The Difference Between Winter and Summer Formulas of Nail-Free Adhesive

The Difference Between Winter and Summer Formulas of Nail-Free Adhesive

Winter Formula (Low Temperature, Low Humidity Environment: 0-15°C)
The core issues in winter are slow curing due to low temperatures, high viscosity (difficult application), and brittle cracking of the adhesive layer. Formula adjustments should focus on accelerating curing, reducing viscosity, and improving low-temperature toughness.
Workability: Ensure viscosity ≤ 10,000 mPa·s at low temperatures (allowing normal extrusion and coating).
Curing Speed: Fully cures within 24 hours at 25°C and within 48 hours at 0°C.
Adhesion Performance: Shear strength ≥ 1.5 MPa at -10°C (avoids low-temperature cracking and debonding).

Summer Formula (High Temperature, High Humidity Environment: 25-40°C)
The core issues in summer are accelerated curing due to high temperatures (prone to “false cure” (drying the surface but not the interior), blistering of the adhesive layer due to high humidity, and yellowing/creeping at high temperatures. Formula adjustments should focus on delaying curing, preventing moisture and foaming, and improving heat resistance. Workability: Ensure an open time of ≥30 minutes at high temperatures (enough time to adjust the substrate position).
Curing Performance: Fully cures within 24 hours at 40°C, free of bubbles or hollows.
Weather Resistance: Shear strength ≥1.8 MPa at 70°C, with no noticeable yellowing after three months of outdoor exposure.