Polyurethane adhesives play a crucial role in the field of ink printing. Their main function is to serve as binders (or bonding materials), and they are the core components that determine the performance of inks.
Main Functions:
1. Excellent adhesion: The polyurethane molecular chain contains highly polar urethane bonds, which can form a strong adhesive force with various polar (such as plastic films, metal foils) and non-polar substrates (such as polyolefins treated with corona), ensuring that the ink adheres firmly to the surface of the substrate and preventing it from peeling off.
2. Excellent film-forming property:
Polyurethane Resin can form a tough, smooth and durable ink film. This ink film not only provides excellent protection for the substrate but also presents outstanding gloss and rich colors, enhancing the visual effect of the printed matter.
3. Excellent wear resistance: Polyurethane adhesives endow the ink film with outstanding flexibility, scratch resistance and wear resistance. This is crucial for packaging materials that frequently need to be handled and rubbed, such as food flexible packaging and handbags, ensuring that the patterns and characters remain intact during the circulation process.
4. Excellent composite performance: In composite inks, polyurethane adhesives not only serve as the printing layer but also have good chemical compatibility and adhesion with the subsequent applied polyurethane adhesives, providing a solid foundation for multi-layer composite structures (such as plastic,aluminum foil,plastic) and simplifying the production process.
Main Applications:
Based on the above characteristics, polyurethane adhesives are mainly used to formulate high-performance polyurethane inks and are widely applied in various flexible packaging printing fields.
1. Flexible packaging for food and daily chemicals: It is often used for printing plastic films such as PET, BOPP, NY, CPP, and aluminum foil, and is used to make snack bags, retort bags, beverage bags, detergent packaging, etc. Its weather resistance and resistance to contents (oil resistance, acid resistance, and alkali resistance) can effectively protect the contents.
2. Special printing: Due to its good flexibility, it is also often used for printing self-adhesive labels, leather and certain fabrics.
3. Composite ink: It is the most commonly used type of ink in dry lamination processes. After printing, it can be directly combined with adhesives for lamination processing to form strong packaging materials.
In conclusion, polyurethane adhesives, with their strong adhesion, film-forming property and toughness, have greatly enhanced the comprehensive performance of printing inks and are indispensable key materials for modern high-performance printing, especially for flexible packaging printing.
