Abstract: A polyethylene composition having the following features: 1) density from about 0.945 to about 0.955 g/cm3, determined according to ISO 1183 at 23° C.; 2) ratio MIF/MIP from about 23 to about 40; 3) MIF from about 8.5 to about 18 g/10 min.; 4) HMWcopo index from about 3.5 to about 20; and 5) long-chain branching index, LCBI, equal to or greater than about 0.45. The polyethylene composition can be used to produce pipes and films.

Abstract: A polyolefin composition made from or containing: A) from 55 to 75 wt % of a polyethylene having a density of 0.920 to 0.940 g/cm3 and a fraction soluble in xylene (XSA) of less than 10%, based upon the weight of the polyethylene; B) from 25 to 45 wt. % of a copolymer of ethylene with one or more comonomers selected from ?-olefins having formula HC2?CHRI, where RI is an alkyl radical, linear or branched, having from 1 to 8 carbon atoms, made from or containing from 50 to 70 wt. %, based upon the weight of the copolymer of ethylene, of ethylene and having a fraction soluble in xylene (XSB) of at least about 50 wt. %, based upon the weight of the copolymer of ethylene; the polyolefin composition having a flexural modulus of less than 260 MPa as measured according to ISO 178. The polyolefin composition is useful for producing geomembranes.

Abstract: Process for preparing a polyolefin polymer comprising the steps of a) forming a particulate polyolefin polymer by polymerizing one or more olefins in the presence of a polymerization catalyst system in a polymerization reactor; b) discharging the formed polyolefin particles from the polymerization reactor; c) degassing the polyolefin particles by a process comprising at least a final step of contacting the polyolefin particles with a nitrogen stream in a degassing vessel; and d) transferring the polyolefin particles from the vessel, in which the contacting of the polyolefin particles with the nitrogen stream is carried out, to a melt mixing device, in which the polyolefin particles are melted, mixed and thereafter pelletized, without passing the particles through a buffering device, wherein the degassing vessel is only partly filled with polyolefin particles and the empty volume within the degassing vessel is sufficient to take up additional polyolefin particles for at least 3 hours if the transfer of pol

Abstract: A polyethylene composition made from or containing a polyethylene, having the following features: 1) a density from about 0.930 to about 0.945 g/cm3, determined according to ISO 1183 at 23° C.; 2) a ratio of MIF/MIP from about 10 to less than about 30; 3) a MIF from about 3 to about 25 g/10 min.; 4) a Mz equal to or greater than about 1,500,000 g/mol; and 5) a long-chain branching index, LCBI, equal to or lower than about 0.55, wherein the LCBI is the ratio of the measured mean-square radius of gyration Rg, measured by GPC-MALLS, to the mean-square radius of gyration for a linear PE having the about same molecular weight of 1,000,000 g/mol.

Abstract: Ethylene polymer composition having a fusion enthalpy ?Hfus, measured by Differential Scanning Calorimetry with a heating rate of 20° C. per minute, of 60 J/g or more, comprising, all percent amounts being by weight: A) 25-55% of an ethylene polymer containing 10% or less, referred to the weight of A), of a fraction XSA soluble in xylene at 25° C.; B) 45-75% of a copolymer of ethylene and propylene containing from 45% to 70%, of ethylene and 60% or more of a fraction XSB soluble in xylene at 25° C., both the ethylene of the copolymer and XSB amounts being referred to the weight of B); wherein the amounts of A) and B) are referred to the total weight of A)+B).

Abstract: Ethylene polymer composition comprising, all percent amounts being by weight: A) 30-60% of an ethylene polymer containing 10% or less, referred to the weight of A), of a fraction XSA soluble in xylene at 25° C.; B) 40-70% of a copolymer of ethylene with at least one olefin of formula HC2?CHR, where R is a alkyl radical, linear or branched, having from 2 to 8 carbon atoms, containing 65-90% of ethylene and 55-15% of a fraction XSB soluble in xylene at 25° C., both the ethylene of the copolymer and XSB amounts being referred to the weight of B), the intrinsic viscosity [?] of the XSB fraction ranging from 0.8 to 3.2 dl/g; wherein the amounts of A) and B) are referred to the total weight of A)+B).

Abstract: A polyethylene composition having the following features: 1) density from about 0.945 to about 0.951 g/cm3, determined according to ISO 1183 at 23° C.; 2) ratio MIF/MIP from about 25 to about 43; 3) MIF from about 3.5 to less than about 8.5 g/10 min.; 4) HMWcopo index from about 1 to about 40; and 5) long-chain branching index, LCBI, equal to or greater than about 0.83. The polyethylene composition can be used to produce pipes.

Abstract: A slurry polymerization process for the preparation of polyethylene in a reactor cascade of two or more polymerization reactors including the steps of feeding to a polymerization reactor amounts of ethylene, of a Ziegler catalyst, of fresh aluminum alkyl and of a diluent; feeding the slurry product withdrawn from the polymerization reactor to a second polymerization reactor; and feeding additional amounts of ethylene and of diluent wherein the ethylene is first passed through an ethylene purification unit, which reduces at least the concentration of carbon monoxide, carbon dioxide, oxygen, acetylene and water contained in the ethylene, before it is fed to the two or more polymerization reactors of the reactor cascade.

Abstract: A method for cleaning a metal surface of a metal component of an industrial plant is disclosed comprising measuring the electrical resistance RA1 of a metal component over a cleaned area of the metal surface with a resistance meter, comparing the electrical resistance RA1 measured with a pre-determined electrical resistance value RDET, assessing whether RA1 is greater, smaller or equal to RDET, and repeating cleaning if the electrical resistance RA1 measured is greater than RDET, or terminating cleaning of the surface area of the metal component if RA1 is smaller than or identical to RDET.

Abstract: Methods of detecting carburization, nitriding or chromium depletion in a non- or weakly ferromagnetic test object using a permanent magnet having a magnet pull force equal to or greater than about 75N and measuring either the adhesive force to detach the magnet from the test object or the attractive force in which the magnet is being pulled towards the surface of the test object.

Abstract: A polyethylene composition having the following features: 1) density from about 0.945 to about 0.958 g/cm3, determined according to ISO 1183 at 23° C.; 2) ratio MIF/MIP from about 20 to about 43; 3) MIF from about 4.0 to less than about 8.5 g/10 min.; 4) HMWcopo index from about 3.5 to about 20; and 5) long-chain branching index, LCBI, equal to or lower than about 0.82. The polyethylene composition can be used to produce blown films.

Abstract: A process for starting a multizone circulating reactor containing no polyolefin particles, comprising the steps of conveying gas through the reactor and the gas recycle line, feeding a particulate material comprising a polymerization catalyst and optionally polyolefin into the reactor, controlling the gas flow in a vertical reactor zone equipped with a throttling valve at the bottom so that the upwards gas velocity in the bottom part of this reaction zone is lower than the terminal free-fall velocity of the particulate material fed into the reactor, and, after the weight of the particulate polyolefin in this reactor zone is higher than the drag force of the upward moving gas, controlling the circulation rate of the polymer particles within the multizone circulating reactor by adjusting the opening of the throttling valve and adjusting the flow rate of a dosing gas.

Abstract: Process for copolymerizing ethylene and esters of vinyl alcohol in the presence of free-radical polymerization initiators at pressures in the range of from 110 MPa to 500 MPa and temperatures in the range of from 100° C. to 350° C. in a continuously operated polymerization apparatus comprising a polymerization reactor and one or more compressors, which compress the monomer mixture fed to the polymerization reactor to the polymerization pressure, wherein the monomer mixture is compressed by a sequence of compression stages in which the compressed gas mixture is cooled after each compression stage and the fraction of the monomer mixture, which is liquid after this cooling, is separated off and returned to the polymerization apparatus in liquid form, and wherein at least a part of the liquid fractions obtained after compressing the monomer mixture in the respective compression stage to a pressure of from 0.2 MPa to 10 MPa is purified before being returned to the polymerization process.

Abstract: The present disclosure relates to a plant for performing polymerization, such as the polymerization of ethylene, having a recycle connection with two or more cooling channels arranged in parallel, a process for polymerization and downstream processes, and a plant for polymerization, comprising the following plant components in fluid communication: a) A reactor with an inlet side and an outlet side; b) A recycle connection positioned in fluid communication between the outlet side of the reactor and the inlet side of the reactor; wherein the recycle connection comprises two or more cooling channels arranged in parallel.

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: A process for preparing a polyolefin, including polymerizing olefins in the presence of an antistatic agent made from or containing an alkylene oxide derived polymer made from or containing in average from about 10 to about 200 repeating units —(CH2—CHR—O)— with R being hydrogen or an alkyl group having from 1 to 6 carbon atoms, wherein the alkylene oxide derived polymer is a random copolymer of ethylene oxide and other alkylene oxides and a ratio of n:m is in the range of from 6:1 to 1:1, wherein (n) is the average number of repeating units —(CH2—CH2—O)— derived from ethylene oxide and (m) is the average number of repeating units —(CH2—CHR?—O)— derived from the other alkylene oxides with R? being an alkyl group having from 1 to 6 carbon atoms, and the end groups of the alkylene oxide derived polymer are —OH groups.

Abstract: A process for separating polymeric and gaseous components of a polymer-monomer mixture at a pressure of from 0.12 MPa to 0.6 MPa and a temperature of from 120° C. to 300° C. in a separation vessel is provided. The separation vessel has a vertically arranged cylindrical shape with a ratio of length to diameter L/D of from 0.6 to 10 and an inlet pipe capable of introducing the polymer-monomer mixture into the separation vessel which the inlet pipe extends vertically from the top of the separation vessel into the separation vessel. Further a process for preparing ethylene homopolymers or copolymers from ethylenically unsaturated monomers in the presence of free-radical polymerization initiators at temperatures from 100° C. to 350° C. and pressures in the range of from 110 MPa to 500 MPa comprising such a process for separating a polymer-monomer mixture is provided.

Abstract: The present disclosure relates to a continuous process for the preparation of ethylene homopolymers or ethylene copolymers comprising polymerizing ethylene or copolymerizing ethylene and one or more other olefins in the presence of a chromium catalyst in a gas-phase polymerization reactor which is equipped with a cycle gas line for withdrawing reactor gas from the reactor, leading the reactor gas through a heat-exchanger for cooling and feeding the reactor gas back to the reactor, wherein the polymerization is carried out at a temperature from 30° C. to 130° C. and a pressure of from 0.1 to 10 MPa and an aliphatic carboxylic acid ester having from 8 to 24 carbon atoms is added.

Abstract: A process for preparing a polyolefin, including polymerizing olefins in the presence of an antistatic agent made from or containing an alkylene oxide derived polymer made from or containing in average from about 10 to about 200 repeating units —(CH2—CHR—O)— with R being hydrogen or an alkyl group having from 1 to 6 carbon atoms, wherein the alkylene oxide derived polymer is a random copolymer of ethylene oxide and other alkylene oxides and a ratio of n:m is in the range of from 6:1 to 1:1, wherein (n) is the average number of repeating units —(CH2—CH2—O)— derived from ethylene oxide and (m) is the average number of repeating units —(CH2—CHR?—O)— derived from the other alkylene oxides with R? being an alkyl group having from 1 to 6 carbon atoms, and the end groups of the alkylene oxide derived polymer are —OH groups.

Abstract: The present technology relates to a process for polymerizing or copolymerizing ethylenically unsaturated monomers in the presence of free-radical polymerization initiators, wherein the polymerization is carried out in a continuously operated tubular reactor at temperatures from 100° C. to 350° C. and pressures from 180 MPa to 340 MPa, with a specific reactor surface area Asp of 2 m2/(t/h) to 5.5 m2/(t/h), and the tubular reactor has a specific ratio RDsp of 0.0050 MPa?1 to 0.0069 MPa?1 and an inner surface which has a surface roughness Ra of 2 ?m or less.