7 Reasons FT-NIR is the Best Method for Analyzing Polymer Pellets

With the high production rates in the polymer industry, it is essential that a quick, accurate, and easy-to-use analytical technique is available to monitor the quality of the material produced. For heterogeneous materials such as polymer pellets, a small sample may not be representative of the bulk material. Each pellet or group of pellets may have a slightly different composition than the next, so it is critical to obtain a measurement that is representative of the bulk sample rather than a small fraction of the material.

Fourier Transform Near-Infrared spectroscopy (FT-NIR) is an ideal tool for at-line or near-line quality control analysis of polymer pellets. NIR is a proven technology that is very useful for probing bulk material with little or no sample preparation. This spectroscopic method uses the near-infrared region of the electromagnetic spectrum, and is based on overtones and combinations of bond vibrations in molecules. It is a common tool used for the analysis of industrial materials because it can typically penetrate much further into a sample than FTIR, and unlike Raman, is not affected by fluorescence. Although Near-Infrared spectroscopy is not as chemically specific as Raman or FTIR, accurate results can be achieved when a representative sampling method is used.

FT-NIR offers several advantages over traditional quality control techniques, including:

Availability of answers in minutes allowing faster feedback to the production personnel and improvement of process efficiency
Ability to perform analyses at-line
No sample preparation
Elimination of the need for purchase and disposal of hazardous reagents
Improved operator-to-operator reproducibility
Reduced cost of quality control testing
Non-destructive testing making the samples available for analysis by other techniques

We conducted a study involving the determination of the concentration of an ultraviolet (UV) stabilizer additive in polystyrene pellets using a FT-NIR analyzer with a sample cup spinner and discovered these seven advantages above. You can read an overview of the study and its results in: How Can You Get Accurate Results when Measuring Bulk Polymer Pellets? and How To Get Accurate Results when Measuring Bulk Polymer Pellets: The Experiment.