Submitted to: Textile Research Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/13/2014
Publication Date: 10/7/2014
Citation: Sawhney, A.P., Condon, B.D., Allen Jr, H.C., Reynolds, M.L., Slopek, R.P. 2014. Bleaching of hydroentangled greige cotton nonwoven fabrics without scouring. Textile Research Journal. 84(18):1931-1938.
Interpretive Summary: Classical bales of greige/raw lint cotton invariably contain varying amounts of some foreign matter such as the plant debris and other trash. The cotton fiber itself also has some natural non-cellulosic contaminants, such as the waxes of high molecular-weight that are water repellant and, hence, non-absorbent and the indigenous substances that yield the fiber its usual ‘off-white’ color shade. A user mill of raw cotton must process the fiber to first clean it by removing any extraneous matter. Furthermore, any yarn or fabric (whether woven, knitted or nonwoven) made with the cleaned cotton fiber must be also be chemically scoured at the first opportunity to remove the fiber’s natural waxes and then, if required, the scoured material must be bleached to obtain desired whiteness and/or dyed and/or functionally finished. The ARS-USDA research presented here has shown that an optimally hydroentangled greige cotton fabric may not need scouring to bleach and possibly dye it. Thus, the possible reduction or elimination of the chemical scouring process in production of cotton-based nonwoven fabrics is believed to benefit the cotton producers, users, consumers and the environment.
Technical Abstract: This work investigated whether a hydroentangled greige cotton nonwoven fabric made at a relatively high hydroentangling water pressure, say, 135-bar, could be successfully bleached to attain the desired whiteness, absorbency and other properties without traditional scouring. Accordingly, the scoured-and-bleached and the bleached-only versions of an optimally fabricated, hydroentangled fabric were produced and tested for their important properties including whiteness and absorbency, using standard test methods. The hydroentangled (only) control fabric and its scoured-only version were also similarly tested for comparison. The results showed little difference in the whiteness indices of the two bleached versions of the fabric. Both the bleached versions were also fully absorbent. Furthermore, their whiteness and absorbency values interestingly were similar to those of a similar fabric made with commercially scoured and bleached cotton fiber that is mostly used in any existing cotton-based nonwoven fabrics. In short, a hydroentangled, pre-cleaned, greige cotton fabric can be satisfactorily bleached without the chemical scouring process that is costly and environmentally sensitive. This manuscript describes the fiber and fabric properties and the various production processes.