Detailed Explanation of Common Flexible Packaging Film Materials: Differences and Application Scenarios for PET, Metallized Films, Matte-Gloss (Yin-Yang) Films, etc.

PET is the most widely used outer-layer film in flexible packaging—and serves as the 'face layer' for the vast majority of printed pouches. Its core advantages include high gloss, excellent stiffness, precise print reproduction, strong tensile resistance, and stable heat tolerance—yielding crisp, fine-printed graphics and outstanding shelf appeal. It also delivers excellent aroma retention, gas barrier properties, and abrasion resistance, making it ideal for conventional food and daily-use product outer packaging. PET’s key limitation is clear: it cannot be heat-sealed on its own and therefore cannot serve as a standalone sealing layer for pouches. It must be laminated with an inner heat-sealable film to form a functional composite structure. Application scenarios: snack bags, dried-food pouches, gift-printed pouches, and general industrial outer packaging—offering an optimal balance of cost-effectiveness and visual quality as a universal base material. II. Metallized Film (VMPET) — A High-Value, Light-Blocking, Moisture-Barrier Film Metallized film is produced by vacuum-depositing an ultra-thin aluminum layer onto a PET substrate—distinct from heavy-duty pure aluminum foil, offering lower cost and greater practicality. Advantages: superior light blocking, moisture and oxygen barrier, and light-shielding aroma preservation; effectively prevents light-induced oxidation of contents and significantly extends shelf life. Its matte metallic finish conveys higher perceived quality than standard transparent pouches. Limitations: fully opaque—prevents product visibility—and exhibits only moderate tensile toughness. Application scenarios: light-sensitive products such as tea, powdered seasonings, puffed snacks, and dried fruits—making it the most common light-blocking barrier material in the food industry. III. Matte-Gloss (Yin-Yang) Metallized Film — A Hybrid Solution Balancing Aesthetics and Functionality Many customers confuse metallized film with yin-yang film—the key distinction lies in one simple fact: yin-yang film features partial metallization (i.e., selective aluminum coating) alongside transparent areas. On a single film sheet, one region remains transparent—serving as a product-viewing window—while another is metallized for light blocking. This elegantly resolves the trade-off between full metallization (no visibility) and full transparency (no light protection). Advantages: harmonizes product visibility with light shielding and freshness preservation; offers premium aesthetics compatible with mainstream trendy packaging formats. Limitations: more complex manufacturing process than standard metallized film, slightly higher customization cost, and stricter registration accuracy requirements for printing. Application scenarios: floral teas, nuts, health supplements, and premium snack eight-side-seal pouches—currently a popular choice for high-end custom packaging. IV. BOPP (Biaxially Oriented Polypropylene) Film — Highly Transparent, Cost-Effective, General-Purpose Film BOPP—commonly referred to as OPP—is the most transparent and cost-efficient foundational packaging film. Advantages: exceptional clarity and cleanliness, good moisture resistance, vibrant print color reproduction, and lightweight construction—enabling extremely low mass-production costs. Limitations: poor puncture resistance, unsuitability for high-temperature retort processing, brittleness at low temperatures, and inability to be directly heat-sealed. Application scenarios: pasta (e.g., noodles), ordinary snacks, daily-use items, and gift outer pouches—primarily used where high-level freshness retention or impact resistance is not critical. V. BOPA (Biaxially Oriented Polyamide/Nylon) Film — A Core Functional Film for Puncture Resistance and Oil Resistance

From Food Packaging to Engineering Waterproofing: Precise Matching of Seven Plastic Film Types to Their Optimal Application Scenarios—Don’t Use the Wrong One!

CPP is a non-oriented, cast film manufactured via melt-casting and rapid quenching. Its primary production advantage lies in high speed, high output, and excellent forming efficiency. The film boasts exceptional transparency and gloss, uniform thickness, and consistently balanced overall performance. Its smooth surface facilitates downstream processes—including printing, lamination, and adhesive bonding—making it widely adopted for lightweight packaging of textiles, fresh flowers, daily-use goods, and ordinary food items. VII. Metallized Plastic Films Metallized plastic films are functional composite films created by depositing a thin aluminum layer onto standard plastic substrates—combining the flexibility of plastics with the light-blocking and barrier properties of metals. The surface aluminum layer effectively blocks visible light and UV radiation, substantially extending product shelf life while enhancing packaging aesthetics. Its cost-performance ratio far surpasses that of traditional aluminum foil. Primary applications include packaging for dry foods such as biscuits and puffed snacks, as well as outer packaging for pharmaceuticals and cosmetics. Three Core Industrial Processes for Plastic Films—and the Role of Electromagnetic Induction Heating Rolls All industrially produced plastic films rely fundamentally on three core processes: stretching, casting (or extrusion-casting), and coating. Electromagnetic induction heating rolls—serving as the industry’s high-precision temperature-control backbone—run through every stage of these processes. They are essential for ensuring final film quality, minimizing defect rates, and enabling large-scale, high-quality production—effectively resolving longstanding industry pain points such as large thermal gradients, uneven film surfaces, and coating delamination caused by conventional heating methods. 1. Stretching Process (Primarily Biaxial Stretching): Mainly applied to BOPP, PET, and nylon film production. The process involves extruding molten resin into a thick cast sheet, then subjecting the solidified sheet to simultaneous or sequential longitudinal and transverse stretching. This reorients polymer molecular chains to enhance film strength, transparency, and toughness. Temperature precision is critical: even minor fluctuations cause stretching breaks, thickness variation, or embrittlement. Multiple electromagnetic induction heating rolls enable segmented, gradient temperature control—ensuring uniform global heating and precise thermal regulation. This allows stable matching to each material’s optimal stretching temperature window, promoting orderly molecular alignment and significantly improving both mechanical and optical film properties. 2. Casting Process (Flat Die Extrusion & Rapid Quenching): Primarily used for mass-producing CPP and LDPE films. In this process, molten resin is extruded through a flat die head, spread into a continuous film, and rapidly cooled and solidified. It offers high speed, high output, and excellent surface flatness. However, the highly fluid molten polymer is prone to instability—leading easily to wrinkles and thickness inconsistencies. Here, electromagnetic induction heating rolls primarily perform leveling and constant-temperature shaping: their uniformly distributed gentle heat smoothes out flow marks, balances web tension, and corrects thickness deviations—dramatically improving flatness, gloss, and uniformity to meet high-speed, continuous mass-production demands. 3. Coating Process (Functional Modification): Used mainly for deep-processing high-barrier composite films (e.g., PVA-based films) and functional laminated films. This involves applying a uniform functional coating—such as water-based PVA barrier coatings—onto a base film substrate to impart value-added properties like high barrier performance, freshness retention, or moisture resistance. Water-based coatings require strict temperature stability during curing. Conventional heating often causes cracking, peeling, or uneven curing. Electromagnetic induction heating rolls enable gentle, low-speed, constant-temperature drying and curing: their uniform, mild thermal energy ensures tight adhesion between coating and substrate, delivering stable, reliable curing results—and maximizing retention of the film’s core functional attributes: high barrier performance, environmental friendliness, and freshness preservation.

Toppan launches new BOPP film manufacturing line in Italy

just now

Toppan and Irplast inaugurated a new BOPP film line in Italy with 30,000 metric tons annual capacity, targeting commercial operations by late 2026. The facility uses advanced stretching technology to produce recycle-ready packaging substrates compliant with EU regulations.

chemweek

2026-09-22

Toppan launches new BOPP film manufacturing line in Italy

Toppan launches new BOPP film manufacturing line in Italy

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