Effects of short-cut fiber type and water-jet pressure sum on wet strength and dispersibility of wood pulp-based wetlaid/spunlace wipes

Wetlaid/spunlace (wetlace) materials consisting of wood pulp and short-cut fibers are leading the way in the development of dispersible moist wipes due to their wet strength during use and disintegration under flow field. However, short-cut fibers are still not well understood in terms of reasonable balance between material wet strength and dispersibility. In this study, wetlace materials were prepared via four types of water-jet pressure sums, and the effects of four types of short-cut fibers (Lyocell, Danufil, Viloft and hydrophilic polyester) on the wet strength and dispersibility of wetlace materials were investigated for the first time. The results suggest that at a water-jet pressure sum of around 190 bars, wood pulp/Lyocell wetlace material reaches the dispersion threshold, but wood pulp/hydrophilic polyester material has lost dispersibility, and the former wet strength is much higher than the latter. However, the required water-jet pressure sum at the dispersion threshold of wood pulp/Danufil or wood pulp/Viloft wetlace materials are more than 200 bars, and the corresponding wet strength is close to that of wood pulp/Lyocell wetlace material. Overall, Lyocell entanglements as reinforcement of wetlace material can achieve sufficient wet strength and excellent dispersibilty with low water-jet pressure sum, providing guidelines for the production of excellent pulp-based moist wipes.