Biaxially oriented polypropylene (BOPP) processes

Abstract

Orientation of polymers enhances many of their properties, particularly the mechanical, impact, barrier and optical properties. Biaxial orientation has the added advantage of allowing this enhancement in two directions, avoiding any weakness in the transverse direction. Biaxial orientation is particularly important in films, where it allows the production of thinner films having superior mechanical, optical and barrier properties and, if required, the ability to shrink when reheated. For example, shrink and barrier properties are particularly important in meat packaging, whereas good mechanical and optical properties and no shrinkage are desired in box overwrap applications of tape cassettes and CDs.