Multi-layered polyethylene films oriented in the machine direction and articles comprising the same

D) A method of forming a machine direction oriented polyethylene film, comprising:

• extruding a film having:
• (a) a core layer comprising a first ethylene-based polymer having a density of 0.885 g/cm3 to 0.920 g/cm3 measured according to ASTM D 792, a peak melting point of 82 to 126° C. and a percent crystallinity by weight of 15 to 30 calculated according to Equation 1 as provided herein;
• (b) a skin layer comprising a second ethylene-based polymer having a density of 0.940 g/cm3 to 0.965 g/cm3 measured according to ASTM D 792, a peak melting point of 130 to 135° C. and a percent crystallinity by weight of 30 to 80 calculated according to Equation 1 as provided herein;
• and
• (c) a sub-skin layer in-between and in contact with the core layer and the skin layer, the sub-skin layer comprising a third ethylene-based polymer having a density of 0.920 g/cm3 to 0.950 g/cm3 measured according to ASTM D 792, a peak melting point of 125 to 130° C. and a percent crystallinity by weight of 40 to 65 calculated according to Equation 1 as provided herein, wherein each value for the density, peak melting point and percent crystallinity by weight increases from the core layer to the sub-skin layer and from the sub-skin layer to the skin layer and wherein a ratio of the percent crystallinity by weight of the core layer to the skin layer has a value of 0.25 to 0.91 and a ratio of the peak melting point of the core layer to the skin layer, each expressed in the Kelvin temperature scale, has a value of 0.870 to 0.990;
• and
• orienting the film in a machine direction at a temperature of 115° C. to 130° C. in the machine direction at a draw ratio of 4.5:1 to 7.5:1 to form the machine direction oriented polyethylene film.