In the production of flexible packaging composites such as food, daily necessities, and medicine, polyurethane laminating adhesives are the mainstream composite adhesives in the industry. Due to their unique molecular structure advantages, they are suitable for various film lamination processes. Compared with ordinary water-based adhesives and chloroprene adhesives, they have significant advantages. The core features include five aspects, which fully meet the production and usage requirements of the flexible packaging industry.
1. Wide substrate compatibility and excellent bonding strength
This adhesive has extremely strong adhesion to various commonly used substrates in flexible packaging such as PET, BOPP, nylon film, aluminum foil, and PE film. After curing, the peel strength is high, and the composite film is not prone to delamination or detachment. It can meet the bonding requirements of different products such as ordinary snack packaging and high-barrier aluminum foil composite films, and is suitable for the majority of flexible packaging lamination scenarios.
2. Wide temperature tolerance range, stable cold and hot environments
The product has excellent high and low temperature tolerance capabilities. In the low-temperature refrigeration environment, the adhesive layer will not crack or fail. It is suitable for packaging frozen foods. At the same time, it can withstand high-temperature sterilization processes of up to 121℃ or above, and the adhesive layer will not soften or peel off. It perfectly adapts to high-temperature sterilization of flexible packaging such as braised foods and cooked foods.
3. Resistant to medium erosion and strong anti-corrosion performance
After curing, it forms a dense three-dimensional network structure with extremely strong chemical stability. It can resist the penetration corrosion of substances such as oils, salts, spicy seasonings, and flavorings, avoiding problems such as blistering, delamination, and migration of the adhesive layer when the packaging is stored for a long time, and significantly extending the shelf life of the packaging.
4. The adhesive layer has excellent flexibility and can conform to the deformation of the flexible packaging.
During the processes of bag-making, bending, and compression of flexible packaging, it undergoes frequent deformations. After the polyurethane laminating adhesive cures, the adhesive layer becomes soft and resilient, allowing it to stretch synchronously with the film. It will not crack or peel off due to bending, ensuring the overall integrity of the packaging.
5. Green and environmentally friendly compliance, with high process adaptability
The current product models include solvent-free and water-based types, with extremely low VOC emissions. They comply with national food contact material safety standards and EU environmental regulations. At the same time, the coating has good leveling properties, is compatible with high-speed laminating production lines, and the curing speed is controllable. It balances production efficiency and product appearance, without white fog or white spot defects.
