Development and Use of an Attenuated Total Reflectance/Fourier Transform Infrared (ATR/FT-IR) Spectral Database To Identify Foreign Matter in Cotton

Abstract

The presence of foreign matter in cotton seriously affects the cotton grade and thus the price per bale paid by the spinner to the grower, the efficiency of the spinning and ginning operations, and the quality of the final woven product. Rapid identification of the nature of the extraneous matter in cotton at each stage of cleaning and processing is necessary to permit actions to eliminate or reduce its presence and improve efficiency and quality. Although several instruments are being successfully employed for the measurement of contamination in cotton fibers based on particle size/weight, no commercial instrument is capable of accurate qualitative identification of contaminants. To this end, ATR/FT-IR spectra of retrieved foreign matter were collected and subsequently rapidly matched to an authentic spectrum in a spectral database. The database includes contaminants typically classified as "trash", cotton plant parts (hull, shale, seed-coat fragments, bract, cacyx, leaf, bark, sticks, and stems) and grass plant parts (leaf and stem); "foreign objects and materials", synthetic materials (plastic bags, film, rubber, bale wrapping and strapping); organic materials (other fibers, yarns, paper, feathers, and leather); plus entomological and physiological sugars and inorganic materials (sand and rust). The spectral matching resulted in consistently high-score identification of the foreign matter based on chemical composition, irrespective of its particle size. The method is envisioned to be employed with stand-alone rugged infrared instrumentation to provide specific identification of extraneous materials in cotton as opposed to only general classification of the type by particle size or shape.

Fourier-Transform Imaging of Cotton and Botanical and Field Trash Mixtures

“…In the fingerprint region, including the CO and CH stretching region, between 1100-900 cm −1 , all spectra had the C-O bands and at 900 cm −1 a beta-linkage appears between two glucose units due to cellulose synthesis [19]. Cotton did not have a strong band at 1800-1500 cm −1 signifying the C=O stretch, whereas the trash spectra all have this fine structure [15]. Among each other, the botanical trash types were distinguished by the fingerprint region having Figure 3B, had a distinctive CO band at 1750 cm −1 and a CH doublet between 1500-1250 cm −1 [19].…”

“…Cotton and botanical trash had a broad peak at around 3300 cm −1 due to the O-H stretch. At 2900-2800 cm −1 the C-H stretch was present in both botanical trash spectral bands, as well as the cotton spectrum [15]. In the fingerprint region, including the CO and CH stretching region, between 1100-900 cm −1 , all spectra had the C-O bands and at 900 cm −1 a beta-linkage appears between two glucose units due to cellulose synthesis [19].…”

“…Figure 5A,B shows the chemical images of cotton and leaf botanical trash mixtures. In Figure 5A, the chemical image of the cotton was integrated over the 1765-1480 cm −1 fingerprint region, which includes the COC spectral bands [15]. The color intensity for the cotton representation in the image is low.…”

“…Near-infrared spectroscopy was also used to classify and distinguish field trash and botanical trash previously using a spectral database [14]. Himmelsbach et al garnered the identification of botanical and field trash using ATR-FTIR spectroscopy [15]. This report demonstrated the feasibility of using ATR-FTIR spectroscopy as a technique to identify pure trash components which could be used to start a database.…”

Fourier Transform Spectroscopy of Cotton and Cotton Trash

“…Cotton trash present with cotton fiber affects the quality, appearance, price paid by textile mills to producers, yarn and fabric properties, as well as the performance of ginning and spinning equipment (Himmelsbach et al, 2006). In addition, cotton trash identification is important to the textile industry because certain types of trash have different effects on the textile processing of cotton and the marketability of the final fabric.…”