Fiber Oil Content Measurement – NMR-Based Method

Published on: 2022-01-25 16:05

PQ001 NMR Fiber Oil Content Analyzer

The oil content in chemical fibers refers to the dry weight of the applied oiling agent as a percentage of the total dry fiber weight. The term “fiber oiling rate” typically refers to the percentage of oiling agent relative to the fiber’s dried weight after degreasing. Oil content is closely tied to spinnability—too little oil results in static buildup, while too much causes fiber sticking and tangling. Both negatively impact textile processing. Therefore, fiber oil content should be controlled precisely to meet antistatic and lubrication requirements while minimizing unnecessary oil usage. Common testing methods include solvent extraction and low-field nuclear magnetic resonance (LF-NMR).

The LF-NMR method works by applying pulsed magnetic fields to the fiber sample. After the field is removed, the hydrogen nuclei (H) in the sample emit magnetic signals. Since fiber-related signals decay faster than oil-related signals, the difference in relaxation behavior can be used to calculate the oil content using appropriate algorithms.

Test procedure: Calibrate the system using 3–6 fiber samples with known oil content. After calibration, unknown samples can be tested within 30 seconds to 3 minutes. The process is fast, non-destructive, and suitable for inline industrial quality control.

Compared to chemical methods, NMR offers better repeatability, no need for solvents, and easier operation.

Advantages of Using NMR to Measure Fiber Oil Content:

1. Extremely fast testing—results available within seconds;

2. Simple calibration process;

3. Superior repeatability and reproducibility compared to traditional methods;

4. Ideal for industrial quality inspection and process control—reduces labor and improves efficiency;

5. Easy to operate—no special technical background required;

6. Powerful functionality—designed for fiber oiling rate measurements;

7. No restrictions on sample shape;

8. Non-invasive and non-destructive—enables repeated measurements on the same sample;

9. NMR signals are generated from all hydrogen nuclei throughout the entire sample volume. Measurement accuracy is unaffected by surface texture or color.

Recommended Instrument

The PQ001 NMR Fiber Oil Content Analyzer is a compact, fiber-specific NMR system designed for the rapid, accurate analysis of oil content in synthetic fibers. It comes with dedicated software tailored for fiber oiling rate measurement, offering user-friendly operation and efficient workflow. The PQ001 integrates advanced design in hardware, software, and UI for excellent performance and a seamless user experience.

Main Technical Specifications:

1. Magnet type: Permanent magnet

2. Magnetic field strength: 0.5 ± 0.08 T

3. Probe coil diameter: 25 mm