Abstract: The present invention relates to a process for the preparation of ethylene polymers using a number of reactors arranged in series comprising the steps in which a) ethylene, a diluent, a catalyst, a co-catalyst and optionally comonomers and hydrogen are introduced into a first reactor, b) polymerization of ethylene and optionally comonomers is carried out in the reaction mixture of said first reactor to make ethylene polymers, c) reaction mixture is discharged from said first reactor, d) said reaction mixture and fresh ethylene and optionally comonomers and hydrogen are introduced into the consecutive reactor to make additional ethylene polymers, e) said reaction mixture is discharged from said consecutive reactor and introduced into the further consecutive reactor, if any, with fresh ethylene and optionally comonomers and hydrogen to make additional ethylene polymers, steps c) and d) are repeated until the last reactor of the series, f) reaction mixture is discharged from last reactor of the series and ethyl

Abstract: The present invention relates to a process for the preparation of ethylene polymers using a number of reactors arranged in series comprising the steps in which a) ethylene, a diluent, a catalyst, a co-catalyst and optionally comonomers and hydrogen are introduced into a first reactor, b) polymerization of ethylene and optionally comonomers is carried out in the reaction mixture of said first reactor to make ethylene polymers, c) reaction mixture is discharged from said first reactor, d) said reaction mixture and fresh ethylene and optionally comonomers and hydrogen are introduced into the consecutive reactor to make additional ethylene polymers, e) said reaction mixture is discharged from said consecutive reactor and introduced into the further consecutive reactor, if any, with fresh ethylene and optionally comonomers and hydrogen to make additional ethylene polymers, steps c) and d) are repeated until the last reactor of the series, f) reaction mixture is discharged from last reactor of the series and e

Abstract: The present invention relates to a process for the preparation of ethylene polymers using a number of reactors arranged in series comprising the steps in which a) ethylene, a diluent, a catalyst, a co-catalyst and optionally comonomers and hydrogen are introduced into a first reactor, b) polymerization of ethylene and optionally comonomers is carried out in the reaction mixture of said first reactor to make ethylene polymers, c) reaction mixture is discharged from said first reactor, d) said reaction mixture and fresh ethylene and optionally comonomers and hydrogen are introduced into the consecutive reactor to make additional ethylene polymers, e) said reaction mixture is discharged from said consecutive reactor and introduced into the further consecutive reactor, if any, with fresh ethylene and optionally comonomers and hydrogen to make additional ethylene polymers, steps c) and d) are repeated until the last reactor of the series, f) reaction mixture is discharged from last reactor of the series and ethyl

Abstract: The present invention relates to a process for the preparation of ethylene polymers using a number of reactors arranged in series comprising the steps in which a) ethylene, a diluent, a catalyst, a co-catalyst and optionally comonomers and hydrogen are introduced into a first reactor, b) polymerization of ethylene and optionally comonomers is carried out in the reaction mixture of said first reactor to make ethylene polymers, c) reaction mixture is discharged from said first reactor, d) said reaction mixture and fresh ethylene and optionally comonomers and hydrogen are introduced into the consecutive reactor to make additional ethylene polymers, e) said reaction mixture is discharged from said consecutive reactor and introduced into the further consecutive reactor, if any, with fresh ethylene and optionally comonomers and hydrogen to make additional ethylene polymers, steps c) and d) are repeated until the last reactor of the series, f) reaction mixture is discharged from last reactor of the series and e

Abstract: The present invention relates to a process for the preparation of ethylene polymers using a number of reactors arranged in series comprising the steps in which a) ethylene, a diluent, a catalyst, a co-catalyst and optionally comonomers and hydrogen are introduced into a first reactor, b) polymerization of ethylene and optionally comonomers is carried out in the reaction mixture of said first reactor to make ethylene polymers, c) reaction mixture is discharged from said first reactor, d) said reaction mixture and fresh ethylene and optionally comonomers and hydrogen are introduced into the consecutive reactor to make additional ethylene polymers, e) said reaction mixture is discharged from said consecutive reactor and introduced into the further consecutive reactor, if any, with fresh ethylene and optionally comonomers and hydrogen to make additional ethylene polymers, steps c) and d) are repeated until the last reactor of the series, f) reaction mixture is discharged from last reactor of the series and ethyl

Abstract: The present invention relates to a method for preparing and extruding a bimodal polyethylene product, which comprises a first polyethylene fraction and a second polyethylene fraction having a different molecular weight than the first polyethylene fraction. More specifically, the present invention relates to a method for controlling the specific energy applied on said bimodal polyethylene product by regulating the amount of the polyethylene fraction having the higher molecular weight in said bimodal polyethylene product. According to the present invention regulation of the amount of said polyethylene fraction having the higher molecular weight in said bimodal polyethylene product is obtained by regulating the polymerization conditions for preparing the bimodal polyethylene product, and in particular by adjusting ethylene monomer feed during the polymerization process.

Abstract: The invention relates to a long chain branched medium and low density polyethylene having a combination of the following properties: a) a density of from 0.910 to 0.945 g/cm3; b) an HLMI of from 2 to 150 dg/min and an MI2 of from 0.01 to 2 dg/min; c) a polydispersity index (PDI) Mw/Mn of at least 7, wherein Mw is the weight average molecular weight and Mn is the number average molecular weight of the polyethylene; and d) and a minimum amount of long chain branching measured by a value selected from one of grheo and LCBI. The invention also relates to a process for obtaining said polyethylene comprising the following steps: a) injecting ethylene, one or more alpha-olefinic comonomers comprising 3 to 10 carbon atoms and an activated chromium-based catalyst into a gas phase polymerisation reactor; b) copolymerising said ethylene and comonomer in said reactor in the gas phase; and c) retrieving an ethylene copolymer having a density of from 0.910 to 0.

Abstract: The present invention provides a process for preparing a supported chromium-based catalyst for the production of polyethylene comprising the steps of a) providing a silica-based support having a specific surface area of at least 250 m2/g and of less than 400 m2/g and comprising a chromium compound deposited thereon, the ratio of the specific surface area of the support to chromium content being at least 50000 m2/g Cr; b) dehydrating the product of step a); and c) titanating the product of step b) in an atmosphere of dry and inert gas containing at least one vaporised titanium compound of the general formula selected from RnTi(OR?)m and (RO)nTi(OR?)m, wherein R and R? are the same or different hydrocarbyl groups containing from 1 to 12 carbon atoms, and wherein n is 0 to 3, m is 1 to 4 and m+n equals 4, to form a titanated chromium-based catalyst having a ratio of specific surface area of the support to titanium content of the titanated catalyst ranging from 5000 to 20000 m2/g Ti.

Abstract: The present invention relates to a process for the preparation of ethylene polymers using a number of reactors arranged in series comprising the steps in which a) ethylene, a diluent, a catalyst, a co-catalyst and optionally comonomers and hydrogen are introduced into a first reactor, b) polymerization of ethylene and optionally comonomers is carried out in the reaction mixture of said first reactor to make ethylene polymers, c) reaction mixture is discharged from said first reactor, d) said reaction mixture and fresh ethylene and optionally comonomers and hydrogen are introduced into the consecutive reactor to make additional ethylene polymers, e) said reaction mixture is discharged from said consecutive reactor and introduced into the further consecutive reactor, if any, with fresh ethylene and optionally comonomers and hydrogen to make additional ethylene polymers, steps c) and d) are repeated until the last reactor of the series, f) reaction mixture is discharged from last reactor of the series and ethyl