摘要:
A unimodal LLDPE formed from ethylene and at least one C3-12 alpha-olefin comonomer by single site catalysis having the following properties: a density of 915-950 kg /m3; MFR2 in the range 0.5 to 6; Mw/Mn in the range 2.5 to 4; a shear thinning SHI (1/100) of at least 1.7; a comonomer content of 2 to 10 wt% ; a melting temperature (Tm) of 115 to 128°C; and no long chain branching.
摘要:
A shrink film comprising a polyethylene film of thickness 5 to 500 µm, characterized in that said polyethylene comprises an ethylene homopolymer-copolymer mixture having a molecular weight distribution in the range 5 to 40, and a weight average molecular weight of at least 100 kD.
摘要:
The present invention concerns a bimodal film-making HDPE composition, a process for the preparation thereof, a film prepared thereof and a film-making process. The composition comprises at least one polyethylene component having a relatively low molecular weight and another polyethylene component having a relatively high molecular weight. The composition has a shear thinning index defined by the relationship: SHI5/300≤0.00014 θ5kPa + 78 wherein θ5kPa is the complex viscosity at G*=5Pa and SHI5/300 is the ratio of complex viscosity at G*=5kPa to the complex viscosity at G*=300kPa. By means of the invention it is possible to produce material for making HDPE blown films with good mechanical properties in a process where the whole range of PE products from LLD to HD can be produced.
摘要:
A shrink film comprising a polyethylene film of thickness 5 to 500 µm, characterized in that said polyethylene comprises an ethylene homopolymer-copolymer mixture having a molecular weight distribution in the range 5 to 40, and a weight average molecular weight of at least 100 kD.
摘要:
The present invention concerns a process for producing homogeneous polyethylene materials and processes for making high density, medium density and low density films therefrom. The process comprises producing a polyethylene composition in a multistage reaction sequence of successive polymerization stages in the presence of an ethylene-polymerizing catalyst system. According to the invention, the process is carried out using an unsupported catalyst comprising magnesium and titanium as active constituents, in at least one loop polymerization stage and at least one gas phase polymerization stage and, operated with different amounts of hydrogen and comonomers to produce a high molecular weight portion in one of the polymerization stages and a low molecular weight portion in another so as to provide a polyethylene composition with the low molecular weight part having an MFR2 of 250 g/10 min or more. By means of the process it is possible to obtain homogeneous bimodal polyethylene material.
摘要:
A shrink film comprising a polyethylene film, characterized in that said polyethylene is an ethylene copolymer mixture having a molecular weight distribution in the range 10 to 35, a density of 915 to 940 kg/m3, a weight average molecular weight of at least 100000 D and an MFR2.16 (190 °C) of 0.1 to 0.9 kg/m3, which copolymer mixture is produced by a two or more stage copolymerization of ethylene and 2 to 10 % mole (relative to ethylene) of a C3-12 alpha-olefin comonomer in a series of reactors including at least one slurry loop reactor and at least one gas phase reactor using a heterogeneous Ziegler-Natta catalyst.