Corrugated molecularly oriented plastic strapping

Abstract

A strapping formed of thermoplastic polymeric material having a transverse cross-section which is of generally uniform thickness and of corrugated configuration, with polymer molecules thereof oriented along biaxial directions and predominantly in the longitudinal direction of such strapping. This strapping possess a high tensile strength, improved resistance to longitudinal splitting, good longitudinal stiffness, a reduced tendency to shell when wound as a roll, reduced surface abrasion during transit through strapping equipment and provides for high strength heat seals. Manufacture of this strapping is by a method and apparatus in which a band formed of essentially unoriented thermoplastic polymeric material is provided with a transverse cross-section which is of corrugated configuration and is generally uniform in thickness, with at least portions of such band being compressed so as to orient polymer molecules in the transverse direction of the band, after which the band is elongated to orient polymer molecules thereof also and predominantly in the longitudinal direction of the band.

Dependencies are inferred from the claim text.