InGaAs Sensor Selection for Foreign Matter Detection
Select standard InGaAs for cost-effective detection up to 1700 nm, or cooled extended InGaAs to capture 2200 nm polypropylene combination bands cleanly.
Vibrational Spectroscopy
Analytical Technique
Molecular interactions with infrared radiation provide a non destructive method for identifying the chemical composition of textile materials. This vibrational spectroscopy measures the energy absorbed by atomic bonds as they bend and stretch at specific frequencies. Each fiber type, whether natural or synthetic, produces a unique spectral fingerprint.
Laboratories use this data to confirm fiber content and detect the presence of finishing agents.
Photon Interaction
Light energy must match the internal frequency of the molecular vibration to be absorbed. During vibrational spectroscopy, the sample is exposed to a range of wavelengths, and the resulting absorption spectrum is recorded by a sensor. This process reveals information about the functional groups within the polymer, such as the amide groups in wool or the ester groups in polyester.
The intensity of the peaks relates to the concentration of the material being tested.
Sample Preparation
Accuracy of the results depends on how the fabric or yarn is presented to the instrument. While some methods require grinding the fiber into a powder, newer vibrational spectroscopy techniques can scan the surface of a finished garment directly. Modern portable devices allow for on site testing at the factory or the warehouse.
This speed is essential for verifying the authenticity of high value raw materials.
Fiber Composition
Distinguishing between chemically similar materials is a primary use for this technology in the textile industry. This vibrational spectroscopy can differentiate between different types of nylon or identify the presence of specific coatings like fluorocarbons. It serves as the definitive test when visual inspection or simple burn tests are insufficient.