Flexible packaging inks must deliver strong adhesion, high gloss, good flexibility, lamination and retort resistance, and smooth performance on high-speed presses. Polyurethane resin have become one of the most widely used binder systems because they meet these demanding requirements better than many alternative chemistries. Flexible packaging is usually printed on plastic film and then laminated with other layers. PU resins adhere well to many plastic substrates, stay flexible through folding and handling, and resist the solvents and adhesives used in lamination. This makes them practical for applications ranging from dry snack packaging to retort pouches. Key Performance Benefits： Adhesion and lamination bond strength: Film-forming PU resins bond firmly with laminating adhesives, reducing the risk of delamination during storage, transport, or final use. Gloss, color, and print quality: PU resins help pigments disperse evenly, delivering vibrant graphics and consistent color over long production runs. Flexibility and mechanical stress: Printed films can bend and fold without cracking or losing adhesion, unlike more brittle resin systems. Retort and heat resistance: Retort-grade PU resins maintain bond strength under high heat and pressure, helping prevent delamination or seal failure during sterilization. NC-Free PU Inks and Sustainability The shift toward nitrocellulose-free PU inks is growing because nitrocellulose raises concerns about flammability, storage safety, and supply stability. NC-free PU systems maintain flexibility, adhesion, and gloss while supporting lower solvent content and better recyclability. Plasticized PU Resins for Laminating Adhesives Plasticized PU resins improve the flexibility and bond strength of laminating adhesives, especially for frozen and refrigerated packaging. They remain flexible across a wide temperature range, helping protect package integrity throughout the cold chain. Choosing the Right Grade Sunman can supply different type PU resin. Formulators should consider molecular weight, solvent compatibility, film-forming speed, substrate, printing process, and end-use conditions. Working early with an experienced PU resin manufacturer can speed up grade selection and reduce costly trial cycles. PU vs. Other Binders Nitrocellulose, polyamide, and acrylic resins still serve specific or cost-sensitive applications. However, PU resins offer a strong balance of flexibility, lamination bond strength, and sustainability. The right choice depends on the packaging application’s cost and performance needs. If you need more informations or TDS with different grade about PU resin, pls contact with us.

PVB resin(Polyvinyl Butyral) is widely used due to its adhesion, flexibility, toughness, and clear film formation. As an interlayer in laminated safety glass, PVB bonds glass layers together and enhances impact resistance. In coatings and paints, it improves film formation, adhesion, flexibility, and surface protection. It also serves as a binder for alcohol-soluble or solvent-based systems in printing inks, and can function as a temporary binder or processing aid in ceramics. PVB resin applications include: coatings, inks, wash primers, ceramic substrates, composites, structural adhesives, laminated safety glass interlayers,ceramic injection molding, and vacuum aluminum-plated paper. The Key Question for Buyers For buyers, the critical question is not simply "Can PVB be used in my product?" A more useful question is: "Which PVB grade best suits my solvent system, viscosity target, substrate, processing method, and final performance requirements?" How to Choose the Right PVB Resin Grade PVB resin selection should be driven by the final application: Printing inks: Check solubility, solvent release, pigment wetting, adhesion to film or paper, and final ink transfer. Coatings: Check film hardness, flexibility, adhesion, clarity, chemical resistance, and compatibility with other resins. Laminated safety glass: Prioritize optical clarity, mechanical strength, moisture control, and long-term stability. Sunman offers PVB product types from A-10 to A-70, with varying ranges of viscosity, volatile content, polyvinyl butyral content, hydroxyl content, rotational viscosity, and ash. This broad range of grades enables formulators to select PVB based on practical processing and performance requirements rather than settling for a general-purpose grade. A practical selection process should include sample testing. Buyers should prepare a small resin solution using the intended solvent system, verify dissolution time, check clarity, perform a filtration test, and evaluate film behavior. In coating and ink systems, the resin should also be tested with pigments, additives, and the final substrate. So if you are interesting and need samples for test, pls contact us now.

Chlorinated Polypropylene (CPP) is a versatile functional polymer that has gained widespread use across multiple industrial sectors due to its exceptional adhesion properties, compatibility with various resins, and ability to modify surface characteristics of low-energy materials. Below are the three primary application fields of CPP, each playing a critical role in modern manufacturing and coating technologies. 1.CPP for Inks (Chlorinated Ink Resin) High-molecular-weight CPP is specifically designed for printing inks on PP substrates, available in both toluene-soluble and ester-soluble systems. It is mainly used in packaging printing to effectively enhance ink adhesion on PP film surfaces, preventing the printed layer from detaching during processing or end-use. The most common end-use is in rotogravure and flexographic printing of PP films, which are extensively used for snack food packaging, confectionery wraps, shrink sleeves, and laminated stand-up pouches. The inherent non-polar nature of PP films causes conventional inks to exhibit poor wetting and weak anchorage, leading to smudging, rubbing, or complete detachment during handling or transportation. By utilizing high-molecular-weight CPP as the ink vehicle or as a co-binder, the ink layer forms a strong physical and chemical bond with the PP surface, ensuring excellent rub resistance, block resistance, and adhesion even under high-speed printing and subsequent converting operations. Additionally, the high molecular weight imparts improved pigment wetting and dispersion stability, resulting in vibrant colors and consistent print density across long production runs. 2. Adhesion Promoter for PU Inks Low-molecular-weight CPP is used as an adhesion promoter for PU inks, primarily to solve adhesion problems on PP and PE films. This application is common in packaging printing, where it strengthens the bond between the ink layer and low-surface-energy substrates, effectively preventing ink peeling, smudging, and other defects, thereby ensuring print quality. 3.Automotive Coatings and Adhesives CPP exhibits strong affinity for polyolefin substrates such as PP and TPO, and shows good compatibility with resins like acrylics and polyurethanes, significantly improving coating adhesion. Specific applications include: •Automotive bumper coatings (high-flexibility grades); •Interior trim coatings (low-VOC, environmentally friendly formulations); •Adhesion-promoting primer layers for polymer substrates; •Adhesives for structural bonding of PP to metals and PP to rubber. We can supply many different types of CPP resin. So any more informations, pls let us know.