Determination of cotton fiber maturity and linear density (fineness) by examination of fiber cross-sections. Part 2: A comparison optical and scanning electron microscopy

Abstract

Previous researchers established a set of reference cottons with known fiber maturity and linear density (fineness) values based on the analysis of a large number of individual transverse fiber cross-sections viewed under the optical microscope. Part 1 identified that the limited optical resolution of the captured images may be the source of a significant systematic error in the assigned values of cell wall area and hence fiber maturity and linear density values. In this paper the optical microscopy technique was implemented. Individual cross-sections were measured using this approach and also higher resolution and higher magnification images were obtained using scanning electron microscopy. It was found that the data obtained from optical microscopy were similar to the SEM data, with the perimeter being 2% smaller, the cell wall area being 6% larger and the maturity ratio values being 8% higher. It was concluded that the combined approach of utilizing SEM in conjunction with optical imaging is a useful approach for verifying and perhaps correcting the data obtained from optical imaging. Further the SEM images highlighted that the current experimental protocol does not adequately address the challenge of ensuring that the fibers are mounted normal to the plane of cutting the transverse cross-section. Modeling demonstrated that while maturity ratio values are relatively insensitive to this misalignment, measured cell wall area values and hence fiber linear density values will be overestimated. This may be the major source of error associated with the technique and warrants further attention in future studies.

Edge Detecting Method for Microscopic Image of Cotton Fiber Cross-Section Using RCF Deep Neural Network

“…(b) represents the edges that are used for maturity evaluating: the red line is the outer edge of the cross-section (denoted by L o ) and the green line is the edge of the inner cavity (denoted by L i ). Let A (•) and P (•) denote functions to calculate the area and perimeter of the image region enclosed by an edge, respectively, then the maturity of the cotton fiber, as denoted by θ, can be calculated according to its outer edge L o and inner edge L i [24] by Formula (1) :…”

A Simplified Microscopy Technique to Rapidly Characterize Individual Fiber Traits in Cotton

“…Initially, during the growth phase, the fiber exhibits an approximately circular cross-section. However, as the fiber undergoes desiccation, its shape becomes irregular, assuming a kidney-shaped appearance that is contingent upon the thickness of the secondary cell wall [15]. Specific genetic mechanisms regulate key fiber attributes such as length, strength, uniformity, and micronaire values [16].…”

“…Right (C). Graphical depiction of error induced when fibers are not oriented to a vertical axis, taken from [15].…”