Borealis Technology Oy

Borealis A/s

Svein Staal Eggen

Ivar Martin Dahl

Arild Follestad

Richard Blom

Katrin Nord-Varhaug

Klaus-Joachim Jens

Rune Nygaard

Hans Joerg Fell

Hans Eklind

Philipp Walter

Solveig Johansson

Hege Vale Baann

Bernt-Ake Sultan

Irene Helland

Anneli Malmberg

The present invention relates to a multimodal polyethylene composition wherein (i) the composition has an MFRof 0.1 to 100 g/10 min, (ii) the shear thinning index SHIand the log MFRof the composition satisfy the following relation: SHI&#x2267;&#x2212;10.58 log MFR[g/10 min]/(g/10 min)+12.94, and (iii) the composition has an environmental stress crack resistance ESCR of 10 h or more. Furthermore, the present invention relates to a process for the production of said composition, an injection moulded article, in particular a cap or closure, comprising said composition and to the use of said composition for the production of an injection moulded article.

Polyethylene composition for injection molded caps and closure articles

A mixing device for compounding polymers by elongational deformation is described. The device has a casing (,) with an inlet (,) and an outlet (,). The casing has inner walls (,) defining an enclosure (,) which communicates with the inlet and the outlet. A core (,) is arranged in the enclosure and defines a mixing space (,) between the core (,) and the enclosure wall (,). The mixing space (,) is divided into several slits (,) and chambers (,) by protrusions (,). The device is characterised in that the enclosure (,) and the core (,) are concentrically arranged around a common axis (A) and are conically tapered towards the outlet (,), and that the protrusions (,) are circumferentially arranged on at least one of the core (,) and the enclosure wall (,) with a slit gap in the range from about 0.5 mm to about 10 mm and a width of the slit gap in the range of 0 to about 5 mm. Preferably, the enclosure wall (,) and the core (,) are adjustable relative to each other for adjustment of the slit gap. The mixing device is preferably incorporated in a compounding equipment comprising a melting extruder (,), the mixing device, a homogenizing extruder (,) and a pelletizer (,).

Mixing device

A process for the polymerization of ethylene and optionally &agr;-olefins to form ethylene homopolymer or copolymers having a broad molecular weight distribution, comprising polymerization of 100-80 wt. % of ethylene and 0-20 wt. % of comonomer in the presence of two independent, simultaneously present catalysts A and B, wherein catalyst A, deposited on an inorganic support, comprises chromium in a predominantly oxidant state of 2 and catalyst B comprises a bis-cyclopentadienyl chromium compound reacted with an inorganic support.

Process for producing polyethylenes having a broad molecular weight distribution, and a catalyst system used thereby

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Eidanger, Norway

Svein Staal Eggen