Analytical Characterization
Infrared spectroscopy utilizing attenuated total reflectance constitutes a non-destructive analytical method for identifying the chemical composition of textile fibres at a shipment intake checkpoint. This technique, known as atr-ftir spectroscopy, measures the interaction of infrared light with a fabric sample pressed against a high refractive index crystal. It provides immediate identification of synthetic polymers such as polyester or nylon, though it does not measure deep internal finishes due to its limited penetration depth of a few micrometres.
An inherent surface sensitivity ensures that superficial coatings or sizing agents can be isolated and evaluated without destroying the underlying weave structure.
Crystal Interface
The optical crystal made of zinc selenide or diamond guides the infrared beam to generate an evanescent wave that enters the specimen surface. When atr-ftir spectroscopy is applied to finished garments, the operator must ensure uniform pressure to avoid air gaps. Insufficient contact leads to weak signal intensity and distorted baseline readings.
Spectral Identification
Absorbance peaks in the resulting spectrum correspond to specific molecular bonds such as carbonyl or hydroxyl groups. In commercial mill audits, atr-ftir spectroscopy detects the presence of unauthorized acrylic sizing agents or polyurethane coatings. This method distinguishes between pure natural cotton and polyester blends by analyzing the characteristic ester peak at seventeen hundred wavenumbers.
Fibre Verification
Quality control teams run these tests to verify the authenticity of incoming raw materials before fabric cutting begins. Utilizing atr-ftir spectroscopy ensures that the composition matches the supplier declaration sheet. This screening prevents the processing of mislabelled synthetic blends.
