New National Standard for Determination of Viscosity of Polyvinyl Chloride Resin Officially Released
2025-11-20
Recently, the national standard Plastics-Determination of Viscosity of Dilute Polymer Solutions Using Capillary Viscometers-Part 2: Polyvinyl Chloride Resins (GB/T 1632.2-2025) has been released. This standard replaces GB/T 3401-2007 and will come into force on May 1, 2026.
Since its implementation in 2008, GB/T 3401-2007 has played a crucial role in standardizing the determination of the viscosity of dilute solutions of polyvinyl chloride (PVC) resins. However, with the continuous development of the PVC industry and advancing technologies, higher requirements have been put forward for the accuracy, scientificity, and practicality of the determination method. The release of GB/T 1632.2-2025 represents an upgrade and replacement of the original standard.
Through revisions, the new national standard adopts the ISO 1628-2:2020 standard and makes adjustments based on actual production of the domestic resin industry. On one hand, it incorporates the standard number into the GB/T 1632 series, improving the standard system for the determination of viscosity of dilute polymer solutions. On the other hand, it expands the scope of application to cover various resin types such as vinyl chloride binary copolymers and ternary copolymers.
Viscosity number and K-value are key indicators for measuring resins. By accurately determining viscosity, enterprises can better control production processes, improve product quality, and manufacture high-quality PVC products that meet market demands. This will in turn enhance the product quality and market competitiveness of the entire PVC industry. Additionally, the new standard will provide technical support for unifying testing methods in the industry and improving the consistency of product quality, which is conducive to reducing technical barriers to trade among companies and promoting the continuous development of the standardization process in China¡äs plastics industry.
Since its implementation in 2008, GB/T 3401-2007 has played a crucial role in standardizing the determination of the viscosity of dilute solutions of polyvinyl chloride (PVC) resins. However, with the continuous development of the PVC industry and advancing technologies, higher requirements have been put forward for the accuracy, scientificity, and practicality of the determination method. The release of GB/T 1632.2-2025 represents an upgrade and replacement of the original standard.
Through revisions, the new national standard adopts the ISO 1628-2:2020 standard and makes adjustments based on actual production of the domestic resin industry. On one hand, it incorporates the standard number into the GB/T 1632 series, improving the standard system for the determination of viscosity of dilute polymer solutions. On the other hand, it expands the scope of application to cover various resin types such as vinyl chloride binary copolymers and ternary copolymers.
Viscosity number and K-value are key indicators for measuring resins. By accurately determining viscosity, enterprises can better control production processes, improve product quality, and manufacture high-quality PVC products that meet market demands. This will in turn enhance the product quality and market competitiveness of the entire PVC industry. Additionally, the new standard will provide technical support for unifying testing methods in the industry and improving the consistency of product quality, which is conducive to reducing technical barriers to trade among companies and promoting the continuous development of the standardization process in China¡äs plastics industry.