The process parameters of hydroentanglement have an important influence on the performance of spunlace non woven. This paper briefly introduces the influence of process parameters on spunlace non woven fabric from three aspects: fiber orientation, water needle and net curtain.
The mechanical properties of spunlace non woven, including tensile strength and bending stiffness, depend on the orientation of fibers in the fiber web. Fiber orientation is affected by web forming, entanglement and transfer. Because the fibers that cross into a network are preferentially oriented in the direction perpendicular to the machine, the tensile strength of the fiber network perpendicular to the direction of the equipment is stronger than that parallel to the direction of the equipment.
High water pressure, less jet heads, and large jet spacing will make the structure of high-density area and low-density area of spunlace non woven. Low jet pressure, multiple needles, and small water needle spacing are easy to produce fiber nets with relatively uniform fiber distribution. The water pressure of the jet head will also affect the structure of the fabric, and low water pressure will form a low-density structure. Specific energy, which is the water jet energy per unit mass, is an independent factor affecting tensile strength, elongation and pore size. Under the same specific energy, the structure of spunlaced fabric produced by smaller jet pressure and more Spunlaced units is different from that produced by multiple Spunlaced areas and lower water pressure. Compared with single-sided Spunlaced fabric, double-sided Spunlaced fabric has better mechanical properties. It is reported that increasing the specific energy above the critical value has little effect on the tensile properties.
Net curtain for transporting fiber nets can provide sufficient support and is conducive to removing trapped water in the entanglement area. The water trapped on the surface of fiber mesh is a key problem of spunlaced method. It is reported that the mesh size may affect the transfer mechanism of actual fibers. The tensile strength of spunlace non woven will decrease with the reduction of mesh. The metal screen curtain is easy to squeeze the fibers in the fiber mesh under the high pressure of the fluid. The metal net curtain with fine pores is very suitable for improving the inclusiveness of fiber nets to short fibers. The properties of non-woven fabrics produced by metal net curtain and plastic net curtain are different. Increasing the conveying speed of net curtain will reduce the tensile strength of the web.
The research in this paper is helpful to understand the potential impact of the changes of hydroentanglement process parameters on the structure and performance of spunlace non woven, and also helps to formulate a process plan to improve the performance of spunlace non woven fabric.