The 100-micron transparent PVC overlay serves as the core protective layer in card manufacturing; it exhibits strong compatibility with the white PVC printing layer and the core layer, making it a standard component for various PVC cards, such as bank cards, membership cards, and access control cards.

I. Material Characteristics and Compatibility

The 100μm transparent PVC overlay (also known as lamination film or adhesive-coated film) is composed of semi-rigid PVC material and typically features a surface coating of hot-melt adhesive, ensuring compatibility with both the white PVC printing layer and the core layer. Its moderate thickness strikes a balance between flexibility and rigidity, making it resistant to bending and deformation. Furthermore, it boasts high transparency, ensuring that the clarity and color fidelity of the printed patterns remain unaffected. The surface dyne level exceeds 42 mN/m, ensuring strong adhesion to the white PVC printing layer; post-lamination, the peel strength exceeds 5.8 N, eliminating issues such as delamination or edge curling. It demonstrates excellent thermal-pressing compatibility with the white PVC core layer, featuring a Vicat softening point of ≥70°C. This makes it suitable for lamination processes conducted within the 120–160°C temperature range, resulting in a finished card with a stable overall thickness of 0.76 mm (the standard card thickness).

II. Core Functions

Protection of the Printing Layer: Applied over the white printing layer, it acts as a barrier against scratches, grease, and moisture, preventing pattern fading and abrasion while extending the card's service life.

Enhanced Aesthetics and Texture: It offers a choice of glossy or matte finishes, rendering the card smoother and more rigid, thereby providing a premium tactile experience.

Structural Stability: Through thermal-pressure bonding with the core and printing layers, it forms a robust three-layer structure that enhances the card's resistance to bending and impact.

Compatibility with Functional Components: It does not interfere with the embedding or signal transmission of chips, magnetic stripes, or antennas, making it fully compatible with the production of IC cards, magnetic stripe cards, and RFID cards.

III. Production Process and Applications

During production, the white PVC printing layer is first imprinted using offset, screen, or digital printing methods. Subsequently, the 100μm transparent PVC overlays, the printed layers, and the white PVC core layer are stacked in the sequence: "Overlay – Printed Layer – Core Layer – Printed Layer – Overlay." This stack is then subjected to heat and pressure in a laminating machine to form a composite structure, which is finally die-cut into standard-sized cards measuring 85.5 × 54 mm. Widely utilized for financial cards, membership cards, access control cards, campus cards, ID cards, and similar applications, this combination of materials represents the mainstream standard within the card manufacturing industry.

IV. Comparison of Advantages

Compared to an 80μm surface layer, the 100μm thickness offers superior protection and a more substantial tactile feel. Furthermore, when compared to a PETG surface layer, PVC features lower production costs, benefits from a more mature lamination process, and demonstrates optimal compatibility with white PVC substrate materials.