Optoelectronic Sensor Setup for Blowroom Polymer Removal
Optoelectronic blowroom sorters combine polarized, UV, and SWIR sensors with high-speed valve arrays to detect and eject synthetic polymers from cotton tufts.
Short-Wavelength Infrared
Infrared Sorting
Optical monitoring techniques using the electromagnetic spectrum between 1.4 and 3 micrometres enable the non-destructive identification of textile fibres and moisture content during continuous processing. In the inspection of industrial fabrics, short-wavelength infrared provides distinct spectral signatures for different polymers, allowing automatic sorting systems to separate polyester, nylon, and cotton. This technology is integrated directly into automated recycling and sortation systems.
Absorption Measurement
Dynamic measurement of residual moisture in fabric webs utilizes the specific absorption bands of water within this spectral range. Since short-wavelength infrared is absorbed strongly by water molecules, the intensity of the reflected light is inversely proportional to the moisture level. In finishing mills, this measurement is used to control the speed of drying ovens, preventing both over-drying and under-drying.
This real-time control improves energy efficiency and maintains fabric hand.
Spectroscopic Identification
Automated recycling plants use these sensors to sort garments based on their chemical composition. The sensor detects the difference in reflection between natural and synthetic fibres, activating air jets to sort the clothes. This separation is necessary to create high-purity recycled feedstock.
Dye Interference
Dark-colored fabrics and those containing heavy black dyes absorb too much light to return a clear signal. This absorption difference restricts short-wavelength infrared analysis to light and medium fabric shades.