Carding Kenaf for Nonwovens

Kenaf is a bast fiber that offers the advantage of being biodegradable, renewable, and environmentally safe. Unfortunately, mechanically harvested (raw) kenaf fibers are coarse, brittle, and difficult to process through conventional textile and nonwoven equipment. Kenaf batts can be prepared by an air-laid process, but the batts do not have stable uniform structures. In earlier work, we attempted to card kenaf on a cotton card, since carded batts should provide better structural integrity than air-laid batts. Unfortunately, it was impossible to card raw kenaf fibers on a conventional cotton card, because the raw kenaf was discharged from the card as trash. Carding of treated ( chem ically processed) kenaf was moderately successful, although a fair proportion of kenaf was still lost during the carding process. We modified a conventional cotton card to process kenaf fibers into nonwoven structures by using different wire combinations, carding plates, card speeds, and settings. Kenaf batts (pure or blended with polypro pylene) were carded on this modified machine. Nonwoven mats were made using three methods: through-air thermal bonding, needle punching, and needle punching followed by thermal bonding. Although each of these procedures produced kenaf mats with good strength and uniformity, the combined treatment produced the strongest mats. Details of card modification as well as gathered data and properties of the mats are presented.