Study Of Forming Capability Of Nonwoven Flax Mat And Nonwoven Flax Mat Reinforced Composites

According to increasingly development of natural fiber reinforced composites and enormous flax fiber resources advantage in China, the paper selected flax fiber as research object, utilizing compression mold method which is a kind of low-cost and easily-automotive way to manufacture irregularly geometric composites. Because of restriction for forming capability of 2D textile while molding, the paper tried to prepare 2D textile by way of nonwoven production that is a easily handled and efficient way, with the result of excellent forming capability in 2D nowoven and possibility of depth molding found in experiment.State of compression during mold process affected product quality and tool dramatically. In this paper, two dimensional reduced model was analyzed by finite element method as a try to study this process. Compared with experimental result, exact coincidence was found between the calculated model and experimental result. The analysis result could be theoretical reference for parameters amelioration and further optimization design of tool.In order to improve mechanical property of nonwoven flax mat and fiber volume content , nonwoven flax mat was reinforced by stitching before compression-mold experiment. Through tests for composite plate, the result that tensile property improved apparently and bend property decreased a bit was found. Sum up of effect on interlaminar property, tensile and bend property, feasibility of stitching was confirmed.The forming capability of 2D dimensional fabrics could greatly affect the quality of compression-mold product. In order to research the forming capability of nonwoven flax mat, firstly the method of cooling compression experiment was conducted to manufacture hemisphere composite under low press. Comparison between nonwoven flax mat and multilayers of glass fiber plain textile showed that forming capability of stitched nonwoven flax mat are excellent and some abnormal events did not occur during compression mold process, such as textilebulking and wrinkle. Moreover test showed proper stitching has improved mechanical property of hemisphere composite. Secondly irregularly geometric composite was made under the high temperature and press experimental condition on the basis of cooling compression experiment. Due to fiber content increasing greatly, the product eliminated shortcomings of cooling compression product, such as too small fracture strain, easily fragile fracture etc, showing characteristics of large fracture strain and not sensitive to stress concentration.