Research On Structure And Performance Of Spunlaced Nonwovens And Its Combinations

Because of its unique advantages, spunlace technology is widely used in medical and healthfield in recent years. According to their specific function in the field of medical and health care,the nonwovens’ research and development trend are mainly concentrated on the filtrationperformance, the anti-permeability of synthetic blood performance. The performance all havelarge relationship with the structure and pore size of nonwoven fabric.According to the above, structure and performance of single-layered spunlaced nonwovenswere studied in this thesis. Then, the influence of the structure and performance on traditionalfabric which was acted by the spunlace technology was studied. Furthermore, compositenonwovens were prepared under different mode and process, and the structure and properties ofcomposites were tested and analyzed. The experimental results show as followed:The surface density single-layer spunlaced nonwoven samples used in this research is35~50g/m2, the thickness is0.32~0.53mm. The porosity is over90%, less than95%, meanpore size is35~72μm. The porosity and the mean pore size have a significant effect on airpermeability, especially the mean pore size. The air permeability increased with the mean poresize increasing. The moisture permeable coefficient decreases then increases with polyestercontent increasing.After the woven fabric and knitted fabric were acted by spunlace technology, their thicknessand surface density are increased. The mean pore size and the largest pore size are decreased.The air permeability is decreased, and the filtration efficiency and the filtration resistance rise up.The warp strength of the woven fabric and knitted fabric is much larger than weft strength, andthe strength unchanged after the difference spunlacing.The thickness of double-layered silk woven fabric has a linear relationship with that of thesilk woven fabric before combined. There is no linear relationship between the silk woven fabriccombined with spunlace nonwoven and the single-layered silk woven fabric. The pore size ofcomposite fabrics is depending on that of single-layered silk woven fabric. The filtration efficiency of silk woven fabric combined with itself names SS1、SS2、SS3are decreased, but thefiltration efficiency of silk woven fabric combined with spunlace nonwoven names SP1、SP2、SP3are increased. The filtration efficiency of composite fabrics which names SS4、SS5、SS6、SS7and SP4、SP5、SP6、SP7are increased.The surface density of different spunlace composite nonwovens F1-F9is bigger than140g/m2. The thickness of the spunlace composite is much less than the sum of single-layerspunlaced nonwoven and single-layer melt-blown nonwoven. The mean pore size and largestpore size of spunlace composite nonwovens substantially show the same trend. The airpermeability of spunlace composite nonwovens is less than6mm/s. The filtration efficiency ofspunlace composite nonwovens is74~82%. The anti-permeability of synthetic bloodperformance grade is above4. The vertical breaking strength is more than45N, and thehorizontal breaking strength is less than45N.