e) magnesium hydroxide, wherein the components (a)-(e) being present in amount such that the weight ratio (e)/polyolefin portion ranges from 0.8:1 to 1.75:1, the weight ratio (a)/(b) ranges from 0.75:1 to 1.25:1, and the weight ratio (a)/(e) ranges from 0.15:1 to 0.4:1; and wherein the thermoplastic composition has a melt flow rate of at least 2 g/10 min.

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 process for preparing a multimodal ethylene copolymer in suspension in a reactor cascade including a first polymerization reactor and subsequent polymerization reactor(s) including polymerizing ethylene and C3-C12-1-alkenes and forming a suspension of multimodal ethylene copolymer particles in a suspension medium made from or containing a diluent, transferring the suspension into a separator, wherein the suspension is separated into multimodal ethylene copolymer particles and recovered suspension medium, purifying part of the recovered suspension medium for producing purified components of the recovered suspension medium, and recycling part of the purified components of the recovered suspension medium to the first polymerization reactor of the reactor cascade, wherein the purified components of the recovered suspension medium recycled to the first polymerization reactor and made from or containing the diluent, undergo catalytic hydrogenation before being introduced into the first polymerization reactor.

Abstract: An apparatus for polymerizing olefins including a polymerization reactor and a vessel system for pre-activating a solid catalyst component, wherein the vessel system is arranged upstream of the polymerization reactor. The vessel system includes a contacting vessel which includes a main portion, a base portion, a head portion, an inlet, an outlet, and a stirrer positioned within the contacting vessel, wherein the ratio (H/D) of the height (H) of the main portion to the diameter (D) of the main portion is 1.8 or greater. The stirrer is located at a position between the inlet and the outlet.

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 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: 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: 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: Method for the preparation of dried polymer pellets in a facility having a dryer with a first chamber and a mechanical agitator, and the facility further having a degassing silo with a second chamber, the method includes the steps of guiding a drying gas flow made from or containing a first gas mixture for drying wet polymer pellets into the first chamber, transferring the dried polymer pellets into the second chamber, guiding a second gas mixture for degassing the dried polymer pellets into the second chamber thereby transforming the second gas mixture into a third gas mixture and guiding a portion of the third gas mixture into the first chamber; and process for manufacturing LDPE pellets.

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: A polyethylene composition for preparing filaments and fibers, made from or containing: A) from 65% 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 35% by weight of a polyolefin composition made from or containing: BI) from 5% to 35% by weight of a propylene homopolymer; BII) from 20% to 50% by weight of an ethylene homopolymer or a copolymer of ethylene with up to 5% by weight of alpha-olefin comonomers, containing 5% by weight or less of a fraction soluble in xylene at 25° C.; and BIII) from 30% to 60% by weight of a terpolymer of ethylene, propylene, and 1-butene containing from 30% to 85% by weight of a fraction soluble in xylene at 25° C.