Polyvinyl Alcohol 0498

Food and consumer goods packaging is undergoing significant technological upgrades. On the one hand, the market demands longer food shelf life and reduced reliance on preservatives; on the other hand, sustainable development and regulatory compliance are driving the transformation of packaging materials towards recyclability and biodegradability. In this context, the demand for barrier properties in paper and cardboard packaging has increased significantly, especially in terms of oxygen, grease, and mineral oil barrier properties. Traditional plastic films (such as PE and PP) have limited oxygen barrier performance, while multi-layer composite materials, although offering excellent performance, increase the difficulty of recycling and compliance. In contrast, water-based barrier coatings can significantly improve the functionality of the material without significantly altering the paper substrate structure, giving paper packaging performance close to that of high-barrier materials while maintaining good recyclability. Among the many water-based barrier materials, polyvinyl alcohol (PVOH) system coatings have become an important solution for current paper-based packaging barrier technology due to their excellent oxygen and grease barrier properties and mature industrial application base. The KURARAY POVAL (POVAL 6-98), ELVANOL, and EXCEVAL series of products are representative material systems based on PVOH.   1. PVOH Barrier Mechanism and Performance Advantages in Paper Packaging Polyvinyl alcohol is a non-ionic, water-soluble, linear crystalline polymer, whose molecular chains can form a large number of hydrogen bonds. This highly ordered molecular arrangement makes it difficult for oxygen molecules to diffuse, which is the fundamental reason for its excellent oxygen barrier performance. Under suitable coating and drying conditions, the PVOH coating can form a dense and continuous film layer, thereby significantly reducing the oxygen transmission rate (OTR) of the paper substrate material. In addition, the hydrophilic nature of PVOH makes it equally outstanding in blocking grease and mineral oil, which is particularly crucial for the packaging of bread, coffee, baked goods, etc. By coating ordinary starch-based paper with EXCEVAL HR-3010, with a coating weight of only 7 g/m², the OTR (Oxygen Transmission Rate) can be reduced from >2000 mL/m²/d to <1 mL/m²/d (23℃, 50% RH), demonstrating extremely high barrier efficiency.   ♠ Compared to other common barrier materials, PVOH is a leading material in terms of oxygen barrier performance: Polyethylene, Polypropylene: Weak barrier PET, PA6: Medium barrier PVDC: High barrier but with environmental concerns EVOH / PVOH: Extremely high oxygen barrier performance   At the same time, PVOH has been certified by BfR and FDA for food contact regulations, making it safe for use in food packaging systems, which is an important prerequisite for its widespread use in the packaging coating field.   2. PVOH Barrier Coating Product System and Typical Performance Parameters We offer a variety of PVOH product models suitable for paper-based packaging barrier coatings. Different models vary in viscosity, barrier focus, and application suitability, allowing for selection based on actual needs. The following is a performance comparison table: From an application perspective, low-viscosity models (such as EXCEVAL AQ-4104) are more suitable for high-speed coating or low-coating weight systems, while high-viscosity models (such as ELVANOL 71-30) are beneficial for forming thicker, denser barrier layers. The above products are compatible with various common coating processes, such as blade coating, gravure coating, or curtain coating, and have good process compatibility.   In summary, water-based barrier coatings based on PVOH provide a well-balanced solution for paper-based packaging in terms of performance, sustainability, and regulatory compliance, especially suitable for food packaging scenarios sensitive to oxygen and grease.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com