Polyurethane adhesive, as a high-performance adhesive material, plays an indispensable role in the flexible packaging industry. With the continuous improvement of consumers' requirements for packaging quality and the increasingly strict environmental protection regulations, polyurethane adhesive has become the preferred bonding solution in flexible packaging composite technology because of its excellent performance characteristics.
Three core advantages of polyurethane adhesive
1. Excellent adhesion: Polyurethane adhesive shows strong adhesion to various flexible packaging substrates (such as BOPP, PET, aluminum foil, aluminized film, etc.). The polar groups in its molecular structure can form strong chemical bonds and physical adsorption with various materials, which ensures that the packaging will not be layered during transportation and storage. Especially for polyolefin materials such as PE and PP, which are difficult to bond, ideal bonding effect can be obtained by using polyurethane adhesive after corona treatment.
2. Excellent weather resistance and medium resistance: Soft packaging often faces harsh environments such as high-temperature cooking, low-temperature freezing and oil penetration. Polyurethane adhesive has excellent temperature resistance (above -40℃ to 121℃) and chemical resistance, which can resist the corrosion of water vapor, grease, acid and alkali, ensure the structural integrity of packaging under the action of various food contents, and effectively extend the shelf life of products.
3. Environmental protection, safety and process adaptability: Modern polyurethane adhesives have developed low-solvent or solvent-free products that meet strict regulations such as FDA and EU, and meet the requirements of direct food contact. At the same time, its fast curing speed and good coating performance are suitable for high-speed automatic production lines, and it can adapt to many processes such as dry compounding and solvent-free compounding, which significantly improves production efficiency and reduces energy consumption.
Industry application prospect
Under the trend of sustainable development, polyurethane adhesive technology is developing towards water-based and bio-based raw materials. In the future, with the increasing demand for high-barrier, recyclable flexible packaging, polyurethane adhesives will continue to provide more environmentally friendly and high-performance bonding solutions for the industry through formula innovation, and promote the transformation and upgrading of the flexible packaging industry to a green and functional direction.
