This study determined the effects of fiber length, the length uniformity index, micronaire (fineness), and strength of greige cotton lint on properties of nonwoven fabrics. Seven bales of pre-cleaned greige ( non-bleached) cotton were procured from a US cotton producer and ginner. Each bale primarily had only one particular fiber quality parameter (e.g., length, length uniformity, micronaire, or strength) as a significant variable of interest, while other metrics remained subdued to the most practically possible extent. The fiber stock from each separate bale was processed into a lightly needlepunched substrate/fabric and then uniformly converted into a hydroentangled nonwoven fabric structure of the same nominal weight. All of the fibers and fabrics involved in the study were analyzed for their quality attributes. Although this study did not reveal any clear-cut, significant effects (obvious relations or correlations) of the fiber quality variables/metrics investigated, for the first time ever new information has been given that may be useful in the selection of optimally economical cotton for the production of cotton-based nonwoven fabrics for certain applications. At the minimum, this study has demonstrated that, unlike in traditional yarn-based textile processing, the greige cotton lint(s) of (typically) varied fiber metrics could be satisfactorily processed into viable nonwoven fabrics of acceptable physical and mechanical properties, as determined by standard test methods and procedures.

A total of seven source fiber types were selected for use in the manufacturing of nonwoven roll goods: polyester; polypropylene; rayon; greige cotton from two sources; mechanically cleaned greige cotton; and scoured and bleached cotton. The microbial burden of each source fiber was measured as a preliminary assessment of microbial contamination using heterotrophic spread plate counts. Greige cotton fibers exhibited the highest levels of total microbial contamination, which were reduced by both storage time and trash removal in the form of mechanical cleaning. Changes in microbial burden levels were measured at each step in the nonwoven manufacturing process. The hydroentanglement process resulted in the greatest overall reduction in microbial burden with no detectable levels of aerobic microbial contamination present on any of the final hydroentangled roll goods regardless of the source fiber. No detectable levels of aerobic microbial regrowth were observed on any fabrics despite storage time or ambient storage conditions. Analysis of suspended solids present in hydroentanglement effluents collected during fabric production revealed significantly less suspended solids from synthetic fibers compared to all cotton fiber types. The study provided insight and potential guidelines that could be incorporated into a nonwoven processing line to ensure specific sterility requirements are met for various converters in end-uses such as hygiene and medical applications.