Patent ID: 8338551

Claim:
A method for the preparation of a blown film containing 300-600 gels/m 2 of size in the range 100-2000 μm as measured by an optical control system device ME-20/26 V2 type consisting of a 20 mm single screw extruder, a flat die, a chill roll, a winding station and an optical detector as follows screw speed 25 rpm, temperature profile 190-200-205-210-215-220° C., chill roll temperature 75° C., take off speed 2.5 m/min, winder tension of 5% and roll torque of 5 Nm, said film being derived by extrusion of an ethylene-α-olefin copolymer, said method comprising preparing said ethylene-α-olefin copolymer in a particle forming polymerisation process in the presence of a single site catalyst system comprising: (a) a single site catalyst, (b) a cocatalyst, and (c) a support material.