BOPA stands for “Biaxially Oriented Polyamide”. Its base material is nylon (polyamide), produced through a sophisticated biaxial stretching process.

This biaxial stretching transforms the nylon molecular chains from a disordered state into a highly ordered, tightly packed network structure, giving BOPA film its unique and superior properties.

Extrusion Casting: Nylon chips are first heated and melted, then extruded through a die to form a thick sheet (cast film).

Longitudinal Stretching: The thick sheet passes through a set of preheated rollers and is then stretched between rollers of varying speeds, achieving longitudinal orientation of the molecular chains.

Transverse Stretching: The film then enters a tentering machine, where it is clamped on both sides at high temperatures and gradually widened in the transverse direction, achieving transverse orientation of the molecular chains.