Abstract: A process for polymerizing olefins at temperatures of from 30° C. to 140° C. and pressures of from 1.0 MPa to 10 MPa in the presence of a polymerization catalyst in a multistage polymerization of olefins in at least two serially connected gas-phase polymerization reactors, and apparatus for the multistage polymerization of olefins, comprising at least two serially connected gas-phase polymerization reactors and a device for transferring polyolefin particles from an up-stream gas-phase polymerization reactor to a downstream gas-phase polymerization reactor, the transferring device comprising—a gas/solid separation chamber placed downstream of the upstream gas-phase polymerization which gas/solid separation chamber is equipped at a lower part with an net for introducing a fluid, and—connected to the gas/solid separation chamber at least two lock hoppers, placed in a parallel arrangement, each connected to the downstream gas-phase polymerization reactor.

Abstract: The present technology relates to a polyethylene composition suitable for producing small articles such as flexible and collapsible tubes by blow molding comprising: 1) a density from 0.948 to 0.955 g/cm3; 2) a MIF/MIP ratio from 12 to 25; 3) a MIF from 25 to 40 g/10 min; 4) a Mz from 1000000 to 2000000 g/mol; and 5) a long-chain branching index, LCBI, equal to or greater than 0.55.

Abstract: Polyethylene composition with improved balance of impact resistance at low temperatures and Environmental Stress Cracking Resistance (ESCR), particularly suited for producing protective coatings on metal pipes, said composition having the following features: 1) density from 0.938 to 0.948 g/cm3; 2) ratio MIF/MIP from 15 to 25; 3) MIF from 30 to 45 g/10 min.; 4) Mz equal to or greater than 1000000 g/mol; 5) LCBI equal to or greater than 0.55.

Abstract: Polyethylene composition with improved swell ratio and mechanical properties, particularly suited for preparing blow-moulded articles, said composition having the following features: 1) density from 0.952 to 0.960 g/cm3; 2) ratio MIF/MIP from 17 to 30; 3) Shear-Induced Crystallization Index SIC from 2.5 to 5.0.

Abstract: A process for the preparation of polyolefins by polymerizing olefins at temperatures of from 20 to 200° C. and pressures of from 0.1 to 20 MPa in the presence of a polymerization catalyst and an antistatically acting composition in a polymerization reactor, wherein the antistatically acting composition is a mixture comprising an oil-soluble surfactant and water and the use of an antistatically acting composition comprising an oil-soluble surfactant and water as antistatic agent for the polymerization of olefins at temperatures of from 20 to 200° C. and pressures of from 0.1 to 20 MPa in the presence of a polymerization catalyst.

Abstract: A process for the gas-phase polymerization of ethylene or a mixture of ethylene and one or more 1 olefins in the presence of a polymerization catalyst system comprising the steps a) feeding a solid catalyst component, which was obtained by contacting at least a magnesium compound and a titanium compound, to a continuously operated apparatus and contacting the solid catalyst component with an aluminum alkyl compound at a temperature of from 0° C. to 70° C. in a way that the mean residence time of the solid catalyst component in contact with the aluminum alkyl compound is from 5 to 300 minutes; b) transferring the catalyst component formed in step a) into another continuously operated apparatus and prepolymerizing it with ethylene or a mixture of ethylene and one or more 1 olefins in suspension at a temperature of from 10° C. to 80° forming polymer in an amount of from 0.

Abstract: A process for polymerizing olefins in at least two serially connected gas-phase polymerization reactors, the process for transferring polyolefin particles from a first gas-phase polymerization reactor to a second gas-phase polymerization reactor comprising the steps of: a) discharging polyolefin particles into a separation chamber being at a lower pressure than the pressure in the first reactor; b) transferring the polyolefin particles within the separation chamber into a lower part which contains a bed of polyolefin particles which moves from top to bottom of this part of the separation chamber and into which a fluid is introduced so that an upward fluid stream is induced, c) withdrawing polyolefin particles from the lower end and transferring them to one of at least two lock hoppers working intermittently in parallel; and d) simultaneously pressurizing another of the at least two lock hoppers working intermittently by means of a gas comprising reaction gas coming from the second reactor.

Abstract: A process for homogenizing and pelletizing a polyethylene composition comprising the steps of a) providing a polyethylene composition having a density of from 0.90 g/cm3 to 0.97 g/cm3 and a melt flow rate MFR21.6 at 190° C. under a load of 21.6 kg of from 1 g/10 min to 80 g/10 min, b) melting the polyethylene composition; c) passing the melt through a combination of screens consisting of screens having a mesh opening of at least 205 ?m and comprising at least two screens having a mesh opening of from 205 ?m to 350 ?m; and e) pelletizing the molten polyethylene composition, the use of a polyethylene composition obtained by such a process for the preparation of films, fibers, pipes, blow-molded articles, injection-molded articles, compression-molded articles or rotomolded articles and films, fibers, pipes, blow-molded articles, injection-molded articles, compression-molded articles or rotomolded articles prepared from a polyethylene composition obtained by such a process.

Abstract: A novel gas phase polymerization method is devised, for polymerization of low and ultralow density polyethylene.

Abstract: A novel polyethylene is devised which polyethylene is particularly advantageous for manufacturing rotomoulded articles.

Abstract: The present invention relates to a slurry process for preparing an ethylene polymer having a melt flow ratio F/P, which is the ratio among the melt index value measured according to ASTM 1238 condition “F” and the melt index value measured according to ASTM 1238 condition “P” of equal to or lower than 27, carried out in two or more stages of polymerization at temperatures in the range from 60 to 120° C., in which at least two of the said two or more polymerization stages are carried out under different amounts of molecular weight regulator, said process being carried out in the presence of (A) a solid catalyst component comprising Ti, Mg, halogen, having a porosity (PF), measured by the mercury method and due to pores with radius equal to, or lower than, 1 ?m, of at least 0.3 cm3/g and a surface area determined by BET method, of lower than 100 m2/g, and being further characterized by the fact that more than 50% of the titanium atoms are in a valence state lower than 4 and (B) of an organoaluminum compound.

Abstract: Polyethylene composition with improved balance of environmental stress cracking resistance (FNCT) and impact resistance (Charpy), particularly suited for preparing pipes, said composition having the following features: 1) density from 0.945 to 0.955 g/cm3; 2) ratio MIF/MIP from more than 30 to 45; 3) Shear-Induced Crystallization Index SIC from 1.0 to 2.5; 4) Long Chain Branching index equal to or greater than 0.85.

Abstract: Polyethylene composition with improved swell ratio and mechanical properties, particularly suited for preparing blow-moulded articles, said composition having the following features: 1) density from 0.952 to 0.960 g/cm3; 2) ratio MIF/MIP from 17 to 30; 3) Shear-Induced Crystallization Index SIC from 2.5 to 5.0.

Abstract: Polyethylene composition with improved swell ratio and mechanical properties, particularly suited for preparing blow-moulded articles, said composition having the following features: 1) density from 0.945 to less than 0.952 g/cm3; 2) ratio MIF/MIP from 15 to 30; 3) Shear-Induced Crystallization Index SIC from 2.5 to 5.5.

Abstract: Process for transferring polyolefin particles from a first gas-phase polymerization reactor to a second gas-phase polymerization reactor in a multistage polymerization of olefins carried out in at least two serially connected gas-phase polymerization reactors, wherein the first gas-phase reactor is a fluidized-bed reactor comprising a gas distribution grid and a settling pipe, which is integrated with its upper opening into the distribution grid and contains a bed of polyolefin particles which moves from top to bottom of the settling pipe, the process comprising the steps of introducing a fluid into the settling pipe in an amount that an upward stream of the fluid is induced in the bed of polyolefin particles above the fluid introduction point; withdrawing polyolefin particles from the lower end of the settling pipe; and transferring the withdrawn polyolefin particles into the second gas-phase polymerization reactor, process for polymerizing olefins comprising such a process for transferring polyolefin p

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: New plastomer material for use in automotive parts such as bumpers is devised here, which is a novel polyethylene produced by a gas phase process.

Abstract: A novel PE material is devised showing excellent mechanical/optical properties and process ability, e.g. for film extrusion. The polyethylene of the invention is produced in one single e.g. gas phase reactor.

Abstract: A novel adhesive composition suitable for composing multilayered coatings onto large, industrial equipment such as pipeline tubes is devised. The composition is a blend based on a polyethylene which determines the blend's favorable properties, which polyethylene itself can be used further in coating cables and for producing moldings, especially rotomoulded articles.

Abstract: Process for transferring polyolefin particles from a first gas-phase polymerization reactor to a second gas-phase polymerization reactor in a multistage polymerization of olefins carried out in at least two serially connected gas-phase polymerization reactors, wherein the first gas-phase reactor is a fluidized-bed reactor comprising a gas distribution grid and a settling pipe, which is integrated with its upper opening into the distribution grid and contains a bed of polyolefin particles which moves from top to bottom of the settling pipe, the process comprising the steps of introducing a fluid into the settling pipe in an amount that an upward stream of the fluid is induced in the bed of polyolefin particles above the fluid introduction point; withdrawing polyolefin particles from the lower end of the settling pipe; and transferring the withdrawn polyolefin particles into the second gas-phase polymerization reactor, process for polymerizing olefins comprising such a process for transferring polyolefin partic