Spin Finish on Fibers

Oil Pick Up without Sample Weighing

Fiber manufacturing often uses a thin layer of finish to assist the fiber’s performance and its ability to run in downstream spinning processes. This Spin Finish guarantees the lubrication of the fiber surface, the cohesion of filaments, and static protection for the fiber bundle as essential properties in the production of fibers, yarn and non-woven fabrics.

The determination of the Spin Finish content by time-domain (TD) NMR is an established method. The most accurate measurement techniques usually require sample weighing (see application note ”Spin Finish on Fibers – Oil Pick Up with Sample Weighing”), which is considered as time consuming.

Application Method

The TD-NMR signal of a fiber sample exhibits different components. Fibers, moisture and Spin Finish are each characterized by a typical decay behavior. The TD-NMR signal of Spin Finish is well separated from the other signals and can be quantitatively analyzed.

For the application Spin Finish on Fibers without Sample Weighing, both FID and Hahn echo are recorded. The amplitude of the FID signal (S1) corresponds to the total signal, while the amplitude of the echo signal (S2) relates only to the Spin Finish component. The ratio of the amplitudes correlates with the Spin Finish concentration. Thus, weighing the sample is not required.