Nova Chemicals (International) S.a.

Nova Chemicals Inc.

Derek Wasylenko

Tony Tikuisis

P Scott Chisholm

Gilbert Alexander Arnould

Owen Lightbody

Fraser Waldie

XiaoChuan Wang

Norman Aubee

Douglas Checknita

Henry Hay

Brant Wunderlich

Polyethylene blends made from recycled polyethylene and a bimodal polyethylene composition are disclosed. The polyethylene blends are suitable for compression molding or injection molding applications and are particularly useful in the manufacture of caps and closures for bottles.

Use of recycled polyethylene in closures for bottles

In the manufacture of extruded polymers there are a number of surface defects referred to as sharkskin, snakeskin and orange peel which all generally relate to the rheology of the polymer melt. A severe form of surface defect is 'melt fracture' which is believed to result when the shear rate at the surface of the polymer is sufficiently high that the surface of the polymer begins to fracture. That is, there is a slippage of the surface of the extruded polymer relative to the body of the polymer melt. The surface generally can't flow fast enough to keep up with the body of the extrudate and a fracture in the melt occurs generally resulting in a severe loss of surface properties for the extrudate. A polymer extension process is disclosed wherein these undesirable surface defects are eliminated.

Polymer extrusion process

Barrier films are prepared from a composition comprising 1) a blend of two high density polyethylene HDPE blend components, 2) zinc glycerolate and 3) a dispersion aid/synergist. The two high density polyethylene blend components have substantially different melt indices. It is difficult to properly mix the zinc glycerolate into this HDPE blend. The use of the dispersion aid/synergist improves the water vapor transmission rate (WVTR) of polyethylene film (in comparison to barrier films made with zinc glycerolate, in the absence of the dispersion aid/synergist). The resulting barrier films are suitable for the preparation of packaging for dry foods such as crackers and breakfast cereals.

Barrier film composition

Rotomolded polyethylene containers that are used to store sulfuric acid can become discolored on the interior surface which is in contact with the acid. This problem may be mitigated by the use of an additive package that contains two primary antioxidants.

Acid resistant polyethylene containers

The present disclosure relates to systems including a ternary stabilization package that contains a first phosphite, a second phosphite and a primary antioxidant is used in combination with a polyethylene that is polymerized with a mixed catalyst system that contains two different types of catalysts. In some embodiments the stabilized polyethylene exhibits improved color performance.

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Calgary, Canada

Derek Wasylenko