High Tensile Strength BOPET Film 230MPa Printing Lamination Grade

High Tensile Strength BOPET Film — 230MPa Printing & Lamination Grade

Modern rotogravure and flexo presses run faster than ever, and the limiting factor is often the substrate, not the machine. This  BOPET film is built with ≥230 MPa machine-direction tensile strength so that thin-gauge webs survive high tension, rapid acceleration and the thermal load of drying tunnels without necking, sagging or breaking.

Problem

Converters pushing 12-15 μm film on high-speed rotogravure lines see recurring web breaks, tension flutter and register drift. As the web is pulled through multiple print units and a drying tunnel, insufficient MD strength lets the film elongate elastically; the register moves between colours, and at the limit the web fractures at a splice or a roller nip. The usual workaround — dropping press speed — directly cuts output.

Cause

The tensile strength of biaxially oriented PET is governed by intrinsic viscosity (IV) and the stretch ratio applied during orientation. A low-IV chip or a conservative stretch leaves residual chain mobility, so MD tensile falls and elongation rises. Thermal effects compound this: at drying-tunnel temperatures, residual orientation relaxes, reducing effective modulus exactly when tension peaks. Unbalanced MD/TD stretching also creates cross-web weakness that shows up as edge tears.

Solution

This grade uses a high-IV film-grade chip and a high MD/TD stretch ratio, producing strong, well-aligned molecular chains. The result is ≥230 MPa MD and ≥220 MPa TD tensile with controlled elongation, so the web holds tension without permanent deformation. A heat-set finishing step limits shrinkage to ≤2.5% MD and ≤0.3% TD at 150°C, keeping register stable through the dryer. Friction is controlled at 0.30-0.50 to give clean tracking without blocking on the roll.

Application

Ideal as the print or lamination base for high-speed flexible packaging: snack and confectionery wrappers, sachets, labels and general laminates. It is equally suited to adhesive-tape backing and metallising base where a strong, thermally stable web is needed.

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