What's the Difference Between Dry Lamination and Solventless Lamination?
2025-06-11
Dry lamination and solventless lamination are common lamination methods in the production of plastic packaging bags. Both methods have their own advantages and disadvantages. Today, we will compare and analyze them.
Dry Lamination
Dry lamination is a lamination method where adhesive is evenly coated onto a base film using a gravure roller, dried in an oven, and then bonded into a composite film by a pressure roller in the lamination section. Packaging films produced by dry lamination have a wide range of applications and excellent resistance to chemical media. They are widely used for packaging corrosive contents such as alkali, spicy substances, and oil, as well as ingredients like fragrances and emulsifiers in cosmetics. They are particularly advantageous for packaging that requires high-temperature retort processing.
Advantages of Dry Lamination:
- Wide range of base materials: It can laminate plastic to plastic, plastic to paper, plastic to metal, fabric, non-woven fabric, etc., and even composite paper to metal without plastic.
- High bonding strength: The interlayer peel force can reach over 1000g/25mm width, suitable for producing high-end packaging products such as high-temperature retort pouches.
- Precise thickness control: The thickness of each layer can be freely selected and accurately controlled.
- Flexible printing options: It supports both surface printing and reverse printing.
- High production efficiency: The general operating speed is 150-180m/min, with a maximum speed of over 200m/min.
Disadvantages of Dry Lamination:
- Residual solvent issues: The use of adhesives may cause toxicity from residual solvents. Therefore, dry-laminated packaging materials, especially those cured with two-component polyurethane adhesives, are not allowed in the North American and European markets and can only be sold in regions like Southeast Asia and Africa. In China (similar to Japan), dry-laminated products that meet national standards (total residual toxic components ≤15mg/㎡) can be used for food and pharmaceutical packaging.
- Environmental and safety risks: The use of solvent-based adhesives leads to environmental pollution from organic solvent volatilization and potential fire/explosion hazards.
- High cost: Large adhesive consumption and additional costs for solvent recovery/incineration systems make the overall cost higher.
Solventless Lamination
Solventless lamination differs from dry lamination in that it does not use organic solvents. This not only avoids environmental pollution from solvent volatilization but also eliminates the need for solvent evaporation and drying processes, directly reducing production costs. Additionally, it prevents damage to base materials caused by solvents and high-temperature drying, ensuring better dimensional stability of the packaging film.
Advantages of Solventless Lamination:
- Environmental protection: No solvent emissions mean no pollution. The compact design (without a drying oven) also makes solventless equipment much quieter (70-75dB) compared to solvent-based equipment (85-100dB).
- Cost-effective:
- Lower equipment investment: Compact design reduces floor space and equipment cost, eliminating the need for solvent storage.
- Energy savings: Motor power is tens of kilowatts lower than solvent-based equipment.
- Hygiene and safety: No residual solvents to contaminate contents or cause odors, making it safer for food packaging. Eliminating solvents also removes fire/explosion risks, requiring no explosion-proof measures.
- Superior product quality: Lower operating temperatures prevent film deformation. It can produce ordinary composite films and even high-temperature retort films (resistant to 121℃).
Disadvantages of Solventless Lamination:
- The coating system requires heating, and the coater needs thermal insulation.
- Short pot life of the adhesive (effective use time <30 minutes after mixing).
- Difficulty in meeting requirements for heavy packaging, high medium resistance, and ultra-high-temperature sterilization.
- Low initial adhesion and long curing time.
- High requirements for coating precision.
Conclusion
Both lamination methods have unique advantages. When choosing between them, factors such as the properties and weight of the packaged content should be prioritized. If uncertain, consulting an experienced packaging bag manufacturer is recommended.
Let's Talk About the Key Material for Packaging Pouch Batteries - Aluminum-Plastic Film
Application and Prospects of Aluminum-Plastic Composite Films in Green Packaging
Related Article
