- Custom waterproof stickers Use Cases and Key Requirements
Waterproof sticker materials depend on where they will be used:
Outdoor use (like building walls or cars): needs to resist UV rays, rain, and temperature changes.
Bathrooms: needs to resist moisture, heat, mold, and cleaning chemicals.
Industrial machines: must handle oil, chemicals, and rubbing.
Food packaging: needs to be eco-friendly and work in cold temperatures.
Main needs include:
Long-lasting waterproofing – Stickers should stay in place even in wet or changing environments (e.g. pool stickers should last 1–2 years underwater).
Environmental durability – Stickers should work from -40°C to 120°C, and resist salt, acid, or alkali.
Good for processing – Materials should work well with printing, cutting, and layering without damaging the waterproof surface.
- Main Waterproof Materials and How They Work
Waterproof stickers have 3 layers:
Base film + Adhesive layer + Protective coating
A. Base Film – the waterproof foundation
Plastic Films:
PVC: Cheap and waterproof, but not great outdoors long-term (can turn yellow/crack).
PET: Strong, clear, works in -70°C to 150°C, good for high-end stickers.
PP: Light, bendable, resists acid/oil, but hard to print on unless surface-treated.
Special Materials:
TPU: Flexible, stretchable, and waterproof – great for curved surfaces.
Fluorine films (PTFE/ETFE): Very water-repellent and self-cleaning, but very expensive (used in aerospace).
B. Adhesive Layer – for sticking and waterproofing
Acrylic Adhesives:
Solvent-based: Strong hold, good waterproofing, but less eco-friendly.
Water-based: Safer, but weaker waterproofing unless crosslinked (special additives make a stronger bond).
Silicone Adhesives:
Can handle extreme temperatures and resist aging, but initial stickiness is low (needs primer).
Hot Melt (EVA):
Quick to apply, medium waterproof, best for short-term use. Need the right mix for flexibility and water resistance.
C. Protective Coating – outer waterproof layer
UV Coating:
Fluorinated UV coatings are scratch-resistant and super water-repellent (water slides right off).
Nano Coating:
Tiny particles (like SiO₂) fill gaps and block water. Best amount is 5–8%; too much makes the coating brittle.
Superhydrophobic Coating:
Uses rough surface + low-energy material to copy lotus leaf effect (water beads up and rolls off). Very waterproof but complex and costly to make.
- How to Test and Choose the Right Material
Key Waterproof Tests:
Soak Test: Put the sticker in hot water (e.g. 70°C) for 7 days. Check if glue turns white or peels off. The base film should keep 80% of its strength.
Spray Test: Spray with water at 80 kPa pressure for 1 hour to mimic heavy rain. No water should seep through the back.
