| 摘要 |
Polyethylene film having a combination of a high melt strength and a high dart impact strength is prepared from a linear low density polyethylene resin having a melt index, ("I2"), of from 0.4 to 1.5 g/10 minutes, a broad molecular weight distribution (of from 3.5 to 7) and a quasi homogeneous comonomer distribution (as evidenced by a copolymer/homopolymer ratio of from 3 to 19). The polyethylene resin is prepared in a dual reactor polymerization process. The film is especially useful for industrial and "heavy duty" packaging applications such as the manufacture of plastic packages used to contain goods for the construction, gardening and agricultural businesses. Examples of such goods include peat moss, fertilizer, soil, sand, salt, fiberglass insulation and crushed stone. The film has improved strength properties which are typically associated with those made from homogeneous (or "metallocene") polyethylene resins, yet also retains a stiff plastic "feel" which is not present in many metallocene resins. Most importantly, the plastic film of this invention may be produced at very high line speeds (i.e. improved production rates/efficiencies) in comparison to films made from prior art resins.
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