Multilayer thin plastic film, useful for shrink overwrap packaging

A process for making a biaxially stretched, heat shrinkable, heat sealable, multilayer, flexible, thermoplastic film comprising:

• (a) coextruding in a tubular form, around a volume of air, melt plastified polymeric resins forming a primary tube having at least three layers including:
• layer (a) comprising a blend of:
• at least 45%, based on the weight of said layer (a), of (i) a copolymer of ethylene and at least one C.sub.3 -C.sub.10 .alpha.-olefin, said copolymer having a density of at least about 0.900 g/cm.sup.3 and less than 0.915 g/cm.sup.3, a melting point between 85.degree. C. and 125.degree. C., and having at least 80 wt. % of its polymeric units derived from ethylene;
• and at least 5%, based on the weight of said layer (a), of (ii) a high density polyethylene;
• layer (b) comprising at least 45%, based on the weight of said layer (b), of (i) a copolymer of ethylene and at least one C.sub.3 -C.sub.10 .alpha.-olefin, said copolymer having a density of at least about 0.900 g/cm.sup.3 and less than 0.915 g/cm.sup.3, a melting point between 85.degree. C. and 125.degree. C., and having at least 80 wt. % of its polymeric units derived from ethylene;
• and
• layer (c) comprising a blend of:
• at least 45%, based on the weight of said layer (c), of (i) a copolymer of ethylene and at least one C.sub.3 -C.sub.10 .alpha.-olefin, said copolymer having a density of at least about 0.900 g/cm.sup.3 and less than 0.915 g/cm.sup.3, a melting point between 85.degree. C. and 125.degree. C. and having at least 80 wt. % of its polymeric units derived from ethylene;
• and at least 5%, based on the weight of said layer (c), of (ii) a high density polyethylene;
• wherein layer (b) is disposed between layers (a) and (c), and said layer (b)comprises 30-80% of the total thickness of the primary tube, said layers (a) and (c) each comprising at least 10% of the total thickness of the primary tube;
• (b) cooling and collapsing said primary tube;
• (c) reheating said primary tube to an orientation (draw) temperature;
• (d) simultaneously biaxially stretching said primary tube forming an expanded, biaxially stretched, secondary tube having a less than 2.0 mil (50.8.mu.) in thickness;
• and
• (e) rapidly cooling said stretched film thereby forming a heat shrinkable film having at least 60% shrink at 127.degree. C. in at least one of the machine or transverse directions.