I. Pre-Use Preparation
- Substrate Treatment
- Surface Cleaning: Ensure the BOPP film and the substrate (e.g., paper) are free of dust, oil, or moisture. Wipe with alcohol if necessary.
- Corona Treatment: The BOPP film surface must undergo corona treatment to increase surface energy (≥38 dynes/cm) for better adhesive bonding.
- Adhesive Selection
- Choose the adhesive type based on the process:
- Water-based adhesive: Eco-friendly, odorless, requires drying (e.g., for paper-film lamination).
- Solvent-based adhesive: Fast-drying, suitable for high-speed lamination (ensure proper ventilation).
- Solvent-free adhesive: Requires specialized equipment, eco-friendly but sensitive to operating temperature.
- Choose the adhesive type based on the process:
- Equipment Inspection
- Ensure the coating machine, laminator, drying oven, etc., are clean and that temperature and pressure settings are adjustable.
II. Adhesive Preparation (If Required)
- Dilution: Adjust viscosity using a dedicated thinner (water, alcohol, etc.) according to the manual, typically measured with a Zahn cup (e.g., 25-30 sec).
- Additives: Some adhesives require a hardener (usually 1-3% ratio). The mixture must be used within the specified time.
III. Coating and Lamination
- Coating
- Use an anilox roller or doctor blade to apply the adhesive evenly. The coating thickness is generally 1.5-3 μm (dry adhesive amount: ~1.5-3 g/m²).
- Insufficient coating may cause delamination, while excessive coating may lead to wrinkles or poor drying.
- Drying (for solvent-based/water-based adhesives)
- Drying temperature: 50-80°C (higher for water-based adhesives). Ensure complete solvent evaporation to avoid bubbles or residue.
- Lamination
- Press the coated BOPP film and substrate together using laminating rollers. Typical pressure: 0.2-0.6 MPa; temperature: 40-60°C.
IV. Curing and Aging
- Initial Curing: Lightly press immediately after lamination to remove air bubbles. Allow initial curing at room temperature (~1-2 hours).
- Aging: Place in an aging chamber (40-50°C) for 24-48 hours to ensure complete adhesive cross-linking and final bond strength.
V. Quality Inspection
- Appearance: Check for bubbles, wrinkles, or delamination.
- Peel Strength: Test according to standards (e.g., ≥1.5N/15mm).
- Weather Resistance: Evaluate temperature and humidity resistance (e.g., 80°C oven or freeze testing).
VI. Precautions
- Environmental Control: Maintain humidity ≤70% and temperature at 15-30°C.
- Safety Measures: Use explosion-proof ventilation for solvent-based adhesives; wear gloves and masks.
- Adhesive Storage: Store in a sealed, dark place. Water-based adhesives should be protected from freezing; solvent-based adhesives must be kept away from ignition sources.
- Equipment Maintenance: Regularly clean coating rollers to prevent adhesive buildup.
Troubleshooting Common Issues
- Delamination: Check corona treatment, adhesive coating amount, or aging time.
- Bubbles: Adjust drying temperature or laminating pressure.
- Adhesive Skinning: Seal the container immediately after use.
Before first-time use, conduct a small-scale test and strictly follow the adhesive manufacturer’s technical guidelines. Different brands (e.g., H.B. Fuller, Kangda) may have specific requirements—refer to their manuals for details.

