Matte Metallic Texture and Heat-Resistant Silver White PP Self-Adhesive

PP self-adhesive labels are label materials with a polypropylene (PP, Polypropylene) film base, coated with pressure-sensitive adhesive on the back, and pre-treated (such as corona treatment, coating) on the surface. Their structure typically includes: PP film base (thickness 20-100 μm), printing layer, pressure-sensitive adhesive layer (acrylic or rubber adhesive), and release paper. PP materials, due to their low density (0.9-0.91 g/cm³), good flexibility, and outstanding chemical resistance, have become the preferred choice for lightweight and bendable labels, widely used in scenarios that require a balance between cost and performance, such as cosmetics, food, and logistics.

Core characteristics of PP self-adhesive labels

1. Physical and mechanical properties

Lightweight and flexibility:

Density is only 60% of PET (0.9 g/cm³), lighter than the same thickness, suitable for lightweight packaging (such as mineral water bottle labels);

Tensile elongation ≥ 300% (ordinary PET is about 200%), bending resistance ≥ 10,000 times (GB/T 17200), suitable for curved surface labeling (such as soft tubes, circular bottle bodies) and frequent folding scenarios (such as folding carton labels).

Temperature resistance and weather resistance:

Regular type - 20°C to 80°C, special modified PP can withstand 120°C (such as heat-filled beverage labels), short-term resistance to 150°C without melting, but the dimensional stability is slightly inferior to PET (thermal shrinkage rate ≤ 2% @ 100°C/1h);

Ultraviolet resistance is moderate (color difference ΔE ≤ 5 after half a year of outdoor exposure), requires UV ink or coating to enhance weather resistance, suitable for indoor or short-term outdoor use (such as courier package labels).

2. Chemical and environmental resistance

Chemical corrosion resistance:

Resistant to acids (pH 3-11), resistant to oil (oil wiping 50 times without change), but resistant to strong alkalis (10% NaOH solution immersion for 24 hours may cause swelling), suitable for cosmetics (such as shampoo, body wash) and food packaging (such as soy sauce bottle labels);

Good moisture resistance, water vapor transmission rate 10-20 g/(m²·24h) (23°C, 90% RH), better than coated paper but slightly lower than PET, suitable for humid environments (such as refrigerated food labels).

Tear resistance and wear resistance:

Tear strength 20-30 N/mm (GB/T 16578), surface hardness 2H (pencil test), wear resistance 500-800 times (Taber abrasion), suitable for medium-intensity contact scenarios (such as supermarket shelf product labels).

3. Printing and processing performance

Surface treatment and ink compatibility:

After corona treatment, surface tension ≥ 38 mN/m, suitable for solvent-based, water-based inks and flexographic printing, ink adhesion strength 3-4 grades (hundred-grain test), color durability 3-5 years indoors;

Base material options include transparent, white, pearlescent, etc.:

Transparent PP: transmittance ≥ 85%, suitable for transparent labeling (such as transparent bottle body labels showing the content color);

White PP: coverage ≥ 95% (ISO brightness), suitable for printing on dark substrates;

Pearlescent PP: adding mica powder, presenting metallic luster (such as cosmetics labels enhancing texture).

Cutting and labeling adaptability:

Suitable for high-speed cutting (speed ≥ 100 m/min), smooth edges, suitable for mass production (such as logistics barcode labels);

Flexibility of adhesive layer types:

Permanent adhesive: holding strength ≥ 48 hours (GB/T 4851), suitable for fixed labels (such as product manual stickers);

Removable adhesive: peel force 0.3-0.8 N/25mm, no residue when removed (such as promotional labels, temporary price tags).

4. Environmental and special functions

Recyclability and degradability: The PP substrate can be recycled through physical means (recycled PP is used for injection molding parts), but the coated layers need to be treated separately; bio-based PP (such as plant-based PP) and degradable PP (modified with starch) labels are gradually being applied in environmental protection scenarios (such as recyclable food packaging labels).

Special functional coatings:

Anti-static PP: Surface resistance 10⁶ - 10⁹ Ω, used for lightweight labels for electronic components (such as battery compartment stickers);

Anti-fog PP: Hydrophilic coating treatment, suitable for refrigerated food labels (such as yogurt cup labels to prevent condensation water mist);

Low-temperature resistant PP: Does not deform at -40℃, used for frozen food labels (such as ice cream packaging).