Three layers PC/PMMA composite sheet
Three Layer PMMA/PC/PMMA Composite Sheet
This product adopts the co-extrusion process to form a symmetrical sandwich structure:
- Top & bottom layers: PMMA (Polymethyl Methacrylate), providing high surface hardness, scratch resistance, high gloss and excellent optical transparency;
- Core layer: PC (Polycarbonate), delivering outstanding impact toughness, bending resistance and a wide thermoforming processing window.
Compared with the two-layer PC/PMMA structure, the core advantages of the symmetrical three-layer design are as follows:
- Superior optical symmetry with consistent appearance on both sides, minimizing warpage and unidirectional deviation of internal stress;
- More predictable weathering and anti-aging performance, as dual PMMA layers isolate the PC core from ambient conditions;
- Higher overall production yield and reliability for decorative panels and optical windows that demand strict surface hardness and forming yield standards.
The product line consists of three subgrades:
① Non-impact sheet: Primarily used as standard substrates for decorative parts and optical windows;
② High-impact sheet: Formulated with enhanced toughness for the PC core, suitable for demanding cold bending and thermoforming processes;
③ Hard-coated sheet: Subjected to surface hard coating treatment to further boost pencil hardness and scratch resistance. Ideal for exposed decorative surfaces, smartphone back covers and other drop-prone applications. It produces no signal shielding and serves as an effective glass replacement.
Typical Specifications
- Thickness: 0.125–3.0 mm; the production line is capable of manufacturing gauges ranging from 0.070 mm to 3.000 mm
- Width: Max. 1320 mm (≤52 inches), with upper limits adjusted according to sheet thickness and grade
- Color: Natural transparent as standard; tinted variants fall under the colored multi-layer PC/PMMA product series
- Surface finish: Double-sided polished as standard. Custom textures including flowing light grain, leather grain and matte finishes are available via textured moulds
Typical Optical & Mechanical Properties (Reference Values)
- Density: Approx. 1.20 g/cm³
- Light transmittance: ≥90%; Haze: <0.5%; Yellowness Index: <1.0
- Pencil hardness (PMMA surface, 750g load): HB ~ H
- Tensile strength: ≥55 MPa
- Dart impact penetration (112g dart): ≤100mm (varies by product grade)
- Thermal shrinkage at 135°C: ≤1%
- Vicat softening point (B50): Approx. 140°C
Typical Applications
Smartphone back covers and decorative lids (especially hard-coated grades), protective films for optical windows,
IMD/FIM high-pressure thermoforming decorative base films, decorative panels for consumer electronics,
decorative trims surrounding automotive display screens and central controls, dashboard interior components,
industrial control panels, as well as rigid decorative substrates for luggage and helmet casings.
