12 Micron BOPET Film Low Haze ≤4% High Transparency Grade for Flexible Food Packaging

12 Micron BOPET Film — Low Haze ≤4% High Transparency Grade for Flexible Food Packaging

In flexible food packaging, clarity is not a cosmetic detail — it is the shelf presence of the brand. This 12 micron BOPET film is engineered for the outer print layer of food laminates, delivering haze ≤4% and light transmission ≥89% so that printed graphics stay sharp and brand colours do not drift toward grey. The grade is built on a low-particulate, food-contact PET chip and a balanced machine-direction / transverse-direction stretch profile, which keeps internal light scattering low while preserving the mechanical strength a converting line needs.

Problem

Brand owners and converters working with thin 12 μm polyester repeatedly report the same failure: the film looks perfectly clear on the roll, but after lamination it reads milky and washed-out. Printed images lose contrast, white areas turn grey, and metallised or transparent windows look dull. Converters compensate by moving up to 15 μm or 16 μm film, which raises material cost per square metre and reduces the yield of the packaging run.

Cause

Haze in thin BOPET is dominated by two scattering paths. The first is surface scattering: at 12 μm the film needs a small amount of surface roughness to wind and slip reliably, and excess roughness scatters light at the air-film interface. The second is bulk scattering from residual crystallites and particulate additives carried over from the PET chip. If the chip is over-nucleated, or if the MD/TD stretch ratio is unbalanced, crystallite size grows and light transmission falls. High-temperature lamination then amplifies the effect because relaxation of residual orientation changes surface micro-topography.

Solution

This film addresses both paths at once. A low-additive, high-intrinsic-viscosity food-grade PET chip minimises bulk scattering, and a tightly controlled biaxial stretch keeps the crystalline fraction uniform across the web. A thin co-extruded skin layer provides the slip and anti-block performance that winding and lamination demand without loading the core with particles. The result is a film that holds haze ≤4% and transmission ≥89% after lamination, while tensile strength stays at ≥180 MPa MD and ≥200 MPa TD.

Application

Typical use is the reverse-printed outer web of triplex and duplex food laminates: snack pouches, coffee and confectionery wrappers, transparent windows and lidding film. It is equally suitable as a metallising base where a smooth, low-haze surface gives a bright, uniform aluminium deposit. Because the grade is food-contact compliant and corona treatable on both sides, it integrates directly into existing solvent, solventless and water-based lamination lines.

Selection Guide

Choose 12 μm when print clarity and low material weight are the priority. Step up to 15 μm if the laminate needs higher stiffness for stand-up pouch structure. If oxygen or moisture barrier is required, keep the 12 μm print layer and add a metallised or AlOx layer rather than thickening the print web.

FAQ