The intrinsic viscosity of general fiber grade polyester chips is 0.645. The intrinsic viscosity mentioned here is used to characterize the molecular weight of polyester in industry. Measuring the intrinsic viscosity can not only correctly evaluate the quality of polyester, but also provide an important basis for formulating spinning process conditions. When the intrinsic viscosity of polyester chip is too low, the molecular weight of polyester is small, the spinning process is difficult to stretch, or even has no spinnability, and it is easy to break. However, if the viscosity is too high, the tensile stress during drawing is too large, and the macromolecules are not well oriented, the intrinsic viscosity has an impact on the spinning operation stability, filament evenness and dyeing evenness. Therefore, ensuring the stability of the intrinsic viscosity is of great help to improve the spinning quality.
