Preparation And Properties Of Palm Fibril And Its Nonwoven Fibric

Windmill palm is widely distributed in China. This abundant resource has a very cheap price.The trunk of windmill palm tree is covered with palm sheath mesh. One can extract individual fibers which are brittle and hard from the mesh. In addition with the over sized diameter the palm fibers can’t meet the requirements of precision processing.In this paper, optimal process of extracting palm fibril was discussed, and the morphology, structure and properties of palm fiber and fibril were analyzed. Wet laying method was used to make palm fiber nonwoven fabrics. Sound absorbing properties and filtering performance of these materials were studied.The results are as follow: the cylindrical palm fiber has a rough surface. Cross-section of palm fiber is irregular round. Palm fibril has slender shape without convolution.Irregular round lumen exists in the cross section. One step alkali treatment process was studied to extract palm fibril. The optimum process is: Na OH20g/L, H2O240 m L/L,temperature is 90℃,bath rate is 1:75, 2.5h. The average length of palm sheath fibril is respectively 643.60 um and large diameter is about 10.35 um, while short diameter is about7.33 um, the average hollowness reaches to 47.21%. The palm sheath fibril which extracted by alkali treatment is mainly composed of cellulose I and the degree of crystallinity is about 62. 3%; palm fibril has a good thermal stability, the moisture regain is about 11.51%.Antibacterial against Staphylococcus aurous was 84.3 % while antibacterial against Escherichia coli was 73.3 %. The antibacterial property is good. Palm fibrils in soil rot for90 d, lost about 72% of its weight, easy to deprecate.Wet laying method was used to prepare non-woven materials which have good sound absorption and filtration performance. With 40% long fiber, bulk density of 196 Kg/m3,areal density of 320g/m2, the average absorption coefficient of palm fibril nonwoven material is 0.43. With 0.5% polyvinyl alcohol, areal density of 320g/m2, the average absorption coefficient above 500 Hz above is 0.73, the highest absorption coefficient appeared at 2500 Hz is 0.97. When the content of long fiber is 40%, areal density of 32g/m2, the filtering property is 69.2±2.9%, while the air permeability is80.0±5.7m3/m2s; With 0.5% PVA, 40% long fiber and a areal density of 128g/m2,palm fibril/ palm fiber/PVA nonwoven material has a filtering property of 88.6±2.9%, a air permeability of 91.0±4.7m3/m2 s.