BOPP Film for Packaging: Types, Properties and Uses

A non-sealable BOPP grade may not close the pack, while excessive jaw heat can wrinkle the web. BOPP packaging film is biaxially oriented polypropylene: polypropylene that has been stretched in both the machine and transverse directions to make a thin, stiff, clear and moisture-resistant film. It is one of the most widely used films in flexible packaging, found as snack bags, candy and bakery wraps, overwraps, labels and as a layer in laminates. As made, it resists water vapor well but does not block oxygen, so barrier performance usually comes from a coating or metallized layer.

Main types of BOPP film

BOPP is sold in many constructions, usually coextruded with thin skin layers that set sealing and surface behavior.

Suppliers define their own grade names, so a data sheet and a trial tell you more than a label.

Metallized BOPP

Metallized BOPP carries a vacuum-deposited aluminum coating on a prepared surface. Coating thickness and optical density need the selected grade’s specification. That layer cuts light transmission and lowers both oxygen and water vapor permeability compared with plain film, and it gives a metallic look. Barrier results depend on the metal’s optical density, its adhesion and what happens to it during lamination and flexing. Barrier film compares metallized, foil and coated films.

White and cavitated BOPP

Cavitated film uses small voids created around particles in the core. The film is opaque, lighter per square meter and has a pearl-like finish. It trades some stiffness and clarity for opacity and yield, which suits wraps that need to hide the product or carry a print without a white ink layer.

Coated BOPP

Acrylic coatings help heat sealing and printing. PVDC coatings historically provided strong oxygen and moisture barrier in a thin layer, though some brand owners avoid chlorinated materials because of recycling and policy concerns. Other high-barrier coatings are used where oxygen protection is needed without foil. Check the recycling position for any coating you choose.

What biaxial orientation does

Orientation changes the properties of the starting sheet; the final result also depends on resin, skins and processing. Stretching it in both directions at controlled temperatures aligns the polymer chains and changes the film in useful ways.

• Stiffness: oriented film has a much higher modulus, so thin gauges hold their shape on forming equipment and run flat through printers.
• Clarity and gloss: orientation reduces crystallite size and gives BOPP its sparkle.
• Moisture barrier: PP is a good water vapor barrier, and orientation improves it. WVTR explains how it is measured and why temperature and humidity must be stated.
• Strength and gauge: specify thickness and tolerances for the selected grade, then check the converted web on the machine.

Oxygen is the weak point. PP is permeable to oxygen, and plain BOPP will not protect oxidation-sensitive products. OTR numbers are comparable only when the test conditions match.

This layer order is schematic; some grades seal on both sides.

Sealing considerations

Sealing behavior depends on the grade you pick.

• Non-sealable grades will not seal to themselves on a normal sealer. They are used as an outer or laminating layer, with a PE or CPP sealant laminated on the inside.
• Heat-sealable grades have skin layers that begin to seal well below the melting point of the PP core. If the jaws run too hot, the oriented core shrinks, wrinkles and distorts. The usable window must be measured for that grade and laminate; orientation alone cannot rank it against PE or CPP. The concept and how to measure it are covered in seal initiation temperature.
• Cold seal coatings let the film seal with pressure alone. They are common on confectionery flow wraps for heat-sensitive products such as chocolate, where heat from jaws would damage the contents.

ASTM F88/F88M-23 measures seal strength, ASTM F1921/F1921M-12(2023) addresses hot tack, and ASTM F2029-16(2021) prepares laboratory seals. Match temperature, pressure, dwell, sealing faces and conditioning when comparing grades.

BOPP versus CPP

BOPP is oriented and CPP is cast without biaxial orientation. BOPP can act as the print web, and CPP can act as the sealant in one laminate. Seal initiation and the useful sealing window depend on the selected skin formulation, grade, laminate and test settings, rather than relying on the process name. The BOPP vs CPP comparison explains how to record those inputs.

Typical uses

• Snack bags: metallized or high-barrier BOPP laminated to another BOPP or to a sealant film is a classic chip and cracker structure (see snack packaging film).
• Confectionery and bakery flow wraps: clear, heat-sealable or cold-seal grades run on horizontal flow wrappers, where the film’s stiffness and slip behavior are critical (see flow wrapper film).
• Overwraps: clear BOPP wraps around cartons, tobacco and cigarette-style packs.
• Labels: clear or white film as pressure-sensitive and wrap-around labels.
• Laminates: a printed BOPP web combined with PE, CPP or a barrier layer.

The format is described in flow wrap packaging.

All-PP structures

Many laminates today combine BOPP or PET outside with a PE sealant, which mixes polymers. An all-PP structure uses BOPP for the print web and a PP sealant (CPP or a PP-based sealant film) so that the whole pack is polypropylene. A thin metallized or coated layer can provide barrier. These structures are designed for recycling streams that accept PP, though collection and acceptance vary widely by region. The design questions are covered in mono-material packaging. If you are deciding between the two outer webs, PET vs BOPP film sets them side by side.

Choosing a BOPP grade

Use the film specification comparison record to align test conditions. The packaging film overview covers the wider family.

Sources and method

A manufacturer’s April 2026 film portfolio distinguishes sealable skins, non-sealable webs and specialty grades. Sources checked October 8, 2026. The portfolio and linked ASTM scopes support grade-specific comparisons, not this site’s testing or a universal CPP/BOPP seal-temperature ranking.