PET/PE plastic tray sealing film

PET Base Layer (Top Layer): As the outer structural layer, PET contributes key performance attributes:

Excellent Rigidity & Mechanical Strength: PET is a rigid thermoplastic that provides the film with good tensile strength and impact resistance. This prevents the film from tearing or deforming during handling, transportation, or opening, ensuring the integrity of the sealed package.

Superior Transparency & Gloss: The PET layer offers high light transmittance (up to 90% or more), allowing consumers to clearly see the contents inside the package (e.g., fresh food, snacks, or medical devices). Its smooth, glossy surface also enhances the visual appeal of the product, making it suitable for retail display.

Strong Barrier Properties: PET effectively blocks oxygen, moisture, and light (especially UV light when modified with additives). This helps slow down product oxidation, mold growth, and quality deterioration, extending the shelf life of perishable items (such as fresh meat, baked goods, and pharmaceuticals).

Heat Resistance: PET can withstand moderate temperatures (continuous use temperature up to 120-150°C), making the film compatible with post-sealing processes like pasteurization or hot filling (for certain food products).

PE Heat-Sealable Layer (Bottom Layer): The inner PE layer is the key to achieving a secure seal with containers:

Excellent Heat-Sealing Performance: When heated to its melting point (typically 110-130°C), PE softens and adheres tightly to a variety of container materials, including PP (polypropylene), PS (polystyrene), and even some paper-based substrates. It forms a strong, leak-proof seal that prevents the escape of contents or the entry of external contaminants.

Good Flexibility & Ductility: PE is a flexible material that allows the film to conform to the shape of irregular container edges (e.g., curved tray rims or textured jar mouths), ensuring uniform sealing without gaps.

Food-Grade Safety: Food-contact-grade PE is non-toxic, odorless, and compliant with global safety standards (e.g., FDA, EU 10/2011). It does not release harmful substances when in contact with food, even at high temperatures during heat sealing or microwave reheating (for microwave-safe grades).