What are Decorative Paper and Decorative Film?

Decorative Paper and Decorative Film: A Professional Analysis of Material Properties, Production Processes, and Application Fields

Definition and Basic Concepts of Decorative Paper and Decorative Film

Decorative paper and decorative film, as two major categories of modern decorative materials, play an irreplaceable role in architectural decoration, furniture manufacturing, packaging design, and other fields. From a professional perspective, decorative paper refers to paper materials that have undergone special processing to feature decorative patterns, textures, or colors, primarily used for surface decoration. According to the International Material Science Association (IMSA), decorative paper is defined as "a specialty paper product that is given decorative functions through processes such as printing, embossing, or coating, with a base material typically consisting of wood pulp paper with an α-cellulose content exceeding 90%."

Decorative film, on the other hand, refers to thin film materials made from polymer-based substrates through extrusion, calendering, or coating processes to achieve decorative functions. The American Society for Testing and Materials (ASTM) defines decorative film as "a polymer composite material with a thickness between 0.05–0.5 mm, containing at least one decorative layer and one protective layer." Compared to decorative paper, decorative film generally exhibits superior performance in weather resistance, mechanical strength, and waterproofing.

Historically, the use of decorative paper can be traced back to late 19th-century Europe, initially for bookbinding and wallpaper production. Large-scale industrial production of decorative film began in the 1950s, with the commercialization of synthetic polymer materials such as polyvinyl chloride (PVC) and polypropylene (PP). China's decorative paper industry started in the 1980s and, after over 40 years of development, has formed a complete industrial chain with an annual output exceeding 5 billion square meters, accounting for approximately 35% of the global market share.

Main Types and Production Processes of Decorative Paper

2.1 Classification System of Decorative Paper

Based on substrate and functional differences, decorative paper can be categorized into the following types:

Printed Decorative Base Paper: Typically with a basis weight of 60–120 g/m², impregnated with melamine-formaldehyde or acrylic resin, offering excellent printability and dimensional stability. The smoothness of such paper can reach 500–1000 s (Bekk method), with whiteness in the range of 85%–92% ISO.

High-Pressure Laminate (HPL) Decorative Paper: Basis weight of 80–150 g/m², capable of withstanding temperatures of 140–180°C and pressures of 5–8 MPa. Its tensile strength is ≥4.5 kN/m longitudinally and ≥2.5 kN/m transversely (ISO 1924 standard).

Low-Pressure Melamine-Impregnated Paper: Lower basis weight (40–80 g/m²), with resin content controlled at 120%–180%, used for furniture surface veneers. Volatile content ≤7%, curing time 90–120 s at 160°C.

Fire-Resistant Decorative Paper: Incorporates flame retardants such as aluminum hydroxide, with an oxygen index ≥30% (ASTM D2863), widely used in public space decoration.

2.2 Core Production Processes of Decorative Paper

Modern decorative paper production involves precise process controls:

Pulping and Sheet Formation: A blend of bleached softwood and hardwood pulp (typically 70:30) with a beating degree of 28–35°SR ensures a balance between fiber bonding and surface smoothness. Advanced twin-wire forming technology can control two-sidedness within 5%.

Surface Treatment: Sizing (ASA or AKD) achieves a Cobb value ≤25 g/m² (60 s). A pre-coating of 5–15 g/m² enhances printability. Nano-silica applications optimize coating porosity to 35%–45%.

Printing Process: Utilizes 7–10-color gravure printing with line counts up to 70–100 lines/cm and registration accuracy ≤0.1 mm. UV curing technology reduces drying energy consumption by 40%.

Impregnation Treatment: Melamine resin solid content is controlled at 50%–55%, viscosity 30–50 cP (25°C). Metering size presses control resin absorption at 120%–160%.

Material Composition and Manufacturing Technology of Decorative Film

3.1 Substrate Selection for Decorative Film

The performance of decorative film largely depends on the choice of polymer substrate:

PVC Decorative Film: Accounts for ~65% of the market, with a density of 1.3–1.45 g/cm³ and tensile strength of 35–50 MPa. Plasticizers like DOP (15–40 phr) adjust flexibility but face environmental regulations (REACH restricts DINP content to ≤0.1%).

PP Decorative Film: Melting point 160–170°C, flexural modulus 1.5–2 GPa, excellent dimensional stability (thermal shrinkage ≤1.5%/100°C). β-nucleating agents can enhance transparency to over 90%.

PET Decorative Film: Outstanding mechanical properties (tensile strength ≥200 MPa) and heat resistance (long-term use at 120°C). Surface energy of 42–45 dyn/cm facilitates subsequent printing.

Emerging Materials: Include TPU (abrasion resistance up to 100,000 Taber cycles) and bio-based PLA (60% lower carbon footprint), though market share is <5%, with annual growth exceeding 25%.

3.2 Key Production Processes for Decorative Film

Extrusion: Multi-layer co-extrusion (3–7 layers) with die temperature control accuracy of ±1°C. Advanced air quenching achieves cooling rates of 200°C/s, minimizing crystallinity differences.

Surface Treatment: Corona treatment power density of 50–100 W·min/m² ensures surface tension ≥38 dyn/cm. Nanoimprint technology replicates 0.1 μm textures with 95% fidelity.

Functional Coatings: PVD aluminum layers (30–50 nm) achieve 85%–92% visible light reflectivity. Anti-scratch coatings reach 3H pencil hardness.

Lamination: Solvent-free polyurethane adhesives applied at 3–5 g/m², cured at 40°C for 72 h, with peel strength ≥4 N/15 mm.

Performance Comparison and Application Analysis

4.1 Key Performance Indicators

4.2 Application Selection Guide

Furniture Manufacturing:

Flat furniture: Melamine-impregnated paper (85% market share), cost-effective, 0.2 mm thickness suffices.

Complex shapes: PVC vacuum-formed film (3:1 stretch ratio).

Premium products: PP seamless wrapping film (weld strength ≥15 N/mm).

Architectural Decoration:

Walls: Fire-resistant paper (Class A, ≤300 g/m²).

Flooring: Wear-resistant film (AC4 rating, ≥6,000 cycles, alumina coating 0.5–1 μm).

Ceilings: Lightweight PP film (density ≤0.95 g/cm³, 30%–70% light transmission).

Automotive Interiors:

Dashboards: Weather-resistant TPU film (haze ≤5%, VOC ≤50 μgC/g).

Door panels: Embossed PVC/ABS film (texture depth 0.05–0.15 mm).

Seats: Breathable PU film (water vapor transmission ≥1,000 g/m²/24h).

Industry Trends and Technological Frontiers

5.1 Sustainable Development

Bio-based Materials: DuPont’s Sorona® (37% bio-based), CNF-reinforced paper (3x strength, fully degradable).

Circular Economy: 65% European film recycling rate; chemical depolymerization yields 99.97% pure BHET monomer.

Eco-friendly Processes: Water-based UV inks (VOC <1%), electron beam curing (1/5 energy consumption, 300 m/min line speed).

5.2 Smart and Functional Innovations

Responsive Materials: Thermo-chromic films (20–50°C range), electroluminescent films (≥100 cd/m², 30,000 h lifespan).

Surface Functionality: Superhydrophobic coatings (contact angle >150°), antimicrobial films (>99.9% efficacy).

Digital Manufacturing: Inkjet printing (1,200 dpi, minimum order 1 m²), 3D embossing (0.01–0.5 mm relief, 10,000+ texture database).

Professional Selection and Usage Recommendations

6.1 Material Selection Checklist

6.2 Application Engineering Notes

Process Control:

Hot pressing: 180±5°C, 6–8 MPa, 30–40 s/mm for paper.

Vacuum forming: PVC film preheat 110–130°C, vacuum ≤-0.095 MPa, ≥15 s hold.

Environmental Adaptation:

High humidity (RH >70%): Use films with ≤3% equilibrium moisture absorption.

Large temperature variations: Match CTE to substrate (difference ≤2×10⁻⁵/°C).

Maintenance:

Cleaner pH: Paper 5.5–7.5; film 5.0–9.0.

Pressure: ≤0.3 MPa for films; avoid abrasives >50 μm.

With continuous advancements in material science and manufacturing, decorative paper and film are evolving toward high performance, multifunctionality, and sustainability. Professional users must consider mechanical properties, environmental adaptability, processing requirements, and lifecycle costs, validated through rigorous testing (e.g., ISO 16978 abrasion, EN 438 chemical resistance). Over the next five years, interdisciplinary innovations in nanotechnology and bioengineering may enable smart surfaces with sensing, responsiveness, and self-healing capabilities, unlocking higher-value applications across industries.